What is the recommended medication regimen for Rapid Sequence Intubation (RSI)?

Recommended Medication Regimen for Rapid Sequence Intubation (RSI)

The recommended medication regimen for RSI in critically ill adults should include a sedative-hypnotic induction agent (etomidate or ketamine) followed by a neuromuscular blocking agent (either succinylcholine or rocuronium), administered in rapid succession to facilitate endotracheal intubation. 1

Medication Selection Algorithm

Step 1: Sedative-Hypnotic Induction Agent

• Strong recommendation: A sedative-hypnotic induction agent must be administered before the neuromuscular blocking agent to prevent awareness during paralysis 2
• Choice of agent:
  • Etomidate (0.3 mg/kg IV): Preferred in hemodynamically unstable patients due to favorable hemodynamic profile 1, 3
  • Ketamine (1-2 mg/kg IV): Alternative first-line agent with sympathomimetic properties that help maintain hemodynamic stability 2, 4
  • Propofol (1.5-2.5 mg/kg IV): Consider only in hemodynamically stable patients due to its potent hypotensive effects 4
  • Midazolam (0.1-0.3 mg/kg IV): Less desirable due to longer onset of action and venodilatory effects 1

Step 2: Neuromuscular Blocking Agent (NMBA)

• Strong recommendation: An NMBA should be administered when a sedative-hypnotic induction agent is used for intubation 1
• Choice of agent:
  • Succinylcholine (1-1.5 mg/kg IV): First-line when no contraindications exist 1
  • Rocuronium (0.9-1.2 mg/kg IV): Alternative when succinylcholine is contraindicated 1, 5

Evidence-Based Considerations

Positioning

• Position the patient in semi-Fowler position (head and trunk inclined) during RSI to improve first-pass intubation success and reduce risk of aspiration 1

Preoxygenation

• Use high-flow nasal oxygen (HFNO) when challenging laryngoscopy is anticipated 1
• Use noninvasive positive pressure ventilation (NIPPV) in patients with severe hypoxemia (PaO2/FiO2 < 150) 1
• Consider medication-assisted preoxygenation in agitated or combative patients 1

Induction Agent Selection

• No mortality difference has been demonstrated between etomidate and other induction agents in critically ill patients 1
• Etomidate may cause transient adrenal suppression, but corticosteroid administration following etomidate is not recommended 1, 3
• Ketamine maintains hemodynamic stability through sympathomimetic effects but may cause tachycardia 2, 4

NMBA Selection

• Both succinylcholine and rocuronium provide excellent intubating conditions 1
• Key differences:
  • Succinylcholine: Faster onset (45-60 seconds), shorter duration (5-10 minutes), but has more contraindications (hyperkalemia, malignant hyperthermia risk, burns, crush injuries) 5, 4
  • Rocuronium: Slightly longer onset (60-90 seconds at high doses), longer duration (30-40 minutes), fewer contraindications 5, 4
  • When using high-dose rocuronium (≥0.9 mg/kg), sugammadex should be available for reversal if needed 1

Common Pitfalls and Caveats

• Failure to provide adequate sedation before paralysis can result in awareness during paralysis, occurring in approximately 2.6% of emergency department intubations 2
• Underdosing induction agents in hemodynamically unstable patients may lead to inadequate sedation and awareness 4
• Inappropriate NMBA selection: Using succinylcholine in patients with hyperkalemia, burns, or crush injuries can precipitate life-threatening hyperkalemia 4
• Inadequate preoxygenation: Failure to properly preoxygenate can lead to rapid desaturation during intubation attempts 1
• Dosing based on ideal body weight: In obese patients, RSI medications should be dosed based on actual body weight to ensure adequate intubating conditions 5

Special Populations

• Hemodynamically unstable patients: Prefer etomidate or ketamine; avoid propofol 1, 4
• Patients with head injury: Etomidate is cerebroprotective and can decrease intracranial pressure while maintaining cerebral perfusion 3
• Obese patients: Dose based on actual body weight rather than ideal body weight to ensure adequate intubating conditions 5