What sedatives and neuromuscular blocking agents are used for intubation?

Sedatives and Neuromuscular Blocking Agents for Intubation

For intubation, a combination of a sedative-hypnotic agent and a neuromuscular blocking agent (NMBA) should always be used, with etomidate and rocuronium being the preferred agents for most critically ill patients. 1, 2

Sedative-Hypnotic Agents

Preferred Options:

• Etomidate (0.2-0.3 mg/kg IV)

  • Rapid onset (5-15 seconds) and short duration (5-15 minutes)
  • Minimal cardiovascular depression
  • Maintains hemodynamic stability, even in hypotensive patients
  • Preferred for patients with cardiovascular compromise or acute decompensated heart failure 2, 3

• Ketamine (1-2 mg/kg IV)

  • Alternative for hemodynamically stable patients
  • Particularly useful in septic or hypovolemic shock
  • Caution: May cause cardiac arrest in catecholamine-depleted patients 2, 4

Other Options:

• Propofol

  • Should be avoided in high doses for patients with cardiovascular compromise due to significant vasodilation and hypotension risk 2

• Midazolam

  • Less desirable due to longer onset of action and potent venodilator effects at RSI doses 2

Neuromuscular Blocking Agents

Preferred Options:

• Rocuronium (0.9-1.2 mg/kg IV)

  • Onset within 1-2 minutes
  • Duration of 30-40 minutes
  • Hemodynamically stable with no histamine release
  • Preferred for most patients, especially those with cardiovascular disease 2, 5

• Succinylcholine (1.5 mg/kg IV)

  • Fastest onset (30-60 seconds)
  • Shortest duration (5-10 minutes)
  • Caution: May cause hyperkalemia in patients with prolonged heart failure 2

Other Options:

• Vecuronium (0.08-0.1 mg/kg IV)

  • Onset within 2-3 minutes
  • Duration of 25-30 minutes
  • Hemodynamically stable 6

• Cisatracurium (0.15-0.2 mg/kg IV)

  • Onset within 1.5-2 minutes
  • Duration of 55-60 minutes
  • Good option for patients with hepatic or renal dysfunction 7

Important Considerations

1. Always use a sedative-hypnotic agent with an NMBA

   • The Society of Critical Care Medicine strongly recommends this combination to prevent awareness during paralysis 1
   • Using an NMBA alone is contraindicated due to risk of awareness 1, 8

2. First-pass success rates

   • Using an NMBA significantly improves first-pass success rates (80.9% vs 69.6% without NMBA) 1
   • Better intubating conditions reduce complications

3. Hemodynamic stability

   • Etomidate maintains or slightly increases blood pressure, making it ideal for critically ill patients 3
   • In hypotensive patients (sBP <100 mmHg), etomidate demonstrated a 12.1 mmHg elevation in systolic BP 3

4. Duration mismatch

   • Be aware that sedative duration (especially etomidate at 3-12 minutes) is often shorter than NMBA duration (25-73 minutes)
   • Additional sedation should be administered before the initial sedative wears off to prevent awareness during continued paralysis 8

5. Dosing considerations

   • For obese patients, dose based on actual body weight rather than ideal body weight 5
   • In elderly patients, consider extending the interval between administration and intubation attempt 7, 5

By following these evidence-based recommendations for sedative and neuromuscular blocking agent selection during intubation, clinicians can optimize first-pass success while minimizing hemodynamic complications and ensuring patient comfort.