CTVS ICU Management

1. Immediate Post-Op Checklist (on arrival to ICU)

2. Hemodynamic Monitoring & Goals

3. Respiratory Management

• Mode: Volume-controlled ventilation (most units use this as default)
• FiO2: Start at 0.5-0.6; O2 toxicity occurs if FiO2 consistently >0.5 for extended periods - avoid prolonged >50% unless essential
• All ventilator air must be humidified
• Tidal volume: 6-8 mL/kg IBW (lung-protective)

1. Pneumothorax
2. Hemothorax
3. ET tube in a main bronchus (causing unilateral ventilation)

• Hemodynamically stable
• No active bleeding
• Blood gases acceptable
• Neurologically alert and cooperative
• Adequate spontaneous respiratory effort

4. Arrhythmia Management

Atrial Fibrillation (most common post-op arrhythmia: 27-40%)

• Peak onset: 2-3 days post-op
• Risk factors: Pre-existing AF, valvular surgery, electrolyte disturbances (hypokalemia, hypomagnesemia), beta-blocker withdrawal, COPD, obesity
• Hemodynamically unstable: Synchronized DC cardioversion immediately
• Hemodynamically stable: Rate control first - beta-blockers, calcium channel blockers (diltiazem/verapamil), amiodarone, IV magnesium
• Correct K+ and Mg2+ in all cases
• Prevention: Maintain K+ >4 mEq/L and Mg2+ >2 mg/dL; restart beta-blockers as early as possible post-op

Ventricular Arrhythmias

• Simple PVCs: Often benign, monitor
• Complex VT/VF: Check for hypoxia, electrolyte abnormalities, ischemia, inotrope toxicity, hypovolemia
• Sustained VT: Amiodarone IV, correct underlying cause; cardiovert if unstable
• Frequent PVCs (>30/hr) or NSVT with reduced EF = high mortality risk - involve cardiology

5. Bleeding and Chest Drain Management

• Acceptable: <200 mL/hr in first few hours, trending down

• >500 mL in 1 hour, OR
• >300 mL/hour for 3 consecutive hours

• Cardiac tamponade (can occur suddenly)
• Massive blood transfusion and coagulopathy
• Clot retention and constrictive physiology

• Keep drains patent and milked regularly (per unit protocol)
• Monitor hourly drainage volumes carefully
• Cardiopulmonary bypass impairs clotting - protamine reverses heparin but factor deficits may persist

6. Low Cardiac Output Syndrome (LCOS)

• Myocardial stunning (post-bypass)
• Tamponade
• Residual structural lesion
• Arrhythmia
• Hypovolemia
• Vasoplegia

1. Optimize preload - fluid challenge if CVP/LA pressure low
2. Correct arrhythmia - rate, rhythm
3. Inotropes:
   • Dobutamine (5-20 mcg/kg/min) - first-line in most
   • Dopamine - alternative (low dose renal, higher dose inotropic)
   • Milrinone (phosphodiesterase inhibitor) - useful post-bypass, also reduces afterload
   • Epinephrine - for severe LCOS
4. Vasopressors (if vasoplegia/low SVR despite adequate CO):
   • Norepinephrine - first-line vasopressor
   • Vasopressin - adjunct, especially post-bypass vasoplegia
5. Mechanical support:
   • IABP (intra-aortic balloon pump): Reduces afterload (deflates during systole), augments diastolic pressure (inflates during diastole) - boosts coronary perfusion
   • Impella / TandemHeart - higher-level support
   • ECMO (VA-ECMO) - refractory cardiogenic shock

7. Fluid and Electrolyte Management

• IV fluid: Usually 5% dextrose at ~500 mL/m2/24 hrs (conservative, avoids overload)
• Hypokalemia: Common post-bypass (causes arrhythmias) - maintain K+ >4.0 mEq/L
• Hypomagnesemia: Predisposes to AF and ventricular arrhythmias - supplement IV magnesium prophylactically (MgSO4 2g IV common practice)

8. Neurological Care

• Recovery of consciousness + ability to move all 4 limbs on command = minimal cerebral injury
• Failure to regain consciousness or move limbs = suspect cerebral microembolism (air, calcium debris, thrombus, fat)

• Dexamethasone 8 mg IV stat, then 4 mg 8-hourly for 3 days (reduces cerebral edema)
• Mannitol (osmotic therapy) - second-line
• Always check and correct hypoxia before attributing neurological symptoms to embolism

• Rule out hypoxia first (get ABG before giving sedatives)
• ICU psychosis is common (day 2-3): Orientation, reassurance, night-cycle lighting
• Agitation + hypoxia mismanaged with sedation = cardiac arrest risk

9. Renal Care

• Target UO >0.5 mL/kg/hr
• Serum creatinine, electrolytes - twice daily in first 48 hrs
• Cardiac surgery-associated AKI (CSA-AKI) is common - avoid nephrotoxins, maintain perfusion pressure
• Furosemide for diuresis if oliguric despite adequate filling

10. GI/Alimentary Care

• Paralytic ileus is nearly universal after cardiac or major thoracic surgery
• NGT on continuous free drainage
• IV fluids until bowel sounds return
• Resume oral feeds only when bowel sounds present and patient extubated and alert

11. Analgesia

• Post-cardiac surgery: Morphine/diamorphine IV in small frequent boluses (e.g., morphine 2.5 mg IV titrated)
• Thoracic epidural analgesia (TEA): Reduces AF, respiratory depression, duration of intubation, and opioid requirements after cardiac surgery - but must weigh against anticoagulation status
• Paravertebral block or truncal fascial plane blocks: Alternatives to epidural for VATS/minimally invasive thoracic procedures with fewer hemodynamic side effects

Summary: "ABCDE" of CTVS ICU

Post-AVR Patient: Dyspnea + Chest Pain + Cough + SpO2 84%

CXR Interpretation

Differential Diagnosis (Ranked by likelihood in post-AVR context)

1. Postpericardiotomy Syndrome (Dressler's / PCIS) - MOST LIKELY if days-weeks post-op

• Occurs in 10-40% of patients after cardiac surgery
• Immune-mediated response to pericardial/mesothelial injury and blood in the pericardial space
• Classic presentation: pleuritic chest pain + fever + dyspnea + pleural effusion ± pericardial effusion
• Usually presents within first month (80% of cases), almost always within 3 months
• Left-sided effusions predominate
• CRP/ESR elevated, leukocytosis
• Rarely causes tamponade (<2%)

2. Hemothorax / Surgical Bleeding

• Post-bypass coagulopathy + surgical trauma can cause delayed hemothorax
• Left pleural hematoma - common after left thoracotomy/pericardiotomy
• Drain may have clotted off
• Urgent if massive - check chest drain output

3. Transudative Effusion / Cardiac Failure

• Low cardiac output post-AVR causing pulmonary venous hypertension
• Bilateral in classical CHF but can be left-sided early
• Look for other signs of fluid overload

4. Parapneumonic Effusion / Empyema

• Post-op pneumonia with pleural extension
• Fever, leukocytosis, purulent sputum

5. Prosthetic Valve Endocarditis (PVE)

• Early PVE (within 60 days): perioperative pathogen (Staph aureus, CoNS)
• Fever + septic emboli + new murmur
• Can cause secondary pleural involvement

6. Prosthetic Valve Thrombosis

• Sub-acute presentation with signs of stenosis/regurgitation
• Decreased/absent valve click on auscultation
• Would NOT directly cause a large pleural effusion unless causing acute LV failure

7. Chylothorax

• Thoracic duct injury during surgery (rare post-AVR, more common with aortic arch/descending aorta surgery)
• Milky fluid on aspiration

Immediate Management

Step 1: Resuscitate and Stabilize

• High-flow oxygen via non-rebreather mask immediately (SpO2 84% is critical)
• Sit patient upright (30-45 degrees) - reduces work of breathing
• IV access, continuous SpO2, ECG, BP monitoring
• If SpO2 doesn't improve rapidly with O2 - prepare for intubation/NIV

Step 2: Urgent Investigations (Order Simultaneously)

Step 3: Therapeutic Thoracentesis (Priority Action)

• Massive effusion (>1.5-2 L estimated)
• SpO2 84% = hemodynamic/respiratory compromise

• Ultrasound-guided thoracentesis - essential (post-surgical adhesions increase blind puncture risk)
• Remove no more than 1500 mL in a single session to prevent re-expansion pulmonary edema
• Send pleural fluid for: protein, LDH, glucose, cell count + differential, Gram stain + culture, pH, cytology, triglycerides (if chylothorax suspected)

Step 4: Treat the Underlying Cause

Key Red Flags Requiring Immediate Escalation

Summary Action Plan

SpO2 84% + Large Left Pleural Effusion Post-AVR
        ↓
1. High-flow O2 → NIV if no improvement → Intubate if deteriorating
2. Urgent bedside ECHO → rule out tamponade/valve dysfunction
3. Ultrasound-guided thoracentesis → drain ≤1500 mL
4. Send pleural fluid for full analysis
5. CBC, CRP, INR, Blood cultures, ABG, BNP
6. Treat underlying cause based on fluid analysis + ECHO findings