Non-Invasive Ventilation (NIV) - Final MD Exam Short Answer Review

Definition

• CPAP (Continuous Positive Airway Pressure) - single fixed pressure throughout the respiratory cycle
• BiPAP/BPAP (Bilevel Positive Airway Pressure) - delivers a higher IPAP during inspiration and a lower EPAP during expiration

• Murray & Nadel's Textbook of Respiratory Medicine, p. 3193

Physiological Rationale / Mechanisms of Benefit

• Tintinalli's Emergency Medicine, p. 217; Rosen's Emergency Medicine, p. 947

Indications

Strong/Standard of Care Indications

Intermediate/Weak Indications

• Asthma exacerbation (intermediate evidence, no mortality benefit proven)
• Post-extubation respiratory failure
• Immunocompromised patients with ARF (avoids intubation and nosocomial infection)
• ARDS (mild-moderate, PaO2/FiO2 > 150)

De Novo Hypoxemic Failure

• Murray & Nadel, p. 3196-3197; Rosen's, Table 60.3

Contraindications

Absolute

• Respiratory / cardiac arrest
• Active vomiting / high aspiration risk
• Severe facial trauma / burns
• Depressed consciousness not caused by hypercapnia
• Inability to clear secretions

Relative

• Hemodynamic instability unresponsive to fluids/vasopressors
• Severe agitation
• Copious secretions
• Recent upper GI / esophageal surgery
• Bullous lung disease (risk of pneumothorax)
• Hypotension (positive pressure worsens preload reduction)

• Rosen's Emergency Medicine, Table 60.3; Tintinalli's, Table 28-5

Initial Settings (COPD exacerbation)

• Rosen's Emergency Medicine, p. 947

Monitoring and Response Assessment

• Respiratory rate (should decrease)
• Accessory muscle use (should improve)
• Mental status
• ABG (pH, PaCO2 should improve)
• Tolerance / mask leak

NIV Failure - Predictors and Definition

Predictors of NIV Failure

• pH < 7.30 at presentation
• High severity score (APACHE II/SOFA)
• Marked mental status alteration
• Persistent or worsening tachypnea despite NIV
• Hemodynamic instability
• Immunocompromised state / high SOFA
• Late NIV initiation
• Inability to tolerate mask

• Murray & Nadel, p. 3197

Advantages Over Invasive MV

Comparison: CPAP vs. BiPAP

NIV in Special Situations

• Weaning from invasive MV: NIV-facilitated extubation reduces re-intubation rates in COPD patients
• Post-operative respiratory failure: Strong evidence for benefit
• Immunocompromised (hematologic malignancy): Reduces need for intubation, lowers mortality (though recent RCTs less conclusive)
• Palliative / DNI patients: NIV as ceiling therapy - reduces dyspnea with acceptable risk
• ALS/NMD (long-term): Nocturnal NIV improves survival and QoL

High-Flow Nasal Cannula (HFNC) vs. NIV

• NIV remains first-line for hypercapnic respiratory acidosis
• HFNC is viable for mild-moderate acidosis when NIV is not tolerated or during breaks
• Cannot reliably correct hypercapnia like BiPAP

• Rosen's Emergency Medicine, p. 948

Exam Mnemonics

1. BiPAP is first-line for COPD exacerbation with respiratory acidosis (pH ≤7.35, PaCO2 ≥45 mmHg) - reduces mortality, intubation, and hospital stay
2. Both CPAP and BiPAP are effective in cardiogenic pulmonary edema - CPAP preferred initially
3. NIV failure is defined by worsening at 1-2 hours - delay in intubation after NIV failure increases mortality
4. Depressed consciousness is a contraindication unless it is due to CO2 narcosis (hypercapnic encephalopathy) - these patients may improve with NIV
5. De novo hypoxemic ARF (ARDS-type) has uncertain benefit with NIV

Communication Skills of the Anaesthesiologist

Long Answer - MD Anaesthesia Finals Examination

Introduction

I. THE PREOPERATIVE VISIT - Foundation of the Anaesthesiologist-Patient Relationship

Importance

Components of the Preoperative Communication

• Introduce yourself and your role clearly
• Address patient by their preferred name
• Make the environment private and comfortable
• Demonstrate empathy, active listening, and non-verbal engagement (eye contact, open posture)
• Acknowledge fears openly - validate anxiety as normal

• Medical and surgical history, drug allergies, previous anaesthetic experiences (especially difficult intubation, awareness, PONV)
• Airway assessment communicated in plain language
• Current medications, smoking, alcohol, recreational drugs
• Family history of anaesthetic complications (malignant hyperthermia, pseudocholinesterase deficiency)

• Describe the type of anaesthesia being planned in lay terms (general, regional, sedation)
• Explain what the patient will experience: "You will receive a medicine through your drip that will make you sleep"; "You will feel a cold sensation, then numbness below the waist"
• Discuss pre-operative fasting instructions (NPO guidelines) clearly - reason, duration, what is permitted
• Explain monitoring (ECG, pulse oximeter, BP cuff) in reassuring terms

• Expected timeline from arrival to OR to recovery
• Post-operative pain management plan
• Likely environment on waking (PACU, HDU, ICU)
• Presence of tubes, catheters, monitoring lines post-op
• Early mobilization and discharge goals (especially day surgery)

II. INFORMED CONSENT - A Core Communication Obligation

Definition and Ethical Basis

Elements of Valid Informed Consent

What Must Be Disclosed in Anaesthesia Consent

• Proposed anaesthetic technique and rationale
• Common risks (PONV, sore throat, dental injury, pain at injection site, headache post-spinal)
• Material risks - even if uncommon, if a reasonable patient would want to know (nerve damage, awareness, anaphylaxis, cognitive dysfunction, death)
• Alternatives available (GA vs. regional vs. sedation; pros and cons of each)
• The anaesthesiologist's professional recommendation
• Who will provide anaesthesia (if residents/trainees are involved, this must be disclosed)
• Plan if the primary technique fails (backup approach)

Practical Communication for Consent

• Use lay language - avoid medical jargon
• Use teach-back method: "Can you tell me in your own words what I just explained?" - to confirm understanding
• Use visual aids - diagrams, videos where available
• Allow time for questions without appearing rushed
• Offer written information leaflets to supplement verbal discussion
• If patient has limited English proficiency - use a qualified interpreter, never a family member alone
• Document the discussion in detail: options discussed, risks mentioned, patient questions, patient understanding, and patient agreement

Special Consent Situations

• Children: Assent from the child + consent from guardian; explain to child in age-appropriate terms
• Elderly with cognitive impairment: Assess capacity; if lacking - involve legal representative; consider advance directives
• Emergency surgery: Implied consent applies if patient is incapacitated and delay would be life-threatening; document thoroughly
• Jehovah's Witnesses: Specific consent regarding blood products; competent adults' refusal must be respected; explore blood conservation strategies
• Do Not Resuscitate (DNR) orders: Discuss and document perioperative management explicitly; the default is NOT to automatically suspend DNR in the OR

III. INTRAOPERATIVE COMMUNICATION

A. Operating Room Team Communication

1. Surgical Safety Checklist (WHO Checklist) - the anaesthesiologist leads or participates in three components:
   • Sign In (before induction): patient identity, consent, site marking, allergy check, airway/aspiration risk review, blood loss anticipation
   • Time Out (before incision): team introduction, procedure confirmation, antibiotic prophylaxis, critical steps, equipment availability
   • Sign Out (before patient leaves OR): procedure performed, instrument counts, specimen labeling, post-op care plan
2. Closed-loop communication during emergencies: sender states instruction → receiver confirms receipt → sender acknowledges. Prevents "heard but not confirmed" errors.
3. Assertive communication: Any team member must feel empowered to speak up about safety concerns. The anaesthesiologist models this culture - using "Two-challenge rule": if a concern is raised twice and ignored, escalate immediately.
4. Communication with the awake/sedated patient: Reassure during regional techniques; explain each step; warn before potentially uncomfortable moments; use calm, slow speech.

B. Communication During Crisis

• Directed - assign tasks by name ("Dr. X, draw up adrenaline"; not "someone get adrenaline")
• Loud and clear - noise in theatre requires deliberate vocal projection
• Prioritized - focus on critical tasks; avoid information overload
• Documented - time-stamped record of events, drugs, and communications

IV. POST-OPERATIVE COMMUNICATION

A. Recovery Room Handover

1. Monitoring transferred to recovery/ICU equipment
2. Ventilator settings initiated (if intubated)
3. Infusions and fluids checked and running
4. Vital signs confirmed stable

• Patient demographics, weight, allergies, baseline vitals
• Diagnosis, procedure performed
• Intraoperative course: any complications, blood loss, fluid balance
• Airway: grade of laryngoscopy, tube size, any difficulty
• Current infusions, analgesic plan, antiemetics given
• Investigations: intraoperative ABG, labs
• Key post-op instructions and vital sign parameters

• The anaesthesiologist must remain with the patient until hemodynamic and respiratory stability are ensured.

B. Post-Operative Visit

• Check on the patient the following day
• Assess adequacy of pain relief
• Inquire about PONV, shivering, sore throat, awareness
• Address complications and explain their management
• Document findings in the anaesthetic record

C. Disclosure of Adverse Events

• Notify hospital risk management promptly
• Have an honest and frank disclosure with the patient and family - most risk managers advocate transparency
• It is possible and appropriate to express sorrow about an adverse outcome without admitting legal liability: "I am very sorry this happened to you" does not equal legal admission of fault
• Accompany the patient with a senior colleague or risk management representative during these discussions
• Document carefully: what was said, who was present, patient's response (Morgan & Mikhail, 7e)

V. COMMUNICATION WITH RELATIVES AND FAMILIES

• Pre-operatively: involve family with patient's consent; explain waiting times; provide contact information
• Intra-operatively: update family if surgery runs long or complications arise
• Post-operatively: communicate outcomes clearly; use simple language; check understanding
• ICU setting: regular family meetings with clear, consistent information; involve palliative care team when appropriate
• Paediatric patients: communicate simultaneously with child (age-appropriate) and parent; their anxiety directly affects the child's anxiety

VI. INTERDEPARTMENTAL AND INTERDISCIPLINARY COMMUNICATION

VII. COMMUNICATION IN SPECIAL CLINICAL CONTEXTS

Difficult Airway Communication

• Warn the patient if a difficult airway is anticipated - explain awake intubation procedure step by step
• Inform the team of airway plan A, B, C before induction
• Post-procedure: document and inform patient of the difficult airway; issue a Difficult Airway Alert card for future encounters; notify their GP/primary physician in writing

Awareness Under Anaesthesia

• This is a deeply distressing adverse event
• Approach the patient with empathy and without defensiveness
• Acknowledge the experience; validate the patient's trauma
• Explain what may have happened; offer psychological support/referral
• Do not minimize or dismiss the report

Communication with Paediatric Patients

• Use age-appropriate language; speak directly to the child, not only to parents
• Describe anaesthesia: "A magic sleep medicine" for young children; honest age-appropriate explanation for older children
• Allow familiar objects (teddy bear, parent presence at induction)
• Children with autism spectrum disorder (ASD): schedule early on list, consider premedication, involve parents extensively, pre-visit familiarization with OR environment

Geriatric Patients

• Speak clearly, slowly, without condescension
• Confirm hearing aid and spectacle availability
• Assess baseline cognitive function pre-operatively
• Address post-operative cognitive dysfunction (POCD) risks honestly

VIII. DOCUMENTATION AS A FORM OF COMMUNICATION

• Pre-operative assessment findings and consent discussion
• Intraoperative monitoring, drug doses, events
• Post-operative instructions and handover summary
• Adverse events, near-misses, and their management

IX. BARRIERS TO EFFECTIVE COMMUNICATION IN ANAESTHESIA

X. COMMUNICATION MODELS RELEVANT TO ANAESTHESIA

• S - Setting (private, calm)
• P - Perception (what does the patient already know?)
• I - Invitation (how much does the patient want to know?)
• K - Knowledge (give information in steps)
• E - Empathy (acknowledge emotion)
• S - Strategy and Summary

• S - Situation (what is happening now)
• B - Background (relevant history)
• A - Assessment (clinical assessment)
• R - Recommendation (what needs to happen)

XI. MEDICO-LEGAL ASPECTS OF COMMUNICATION

• Failure of informed consent is one of the most common bases for anaesthesia litigation
• The "reasonable patient standard" (what a reasonable patient would want to know) has replaced the older "reasonable doctor standard" in most jurisdictions
• Proper communication, documented diligently, is the best defence against litigation
• Communication failures at handover are cited in nearly two-thirds of "sentinel events" (The Joint Commission)

Summary Table: Communication Skills of the Anaesthesiologist

Conclusion

Sources: Barash, Cullen & Stoelting's Clinical Anaesthesia 9e | Morgan & Mikhail's Clinical Anaesthesiology 7e | Miller's Anaesthesia 10e | NMC MD Anaesthesia Curriculum | Anesthesia Patient Safety Foundation (APSF) | Miller's Anaesthesia 10e (ICU Handoff Protocol)