Rapid Sequence Intubation Protocol
Core Definition and Immediate Steps
Rapid sequence intubation involves administering a sedative-hypnotic agent followed immediately by a neuromuscular blocking agent with prompt endotracheal intubation before assisted ventilation, specifically designed for patients at risk of aspiration. 1, 2
Patient Positioning
- Position the patient in semi-Fowler position (head and trunk elevated 20-30 degrees) rather than supine to reduce aspiration risk and potentially improve first-pass intubation success 1, 2
- This positioning increases functional residual capacity and may improve laryngeal visualization 1
Preoxygenation Strategy
Standard Approach
- Administer 100% oxygen (FiO2 1.0) for 3-5 minutes using a completely sealing face mask with oxygen flow >10 L/min 3
- Target end-tidal oxygen concentration >0.9 3
- Use capnography to confirm adequate seal and ventilation 3
Enhanced Preoxygenation for High-Risk Patients
- Use noninvasive positive pressure ventilation (NIPPV) for patients with severe hypoxemia (PaO2/FiO2 <150) 1, 2
- Apply high-flow nasal oxygen (HFNO) when challenging laryngoscopy is anticipated 1, 2
- For agitated, delirious, or combative patients unable to tolerate preoxygenation devices, use medication-assisted preoxygenation (delayed sequence intubation) with ketamine 1-2 mg/kg IV to facilitate adequate preoxygenation before administering the neuromuscular blocker 1, 2
Medication Protocol
Step 1: Induction Agent Selection
Administer a sedative-hypnotic induction agent before the neuromuscular blocker to prevent awareness during paralysis 1, 2, 4
Primary Options:
- Etomidate 0.3 mg/kg IV: Preferred for hemodynamically unstable patients due to favorable cardiovascular profile 2, 4
- Ketamine 1-2 mg/kg IV: Alternative with sympathomimetic properties that maintain hemodynamic stability; preferred over etomidate in septic patients 2, 4, 5
- Propofol 1.5-2.5 mg/kg IV: Option for hemodynamically stable patients 3
The Society of Critical Care Medicine guidelines indicate no significant mortality difference between etomidate and other induction agents 1, 4, though etomidate should be avoided in septic shock due to adrenal suppression concerns 4
Step 2: Neuromuscular Blocking Agent
Administer an NMBA immediately after the induction agent 1, 2
Primary Options:
- Succinylcholine 1-1.5 mg/kg IV: First-line agent when no contraindications exist; provides fastest onset (45-60 seconds) and shortest duration 1, 2, 4, 6
- Rocuronium 1.0-1.2 mg/kg IV: Alternative when succinylcholine is contraindicated; onset time 60-90 seconds 1, 2, 4, 7
Both agents provide comparable intubating conditions, but succinylcholine has a significantly shorter duration of action 6
Timing and Technique
- Wait 45-60 seconds after succinylcholine or 60-90 seconds after rocuronium before attempting laryngoscopy 7, 6
- Do NOT perform bag-mask ventilation during the apneic period in classic RSI to minimize aspiration risk 1
Modified RSI for Pediatric Patients
- In children, provide gentle bag-mask ventilation with peak inspiratory pressure <15 cmH2O if SpO2 drops below 95% to prevent hypoxemia 1
- This "controlled" or "modified" RSI approach reduces hypoxemia risk without increasing aspiration incidence 1
Special Considerations
Gastric Decompression
- Place nasogastric tube for decompression when benefit outweighs risk in patients at high risk of regurgitation 1, 2
Reversal Agent Availability
- When using rocuronium, ensure sugammadex is immediately available for reversal in "can't intubate, can't ventilate" scenarios 4, 7
Obstetric Patients
- Rocuronium is NOT recommended for rapid sequence induction in Cesarean section patients due to inadequate intubating conditions in up to 38% of cases when combined with lower-dose thiopental 7
Pediatric Patients
- Rocuronium is NOT recommended for rapid sequence intubation in pediatric patients per FDA labeling 7
Critical Pitfalls to Avoid
- Never administer an NMBA without first giving a sedative-hypnotic agent - this causes awareness during paralysis, occurring in 2.6% of emergency department intubations 2, 5
- Inadequate preoxygenation increases desaturation risk - ensure proper technique and consider medication-assisted preoxygenation for uncooperative patients 2
- In critically ill patients with depleted catecholamine stores, ketamine may paradoxically cause hypotension despite its sympathomimetic properties 4
- Ensure vasopressors are immediately available as peri-intubation hypotension is common 1
- Do not use etomidate in septic patients - prefer ketamine in this population 4