What is the recommended rapid sequence intubation (RSI) protocol for a patient with acute cholecystitis requiring emergency surgery, considering potential hypotension or hemodynamic instability?

Rapid Sequence Intubation Protocol for Acute Cholecystitis with Hemodynamic Instability

For patients with acute cholecystitis requiring emergency surgery who have or are at risk for hemodynamic instability, use ketamine (1-2 mg/kg IV) as the induction agent combined with either succinylcholine (1.5 mg/kg) or rocuronium (0.6-1.2 mg/kg) as the neuromuscular blocking agent, with ketamine administered before the paralytic to prevent awareness during paralysis. 1, 2

Pre-Intubation Preparation

• Pre-oxygenate with 100% oxygen for 3-5 minutes to maximize oxygen reserves before apnea 3
• Assess hemodynamic status specifically looking for signs of sepsis, hypotension (systolic BP <90 mmHg), tachycardia, or evidence of severe systemic inflammatory response, as Class C patients with acute cholecystitis often present with hemodynamic instability requiring emergent surgery 4
• Prepare vasopressors at bedside before induction, as post-intubation hypotension is common and associated with increased mortality, prolonged ICU stays, and organ dysfunction 5, 2

Medication Selection and Sequencing

Induction Agent: Ketamine (Preferred in Hemodynamic Instability)

• Administer ketamine 1-2 mg/kg IV bolus as the first medication 1, 2
• Ketamine's sympathomimetic properties maintain hemodynamic stability through endogenous catecholamine release, making it superior to other agents in unstable patients 1, 5, 2
• Reduce dose to 1 mg/kg if cardiovascular compromise is severe to minimize hypotension risk 2
• The Society of Critical Care Medicine supports ketamine as a first-line induction agent for RSI in hemodynamically unstable patients 2

Alternative if ketamine is contraindicated: Etomidate 0.2-0.4 mg/kg provides relatively stable hemodynamics, though it lacks ketamine's sympathomimetic benefits 1

Neuromuscular Blocking Agent

Primary choice - Succinylcholine:

• Administer 1.5 mg/kg IV after ketamine has been given 1
• Provides rapid onset (60-90 seconds) and shortest duration of action 3
• The Society of Critical Care Medicine recommends succinylcholine as first-line for RSI when no contraindications exist 1

Alternative - Rocuronium:

• Administer 0.6-1.2 mg/kg IV when succinylcholine is contraindicated 1, 6
• For rapid sequence intubation, doses of 0.6-1.2 mg/kg provide excellent intubating conditions in less than 2 minutes 6
• At 0.6 mg/kg, expect intubation readiness in median 1 minute with maximum blockade in <3 minutes 6
• Higher doses (0.9-1.2 mg/kg) can be used safely without adverse cardiovascular effects 6

Critical Timing Sequence

1. Administer ketamine first (sedative-hypnotic agent) 1, 2
2. Wait 30-60 seconds for ketamine to take effect
3. Then administer neuromuscular blocking agent (succinylcholine or rocuronium) 1, 2
4. Attempt intubation at 60-90 seconds after paralytic administration 6

This sequence is mandatory - failure to provide adequate sedation before paralysis results in awareness during paralysis, which occurs in approximately 2.6% of emergency intubations 1, 5

Special Considerations for Acute Cholecystitis Patients

Hemodynamic Instability Recognition

• Class C patients with complicated acute cholecystitis requiring emergent surgery often have severe hemodynamic instability and diffuse intra-abdominal infection 4
• In these cases, damage control procedures should be considered, with physiological restoration prioritized alongside surgical source control 4

Avoid Midazolam in This Context

• While midazolam can be used in stable patients, its vasodilatory effects make it problematic in hemodynamically unstable patients 1
• Ketamine alone provides adequate sedation without the hypotensive risks of benzodiazepines 1, 5

Post-Intubation Management

• Initiate continuous ketamine infusion at 0.5-1 mg/kg/hr immediately after intubation for ongoing sedation 5, 2
• Apply recruitment maneuver and at least 5 cmH₂O PEEP to improve oxygenation 1
• Monitor for post-intubation hypotension and treat aggressively with vasopressors if needed 5, 2
• Continuous sedation must be maintained to prevent awareness during paralysis 5, 2

Common Pitfalls to Avoid

• Never administer the paralytic before the sedative - this causes awareness during paralysis, a devastating complication 1, 5, 2
• Do not use propofol as the induction agent in hemodynamically unstable patients, as its vasodilatory effects can precipitate cardiovascular collapse 5
• Do not delay intubation in Class C acute cholecystitis patients who are deteriorating - these patients require emergent surgical intervention and airway control 4
• Avoid underdosing ketamine in an attempt to preserve hemodynamics - inadequate sedation is worse than mild transient hypotension 2

Dosing for Obese Patients

• Dose rocuronium based on actual body weight, not ideal body weight 6
• Dosing based on ideal body weight results in longer time to maximum block, shorter clinical duration, and inadequate intubating conditions 6