Management of Severe CAP (Left Lung) with Septic Shock, Septic Encephalopathy, and Coma

1. IMMEDIATE AIRWAY & VENTILATION (First Priority)

• Endotracheal intubation - RSI (Rapid Sequence Intubation). Use ketamine (1-2 mg/kg IV) as induction agent in hemodynamically unstable patients (avoids hypotension unlike propofol/thiopental). Succinylcholine 1.5 mg/kg or rocuronium 1.2 mg/kg for paralysis.
• Mechanical ventilation using lung-protective strategy:
  • Tidal volume: 6 mL/kg predicted body weight
  • Plateau pressure: ≤30 cmH₂O
  • PEEP: titrate to oxygenation (typically start 5-8 cmH₂O, higher in ARDS)
  • Target SpO₂ 92-96%
• For moderate-severe sepsis-induced ARDS (very likely here given CAP + septic shock):
  • Prone positioning ≥12 hrs/day if PaO₂/FiO₂ <150
  • Neuromuscular blockade to facilitate prone positioning (cisatracurium preferred)
• Head of bed elevation to 30-45° (semi-recumbent) unless contraindicated
• Avoid pulmonary artery catheters routinely

Source: Barash Clinical Anesthesia 9e (Table 57-4); Harrison's Principles 22e

2. HEMODYNAMIC RESUSCITATION - Septic Shock Bundle

A. The 1-Hour Bundle (SSC Surviving Sepsis Campaign)

B. Fluid Resuscitation

• Balanced crystalloids preferred (Lactated Ringer's > 0.9% normal saline - normal saline can cause hyperchloremic metabolic acidosis and renal injury)
• Initial bolus: 30 mL/kg over first 3 hours, administered rapidly (5-10 min boluses)
• Do NOT use hydroxyethyl starch/pentastarch (associated with severe AKI and death)
• Albumin may be considered if large volumes of crystalloid are required
• Monitor response dynamically: capillary refill time, passive leg raise, point-of-care echo - NOT CVP alone
• Target urine output ≥0.5 mL/kg/hr
• Serial lactate measurements to guide adequacy of resuscitation

Source: Harrison's 22e; Mulholland Surgery 7e; Barash Clinical Anesthesia 9e

C. Vasopressors (if MAP <65 mmHg despite fluids)

1. Norepinephrine - first-line vasopressor. Target MAP ≥65 mmHg.
2. Vasopressin (0.03-0.04 units/min) - add when norepinephrine reaches 0.25-0.5 μg/kg/min; do NOT use as sole agent
3. Epinephrine - third-line, add if MAP still not achieved with NE + vasopressin
4. Dobutamine - add if myocardial dysfunction (sepsis-induced cardiomyopathy) is detected by echo (decreased LVEF, elevated filling pressures) with persistent hypoperfusion
5. Dopamine - avoid (reserved only for highly selected patients with low risk of arrhythmia)
6. Avoid levosimendan and terlipressin

Note: Up to 50% of septic shock patients have sepsis-induced cardiomyopathy. Bedside echo is essential.

D. Corticosteroids

• If shock persists despite adequate fluids + vasopressors:
  • Hydrocortisone 200 mg/day IV (as 50 mg every 6 hours, or continuous infusion)
  • Taper once vasopressors can be weaned - do NOT perform ACTH stimulation test to guide this decision
  • Do NOT use steroids prophylactically or in non-refractory shock

Source: Harrison's 22e; Washington Manual; Goldman-Cecil Medicine; Barash 9e

3. ANTIBIOTICS - Severe CAP (ICU-Level)

Empiric Regimen for ICU-Admitted Severe CAP:

• Add vancomycin 15 mg/kg IV q12h (adjust to troughs) OR linezolid 600 mg IV q12h

• Use anti-pseudomonal beta-lactam (piperacillin-tazobactam, cefepime, meropenem, imipenem) + ciprofloxacin (high-dose) or aztreonam + macrolide
• Add vancomycin/linezolid if MRSA also suspected

Source: Rosen's Emergency Medicine; Murray & Nadel's Textbook of Respiratory Medicine; Goldman-Cecil

4. SEPTIC ENCEPHALOPATHY & COMA MANAGEMENT

• Altered consciousness (confusion → stupor → coma) within hours of severe systemic infection - occurs in ~70% of severe sepsis
• No focal neurological deficits
• No asterixis or myoclonus (unlike hepatic encephalopathy)
• Paratonia (gegenhalten) is common
• Hyperventilation with respiratory alkalosis is characteristic
• Resolves when infection is treated - there is no specific therapy beyond treating the underlying sepsis

• Non-contrast CT brain (to exclude hemorrhage, mass)
• Serum glucose (check and correct immediately)
• Electrolytes - Na, K, Mg, Ca, phosphate
• LFTs, creatinine, ammonia
• Blood cultures x2, urine culture, sputum culture, Legionella/pneumococcal urinary antigens
• Chest X-ray / CT chest
• EEG if coma persists despite treatment (to rule out non-convulsive status epilepticus)
• Consider LP only if meningitis is suspected (fever + photophobia + neck stiffness) and CT is safe

Source: Plum & Posner's Diagnosis and Treatment of Stupor and Coma; Adams & Victor's Neurology 12e

5. ORGAN SUPPORT & ICU MONITORING

Renal

• Monitor urine output continuously via Foley catheter
• Septic AKI is common - if oliguria/rising creatinine, initiate renal replacement therapy (CRRT preferred in hemodynamically unstable patients)
• For pH <7.2 with AKI, consider IV bicarbonate
• Avoid nephrotoxic drugs where possible (check aminoglycoside levels if used)

Hematologic

• Transfusion threshold: Hb <7 g/dL in absence of active coronary ischemia or hemorrhage (target 7-9 g/dL)
• Watch for DIC: check PT/aPTT, D-dimer, fibrinogen, platelets
• Thrombocytopenia below 100,000 is a minor criterion for severe CAP

Glycemic control

• Target blood glucose 140-180 mg/dL with insulin infusion
• Avoid hypoglycemia (a common cause of worsening encephalopathy)

DVT prophylaxis

• Low-molecular-weight heparin (if no contraindication) once patient is stabilized
• Mechanical compression stockings until anticoagulation is safe

Nutritional support

• Initiate enteral nutrition early (within 24-48 hours) via nasogastric tube
• Parenteral nutrition only if enteral route is not feasible

Sedation/Analgesia

• Use protocols for ventilator sedation - target lightest effective level
• Daily sedation interruption ("spontaneous awakening trials") if on continuous infusion
• Pair with daily spontaneous breathing trials once hemodynamics permit
• Avoid deep sedation where possible (worsens encephalopathy)

6. MONITORING TARGETS (Summary)

7. LOOK FOR COMPLICATIONS

• ARDS - likely already present (CAP + septic shock), manage with lung-protective ventilation + prone positioning
• DIC - monitor coagulation panel
• Sepsis-induced cardiomyopathy - bedside echo essential; present in up to 50%
• Acute liver failure - LFTs, PT/INR
• Critical illness polyneuropathy - may complicate recovery (seen with septic encephalopathy)
• Osmotic demyelination - risk if sodium is corrected too rapidly

8. GOALS OF CARE