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Cardiopulmonary and Brain Resuscitation: Current Concepts and Modified Guidelines (2020/2023/2025)

For MD Anaesthesia Exams & NEET SS Critical Care

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PART 1: FOUNDATIONAL CONCEPTS

The Paradigm Shift: ABC → CAB (Since 2010, reaffirmed 2020/2025)

• Old (pre-2010): A (Airway) → B (Breathing) → C (Circulation)
• Current: C (Circulation) → A (Airway) → B (Breathing) → D (Defibrillation)

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PART 2: BASIC LIFE SUPPORT (BLS) - 2020/2025 AHA GUIDELINES

Chain of Survival (Updated 2025)

1. Surveillance and prevention
2. Activation of emergency response
3. High-quality CPR
4. Defibrillation
5. Advanced resuscitation
6. Post-cardiac arrest care
7. Recovery (newly added in 2020, retained 2025)

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High-Quality CPR Parameters ("Rule of Tens")

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Compression Technique

• Heel of hand on lower half of sternum
• Allow complete chest recoil
• Minimize interruptions
• Rotate compressors every 2 minutes to prevent fatigue
• CPR feedback devices are recommended to improve quality

Ventilation

• 1 breath every 6 seconds (10 breaths/min) when advanced airway is in place (continuous compressions)
• Without advanced airway: 30:2 ratio
• 2025 update: Breaths with chest compressions are recommended for both healthcare professionals AND lay rescuers when willing and capable
• Compression-only CPR preferred if lay rescuer is unwilling/unable to give breaths

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PART 3: ACLS ALGORITHMS

Shockable Rhythms: VF / Pulseless VT

1. CPR 2 minutes + IV/IO access
2. Defibrillate (single shock) → CPR 2 min
3. Epinephrine 1 mg IV/IO every 3-5 min (start as soon as feasible)
4. If VF/pVT persists after 2nd shock: Amiodarone 300 mg IV (or Lidocaine 1-1.5 mg/kg)
5. Repeat amiodarone 150 mg x1 if needed (or Lidocaine 0.5-0.75 mg/kg up to 3 doses)
6. Search and treat reversible causes (H's and T's)

Non-Shockable Rhythms: PEA / Asystole

1. CPR 2 minutes + IV/IO access
2. Epinephrine 1 mg IV/IO as soon as possible (not after 2 failed shocks - key distinction from VF)
3. Repeat every 3-5 minutes
4. Treat reversible causes

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Reversible Causes: H's and T's

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PART 4: PHARMACOLOGY IN RESUSCITATION

• Lidocaine, Epinephrine, Atropine, Naloxone
• Dose: 2-2.5x IV dose, diluted in 5-10 mL NS

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PART 5: DEFIBRILLATION

Biphasic vs. Monophasic

• Biphasic preferred: Delivers energy in two directions; equivalent or better efficacy at lower energy
• Biphasic: 120-200 J (manufacturer recommendation)
• Monophasic: Start at 200 J, escalate
• Survival decreases 7-10% for every minute without defibrillation

Energy Levels

2025 New Recommendations

• Vector change defibrillation: Changing pad position (anterior-posterior vs anterior-lateral) for refractory VF - usefulness not yet established (new recommendation added)
• Double sequential defibrillation (DSD): Two rapid successive shocks - usefulness uncertain, increases time-to-compression; NOT routinely recommended (2020 update maintained 2025)

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PART 6: AIRWAY MANAGEMENT IN CARDIAC ARREST

• Intubation should NOT interrupt compressions for >10 seconds
• Waveform capnography is the standard for confirming and monitoring ETT placement
• If ETCO2 persistently <10 mmHg after 20 min of CPR → poor prognosis indicator
• Supraglottic airway (LMA, i-gel) is an acceptable alternative to ETT during CPR
• No preference between ETT and SGA in current guidelines; choice depends on provider skill

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PART 7: MONITORING DURING CPR

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PART 8: POST-CARDIAC ARREST CARE (BRAIN RESUSCITATION)

Post-ROSC Immediate Priorities

• Waveform capnography to confirm ETT
• FiO2 titrated to SpO2 92-98% (avoid hyperoxia - increases cerebral oxidative injury)
• RR: 10 breaths/min; target PaCO2 35-45 mmHg (avoid hyperventilation - causes cerebral vasoconstriction)

• Systolic BP >90 mmHg OR MAP >65 mmHg
• Crystalloid +/- vasopressor (norepinephrine preferred)
• 12-lead ECG: If ST elevation → emergent coronary angiography (Class I)
• 2023 update: Coronary angiography also reasonable for high-risk patients WITHOUT ST elevation (Class IIa)

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Targeted Temperature Management (TTM) - Brain Resuscitation

• TTM encompasses: therapeutic hypothermia (TH), controlled normothermia, and active fever prevention
• Target temperature: 32°C to 36°C for at least 24 hours
• Applies to: comatose OHCA patients with ROSC, regardless of initial rhythm (shockable or non-shockable)
• Avoid active rewarming; prevent hyperthermia (>37.5°C) for 72 hours

• The emphasis shifts from routine hypothermia induction to active prevention of fever and sustained controlled normothermia
• Core temperature monitoring continuously (esophageal, rectal, bladder)
• Maintain normothermia; avoid fever rather than routinely cooling to 33°C

• 6% reduction in cerebral metabolic rate per 1°C drop
• Preserves ion channel integrity
• Decreases intracellular Ca2+ influx → prevents neuronal apoptosis
• Reduces excitotoxicity, inflammation, free radical production
• Maintains blood-brain barrier integrity

Pediatric TTM:

• Maintain normothermia (NOT hypothermia) to improve neurologic outcome (THAPCA trial evidence)

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Neuroprognostication Post-Cardiac Arrest

• Clinical exam (pupillary responses, corneal reflexes, motor responses)
• Biomarkers: Neuron-specific enolase (NSE), S100B protein
• EEG: Burst suppression, status epilepticus patterns
• Imaging: MRI brain (diffusion-weighted sequences)
• Minimum 72 hours after rewarming before prognostication

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PART 9: EXTRACORPOREAL CPR (ECPR)

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PART 10: SPECIAL SITUATIONS

Pregnancy

• Manual uterine displacement (lateral tilt) while supine preferred over lateral positioning
• Standard BLS/ACLS applies
• Perimortem C-section within 4-5 minutes of maternal cardiac arrest if resuscitation fails

Opioid Overdose (2025 update)

• Expanded emphasis on rapid naloxone use
• Public access to opioid emergency kits recommended
• Naloxone 0.4-2 mg IM/IN/IV; repeat every 2-3 min

Hypothermic Cardiac Arrest

• "Not dead until warm and dead"
• Active rewarming - ECMO is the preferred rewarming method
• Defibrillation may be ineffective until core temp >30°C

Drowning

• Airway/breathing first (exception to CAB rule) - hypoxia is the primary pathophysiology

Bariatric patients (2025 new)

• Standard CPR techniques are effective; no modification needed

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PART 11: PEDIATRIC RESUSCITATION HIGHLIGHTS

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PART 12: 2025 KEY GUIDELINE CHANGES (EXAM TARGETS)

1. Single unified Chain of Survival - applicable to all ages and settings
2. Ventilation: Breaths with compressions recommended for all rescuers (lay and professional) when capable
3. Choking (2025): Adults/children - start with 5 back blows, then alternate with 5 abdominal thrusts until cleared or unresponsive
4. TTM shift: Fever prevention over routine hypothermia
5. ECPR: Class IIa (from IIb) for refractory arrest
6. Coronary angiography: Now Class IIa even without ST elevation in high-risk patients
7. Vector change defibrillation: Added to guidelines (usefulness not established)
8. Vasopressin: Expanded use in 2023; may replace 1-2 epinephrine doses
9. No routine calcium/NaHCO3/Mg during cardiac arrest (2023)
10. Ethics section: Moved to standalone section; expanded guidance on WLST timing
11. Neuroprognostication: Delay WLST decisions; multimodal assessment mandatory
12. Physiologic-guided CPR: ETCO2 + arterial pressure monitoring to titrate compressions (2025)

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PART 13: NEET SS CRITICAL CARE MCQ PRACTICE QUESTIONS

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• A) >40%
• B) >50%
• C) >60%
• D) >70%

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• A) Lidocaine 1.5 mg/kg
• B) Amiodarone 300 mg IV
• C) Epinephrine 1 mg IV
• D) Vasopressin 40 units IV

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• A) Time from collapse to first shock; should be <3 min
• B) Time from last compression to shock delivery; minimize to improve outcomes
• C) Time between two consecutive shocks; should be <5 sec
• D) Time for rhythm check; should be <10 sec

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• A) SpO2 >99%
• B) SpO2 94-100%
• C) SpO2 92-98%
• D) SpO2 88-92%

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• A) All patients with ROSC
• B) Comatose patients with ROSC after OHCA, shockable rhythm only
• C) Comatose patients with ROSC after OHCA, any rhythm
• D) Only when initiated within 30 min of ROSC

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• A) Class I - standard of care
• B) Class IIa - reasonable when resources available
• C) Class IIb - may be considered
• D) Class III - no benefit

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• A) Adequate compressions
• B) Hyperventilation
• C) Poor prognosis and consideration for termination
• D) Need for immediate bicarbonate

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• A) 1-hand heel technique
• B) 2-thumb encircling technique
• C) Palm technique
• D) No preference

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• A) Epinephrine
• B) Amiodarone
• C) Calcium gluconate
• D) Lidocaine

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• A) Time to epinephrine administration
• B) Time to defibrillation
• C) Time to advanced airway
• D) Time to bicarbonate

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• A) ST elevation only
• B) Non-ST elevation MI with high-risk features
• C) Any arrested patient with ROSC
• D) Only when troponin is elevated

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• A) It causes hypernatremia
• B) CO2 (not bicarbonate) crosses cell membranes, worsening intracellular acidosis
• C) It increases serum potassium
• D) It inhibits catecholamine release

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• A) Vasodilation and increased cerebral perfusion
• B) Reduction in cerebral metabolic rate (6% per 1°C) + reduced Ca2+ influx + reduced apoptosis
• C) Increased adenosine release
• D) Prevention of cerebral edema only

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• A) A-B-C-D
• B) C-A-B-D
• C) D-C-A-B
• D) B-A-C-D

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• A) 28°C
• B) 30°C
• C) 32°C
• D) 35°C

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• A) Lidocaine, Epinephrine, Atropine, Naloxone
• B) Lidocaine, Esmolol, Atropine, Norepinephrine
• C) Lidocaine, Epinephrine, Amiodarone, Naloxone
• D) Lorazepam, Epinephrine, Atropine, Naloxone

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• A) Immediate hospital discharge planning
• B) Rehabilitation support and psychological follow-up as part of the chain of survival
• C) Restriction of activity for 6 months
• D) Immediate cardiac surgery

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QUICK SUMMARY TABLE FOR REVISION

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• Morgan & Mikhail's Clinical Anesthesiology, 7e, Chapter 55 (CPR) - primary anaesthesia reference
• Miller's Anesthesia, 10e, Chapter 82 (TTM and Post-Cardiac Arrest Care)
• Roberts & Hedges' Clinical Procedures in Emergency Medicine (ACLS/CPR chapter)
• AHA 2020 CPR-ECC Guidelines
• AHA 2025 Highlights - first full revision since 2020
• PMC review of 2023 updates vs 2020

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SHORT NOTES FOR MD ANAESTHESIA EXAM

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SHORT NOTE 1: HYPOVOLEMIC RESUSCITATION

Definition & Context

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ATLS Classification of Hemorrhagic Shock (10th Edition)

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The Lethal Triad ("Bloody Vicious Cycle")

Hemorrhage → Hypothermia → Coagulopathy → Acidosis
              ↑_____________________________|

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Damage Control Resuscitation (DCR) - Core Principles

1. Permissive Hypotension (Hypotensive Resuscitation)

• Goal: Allow controlled hypotension until surgical hemorrhage control is achieved
• Target without TBI: SBP 80-90 mmHg (MAP 50-60 mmHg) - European guidelines 2023
• Target with TBI (GCS ≤8): MAP ≥80 mmHg
• Rationale: Aggressive fluid resuscitation raises BP → "pops off" the clot → worsens hemorrhage. A brief period of MAP ~60 mmHg avoids clot disruption, hemodilution, hypothermia, and dilutional coagulopathy.
• Contraindications: TBI, spinal cord injury, elderly patients, penetrating cardiac injury, prolonged hypotension
• NOT a definitive treatment - it buys time until surgical control

2. Early Definitive Hemorrhage Control

• Tourniquets, hemostatic dressings, wound packing (pre-hospital)
• Direct pressure, REBOA (Resuscitative Endovascular Balloon Occlusion of the Aorta)
• Emergency surgery/angioembolization

3. Hemostatic (Balanced) Resuscitation

• Replace volume with blood products, NOT crystalloids
• Target ratio: pRBC : FFP : Platelets = 1:1:1
• Rationale: Reconstitutes "whole blood" functionally; combats coagulopathy early
• PROPPR trial (landmark): 1:1:1 ratio showed early (24-hour) survival benefit vs. 2:1:1 ratio; 28-day mortality not significantly different
• Minimal crystalloid - only as bridge to blood products

4. Early Correction of Coagulopathy

• Tranexamic Acid (TXA): 1 g IV over 10 min within 3 hours of injury, followed by 1 g over 8 hours. Antifibrinolytic. (CRASH-2 trial)
  • 2023 guidelines: All patients with severe traumatic injury should receive TXA within 3 hours
• Cryoprecipitate: For hypofibrinogenemia (fibrinogen <1.5-2 g/L)
• Prothrombin Complex Concentrate (PCC): For factor deficiencies, anticoagulation reversal
• Factor VIIa: Salvage in refractory hemorrhagic coagulopathy
• Calcium: Mandatory with every blood product transfusion (chelation by citrate causes hypocalcemia - 2023 DCR guideline)
• Conventional coagulation assays (PT, APTT) are unreliable in trauma - performed at physiologic pH/temperature, miss effects of hypothermia and acidosis

5. Viscoelastic Testing (Goal-Directed Resuscitation)

• Thromboelastography (TEG) or Rotational Thromboelastometry (ROTEM)
• Provides dynamic, real-time picture of clot formation, strength, and fibrinolysis
• More sensitive and specific than PT/APTT/INR for trauma coagulopathy
• Guides targeted blood product use → reduces unnecessary transfusions
• Can predict massive transfusion need on admission

6. Prevention of Hypothermia

• Warm IV fluids, warming blankets, warm OR environment
• Target core temperature >36°C
• Hypothermia causes platelet dysfunction + coagulation factor inactivity + fibrinolysis

7. Reduced Crystalloid Use

• ATLS 10th: Max 1 L isotonic fluid as bridge; RL preferred over normal saline
• Large crystalloid volumes → dilutional coagulopathy, tissue edema, abdominal compartment syndrome, ARDS
• Hypertonic saline (7.5%): Resuscitates with low volume (pulls water into vascular space), immune modulator. Not commercially available as 7.5%; 5% may be used as single bolus. Beneficial in TBI for ICP management.

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Components of DCR (Summary Table from Greenfield's Surgery)

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Massive Transfusion Protocol (MTP)

• ABC Score (Assessment of Blood Consumption): Penetrating mechanism + SBP ≤90 + HR ≥120 + positive FAST. Score ≥2 = MTP activation
• TASH Score, McLaughlin Score

• pRBC + FFP + Platelets in 1:1:1 ratio
• Cryoprecipitate/fibrinogen concentrate
• TXA within 3 hours
• Calcium (1 g calcium gluconate per 4 units blood)
• Warm ALL products to 37°C

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Fluid Types: Key Pharmacology

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End-Points of Resuscitation

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SHORT NOTE 2: DEFIBRILLATION

Definition & Principle

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Indications

• Ventricular fibrillation (VF)
• Pulseless ventricular tachycardia (pVT)

• Asystole (no cardiac activity to depolarize)
• PEA (organized rhythm - no benefit)
• Stable VT with pulse (use synchronized cardioversion)

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Mechanism of Defibrillation

1. Transthoracic electrical current passes through the heart
2. Depolarizes a critical mass of myocardium simultaneously
3. Interrupts re-entry circuits maintaining VF
4. Creates momentary asystole or PEA
5. Intrinsic pacemaker (SA node) resumes - organized rhythm restored
6. CPR must continue immediately after shock (perfusing rhythm rarely immediate)

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Types of Defibrillators

1. Monophasic (Older, less common)

• Current flows in one direction only
• Higher energy required (360 J)
• Greater myocardial injury
• Waveform: Monophasic Damped Sine (MDS)

2. Biphasic (Current standard)

• Current flows in two directions (positive then negative phase)
• More effective at lower energy levels
• Less myocardial injury
• Two types:
  • Biphasic Truncated Exponential (BTE): Energy 150-200 J
  • Biphasic Rectilinear Waveform (BRW): Energy 120 J
• 90%+ first-shock success rate with biphasic
• Impedance-compensating: Adjusts for patient chest impedance

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Energy Levels (AHA 2020/2025)

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Electrode Placement

• Sternal electrode: Right of sternum, below right clavicle
• Apical electrode: Mid-axillary line, 5th-6th intercostal space (V4 position)

• Anterior pad: Left of sternum
• Posterior pad: Directly behind (scapular region)
• Preferred for patients with pacemakers/ICDs (place pads ≥10 cm from device)
• Also used for cardioversion of AF

• Changing pad position between attempts (e.g., anterolateral → anteroposterior) for refractory VF
• Usefulness not yet established (new 2025 recommendation - evidence insufficient)

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Single vs. Stacked Shocks

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Factors Affecting Transthoracic Impedance (TTI)

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Key Procedural Steps (Roberts & Hedges)

1. Turn on defibrillator/AED
2. Attach leads and electrode pads
3. Continue CPR while charging
4. Assess rhythm
5. Confirm VF/pVT
6. Select energy level (manufacturer-specific)
7. Ensure unsynchronized mode (critical - synchronized mode won't fire during VF as no QRS to detect)
8. Charge defibrillator while continuing CPR
9. Minimize pre-shock pause
10. Clear patient: "I'm clear, you're clear, everybody's clear"
11. Deliver shock at end-expiration (reduces impedance)
12. Immediately resume CPR (do not check pulse first)
13. After 2-minute CPR cycle, check rhythm

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Automated External Defibrillator (AED)

• First AED introduced in 1979
• Analyzes rhythm automatically; prompts defibrillation only for shockable rhythms (VF/rapid VT)
• Enables bystander defibrillation
• Apply pads → activate → follow voice prompts → deliver shock when prompted
• Public access defibrillation significantly improves OHCA survival

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Special Situations in Defibrillation

Implanted Devices (Pacemaker/AICD)

• Standard CPR can be performed safely
• Place pads/paddles ≥10 cm from pulse generator
• Anterior-posterior pad placement preferred
• Use lowest effective energy
• If AICD is firing repeatedly during CPR: apply magnet to inhibit
• After ROSC: interrogate device with electrophysiologist

Pregnancy

• Standard defibrillation safely performed; fetal effects negligible
• Remove fetal monitors before shocking

Hypothermia

• VF may not respond until core temperature >30°C
• Defibrillate once, rewarm, then retry

LVAD Patients

• Check that LVAD is connected, charged, has audible hum
• Peripheral pulses absent is normal - does not indicate arrest
• Follow standard ACLS if confirmed arrest

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Synchronized Cardioversion vs. Defibrillation

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NEET SS CRITICAL CARE MCQs

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• A) 1:2:1
• B) 1:1:1
• C) 2:1:1
• D) 3:1:1

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• A) SBP >90 mmHg
• B) MAP >65 mmHg
• C) SBP 80-90 mmHg (MAP 50-60 mmHg)
• D) MAP >80 mmHg

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• A) MAP 50-60 mmHg
• B) MAP ≥65 mmHg
• C) MAP ≥80 mmHg
• D) MAP >90 mmHg

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• A) 1 hour
• B) 2 hours
• C) 3 hours
• D) 6 hours

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• A) PT/INR
• B) aPTT
• C) Thromboelastography (TEG) / ROTEM
• D) Fibrinogen level

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• A) They cause hypernatremia
• B) They cause dilutional coagulopathy AND hyperchloremic acidosis
• C) They worsen cerebral edema
• D) They cause pulmonary edema only

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• A) Class I hemorrhagic shock
• B) Class II hemorrhagic shock
• C) Class III hemorrhagic shock
• D) Class IV hemorrhagic shock

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• A) It can treat asystole
• B) Equal or higher efficacy at lower energy - less myocardial injury
• C) It does not require skin contact
• D) It can be used in synchronized mode only

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• A) During peak inspiration
• B) At end-expiration
• C) After 3 stacked shocks
• D) While compressions are ongoing

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• A) Check pulse
• B) Check rhythm on monitor
• C) Resume CPR immediately (do not check pulse)
• D) Give epinephrine 1 mg IV

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• A) Asynchronized mode
• B) Defibrillation mode
• C) Synchronized mode (shock timed to R-wave)
• D) AED auto mode

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• A) GCS, lactate, base deficit, INR
• B) Penetrating mechanism, SBP ≤90, HR ≥120, positive FAST
• C) Age, blood group, crystalloid given, RR
• D) APACHE II score components

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• A) Class I recommendation for refractory VF
• B) Routinely recommended after 2 failed shocks
• C) Usefulness is uncertain; NOT routinely recommended
• D) Standard of care in all out-of-hospital arrests

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• A) It is always available and requires no refrigeration
• B) It provides pRBC, FFP, and platelets in physiologic ratios without citrate-induced hypocalcemia
• C) It has longer shelf life than component therapy
• D) It prevents hemolytic transfusion reactions

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• A) It delivers higher energy
• B) In VF there are no QRS complexes - synchronized mode would fail to fire as it looks for R-wave
• C) It prevents skin burns
• D) It charges faster

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QUICK REVISION COMPARISON TABLE

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• Mulholland and Greenfield's Surgery, 7e (Damage Control Resuscitation, Lethal Triad)
• Schwartz's Principles of Surgery, 11e (DCR, Massive Transfusion)
• Miller's Anesthesia, 10e (Defibrillation, AED, Single vs. Stacked shocks)
• Roberts & Hedges' Clinical Procedures in Emergency Medicine (Energy selection, Electrode placement)
• Barash's Clinical Anesthesia, 9e (ECPR, Defibrillation)
• European Guidelines on Bleeding/Coagulopathy 6th edition 2023
• ATLS 10th Edition, American College of Surgeons

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ICU SEDATION AND ANALGESIA: CURRENT STRATEGIES

MD Anaesthesia Exam | NEET SS Critical Care

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THE PADIS FRAMEWORK: EVOLUTION OF GUIDELINES

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PART 1: WHY SEDATION AND ANALGESIA MATTER

• Deep sedation within 48 hours doubles hospital mortality (Shehabi et al.)
• Benzodiazepines increase delirium risk 2-4 fold
• Prolonged sedation → longer ventilator duration, longer ICU stay, post-ICU cognitive impairment, PTSD, ICU-acquired weakness (ICUAW)
• The "No Sedation" strategy (Strom et al.) reduced ventilator days and ICU stay

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PART 2: THE A2F / ABCDEF BUNDLE

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PART 3: PAIN ASSESSMENT IN THE ICU

"A" of the Bundle: Assess, Prevent, Manage Pain

Verbal Patients:

• Numerical Rating Scale (NRS): 0-10; 0 = no pain, 10 = worst pain
• Verbal Rating Scale (VRS): Mild / Moderate / Severe

Non-Verbal / Intubated Patients:

• CPOT (Critical Care Pain Observation Tool): Validated, preferred. Assesses:
  • Facial expression (0-2)
  • Body movements (0-2)
  • Muscle tension (0-2)
  • Compliance with ventilator (0-2)
  • Total score 0-8; score ≥3 = significant pain
• BPS (Behavioral Pain Scale): Facial expression + upper limb movements + compliance with ventilation; score 3-12
• NRS-Visual Analogue Scale for patients who can point but not speak

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PART 4: ANALGESIA-FIRST STRATEGY (ANALGOSEDATION)

Current Standard: Analgesia before Sedation

1. Analgesia-First Sedation: An opioid is used BEFORE adding a sedative to reach sedation target
2. Analgesia-Based Sedation: Opioid ALONE is used instead of a sedative to reach sedation goal (no additional hypnotic drug)

• Reduces total sedative use
• Shorter ventilator duration
• Faster extubation
• Reduced delirium risk

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Analgesic Agents in the ICU

Opioids (First-line analgesia)

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Non-Opioid Analgesics (Opioid-Sparing - Multimodal Analgesia)

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PART 5: SEDATION IN THE ICU

Target Sedation Level: LIGHT SEDATION is the goal

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Sedation Assessment Scales

Richmond Agitation-Sedation Scale (RASS) - Most widely used

Riker Sedation-Agitation Scale (SAS): 7-point scale; target SAS 3-4

Ramsay Sedation Scale (older): 6 levels; less granular for agitation

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Sedative Agents

Non-Benzodiazepines (Preferred - PADIS 2018 and 2025)

"We suggest using dexmedetomidine over propofol for sedation in mechanically ventilated adult patients where light sedation and/or a reduction in delirium are highest priorities." (Conditional recommendation; moderate certainty)

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Propofol-Related Infusion Syndrome (PRIS) - High-Yield

• Dose >4 mg/kg/hr (>67 mcg/kg/min)
• Duration >48 hours
• High-carbohydrate, low-fat diet (or total PN)
• Children (especially with respiratory tract infections)
• Catecholamine/glucocorticoid infusions

• Metabolic acidosis (lactic acidosis - high anion gap)
• Rhabdomyolysis
• Myoglobinuria → acute kidney injury
• Lipaemia (hypertriglyceridaemia)
• Cardiac arrhythmias - new RBBB, ST changes, Brugada-like pattern
• Hepatomegaly
• Muscle necrosis

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Benzodiazepines (Avoid where possible - PADIS 2018/2025)

• Alcohol withdrawal (CIWA protocol; benzodiazepines are first-line)
• Seizures / status epilepticus
• Acute agitation where rapid sedation is needed
• Benzodiazepine or barbiturate withdrawal
• Specific procedures (cardioversion - midazolam)
• Patients with severe ARDS where deep sedation is required

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PART 6: SEDATION STRATEGIES

1. Daily Sedation Interruption (Sedation Vacation / SAT)

• Discontinue all sedative infusions once daily at a fixed time
• Re-evaluate neurological status
• Restart at HALF the previous dose if needed (prevents re-accumulation)
• Pairing SAT + SBT (spontaneous breathing trial) = synergistic benefit
• Contraindications to SAT: Active seizures, severe ARDS, elevated ICP, therapeutic paralysis, severe alcohol withdrawal, active hemodynamic instability

2. Protocol-Driven Sedation

• Nurse-driven sedation titration algorithms targeting RASS goal set by physician
• Superior to physician-directed ad hoc dosing
• Reduces total sedative dose and duration of ventilation

3. Target-Based Sedation

• Set daily RASS target (usually -1 to 0)
• Reassess and adjust every 2-4 hours
• Always ask: "Does this patient still need sedation today?"

4. Analgosedation (Analgesia-Based Sedation)

• Treat pain first (opioid/non-opioid)
• Add sedative only if pain control alone is insufficient
• Achieves sedation target with lower sedative doses

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PART 7: DELIRIUM IN THE ICU

Definition

Types

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Assessment Tools

• Feature 1: Acute onset + fluctuating course
• Feature 2: Inattention
• Feature 3: Altered level of consciousness
• Feature 4: Disorganized thinking
• CAM-ICU POSITIVE = Features 1+2, AND either 3 or 4

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Delirium Risk Factors (Predisposing + Precipitating)

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Prevention (PADIS 2018 - Primarily Non-Pharmacologic)

• Early mobilization (most important single intervention)
• Reorientation (clocks, calendars, natural light, familiar objects)
• Hearing aids and eyeglasses
• Family presence and communication
• Sleep promotion (day/night cycle, cluster care, ear plugs, eye masks)
• Remove precipitants (catheters, restraints, unnecessary drugs)

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Treatment of Established Delirium

• Haloperidol: 0.25-1 mg IV/PO q8-12h. Monitor QTc. Avoid in Parkinson's disease (worsens symptoms)
• Quetiapine: 25-100 mg PO BID. Less extrapyramidal effects
• Dexmedetomidine: Preferred for hyperactive delirium in intubated patients; provides sedation while allowing communication

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PART 8: SLEEP DISRUPTION IN THE ICU

• Melatonin 3-10 mg at night
• Ramelteon (melatonin agonist) 8 mg: Shows promise in reducing delirium incidence

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PART 9: NEUROMUSCULAR BLOCKADE (NMB) IN ICU

• Severe ARDS (PaO2/FiO2 <150) - to improve oxygenation, reduce ventilator asynchrony (ACURASYS trial: 48h cisatracurium improved 28-day mortality - BUT ROSE trial 2019 showed no mortality benefit with routine NMB; guideline now more selective)
• Refractory intracranial hypertension
• Life-threatening ventilator asynchrony
• Status epilepticus refractory to medical therapy
• Tetanus, malignant hyperthermia

• Cisatracurium (preferred): Hoffman elimination; not affected by renal/hepatic failure; less histamine release
• Vecuronium: Hepatic metabolism; intermediate duration
• Atracurium: Hoffman + ester hydrolysis; active metabolite laudanosine (CNS stimulant)
• Rocuronium: Reversible with sugammadex; used in RSI, not prolonged infusion typically

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PART 10: SPECIAL SCENARIOS

Alcohol Withdrawal (CIWA-Ar Protocol)

• Benzodiazepines ARE first-line (exception to general ICU rule)
• Lorazepam 2-4 mg IV q1-4h symptom-triggered
• CIWA-Ar score ≥8-10: Initiate treatment
• Phenobarbital as adjunct for refractory withdrawal
• Thiamine 500 mg IV TDS before glucose (prevent Wernicke's)
• Dexmedetomidine as adjunct to reduce agitation (not monotherapy)

Post-Cardiac Surgery ICU

• Propofol infusion standard for short-term sedation post-CABG
• Target extubation within 4-6 hours (fast-track cardiac surgery)
• Dexmedetomidine useful for weaning phase

Traumatic Brain Injury (TBI)

• Sedation needed to control ICP
• Propofol: preferred (reduces CMRO2, ICP; easy to interrupt for neuro assessment)
• Dexmedetomidine: useful in mild-moderate TBI
• Avoid ketamine (relative CI in raised ICP - older recommendation, increasingly challenged)
• Fentanyl preferred opioid (no histamine release, no seizure potential)
• Target CPP >60 mmHg; avoid hypotension

Sepsis

• Analgosedation preferred; minimize benzodiazepines
• Dexmedetomidine or propofol for sedation
• Note SPICE III caution with early dexmedetomidine in non-operative patients ≤65 years

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PART 11: DRUG SUMMARY TABLE

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NEET SS CRITICAL CARE MCQs: SEDATION & ANALGESIA

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• A) Midazolam
• B) Lorazepam
• C) Dexmedetomidine
• D) Ketamine

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• A) RASS -4 to -5 (deep sedation)
• B) RASS -2 to -3 (moderate sedation)
• C) RASS -1 to 0 (light sedation)
• D) RASS 0 to +1 (alert to restless)

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• A) Deep sedation - reduce doses
• B) Significant pain requiring analgesic intervention
• C) Delirium - start haloperidol
• D) Adequate pain control - continue current regime

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• A) Sepsis-related cardiomyopathy
• B) Pulmonary embolism
• C) Propofol Infusion Syndrome (PRIS)
• D) Hypertriglyceridemia from TPN

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• A) Blood gas monitoring and ventilator settings
• B) Both spontaneous awakening trial AND spontaneous breathing trial
• C) Benzodiazepine avoidance
• D) Brain function monitoring (EEG)

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• A) Early mobilization
• B) Reorientation strategies
• C) Haloperidol, atypical antipsychotics, dexmedetomidine (as prophylaxis)
• D) Sleep hygiene protocols

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• A) Morphine
• B) Hydromorphone
• C) Fentanyl
• D) Codeine

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• A) Elderly patients >75 years admitted post-cardiac surgery
• B) Mechanically ventilated patients ≤65 years admitted for non-operative reasons
• C) All septic patients regardless of age
• D) Patients with TBI admitted to neuro-ICU

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• A) Acute onset + disorganized thinking alone
• B) Features 1 (acute onset + fluctuating course) + Feature 2 (inattention), AND either Feature 3 (altered consciousness) OR Feature 4 (disorganized thinking)
• C) All 4 features must be present
• D) Any 2 of 4 features

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• A) Dexmedetomidine infusion
• B) Propofol infusion
• C) Lorazepam or diazepam (benzodiazepines)
• D) Haloperidol

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• A) GABA-A receptor agonism
• B) NMDA receptor antagonism
• C) Selective α2-adrenoceptor agonism at locus coeruleus - produces natural NREM-like sleep
• D) Mu-opioid receptor partial agonism

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• A) Zolpidem 10 mg at bedtime
• B) Propofol nocturnal infusions for sleep induction
• C) Melatonin administration
• D) Low-dose quetiapine

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• A) Hyperactive delirium (agitated, combative)
• B) Hypoactive delirium (quiet, withdrawn, "just sleeping")
• C) Mixed delirium
• D) Subsyndromal delirium

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• A) Should be administered routinely to all ARDS patients
• B) Is reserved for severe ARDS patients not responding to other lung-protective ventilation strategies
• C) Should not be used in ARDS under any circumstance
• D) Should be first-line before trying other ventilator strategies

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• A) Gabapentin
• B) Ketamine
• C) Ketorolac
• D) Lidocaine infusion

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• A) 0.5 kcal/mL
• B) 1.1 kcal/mL (from 10% lipid emulsion vehicle)
• C) 2.0 kcal/mL
• D) No caloric contribution

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RAPID REVISION SUMMARY

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• Miller's Anesthesia, 10e (Dexmedetomidine ICU use, SPICE III, PADIS guidelines)
• Fischer's Mastery of Surgery, 8e (ABCDEF bundle, delirium prevention)
• Sabiston Textbook of Surgery (PRIS, opioid pharmacology, ICU pain)
• SCCM PADIS Guidelines 2018 (Devlin JW et al., Crit Care Med 2018;46(9):e825-e873)
• SCCM PADIS 2025 Focused Update (Lewis K et al., Crit Care Med 2025;53(3):e711-e727)
• PROPPR Trial | CRASH-2 Trial | SPICE III Trial | ROSE Trial

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ASSESSMENT AND MANAGEMENT OF PAIN IN A CRITICALLY ILL ADULT PATIENT WITH CHEST DRAINS AND RYLE'S TUBE FEEDING

MD Anaesthesia Exam | NEET SS Critical Care

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CLINICAL SCENARIO OVERVIEW

• Intubated/mechanically ventilated OR spontaneously breathing but obtunded
• Intercostal chest drain (ICD) in situ (for pneumothorax, haemothorax, pleural effusion, or post-thoracic/cardiac surgery)
• Ryle's tube (nasogastric tube) in situ for enteral nutrition
• In ICU for ≥48 hours

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PART 1: WHY PAIN MATTERS - CONSEQUENCES OF UNDERTREATED PAIN

Physiological Stress Response

Consequences Specifically With Chest Drain

• Splinting: Patient guards the ICD site → inadequate deep breathing → atelectasis → V/Q mismatch → hypoxaemia → longer ventilation
• Inability to cough: Retained secretions → nosocomial pneumonia
• Agitation: Pulls at ICD → dislodgement risk

With Ryle's Tube

• NGT causes nasopharyngeal and oropharyngeal discomfort/pain
• Gastric distension from feeding (if poorly tolerated) → abdominal pain
• Aspiration risk if agitated/coughing due to pain → aspiration pneumonia
• Pain → reduced gastric motility → feed intolerance → inadequate nutrition

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PART 2: SOURCES OF PAIN IN THIS PATIENT

Chronic Background (Resting) Pain

1. Primary illness - injury, surgery, sepsis-related tissue damage
2. ICD site - continuous pleural irritation by tube against parietal pleura, pressure on intercostal nerve/vessels
3. Ryle's tube - nasopharyngeal pressure, oropharyngeal irritation, pharyngeal reflex stimulation
4. Immobilisation pain - pressure areas, joint stiffness
5. ETT - tracheal/laryngeal discomfort (if intubated)
6. IV access sites, arterial lines, urinary catheter

Procedural (Breakthrough) Pain - HIGHEST INTENSITY

ICD-Specific Pain Sources

• Insertion: Intercostal nerve trauma, periosteal trauma
• In situ: Continuous irritation of parietal pleura (highly sensitive), tube movement with respiration
• During drainage: Lung expansion causing pleural friction
• Manipulation: Stripping/milking of tube (now discouraged)
• Clamping for transport or drainage assessment
• Removal: Acute procedural pain spike

Ryle's Tube-Specific Discomfort

• Insertion: Severe nasopharyngeal pain, gag reflex activation, oesophageal/laryngeal irritation
• In situ: Persistent nasopharyngeal pressure → mucosal erosion (sinusitis, otitis media with prolonged use)
• Tube misplacement → aspiration → respiratory pain
• Feeding-related: Bloating, cramping if high rate or osmotic load

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PART 3: BARRIERS TO PAIN ASSESSMENT IN THE CRITICALLY ILL

1. Communication barrier: Intubated patients cannot self-report verbally
2. Sedation: May mask pain behaviours without treating pain - "sedation ≠ analgesia"
3. Paralysis (NMB): Completely abolishes behavioural signs - assume pain present
4. Delirium: Distorts pain expression and interpretation
5. Cultural/language differences
6. Cognitive impairment (prior dementia, encephalopathy)
7. Confounding vital signs: Tachycardia and hypertension may be from sepsis, hypovolaemia, or catecholamines - not just pain
8. Provider knowledge gaps: Misconception that a sedated patient is comfortable
9. Fear of analgesic side effects (respiratory depression, hypotension)

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PART 4: PAIN ASSESSMENT - VALIDATED TOOLS

Step 1: Attempt Self-Report (Verbal Patients)

• "Rate your pain from 0-10" (0 = no pain, 10 = worst imaginable)
• Can be adapted: written scale, visual scale (patient points)
• Most valid when patient can communicate

Step 2: Behavioural Scales (Non-Verbal / Intubated Patients)

CPOT - Critical Care Pain Observation Tool (Recommended by PADIS)

• Score ≥3 = significant pain requiring intervention
• Validated in mechanically ventilated adults; recommended by PADIS 2018
• Superior to BPS in specificity (assesses muscle tension)

BPS - Behavioral Pain Scale

• Score ≥5 = significant pain
• Validated, widely used
• Simpler than CPOT; less specific

FACES Pain Scale (Wong-Baker)

• Visual analogue using facial expressions
• For patients who can see and point but not speak
• Score 4-10 = significant pain

Step 3: Surrogate Pain Indicators (Supporting evidence only, NOT primary assessment)

• Sudden tachycardia or hypertension during a procedure
• Diaphoresis, mydriasis, lacrimation
• BUT: these are non-specific - consider other causes first

Step 4: Family Input

Step 5: Assume Pain is Present

• For patients who cannot self-report AND have no visible behaviours (deeply sedated, paralysed):
• Assume pain is present for known painful conditions (ICD, post-surgery, trauma)
• Treat empirically

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PART 5: ASSESSMENT FREQUENCY

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PART 6: MANAGEMENT PRINCIPLES - THE PADIS FRAMEWORK

Key Principle: "A" of ABCDEF Bundle

1. Treat pain BEFORE adding sedation (Analgesia-first/Analgosedation)
2. Use validated assessment tools to guide treatment, not vital signs alone
3. Protocol-based stepwise approach (not ad hoc)
4. Multimodal analgesia - combine drugs with different mechanisms to reduce opioid burden
5. Differentiate background pain from procedural pain - different strategies needed

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PART 7: PHARMACOLOGICAL MANAGEMENT

A. Background (Continuous) Pain Management

Step 1: Non-Opioid Analgesics (First-line adjuncts)

Step 2: Opioids (Mainstay for moderate-severe pain)

• Oral morphine solution, tramadol solution, liquid paracetamol, gabapentin capsules (opened into liquid) - all can be given via NGT
• Check tube position before administration (auscultation + aspiration of gastric contents + pH test; X-ray confirmation for new NGT)
• Hold tube feeding 30-60 min before and after crushed/dissolved oral medications with enteric coating or those affected by food

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B. Procedural Pain Management (ICD-Specific)

For ICD Manipulation / In-Situ Care:

1. IV opioid (PADIS 2018, Conditional, Moderate QoE): Fentanyl 1-1.5 mcg/kg IV 15-30 min prior to manipulation
2. Ketamine: 0.3-0.5 mg/kg IV slow bolus - excellent for procedural pain (short, predictable)
3. Local anaesthetic infiltration at ICD site: Lidocaine 1-2% at the insertion site + along tube tract for dressing changes

For ICD Removal:

• Opioid IV: Suggested at lowest effective dose (Conditional, Moderate QoE)
• NSAID IV/oral/rectal: Suggested as alternative to opioid (Conditional, Low QoE)
• Cold (cryotherapy): Suggested - cold pack applied to removal site (Conditional, Low QoE)
• Relaxation techniques: Suggested (breathing exercises, music therapy, distraction) (Conditional, Very Low QoE)
• Local anaesthetic infiltration (subcutaneous around ICD site): NOT specifically recommended due to low evidence, but widely used clinically
• Nitrous oxide (50% N2O/O2): NOT recommended by PADIS 2018 for chest tube removal - Low QoE
• Topical NSAID gel (diclofenac): NOT recommended - insufficient evidence

Regional Anaesthesia for Chest Drain Pain (Current Evidence):

• SAPB provides lateral cutaneous intercostal nerve coverage - directly relevant to ICD pain (lateral chest wall)
• Continuous SAPB shown comparable to IV fentanyl for rib-fracture pain with superior early mobilization and shorter ICU stay
• SAPB + ESPB combination provides better anterior and posterior coverage

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C. Ryle's Tube-Specific Pain Management

• Always verify placement before each drug administration
• Flush with 30 mL water before and after each drug
• Crush tablets only if appropriate (NOT modified-release or enteric-coated)
• Use liquid formulations where available
• Optimal drugs via NGT: Paracetamol (Calpol suspension), tramadol drops/liquid, gabapentin capsule contents, pregabalin capsule contents in water

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PART 8: NON-PHARMACOLOGICAL PAIN MANAGEMENT

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PART 9: STEPWISE PROTOCOL - PRACTICAL APPROACH

1. ASSESS: Use CPOT or BPS every 4 hours and pre/post procedure
           CPOT ≥3 or BPS ≥5 = TREAT
           
2. ASSUME: If paralysed/unresponsive with known painful condition (ICD, post-surgery) → TREAT

3. BACKGROUND PAIN:
   → Paracetamol 1g IV/NGT q6h (SCHEDULED, not PRN)
   → + Fentanyl infusion 25-100 mcg/hr (titrate to CPOT <3)
   → + Gabapentin 100-300 mg TID via NGT (if neuropathic component)
   → ± Regional block (SAPB / ESPB / intercostal) for ICD

4. BREAKTHROUGH PAIN (CPOT ≥3 despite background):
   → Fentanyl 25-50 mcg IV bolus PRN q1h
   → Reassess in 30 min

5. PRE-PROCEDURAL (ICD manipulation, removal, repositioning):
   → Plan 30 min ahead
   → Fentanyl 1-1.5 mcg/kg IV OR Ketamine 0.3 mg/kg IV
   → + Non-pharmacologic: cold pack, patient preparation
   → Reassess CPOT 1 hour post-procedure

6. REASSESS DAILY: Is the ICD still needed? Is NGT still needed?
   Early removal = major pain reduction strategy
   
7. MONITOR: Respiratory depression (RR, SpO2), delirium (CAM-ICU)

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PART 10: MONITORING FOR ANALGESIC SIDE EFFECTS

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PART 11: SPECIAL CONSIDERATIONS

Renal Impairment (Common in ICU)

• Avoid morphine (M6G accumulates - prolonged respiratory depression)
• Fentanyl preferred (hepatic metabolism to inactive metabolites)
• Reduce gabapentin/pregabalin dose (renally excreted)
• Avoid ketorolac/NSAIDs (nephrotoxic)
• Paracetamol safe at standard doses

Hepatic Impairment

• Reduce paracetamol (max 2g/day in severe hepatic impairment)
• Fentanyl/morphine increased T½ with cirrhosis - monitor carefully
• Midazolam prolonged sedation - avoid

Haemodynamic Instability

• Fentanyl IV preferred over morphine (less histamine/hypotension)
• Ketamine useful (maintains BP and HR)
• Avoid epidural if haemodynamically unstable (sympathetic block worsens hypotension)
• SAPB/ESPB safe (minimal haemodynamic effect)

Coagulopathy

• Avoid epidural and paravertebral blocks (haematoma risk)
• SAPB, ESPB safe (distant from neuraxis, compressible sites)
• NSAIDs worsen coagulopathy - avoid

Respiratory Failure / Mechanical Ventilation

• Opioids: Titrate carefully to avoid over-suppression; use analgosedation
• Regional blocks (SAPB/ESPB) allow opioid reduction → less respiratory depression → faster weaning
• ICD drainage for pneumothorax/effusion improves respiratory mechanics → reduces pain from respiratory effort

Post-Extubation with ICD Still In Situ

• Critical period - patient now more aware of ICD discomfort
• Multimodal oral/NGT analgesia becomes primary
• Regional block or intercostal nerve block very useful
• Incentive spirometry only feasible with adequate analgesia
• Poor pain control post-extubation → splinting → re-intubation risk

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PART 12: SUMMARY TABLE - PAIN MANAGEMENT MATRIX

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NEET SS CRITICAL CARE MCQs

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• A) Ramsay Scale
• B) BPS (Behavioral Pain Scale)
• C) CPOT (Critical Care Pain Observation Tool)
• D) NRS (Numerical Rating Scale)

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• A) Endotracheal suction
• B) Nasogastric tube insertion
• C) Chest tube/drain removal
• D) Arterial line insertion

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• A) IV opioid at lowest effective dose
• B) Cold therapy/cryotherapy
• C) Relaxation techniques
• D) Nitrous oxide (50% N₂O/O₂)

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• A) Increase propofol infusion rate
• B) Administer IV fentanyl 25-50 mcg as per pain protocol
• C) Perform CAM-ICU to rule out delirium
• D) Check chest X-ray for ICD position

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• A) Morphine (IV infusion)
• B) Hydromorphone (IV infusion)
• C) Fentanyl (IV infusion)
• D) Codeine (via NGT)

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• A) Thoracic epidural analgesia
• B) Paravertebral block
• C) Serratus Anterior Plane Block (SAPB)
• D) Intercostal nerve block with intrathoracic injection

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• A) Administer drug → flush tube → check position → resume feeding
• B) Check tube position → hold feeding → flush 30 mL water → administer drug → flush 30 mL water → resume feeding
• C) Crush tablet → dissolve → flush → administer without checking position
• D) Administer drug directly without flushing - it will reach stomach anyway

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• A) Tachycardia and hypertension should be the PRIMARY parameters to assess pain
• B) Vital signs should NOT be used as the primary assessment tool; use validated behavioural scales instead
• C) A heart rate >100/min always indicates uncontrolled pain in ICU
• D) Stable vital signs confirm absence of pain

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• A) Morphine
• B) Gabapentin
• C) Ketamine
• D) Ketorolac

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• A) No analgesia needed - patient is fully paralysed and cannot feel pain
• B) Assess with BPS/CPOT every 4 hours and treat if score elevated
• C) Assume pain is present and ensure adequate analgesia is in place; pain cannot be assessed behaviourally during NMB
• D) Use only paracetamol as opioids are contraindicated with NMB

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• A) Paracetamol should be given only as rescue medication (PRN) when CPOT ≥3
• B) IV paracetamol is scheduled regularly (around the clock) as an opioid-sparing adjunct
• C) Paracetamol is contraindicated via NGT/Ryle's tube
• D) Paracetamol should not be used in ventilated patients due to hepatic risk

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• A) Increase background opioid infusion to prevent all pain
• B) Maintain current background analgesic; add pre-procedural IV fentanyl 30 min before physiotherapy; consider regional block (SAPB/PVB/epidural) for cough-induced pain
• C) Administer IV diazepam before physiotherapy for anxiolysis
• D) Avoid physiotherapy until CPOT remains ≤2 at all times

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• A) Pregabalin - it undergoes extensive hepatic first-pass metabolism
• B) Gabapentin - it is renally excreted unchanged; accumulates in AKI causing excessive sedation and respiratory depression
• C) Gabapentin - it inhibits CYP450 enzymes causing drug interactions
• D) Pregabalin - it causes severe hypertension in renal failure

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EXAM SUMMARY CARD

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• SCCM PADIS Guidelines 2018 (Devlin JW et al., Crit Care Med 2018;46(9):e825-e873)
• Sabiston Textbook of Surgery (ICU pain, opioid pharmacology)
• Fischer's Mastery of Surgery, 8e (ABCDEF bundle, ICU delirium/pain)
• Puntillo KA et al. Determinants of procedural pain intensity in the ICU: The Europain Study. AJRCCM 2014
• Vandenbrande et al. SAPB reduces opioid consumption after minimally invasive cardiac surgery. Reg Anesth Pain Med 2024
• Non-Neuraxial Chest and Abdominal Wall Regional Anesthesia for ICU Physicians - J Clin Med 2024;13:1104
• SCCM ICU Liberation Bundle - Pain assessment tools

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EXTRACORPOREAL MEMBRANE OXYGENATION (ECMO)

Indications and Procedure in the Critically Ill Adult

MD Anaesthesia Examination | NEET SS Critical Care

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PART 1: DEFINITION AND HISTORICAL CONTEXT

• 1972: First successful adult use (Robert Bartlett)
• 2009: H1N1 influenza pandemic → major expansion of ECMO for respiratory failure (CESAR trial)
• 2018: EOLIA trial - VV ECMO for severe ARDS
• 2020-2022: COVID-19 → exponential global expansion
• 2023 ELSO guidelines updated; ATS 2024, ESICM 2023: formal updated recommendations

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PART 2: COMPONENTS OF THE ECMO CIRCUIT

Patient → Drainage Cannula (venous) → Centrifugal Pump → 
Membrane Oxygenator → Return Cannula (arterial/venous) → Patient

Key Components:

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PART 3: TYPES OF ECMO

A. Venovenous ECMO (VV ECMO) - Respiratory Support Only

• Bifemoral VV: Drainage from femoral vein → Return to internal jugular vein (most common)
• Single-site dual-lumen cannula (Avalon/Crescent): Single cannula via right internal jugular vein - drainage from IVC + SVC, return directed at tricuspid valve. Preferred in awake ECMO
• Return cannula tip must point toward tricuspid valve (echocardiographic guidance essential)

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B. Venoarterial ECMO (VA ECMO) - Cardiac + Respiratory Support

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C. Venoarteriovenous ECMO (VAV ECMO)

• Hybrid configuration: Drainage from femoral vein; return to BOTH femoral artery (VA) AND right internal jugular vein (VV)
• Indication: VV ECMO insufficient oxygenation + cardiac dysfunction (or Harlequin syndrome management)

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PART 4: INDICATIONS

A. VV ECMO Indications (Respiratory Failure)

• CESAR Trial (2009): Transfer to ECMO centre → improved survival without severe disability (63% vs 47%)
• EOLIA Trial (2018): VV ECMO for severe ARDS - 60-day mortality 35% ECMO vs 46% conventional (not statistically significant, but 28% ECMO crossover rate)
• PRONECMO Trial (2023): Prone positioning during VV ECMO - safe and feasible; no difference in 60-day ECMO-free survival

1. Severe ARDS (PF ratio <80 after prone, optimal PEEP, neuromuscular blockade)
2. H1N1/COVID-19/viral pneumonitis with refractory hypoxaemia
3. Severe hypercapnia - post-obstructive (asthma, COPD exacerbation) with respiratory acidosis
4. Bridge to lung transplantation
5. Primary graft dysfunction post-lung transplant
6. Pulmonary haemorrhage/massive aspiration where lung-protective ventilation cannot be achieved

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B. VA ECMO Indications (Cardiac/Cardiorespiratory Failure)

• VA ECMO initiated during active cardiac arrest
• AHA 2023: Class IIa when equipment and trained personnel available, refractory to standard ACLS
• Assessment after ~10 min of unsuccessful conventional CPR
• Candidates: Young, witnessed arrest, reversible cause, short no-flow time, potentially recoverable
• Reversible causes: AMI, PE, refractory VF, hypothermia, drug toxicity, myocarditis
• 2024 NIS analysis: Each 12-hour delay in VA ECMO initiation increases adjusted in-hospital mortality by 6%

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PART 5: CONTRAINDICATIONS

Absolute Contraindications

1. Irrecoverable condition without bridge plan (no destination therapy - futility)
2. Advanced directive refusing ECMO/resuscitation
3. Uncontrolled haemorrhage not amenable to surgical control (relative to heparinisation)
4. Severe aortic regurgitation (VA ECMO increases afterload → worsens AR)
5. Aortic dissection (unless specific plan for repair)

Relative Contraindications (Centre-dependent decisions)

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PART 6: PROCEDURE - STEP-BY-STEP

Pre-ECMO Preparation

• ECMO physician (intensivist/cardiac surgeon/perfusionist)
• Bedside nurse (ECMO-trained)
• Perfusionist
• Vascular surgeon (for surgical cutdown if needed)
• Echocardiographer

• ECMO circuit primed and de-aired (crystalloid/blood prime)
• Centrifugal pump tested
• Membrane oxygenator inspected
• Correct cannula sizes chosen (based on patient weight/BSA - usually 21-25 Fr drainage, 15-21 Fr return)
• Emergency medications: Heparin, vasopressors, emergency drugs
• Imaging: Fluoroscopy OR bedside ultrasound

• ABG, CBC, coagulation (PT, aPTT, fibrinogen, TEG/ROTEM)
• Echo (LV/RV function, valve assessment, thrombus, pericardial effusion)
• CT angiography (vascular anatomy, femoral vessel assessment if time permits)
• 12-lead ECG, CXR
• Blood group and crossmatch
• Baseline ACT (Activated Clotting Time)

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VV ECMO Cannulation Procedure (Bifemoral)

• Supine; sedation + analgesia (RASS -2 to -3)
• Sterile draping of groin and neck

• USS-guided or fluoroscopic guidance
• Seldinger technique: Needle → guidewire → serial dilators → 21-25 Fr multi-stage drainage cannula
• Advance to right atrium/IVC junction (tip at RA-IVC junction ~2 cm above diaphragm)
• Confirm position by X-ray/echo

• Right IJV approached in standard fashion (USS-guided)
• 15-21 Fr return cannula advanced to SVC-RA junction
• Echo guidance to confirm tip position near tricuspid valve

• Connect drainage cannula → pump inlet
• Connect return cannula → oxygenator outlet
• Ensure no air in circuit (de-air check)

• Start pump at low flow (1-2 L/min)
• Administer heparin bolus 50-100 units/kg IV
• Gradually increase flow to target (3-5 L/min or 60-80 mL/kg/min)
• Target: SaO₂ >88-92%, ETCO₂ reduced, acidosis correcting

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VA ECMO Cannulation Procedure (Femoro-Femoral)

• USS-guided femoral vein puncture (10-15 cm below inguinal ligament)
• 21-25 Fr multi-stage drainage cannula → IVC → right atrium
• Confirm by X-ray/TOE: tip at RA-IVC junction

• USS-guided common femoral artery puncture
• CRITICAL: Document and protect distal perfusion - insert 6-8 Fr antegrade perfusion cannula (downflow cannula) into superficial femoral artery to prevent ipsilateral limb ischaemia
• 15-21 Fr arterial return cannula advanced to common iliac artery (NOT beyond aorto-iliac junction to avoid renal/mesenteric ischaemia)

• As above: heparin bolus → connect → start at low flow → gradually increase

• Fluoroscopy or TOE (transesophageal echo) for VA ECMO
• Assess LV for distension (if non-ejecting LV on VA ECMO)

• Maintain MAP 60-80 mmHg
• Vasopressors titrated as needed
• Initial flow ~50% predicted cardiac output, titrate up

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Dual-Lumen Single Cannula (Avalon/Crescent) - VV ECMO

• Right IJV approach
• Single 31 Fr (female) or 27 Fr (male) dual-lumen cannula
• Drainage ports at SVC and IVC (draws from both)
• Return port directed toward tricuspid valve
• Must confirm direction of return port by TOE - critical to avoid recirculation
• Benefits: Single site; enables patient mobilisation; "awake ECMO"

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PART 7: ECMO MANAGEMENT

Initial Targets

Protective Ventilation on ECMO ("Ultra-Protective")

• Tidal volume: 3-4 mL/kg PBW (lower than standard 6 mL/kg)
• PEEP: 10-15 cmH₂O
• FiO₂: 0.3-0.4 (allow lung rest)
• RR: 10-15/min
• Plateau pressure: <25 cmH₂O
• Driving pressure: <15 cmH₂O

Anticoagulation

• Heparin infusion (standard): Continuous unfractionated heparin (UFH) targeting ACT 180-220 sec OR anti-Xa 0.3-0.7 IU/mL
• Monitoring: ACT q4h; aPTT; anti-Xa levels; TEG/ROTEM for comprehensive assessment
• Heparin resistance: Use antithrombin III (AT-III) concentrate or fresh frozen plasma
• Heparin-induced thrombocytopenia (HIT): Switch to argatroban or bivalirudin
• Bleeding: Reduce or hold heparin; transfuse platelets, FFP, cryoprecipitate

Haemodynamic Management on VA ECMO

• Vasopressors to maintain MAP >60 mmHg
• LV venting strategies to prevent pulmonary oedema if LV not ejecting:
  • Intra-aortic balloon pump (IABP) - first-line LV unloading
  • Impella device - more aggressive LV decompression
  • Atrial septostomy (for severe LV distension)
• Inotropes may reduce LV distension by improving native ejection

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PART 8: COMPLICATIONS

A. Circuit Complications

B. Patient Complications

1. Bleeding (Most Common - 17-34% incidence)

• Sites: Cannulation sites, intracranial, GI, pulmonary
• Cause: Systemic anticoagulation + acquired von Willebrand factor deficiency + platelet dysfunction from pump + thrombocytopenia
• Management: Reduce/hold heparin; FFP, platelets, cryoprecipitate, factor VIIa (with caution - fatal thrombosis risk); consider tranexamic acid in life-threatening haemorrhage

2. Thromboembolism

• Systemic thromboembolism more common in VA ECMO
• Intracardiac thrombus: stasis in non-ejecting LV → clot → arterial embolism
• Management: Vigilant ACT monitoring; LV venting to improve LV ejection

3. Limb Ischaemia (VA ECMO - femoral cannulation)

• Retrograde arterial flow diverts blood from distal limb
• Prevention: Antegrade distal perfusion cannula (downflow cannula) into superficial femoral artery - inserted at time of primary arterial cannulation
• Monitoring: Near-infrared spectroscopy (NIRS) on lower limb, hourly pulse assessment
• Management: Fasciotomy for compartment syndrome; surgical thrombectomy

4. Neurological Complications (~7% VV, higher in VA)

• Ischemic stroke (thromboembolic)
• Intracranial haemorrhage (anticoagulation + hypertension)
• Hypoxic-ischaemic brain injury
• Management: Tight BP control (avoid SBP >140); reduce anticoagulation if haemorrhagic; neurology consultation

5. HARLEQUIN SYNDROME / NORTH-SOUTH SYNDROME (VA ECMO - CRITICAL EXAM TOPIC)

• Peripheral VA ECMO returns oxygenated blood retrograde via femoral artery → reaches aorto-iliac bifurcation
• As LV function recovers, native cardiac output begins ejecting deoxygenated blood (since lungs still impaired) FORWARD into aortic arch
• Watershed zone where native (deoxygenated) and ECMO (oxygenated) blood meet moves cranially as cardiac output improves
• Result: Cerebral and coronary circulation perfused by native desaturated blood; lower body perfused by oxygenated ECMO blood

• Right radial artery SpO₂/SaO₂ significantly lower than femoral artery SpO₂/SaO₂
• Right radial is critical monitoring site in all femoro-femoral VA ECMO patients

1. Tolerate if patient improving and cardiac recovery evident
2. Fix the lung: Optimise ventilator (↑FiO₂/PEEP), recruitment, prone, bronchoscopy, diuresis, NO
3. Increase ECMO sweep gas FiO₂ → increases oxygenation of ECMO blood
4. Increase ECMO flow rate (to push watershed point more cranially)
5. Add VV component → VAV ECMO: Add venous return cannula via right IJV to deliver oxygenated blood to RV → perfuses lungs → native cardiac output becomes oxygenated
6. Change to central VA ECMO (antegrade flow from ascending aorta)

6. Left Ventricular Distension (VA ECMO)

• ECMO increases afterload → LV cannot eject against increased resistance → LV dilates → pulmonary oedema
• Assessment: Echo (LVIDD, LVOTO velocity, aortic valve opening frequency)
• Management: IABP (reduces afterload), Impella (direct LV drainage), inotropes, surgical LV venting/atrial septostomy

7. Renal Failure

• Non-pulsatile flow → reduced renal perfusion
• Haemolysis → myoglobinuria
• Management: Continuous renal replacement therapy (CRRT) in-line with ECMO circuit

8. Haemolysis

• Pump speed-related; check lactate dehydrogenase (LDH), plasma haemoglobin, haptoglobin
• High circuit pressures → haemolysis
• Management: Reduce pump speed where possible; check for circuit clots

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PART 9: WEANING AND DECANNULATION

VV ECMO Weaning (Lung Recovery Assessed)

• Improved lung compliance and gas exchange on ventilator
• Oxygen delivery maintained with lower sweep gas FiO₂

1. Reduce sweep gas FiO₂ to 0.21 (room air) and/or reduce sweep gas flow to near zero
2. Maintain ventilator support
3. If ABG acceptable (PaO₂ >70 mmHg, pH >7.35, SpO₂ >92%) on ventilator alone for 1-4 hours → proceed to decannulation
4. Reduce ECMO flow gradually while maintaining sweep gas ("flow trial" vs "cap trial")

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VA ECMO Weaning (Cardiac Recovery Assessed - Echo-Guided)

• LVEF >20-25% (recovering)
• Aortic valve opening with each beat
• LVOT VTI >10 cm (surrogate of stroke volume)
• Absence of LV distension
• Absent pericardial effusion/tamponade

• Decreasing vasopressor requirements
• Improving pulse pressure
• Return of HR variability
• Stable MAP on minimal support

1. Reduce ECMO flow in stepwise fashion: 3L → 2L → 1.5L → 1L
2. At each step: observe MAP, HR, SvO₂, echo findings
3. If tolerated at 1-1.5 L/min → proceed to decannulation
4. If fails: increase flow; reassess in 12-24 hours

• Improving EF on echo at 1-2 L/min ECMO
• Low lactate, stable haemodynamics
• Vasopressor dose decreasing
• Aortic valve opening regularly

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Decannulation

• Femoral artery usually requires surgical repair (arteriotomy closure or patch repair) - in operating theatre under fluoroscopy
• Femoral vein: Manual pressure or suture
• Post-decannulation: Monitor limb perfusion, consider duplex USS

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PART 10: MONITORING PARAMETERS ON ECMO

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PART 11: SUMMARY COMPARISON TABLE

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NEET SS CRITICAL CARE MCQs: ECMO

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• A) PaO₂/FiO₂ <150 with FiO₂ >0.9
• B) PaO₂/FiO₂ <80 mmHg after optimal management including prone positioning
• C) PaO₂/FiO₂ <100 with FiO₂ >0.9 and Murray score ≥3-4 after >6 hours of bailout measures
• D) SAPS-II >90

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• A) It provides the best measure of ECMO circuit oxygenation
• B) It reflects upper body (cerebral/coronary) oxygenation from native cardiac output - critical for detecting Harlequin/North-South syndrome
• C) The right radial has higher accuracy than left due to dominant hand dominance
• D) Femoral artery lines are always more accurate

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• A) Renal failure
• B) Limb ischaemia of the ipsilateral leg
• C) Harlequin syndrome
• D) LV distension

---

• A) VV provides cardiac support; VA provides only respiratory support
• B) VA provides both cardiac and respiratory support; VV provides respiratory support only
• C) Both provide equivalent haemodynamic support
• D) VV provides better oxygenation than VA ECMO

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• A) Circuit failure causing loss of oxygenation
• B) Competition between retrograde oxygenated ECMO return flow and antegrade deoxygenated native cardiac output in a recovering heart with persistent lung failure
• C) Cannula malposition causing venous recirculation
• D) Systemic thromboembolism from LV thrombus

---

• A) Sweep gas FiO₂
• B) Pump speed
• C) Recirculation fraction (amount of oxygenated blood re-entering drainage cannula before reaching patient)
• D) Patient haemoglobin concentration alone

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• A) Conversion to central VA ECMO
• B) Veno-arterio-venous (VAV) ECMO
• C) Increasing ECMO pump speed
• D) Adding a second venous drainage cannula

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• A) Class I - standard of care for all witnessed arrests
• B) Class IIa - reasonable when equipment and trained personnel are available
• C) Class IIb - may be considered with very low evidence
• D) Class III - no benefit, possibly harmful

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• A) Right ventricular overdistension
• B) Left ventricular distension (LV not unloading against increased afterload from ECMO)
• C) Atrial septal defect caused by ECMO flow
• D) Systemic hypertension

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• A) VV ECMO significantly reduced 28-day mortality vs conventional ventilation
• B) Transfer to an ECMO-capable centre improved survival without severe disability (63% vs 47%)
• C) VV ECMO had no benefit over conventional lung-protective ventilation
• D) VV ECMO should be used as first-line therapy before prone positioning

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• A) Directed toward the aorta; confirmed by CXR
• B) Directed toward the tricuspid valve; confirmed by transthoracic or transesophageal echocardiography
• C) Directed toward the SVC; confirmed by fluoroscopy only
• D) Direction does not matter as flow is bidirectional

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• A) 6 mL/kg predicted body weight (standard lung-protective)
• B) 4-6 mL/kg PBW with PEEP 8-10 cmH₂O
• C) 3-4 mL/kg PBW with Pplat <25 cmH₂O and driving pressure <15 cmH₂O
• D) 8-10 mL/kg PBW to recruit lung

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• A) Warfarin is the preferred anticoagulant during ECMO
• B) Unfractionated heparin (UFH) targeting ACT 180-220 sec is the standard; bivalirudin or argatroban used in HIT
• C) No anticoagulation is needed with modern heparin-coated circuits
• D) Anticoagulation is contraindicated if any bleeding occurs on ECMO

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RAPID REVISION TABLE

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• Miller's Anesthesia, 10e (VA ECMO indications, ECPR, ECMO for cardiac failure)
• Barash's Clinical Anesthesia, 9e (ECPR, invasive resuscitation techniques)
• Fischer's Mastery of Surgery, 8e (VA ECMO components, cardiogenic shock)
• ELSO Guidelines for Adult VV ECMO - ASAIO Journal
• StatPearls: Extracorporeal Membrane Oxygenation in Adults
• CESAR Trial (2009) | EOLIA Trial (2018) | PRONECMO Trial (2023)
• AHA 2023 CPR Guidelines (ECPR Class IIa)
• Harlequin Syndrome in ECPELLA - PMC 2025

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WEANING FROM MECHANICAL VENTILATION

Short Note for MD Anaesthesia Examination | NEET SS Critical Care

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DEFINITION AND TERMINOLOGY

1. Failure to pass the Spontaneous Breathing Trial (SBT), OR
2. Need for reintubation within 48 hours of extubation, OR
3. Death within 48 hours following extubation

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CLASSIFICATION OF WEANING (Boles Classification - ATS/ERS Task Force 2007)

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STEP 1: DAILY READINESS SCREENING (Extubation Readiness Assessment)

Clinical Criteria (STOP-BANG-like screening):

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STEP 2: WEANING PREDICTORS / INDICES (Pre-SBT)

Rapid Shallow Breathing Index (RSBI) - Tobin Index

• Formula: RSBI = Respiratory Rate (f) ÷ Tidal Volume in litres (Vt)
• Threshold: RSBI ≤ 105 breaths/min/L → weaning likely successful
• RSBI > 105 → likely weaning failure
• Introduced by: Tobin & Yang, 1991 - New England Journal of Medicine

Other Weaning Parameters:

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STEP 3: THE SPONTANEOUS BREATHING TRIAL (SBT)

Methods of SBT:

Duration of SBT:

• 30 minutes - adequate and recommended; equivalent to 120 minutes in most studies
• 120 minutes - acceptable; no additional benefit demonstrated over 30 min for simple weaning

Criteria for PASSING SBT (Extubation can proceed):

Criteria for FAILING SBT (STOP the trial immediately):

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STEP 4: POST-SBT ASSESSMENT - CUFF LEAK TEST

When to Perform:

• Patient passes SBT but is at high risk for post-extubation stridor

Risk Factors for Post-Extubation Stridor:

• Female sex
• Prolonged intubation (>6 days)
• Larger ETT
• Repeated/traumatic intubation, agitation causing laryngeal trauma
• Previous unplanned extubation and reintubation
• High BMI

How to Perform:

1. Suction oropharynx
2. Deflate ETT cuff
3. Occlude ETT - patient breathes around tube
4. Volumetric method: Measure difference between exhaled Vt (cuff inflated) and exhaled Vt (cuff deflated) over 6 breaths
   • Cuff leak volume ≥110 mL (or >12% of set Vt) = adequate leak = low stridor risk
   • Cuff leak < 110 mL = inadequate leak = positive test = higher stridor risk

Cuff Leak Test Failure Management (ATS/ACCP Guideline):

• Administer systemic corticosteroids for ≥4 hours before extubation
• Methylprednisolone 20 mg q4h (×4 doses) OR dexamethasone 8 mg - reduces post-extubation stridor and reintubation rate
• No need to repeat cuff leak test after steroid administration (ATS/ACCP)
• Extubate with staff and equipment ready for emergency reintubation

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STEP 5: EXTUBATION PROCEDURE

Pre-Extubation Preparation:

1. Explain procedure to patient
2. NPO status ensured (or at least 30 min post-feed for NG tube patients)
3. Position: Head of bed 30-45°
4. Suction oropharynx and ETT thoroughly
5. Pre-oxygenate with FiO₂ 1.0 for 3-5 minutes
6. Have at bedside: bag-valve-mask, laryngoscope, ETT, succinylcholine/rocuronium, crash trolley, NIV/HFNC ready

Extubation Steps:

1. Deflate ETT cuff
2. Remove securing tape
3. Ask patient to take deep breath (or apply positive pressure)
4. Remove ETT on PEAK of inspiration (maximises glottic opening)
5. Immediately apply face mask oxygen
6. Encourage deep breathing and cough
7. Monitor closely for 30-60 min post-extubation

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STEP 6: POST-EXTUBATION MANAGEMENT

High-Risk Features for Post-Extubation Failure:

Post-Extubation Oxygen Support Strategy:

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STEP 7: PROLONGED WEANING STRATEGIES

Causes of Prolonged Weaning (7 Ps):

Strategies for Prolonged Weaning:

1. Tracheostomy (if >14 days anticipated)
   • Reduces dead space and airway resistance
   • Allows talking/eating/mobility
   • Facilitates subglottic suctioning
   • Early tracheostomy (within 4 days) vs late: Cochrane review shows no mortality difference, but early may reduce ICU stay
   • Percutaneous dilational tracheostomy (PDT) preferred in ICU (Ciaglia blue rhino technique)
2. Gradual SBT lengthening
   • Start with 5-10 min SBT
   • Increase by 10 min each day if tolerating
   • Aim for 2-hour SBT before extubation attempt
3. Pressure Support weaning (progressive reduction)
   • Start at PS required for comfort (e.g., 20 cmH₂O)
   • Reduce by 2-4 cmH₂O every 4-8 hours as tolerated
   • Target PS ≤8 cmH₂O before proceeding to SBT/extubation
   • Slower than T-piece weaning; less evidence it's superior
4. SIMV (Synchronized Intermittent Mandatory Ventilation)
   • Reduce mandatory rate gradually (14 → 12 → 10 → 8 → 6 → 4 → 2 → 0)
   • No longer recommended as primary weaning mode (Brochard trial 1994, Esteban trial 1995 showed PSV and T-piece superior; SIMV prolongs weaning)
5. Protocolised rehabilitation and early mobility
   • ATS/ACCP 2017: protocolised rehabilitation directed toward early mobilisation (conditional recommendation)
   • Prevents/treats ICU-acquired weakness
   • Daily physiotherapy, passive/active exercises, sitting out, standing
6. Optimise nutrition
   • Underfeeding: respiratory muscle wasting
   • Overfeeding: ↑CO₂ production → hypercarbia → failed weaning
   • Target 20-25 kcal/kg/day; protein 1.2-1.5 g/kg/day
7. Treat reversible co-morbidities
   • Anaemia: Hb >8 g/dL target (some use >10 g/dL in weaning)
   • Electrolytes: Mg²⁺, PO₄³⁻, K⁺ deficiencies impair respiratory muscle function
   • Thyroid: screen for hypothyroidism in prolonged weaning
   • CIAW: ICU-acquired weakness - treat with mobilisation, nutrition
8. Psychological support
   • PADIS guidelines: manage anxiety; family presence; communication aids
   • Passey-Muir valve for tracheostomy patients to facilitate communication and improve cough
9. Weaning unit/step-down centre
   • For truly prolonged difficult weaning
   • German S2k (2020): patient not permanently ventilator-dependent until 3 months of failed weaning attempts

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DIAPHRAGM ULTRASOUND IN WEANING (MODERN TOOL)

• DTF < 29% = diaphragm dysfunction = higher weaning failure risk
• VIDD (Ventilator-Induced Diaphragm Dysfunction): occurs as early as 18-24 hours of controlled MV
• Combined cardiac/lung/diaphragm USS predicts weaning failure better than individual parameters (Song et al., Ann Intensive Care 2024)

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WEANING FROM MV - ALGORITHM SUMMARY

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GUIDELINE SUMMARY TABLE

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NEET SS CRITICAL CARE MCQs: MECHANICAL VENTILATION WEANING

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• A) RSBI ≤ 105 must always be confirmed before performing an SBT
• B) RSBI is no longer required to determine readiness for SBT
• C) RSBI has replaced the cuff leak test as a pre-extubation assessment
• D) RSBI ≥ 105 is the threshold for extubation readiness

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• A) Conventional oxygen via face mask, monitor
• B) Immediate reintubation prophylactically
• C) Preventive NIV (BiPAP) or HFNC post-extubation
• D) Continue mechanical ventilation for another 24 hours

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• A) Is no longer recommended as of 2024 guidelines
• B) Was recommended by ATS/ACCP 2017 as the preferred method for the initial SBT
• C) Is associated with significantly higher extubation failure rates
• D) Should only be used for COPD patients

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• A) Perform an emergency tracheostomy
• B) Cancel extubation permanently
• C) Administer systemic steroids for ≥4 hours, then extubate with airway team present
• D) Repeat cuff leak test after 30 minutes

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• A) The preferred weaning method in adults according to ATS
• B) Superior to PSV weaning in terms of weaning duration
• C) No longer recommended as primary weaning mode; shown to prolong weaning time compared to PSV or T-piece SBT
• D) Recommended for cardiac post-operative patients

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• A) Sodium
• B) Chloride
• C) Phosphate (hypophosphataemia) and Magnesium
• D) Calcium

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• A) Normal diaphragm function; proceed to extubation
• B) Diaphragm atrophy or dysfunction - associated with higher weaning failure risk (VIDD)
• C) Hyperinflation of the diaphragm
• D) Diaphragmatic paralysis requiring phrenic nerve stimulation

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• A) Using SIMV as the weaning mode
• B) Incorporating a daily extubation readiness screening followed by SBT into a structured care protocol
• C) Administering daily nebulised bronchodilators
• D) Reducing FiO₂ by 10% each hour

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• A) NIV was clearly superior to HFNC in preventing reintubation
• B) HFNC was non-inferior to NIV and superior to conventional oxygen for reducing reintubation at 72 hours
• C) T-piece SBT was the only method associated with reduced failure
• D) Extubation was contraindicated without tracheostomy

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• A) After midnight to reduce staff workload during day shifts
• B) Before noon each day (AARC 2024)
• C) Only on Mondays, Wednesdays, and Fridays per protocol
• D) 6 hours after each arterial blood gas is obtained

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• A) Has proven benefit when used therapeutically (rescue) for post-extubation respiratory failure
• B) Has proven benefit when used preventively in high-risk patients who passed SBT; rescue NIV for frank failure does NOT reduce reintubation or mortality
• C) Should replace standard SBT assessment
• D) Is contraindicated in COPD patients

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• A) After 72-96 hours of mechanical ventilation
• B) After 18-24 hours of controlled mechanical ventilation
• C) Only after 7 days of MV
• D) After 1 month of MV

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• A) T-piece SBT
• B) Pressure Support Ventilation with gradual reduction
• C) SIMV with gradual reduction of mandatory rate
• D) CPAP SBT

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• A) Chest X-ray urgently
• B) Initiate NIV (CPAP)
• C) Administer IV dexamethasone 8 mg, humidified oxygen, nebulised adrenaline (1:1000, 5 mL); reintubation if not responding
• D) Perform tracheostomy at bedside

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• A) A - Assess and treat pain
• B) B - Both SAT and SBT performed daily
• C) C - Choice of analgesia and sedation
• D) E - Early mobility and exercise

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RAPID REVISION BOX

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• Harrison's Principles of Internal Medicine, 22e (Fig. 313-4 algorithm, liberation criteria, high-risk features)
• ATS/ACCP 2017: Liberation from Mechanical Ventilation in Critically Ill Adults (thoracic.org)
• AARC Clinical Practice Guideline 2024: Spontaneous Breathing Trials - PMID 38443142
• SCCM 2024 blog on AARC 2024 guideline changes
• Trivedi V et al., Chest 2022 - RSBI meta-analysis - PMID 34181953
• German S2k Prolonged Weaning Guideline 2020 - PMID 33302267

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ROLE OF THE ANAESTHESIOLOGIST IN PALLIATIVE CARE MEDICINE

MD Anaesthesia Examination | NEET SS Critical Care

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INTRODUCTION

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DOMAINS OF ANAESTHESIOLOGIST INVOLVEMENT IN PALLIATIVE CARE

1. PAIN MANAGEMENT (pharmacological)
2. INTERVENTIONAL PAIN PROCEDURES
3. PALLIATIVE/TERMINAL SEDATION
4. AIRWAY AND SYMPTOM MANAGEMENT
5. END-OF-LIFE CARE IN THE ICU
6. EDUCATION, ETHICS AND COMMUNICATION

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DOMAIN 1: PHARMACOLOGICAL PAIN MANAGEMENT

A. The WHO Analgesic Ladder (Updated 3+1 Step Model)

        ▲ STEP 4 (Added 2018)
        │ Interventional / Neuromodulation
        │
        ▲ STEP 3
        │ Strong opioids (Morphine, Oxycodone, Fentanyl, Hydromorphone)
        │ ± Non-opioid ± Adjuvant
        │
        ▲ STEP 2
        │ Weak opioids (Codeine, Tramadol)
        │ ± Non-opioid ± Adjuvant
        │
        ▲ STEP 1
          Non-opioids: Paracetamol, NSAIDs
          ± Adjuvants

1. By mouth - preferred oral route
2. By the clock - regular dosing, not PRN
3. By the ladder - step-wise escalation
4. For the individual - titrated to patient need
5. Attention to detail - anticipate and treat side effects

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B. Opioid Management in Palliative Care

• Oral morphine 30 mg = IV morphine 10 mg (3:1 ratio)
• Oral morphine 30 mg = oral oxycodone 20 mg
• Oral morphine 30 mg = fentanyl patch 12.5-25 mcg/h
• Oral morphine 30 mg/day → fentanyl patch = 30/2 = 15 mcg/h (approximate)

• Oral - preferred
• Subcutaneous infusion (syringe driver) - when oral route lost; preferred over IM (painful); most palliative drugs compatible
• Transdermal - stable pain; not for acute titration
• IV PCA - for inpatients with rapid titration needs
• Neuraxial (epidural/intrathecal) - see Domain 2

C. Adjuvant Analgesics (Co-Analgesics)

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DOMAIN 2: INTERVENTIONAL PAIN PROCEDURES

A. Peripheral Nerve Blocks

B. Sympathetic and Visceral Nerve Blocks (NEUROLYTIC - Key Exam Topic)

1. Coeliac Plexus Block / Neurolysis (CPB)

• Indication: Visceral pain from upper abdominal malignancies - pancreatic cancer (most common indication), hepatobiliary cancers, gastric cancer
• Anatomy: Coeliac plexus = 2 paired ganglia, anterior to aorta, at T12-L1 level; receives sympathetic input from greater/lesser/least splanchnic nerves + parasympathetic from vagus
• Approach:
  • Posterior (most common): Fluoroscopy or CT-guided bilateral posterior approach (paramedian at L1); needle tip anterior to aorta
  • Anterior: Endoscopic USS-guided (EUS-CPB) - preferred in advanced pancreatic cancer (direct visualisation, anterior approach avoids aorta)
• Neurolytic agents: Absolute alcohol 50-100% (6-20 mL per side) or phenol 6-10%
• Diagnostic block first: Use LA (bupivacaine 0.5%) before neurolysis
• Evidence (Cochrane 2011): Significantly improved pain at 8 weeks + lower opioid consumption and side effects vs standard analgesia
• Complications: Transient orthostatic hypotension (sympathectomy), diarrhoea (parasympathetics unopposed), pneumothorax, intravascular injection, nerve root injury, retroperitoneal haematoma
• EUS-CPB reduces complications compared to percutaneous approach

2. Superior Hypogastric Plexus Block

• Indication: Pelvic visceral pain (cervical, bladder, prostate, rectal cancers)
• Anatomy: Pre-aortic plexus at L5-S1; bilateral sympathetic ganglia
• Approach: Posterior fluoroscopy-guided bilateral approach; anterior USS-guided
• Neurolysis: Alcohol or phenol

3. Ganglion Impar Block (Walther's Ganglion)

• Indication: Perineal/rectal pain, tailbone pain (coccydynia), anorectal and vulval cancers
• Anatomy: Single midline ganglion at sacrococcygeal junction - last ganglion of the sympathetic chain
• Approach: Transcoccygeal or paracoccygeal

4. Stellate Ganglion Block

• Indication: Upper extremity sympathetically maintained pain, Complex Regional Pain Syndrome (CRPS), some head/neck cancer pain
• Neurolysis: Generally diagnostic blocks only; neurolysis rare due to risk

5. Lumbar Sympathetic Block

• Indication: Sympathetically maintained pain in lower extremities, CRPS type 1, peripheral vascular disease-associated pain

C. Neuraxial Techniques

1. Epidural Analgesia

• Continuous infusion: Opioid (morphine/fentanyl/hydromorphone) ± LA (bupivacaine/ropivacaine) ± adjuvants (clonidine, ketamine)
• Benefits over systemic opioids: Lower doses achieve better analgesia; fewer systemic side effects
• Tunnelled epidural catheter for home/hospice use (weeks to months)
• Used for: Thoracic/abdominal/pelvic cancer pain, vertebral metastases, chest wall pain

2. Intrathecal Drug Delivery (ITDD) / Implantable Drug Delivery Systems (IDDS)

• Mechanism: Drug delivered directly to cerebrospinal fluid → directly at spinal cord receptors; 100-300× more potent than oral morphine; massive reduction in systemic doses and side effects
• Implanted pump (programmable) with intrathecal catheter to appropriate spinal level
• First-line ITDD drugs: Morphine + bupivacaine (PACC 2017 - combination recommended)
• Additional drugs: Ziconotide (N-type calcium channel blocker; non-opioid; first-line for neuropathic pain in ITDD), clonidine, hydromorphone
• Morphine oral:intrathecal ratio: ~300:1
• Indications: Cancer patients with inadequate analgesia or intolerable side effects from systemic opioids; expected survival >3 months (for implanted pump); some centres use external pump for shorter prognosis
• Evidence (Implantable Drug Delivery vs Comprehensive Medical Management trial - Smith et al., JAMA 2002): ITDD reduced pain by 52% vs 39%; significantly less toxicity; 6-month survival improved

3. Intrathecal Neurolytic Procedures

• Intrathecal alcohol/phenol block (Intrathecal neurolysis): For patients with cancer pain refractory to all other measures; may produce saddle anaesthesia and sphincter dysfunction - reserved for patients with pre-existing incontinence/colostomy
• Cervical cordotomy (Percutaneous): Interrupts spinothalamic tract at C1-2 level; used for unilateral cancer pain below C5; high success rate; life-limiting complications (Ondine's curse - loss of automatic respiration if bilateral)

D. Neuromodulation

• Spinal Cord Stimulation (SCS): Less evidence in cancer pain (historically avoided due to concern about disease progression and device interference); some centres use for neuropathic cancer pain
• Deep Brain Stimulation (DBS): Specialist centres; refractory cancer pain
• Transcutaneous Electrical Nerve Stimulation (TENS): Non-invasive adjunct; no systemic effects; useful for bone metastases, localised pain

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DOMAIN 3: PALLIATIVE SEDATION (TERMINAL SEDATION)

Definition (EAPC 2023 Revised Framework):

Indications:

• Refractory symptoms unresponsive to all available palliative treatment options:
  • Refractory pain
  • Intractable dyspnoea
  • Refractory agitated delirium
  • Refractory nausea/vomiting
  • Refractory existential distress (controversial - open debate)
• Patient is terminally ill with expected death in hours to days
• Exhausted all alternatives

Types:

Drug Protocol (EAPC 2023 Stepwise Approach):

• Midazolam - drug of choice; titrated SC/IV infusion; start 1-5 mg SC/hour; widely controllable
• Lorazepam - alternative; longer acting; SL/IV

• Levomepromazine (methotrimeprazine) - sedating antipsychotic; SC/IM/IV
• Chlorpromazine - alternative

• Propofol MUST be administered by an anaesthesiologist or person with equivalent expertise (EAPC 2023)
• Used when benzodiazepines + neuroleptics fail
• Continuous infusion: Start 20-50 mg/hour; titrate
• Rapid onset; easily titratable; predictable pharmacokinetics
• Risk: cardiovascular depression, apnoea - requires monitoring

Principle of Double Effect (KEY ETHICAL CONCEPT):

1. The action itself is not intrinsically wrong
2. The agent intends the good effect, not the harmful one
3. The good effect is not produced BY the harmful effect
4. There is proportionate reason for tolerating the harm

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DOMAIN 4: SYMPTOM MANAGEMENT

Dyspnoea (Breathlessness)

Death Rattle (Noisy Terminal Breathing / Terminal Secretions)

• Caused by pooling of oropharyngeal secretions in semi-conscious/unconscious dying patient (unable to clear)
• NOT distressing to patient (unconscious) - but distressing to family
• Management:
  • Reposition patient (lateral/semi-prone)
  • Anticholinergics:
    • Glycopyrrolate 0.2 mg SC q4h (preferred - does NOT cross BBB, less confusion)
    • Hyoscine butylbromide (Buscopan) 20 mg SC q4h
    • Hyoscine hydrobromide (scopolamine) - crosses BBB, more sedating
  • Do NOT attempt suction (stimulates more secretions; distressing)

Nausea and Vomiting

Agitated Delirium (Terminal Restlessness)

• Very common in last 24-48 hours of life
• Pharmacological management:
  • Haloperidol 0.5-2 mg SC q4-6h (first-line)
  • Midazolam 2.5-5 mg SC q1h PRN (for agitation/distress)
  • Levomepromazine (sedating antipsychotic) - for severe terminal agitation

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DOMAIN 5: END-OF-LIFE CARE IN THE ICU

Withdrawal of Life-Sustaining Treatment (WLST)

• Autonomy: Patient's right to refuse treatment
• Non-maleficence: Avoiding futile/burdensome treatment
• Beneficence: Focusing on comfort goals
• Justice: Fair allocation of scarce resources

Terminal Extubation Procedure (Anaesthesiologist Leads):

1. Goals-of-care discussion with family and team
2. DNR order confirmed
3. Consent from family/surrogate
4. Discontinue monitors if family preference
5. Ensure private room, family present

• Morphine 2-5 mg IV (titrate to comfort; dyspnoea anticipated post-extubation)
• Midazolam 1-2 mg IV (anxiolysis; reduces awareness of dyspnoea)
• Glycopyrrolate 0.2 mg IV (reduces secretions/death rattle)
• Start as continuous infusion (morphine 2-10 mg/h + midazolam 1-5 mg/h) via syringe driver to maintain comfort

• Turn off ventilator (or switch to CPAP then off)
• OR deflate cuff and remove ETT (direct terminal extubation)
• Remove all monitors that are not comfort-related
• Provide oxygen only if patient appears distressed

• Continue titrating opioids and benzodiazepines to comfort
• Glycopyrrolate for secretions
• Family at bedside; chaplaincy/spiritual support
• Document physician intent as symptom-directed comfort care

Advance Care Planning and Goals of Care Discussions

• Explain prognosis honestly using validated tools (APACHE II, SOFA, SAPS)
• Facilitate advance directive documentation
• Understand and implement:
  • Living will - documented patient preferences
  • Health care proxy / Durable Power of Attorney for Healthcare
  • POLST (Physician Orders for Life-Sustaining Treatment) - India: equivalent is advance medical directive
  • Futility - medical futility when treatment cannot achieve goals
• Lead family meetings using the NURSE communication framework (Naming, Understanding, Respecting, Supporting, Exploring)

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DOMAIN 6: AIRWAY MANAGEMENT IN PALLIATIVE SCENARIOS

Malignant Upper Airway Obstruction

• Tumours of larynx, trachea, thyroid, neck can cause stridor and acute obstruction
• Anaesthesiologist is the essential team member for emergency airway management
• Options: Awake fibreoptic intubation, tracheostomy (surgical or percutaneous), airway stenting (interventional bronchoscopy), laser ablation under GA, high-flow oxygen as temporising
• Steroids (dexamethasone 8-16 mg IV) reduce tumour oedema acutely
• Heliox (He:O₂ 70:30) reduces turbulent airflow; temporising measure

Anaesthesia for Palliative Procedures

• Palliative radiation (e.g., for bone metastases) - may need sedation/GA for positioning
• Palliative surgical procedures (e.g., gastrostomy, biliary stenting, vertebroplasty for pathological fracture)
• Thoracocentesis, paracentesis, pericardiocentesis - anaesthesiologist provides sedation/analgesia
• Tracheostomy for malignant airway obstruction

Nutritional Access

• Insertion of PEG (Percutaneous Endoscopic Gastrostomy) under sedation by anaesthesiologist
• Central venous access (PICC, ports) for parenteral nutrition, chemotherapy delivery, medication infusion

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MULTIDISCIPLINARY PALLIATIVE CARE TEAM

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SUMMARY TABLE: ANAESTHESIOLOGIST'S SPECIFIC CONTRIBUTIONS

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NEET SS CRITICAL CARE MCQs: PALLIATIVE CARE

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• A) Lumbar sympathetic block
• B) Intrathecal pump with morphine
• C) Coeliac plexus neurolysis with absolute alcohol
• D) Thoracic epidural catheter

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• A) Midazolam
• B) Haloperidol
• C) Propofol
• D) Morphine

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• A) The dual mechanism of morphine on μ and κ receptors
• B) A dose of morphine having two simultaneous analgesic effects
• C) The ethical justification for administering high-dose opioids where intended effect is symptom relief even if death may be unintentionally hastened
• D) The combination of two opioids used simultaneously

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• A) Performing fasciotomy for limb ischaemia
• B) Administering adequate comfort medications (morphine + midazolam) to ensure no suffering during and after ECMO discontinuation
• C) Converting to VV ECMO as a bridge
• D) Performing emergency tracheostomy

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• A) 3:1
• B) 10:1
• C) 100:1
• D) 300:1

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• A) Aggressive oropharyngeal suction every 30 minutes
• B) Repositioning + glycopyrrolate 0.2 mg SC q4h (preferred anticholinergic as it does NOT cross the BBB)
• C) High-dose diuretics to reduce secretions
• D) Endotracheal intubation to protect the airway

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• A) CRASH-2 trial
• B) Smith et al. JAMA 2002 (Implantable Drug Delivery vs Comprehensive Medical Management)
• C) CESAR trial
• D) PROPPR trial

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• A) Administer analgesics in the morning only
• B) Analgesics should be given at regular scheduled intervals to maintain constant blood levels, not just on-demand (PRN)
• C) Analgesics should be given by the fastest available route
• D) Pain should be assessed hourly using a clock-based system

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• A) Rocuronium + ketamine (to prevent movement)
• B) Morphine IV + midazolam IV, with glycopyrrolate to reduce secretions; continue as infusion post-extubation
• C) Propofol bolus + sugammadex
• D) No medications; let nature take its course

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• A) Upper abdominal visceral cancer pain
• B) Pelvic visceral pain from gynaecological malignancy
• C) Perineal and rectal pain, anorectal and vulval cancers
• D) Bilateral lower extremity CRPS

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• A) Stop the pump immediately; naloxone IV titrated in small doses (0.04 mg aliquots)
• B) Flumazenil IV
• C) Neostigmine + glycopyrrolate
• D) Increase the pump rate to flush the drug

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• A) The dose of drug administered
• B) The route of administration (IV vs oral)
• C) The intent of the physician - symptom relief (palliative sedation) vs intentional ending of life (euthanasia)
• D) Whether the patient is awake or unconscious

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• A) Ketamine + clonidine
• B) Morphine + bupivacaine (combination recommended over single agent)
• C) Fentanyl alone
• D) Ziconotide + midazolam

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RAPID REVISION TABLE

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• Harrison's Principles of Internal Medicine, 22e (palliative care framework)
• EAPC 2023 Revised Framework on Palliative Sedation (palliativeprojects.eu)
• Interventional Anesthesia and Palliative Care collaboration - Canadian Journal of Anaesthesia (2019)
• StatPearls: Palliative Sedation in Terminal Illness
• Smith TJ et al. JAMA 2002 - Implantable Drug Delivery vs CMM in cancer pain
• WHO Analgesic Ladder (1986, revised 2018)
• PACC 2017 Intrathecal Drug Delivery guidelines
• Cochrane 2011 - Coeliac plexus block in pancreatic cancer