What is the recommended sedation for intubation in a patient with severe pneumonia, fast atrial fibrillation (A fib), hypotension, and right ventricular (RV) dilation on levophed (norepinephrine) infusion?

Ketamine is the Recommended Induction Agent for This Hemodynamically Unstable Patient

For this critically ill patient with severe pneumonia, rapid atrial fibrillation, hypotension on vasopressors, and RV dilation, ketamine (1-2 mg/kg IV) is the preferred induction agent, combined with rocuronium (1.0-1.2 mg/kg) for neuromuscular blockade. 1, 2, 3

Rationale for Ketamine Selection

Hemodynamic Preservation in Shock States

• Ketamine maintains hemodynamic stability through sympathomimetic properties, making it particularly valuable in patients with significant cardiovascular compromise already requiring high-dose vasopressor support 2, 3
• The American College of Critical Care Medicine supports ketamine as a first-line induction agent alongside etomidate for rapid sequence intubation in hemodynamically unstable patients 2
• While etomidate traditionally offers superior hemodynamic stability, your patient's fast atrial fibrillation at 170 bpm with wide pulse pressure (120/30) and RV dilation suggests significant catecholamine stress and potential RV failure—ketamine's sympathomimetic effects may help maintain cardiac output during induction 1, 2

Dosing Considerations

• Administer ketamine 1 mg/kg IV (lower end of 1-2 mg/kg range) given the patient's already compromised cardiovascular state and high vasopressor requirements 1, 2
• In critically ill patients with depleted catecholamine stores, ketamine may cause paradoxical hypotension, requiring careful titration 3
• Have additional vasopressor boluses immediately available—post-intubation hypotension is common and associated with increased mortality 2

Neuromuscular Blockade Strategy

Rocuronium Dosing

• Administer rocuronium 1.0-1.2 mg/kg IV to ensure optimal intubating conditions and prevent coughing/bucking that could worsen hemodynamics 1, 3
• Insufficient neuromuscular blockade increases risk of hemodynamic instability during intubation, particularly dangerous in patients with poor cardiovascular reserve 1
• Ensure sugammadex is immediately available for reversal in "cannot intubate, cannot ventilate" scenarios 3

Critical Sequencing

• Administer ketamine BEFORE rocuronium to prevent awareness during paralysis 2, 3
• The sedative-hypnotic agent must be given before the neuromuscular blocking agent—this is a fundamental safety principle 2, 3

Special Considerations for This Patient

Atrial Fibrillation Management

• The rapid ventricular response will likely improve with sedation and mechanical ventilation, as sympathetic drive decreases 4
• Avoid propofol for induction or immediate post-intubation sedation in this patient—propofol causes significant vasodilation and can precipitate cardiovascular collapse in hemodynamically unstable patients 4
• Propofol has been associated with refractory atrial fibrillation in critically ill patients and should be avoided in this hemodynamically tenuous situation 5

RV Dysfunction Implications

• The combination of RV dilation, wide pulse pressure, and high vasopressor requirements suggests RV failure with potential septal shift 4
• Maintain adequate preload during induction—consider 500 mL crystalloid bolus immediately before induction if not volume overloaded 1
• Avoid excessive positive pressure ventilation immediately post-intubation, as high intrathoracic pressures worsen RV afterload 4

Post-Intubation Sedation Plan

Immediate Post-Intubation (First 24-48 Hours)

• Initiate fentanyl infusion (25-100 mcg/hr) as first-line analgesic and sedative 4
• Add midazolam boluses (1-2 mg) as needed for breakthrough agitation, but avoid continuous benzodiazepine infusions when possible 4
• In hemodynamically unstable patients like yours, ketamine infusion (0.5-1 mg/kg/hr) can be used for ongoing sedation 2
• Continuous sedation must be initiated immediately after intubation to prevent awareness during paralysis 2

Avoid Propofol Initially

• Given severe hemodynamic instability (already on levophed 4 mcg/min), propofol's vasodilatory effects make it inappropriate for initial post-intubation sedation 4
• Propofol may be considered later during recovery phase if hemodynamics stabilize, but fentanyl-based regimens are preferred in this acute phase 4

Critical Pitfalls to Avoid

Pre-Intubation Preparation

• Position patient head-up (30-45 degrees) if possible to optimize pre-oxygenation and reduce aspiration risk 4
• Ensure high-flow oxygen or non-invasive ventilation for pre-oxygenation—critically ill patients desaturate rapidly 4
• Have backup airway equipment immediately available, including video laryngoscope and cricothyrotomy kit 4

Hemodynamic Monitoring

• Anticipate worsening hypotension immediately post-intubation—have norepinephrine boluses (10-20 mcg) or push-dose pressors ready 2
• The transition to positive pressure ventilation will decrease venous return and may precipitate cardiovascular collapse in RV failure 4
• Consider increasing levophed infusion rate prophylactically before induction 1

Ventilator Settings

• Use lung-protective ventilation with low tidal volumes (6 mL/kg ideal body weight) given severe pneumonia 4
• Keep plateau pressures <30 cm H2O and minimize PEEP initially (start 5-8 cm H2O) to avoid worsening RV afterload 4
• Accept permissive hypercapnia if needed—aggressive ventilation worsening RV function is more dangerous than mild hypercarbia 4