What are the recommended RSI (Rapid Sequence Intubation) drugs for patients with pulmonary edema?

RSI Medications for Pulmonary Edema

For patients with pulmonary edema requiring rapid sequence intubation (RSI), etomidate (0.2-0.3 mg/kg IV) as the induction agent and rocuronium (0.9-1.2 mg/kg IV) or succinylcholine (1.5 mg/kg IV) as the neuromuscular blocking agent are recommended.

Induction Agent Selection

Etomidate

• First-line induction agent for pulmonary edema patients due to its hemodynamic stability 1
• Dosage: 0.2-0.3 mg/kg IV
• Key benefit: Maintains cardiovascular stability in hemodynamically compromised patients 2
• Provides excellent to good intubating conditions in 88.1% of emergency department patients 2
• Even in patients with low pre-RSI blood pressure (systolic BP <100 mmHg), etomidate demonstrated a 12.1 mmHg elevation in systolic BP 2

Ketamine

• Alternative induction agent for pulmonary edema patients
• Dosage: 1-2 mg/kg IV
• Particularly useful in patients with septic or hypovolemic shock 1
• Maintains hemodynamic stability through sympathomimetic effects

Neuromuscular Blocking Agents

Rocuronium

• Dosage: 0.9-1.2 mg/kg IV for RSI 1, 3
• Provides excellent to good intubating conditions within 2 minutes 3
• Recommended when succinylcholine is contraindicated
• Longer duration of action (31-85 minutes) 3

Succinylcholine

• Dosage: 1.5 mg/kg IV 1
• Rapid onset and short duration of action
• Contraindicated in patients with hyperkalemia, burns, crush injuries, and neuromuscular disorders 1

Importance of Neuromuscular Blocking Agents

The Society of Critical Care Medicine strongly recommends administering a neuromuscular blocking agent when using a sedative-hypnotic induction agent for intubation 4. Studies demonstrate higher first-pass success rates (80.9% vs 69.6%) when NMBAs are used compared to sedative-only intubations 4.

Pre-Medications

• Consider lidocaine (1-2 mg/kg IV) to blunt sympathetic response and reduce intracranial pressure 1
• Fentanyl (1-3 mcg/kg) may be considered to attenuate hemodynamic response to intubation 1

Special Considerations for Pulmonary Edema

1. Hemodynamic Support:

   • Have vasopressors immediately available before induction 1
   • Ensure continuous hemodynamic monitoring during the procedure

2. Ventilation Strategy:

   • Apply PEEP of at least 5 cmH2O after intubation to improve oxygenation 1
   • Consider a post-intubation recruitment maneuver in hypoxemic patients 1
   • Pre-oxygenate with high-flow oxygen or non-invasive ventilation when possible 1

3. Timing of Intubation:

   • Consider earlier intubation before severe hypoxemia develops in pulmonary edema patients 1

RSI Procedure for Pulmonary Edema

1. Preparation:

   • Verify all airway equipment
   • Prepare medications (etomidate and neuromuscular blocking agent)
   • Position patient in semi-Fowler position if tolerated
   • Pre-oxygenate for 3-5 minutes with high-flow oxygen

2. Administration Sequence:

   • Either medication order (sedative first or paralytic first) is acceptable
   • Administering the neuromuscular blocking agent first may result in modestly faster time to intubation (approximately 6 seconds) 5

3. Post-Intubation:

   • Confirm tube placement with multiple methods
   • Initiate appropriate sedation/analgesia immediately
   • Apply PEEP and adjust ventilator settings
   • Monitor hemodynamics closely

Pitfalls and Caveats

1. Etomidate and Adrenal Suppression:

   • Etomidate can cause adrenal suppression, but evidence suggests this resolves within 12 hours and doesn't significantly affect mortality outcomes 6, 1

2. Hemodynamic Instability:

   • Avoid propofol in hemodynamically unstable pulmonary edema patients due to risk of hypotension
   • Have vasopressors readily available to manage potential hypotension

3. Medication Shortages:

   • During drug shortages, ketamine (1-2 mg/kg IV) is a reasonable alternative to etomidate 1
   • If rocuronium is used, have sugammadex available for potential reversal in cannot-intubate-cannot-ventilate scenarios 1

By following these recommendations, clinicians can optimize RSI for patients with pulmonary edema while minimizing complications and maintaining hemodynamic stability.