Rapid Sequence Intubation: Steps, Drugs, and Dosing
Core Medication Regimen
Administer a sedative-hypnotic induction agent (etomidate 0.3 mg/kg IV or ketamine 1-2 mg/kg IV) immediately followed by a neuromuscular blocking agent (succinylcholine 1-1.5 mg/kg IV or rocuronium 0.9-1.2 mg/kg IV) to facilitate rapid sequence intubation. 1, 2
Step-by-Step RSI Protocol
Step 1: Preparation and Preoxygenation
- Position the patient in semi-Fowler position (head and trunk inclined) to improve first-pass success and reduce aspiration risk 1, 2
- Preoxygenate for 3-5 minutes using one of the following methods based on patient condition 1:
- Consider nasogastric tube decompression in patients at high risk for regurgitation of gastric contents 1
- Have vasopressors immediately available as even hemodynamically stable agents can cause transient hypotension 2, 3
Step 2: Pretreatment (Optional - 3 Minutes Before Induction)
Pretreatment medications have largely fallen out of favor due to limited evidence, but may be considered in select scenarios 4, 5:
- Atropine 0.02 mg/kg (minimum 0.1 mg, maximum 1 mg) before succinylcholine in pediatric patients to prevent bradycardia 1
- Fentanyl or lidocaine for patients with elevated intracranial pressure (though evidence is limited) 5, 6
Step 3: Induction Agent Administration
Select ONE of the following induction agents 1, 2:
Etomidate (Preferred for Hemodynamic Instability)
- Dose: 0.3 mg/kg IV 1, 2, 3
- Onset: 30-60 seconds 5
- Advantages: Most hemodynamically stable option, minimal effect on blood pressure 2, 3
- Disadvantages: Transient adrenal suppression (do NOT give corticosteroids to counteract this) 1, 2
- Special consideration: May cause less hypotension than ketamine in shock/sepsis patients 4
Ketamine (Alternative First-Line Agent)
- Dose: 1-2 mg/kg IV (use 1 mg/kg in cardiovascularly compromised patients) 2, 7
- Onset: 45-60 seconds 5
- Advantages: Sympathomimetic properties maintain hemodynamic stability, preserves respiratory drive 2, 7
- Disadvantages: May paradoxically cause hypotension in patients with depleted catecholamine stores 2
- Preferred over etomidate in pediatric septic shock 2
Propofol (Use with Caution)
- Dose: 2-6 mg/kg IV (reduce dose if other sedatives given) 1
- Warnings: Causes vasodilation and decreased cardiac output; avoid in cardiovascular dysfunction or volume depletion 1
Step 4: Neuromuscular Blocking Agent (Immediately After Induction)
Critical: The sedative-hypnotic MUST be administered before the NMBA to prevent awareness during paralysis 1, 2, 3
Select ONE of the following NMBAs 1, 2:
Succinylcholine (First-Line When No Contraindications)
- Dose: 1-1.5 mg/kg IV (or 4 mg/kg IM if no IV access) 1, 7
- Onset: 30-45 seconds IV, 3-5 minutes IM 1
- Duration: 5-10 minutes 1
- Advantages: Fastest onset, shortest duration 1, 4
- Absolute contraindications 1:
- Malignant hyperthermia history
- Severe burns/crush injury (>24-48 hours old)
- Spinal cord injury (>24-48 hours old)
- Neuromuscular disease or myopathy
- Hyperkalemia risk (particularly boys <9 years old)
Rocuronium (When Succinylcholine Contraindicated)
- Dose: 0.9-1.2 mg/kg IV for RSI 1, 2, 8
- Onset: 60-90 seconds at RSI doses 2, 8
- Duration: 45-90 minutes (dose-dependent) 1
- Advantages: No hyperkalemia risk, may be safer in traumatic brain injury 3
- Critical consideration: Have sugammadex available for reversal in "can't intubate, can't ventilate" scenarios 2
Vecuronium (Not Recommended for RSI)
- Dose: 0.2 mg/kg for intubation 1
- Onset: 2 minutes (too slow for RSI) 1
- Duration: 45-90 minutes 1
- Not preferred for RSI due to slower onset 1
Step 5: Intubation Timing
- Wait 45-60 seconds after medication administration before attempting intubation 2, 8
- For rocuronium, wait at least 60 seconds or use peripheral nerve stimulator to confirm adequate blockade 2
- Most patients achieve intubating conditions within 2 minutes 8
Step 6: Post-Intubation Management
- Immediately initiate continuous sedation and analgesia to prevent awareness 2, 3
- Apply at least 5 cmH2O PEEP after intubation 7
- Consider recruitment maneuver to improve oxygenation 7
Special Population Considerations
Traumatic Brain Injury
- Preferred regimen: Etomidate 0.3 mg/kg + rocuronium 0.9-1.2 mg/kg 3
- Rocuronium may be safer than succinylcholine (which can increase ICP and cause hyperkalemia) 3
- Maintain cerebral perfusion pressure by having vasopressors ready 3
Pediatric Patients
- Succinylcholine: 1-2 mg/kg IV (2 mg/kg for infants <6 months) 1
- Always give atropine 0.02 mg/kg before succinylcholine to prevent bradycardia 1
- Rocuronium: 0.6-1.2 mg/kg IV 8
- NOT recommended for rapid sequence intubation in pediatric patients per FDA 8
- In pediatric septic shock: Use ketamine, NOT etomidate 2
Obese Patients
- Dose all medications based on actual body weight, NOT ideal body weight 8
- Dosing by ideal body weight results in longer time to maximum block and shorter clinical duration 8
Obstetric/Cesarean Section
- Rocuronium is NOT recommended for rapid sequence induction in Cesarean section 8
- Poor intubating conditions occurred in 5 of 13 women when lower thiopental doses were used 8
Critical Pitfalls and How to Avoid Them
Pitfall 1: Administering NMBA Before Induction Agent
- Consequence: Awareness during paralysis occurs in 2.6% of ED intubations 2, 3
- Solution: ALWAYS give sedative-hypnotic first, then immediately follow with NMBA 1, 2, 3
Pitfall 2: Inadequate Preoxygenation
- Consequence: Rapid desaturation during apneic period 1
- Solution: Use semi-Fowler positioning and appropriate preoxygenation method (HFNO for difficult airways, NIPPV for severe hypoxemia) 1, 2
Pitfall 3: Using Succinylcholine in Contraindicated Patients
- Consequence: Life-threatening hyperkalemia and cardiac arrest 1
- Solution: Screen for burns, crush injuries, spinal cord injuries, neuromuscular disease before selecting succinylcholine; if present, use rocuronium 1, 7
Pitfall 4: Inadequate Rocuronium Dosing for RSI
- Consequence: Delayed onset, inadequate intubating conditions 8
- Solution: Use 0.9-1.2 mg/kg for RSI, NOT the standard 0.6 mg/kg intubation dose 2, 8
Pitfall 5: Forgetting Post-Intubation Sedation
- Consequence: Patient awareness and distress, especially with longer-acting rocuronium 2
- Solution: Immediately initiate continuous sedation/analgesia after successful intubation; consider clinical pharmacist involvement or protocolized post-intubation sedation 3
Pitfall 6: Inadequate Preparation for Hemodynamic Instability
- Consequence: Cardiovascular collapse during induction 2, 3
- Solution: Have vasopressors drawn up and ready before starting RSI; consider push-dose pressors 2, 3
Medication Administration Compatibility
Flush IV line with saline before administering rocuronium or vecuronium to avoid precipitation and IV obstruction 1