Medications for Rapid Sequence Intubation
For rapid sequence intubation in adults, administer a sedative-hypnotic agent (etomidate 0.2-0.4 mg/kg or ketamine 1-2 mg/kg) followed immediately by a neuromuscular blocking agent (succinylcholine 1-1.5 mg/kg or rocuronium 0.9-1.2 mg/kg). 1, 2
Core Medication Components
Sedative-Hypnotic Agents (Induction)
Etomidate is the preferred first-line induction agent for most adult patients due to its hemodynamic stability and ability to lower intracranial pressure, dosed at 0.2-0.4 mg/kg IV (maximum 20 mg). 3, 1 This agent maintains blood pressure and is particularly valuable in patients with cardiovascular disease, head injury, or multisystem trauma. 3, 4
Ketamine (1-2 mg/kg IV) is the preferred alternative, especially in hemodynamically unstable patients, as it provides sympathomimetic effects that help maintain blood pressure. 1, 2 However, ketamine may paradoxically cause hypotension in patients with depleted catecholamine stores and was associated with higher hypotension rates (18.3% vs 12.4%) compared to etomidate in some populations. 2, 4
Midazolam (2-5 mg IV for adults) can be used but causes more hemodynamic instability and should be avoided in unstable patients. 5, 6
Neuromuscular Blocking Agents (Paralysis)
Succinylcholine is the first-line paralytic agent for patients with respiratory or cardiovascular compromise, dosed at 1-1.5 mg/kg IV for adults (higher doses of 2 mg/kg for infants, 1.2 mg/kg for children 1-10 years). 1, 7 This provides optimal intubating conditions within 60 seconds with a short duration of action. 3, 7
Rocuronium (0.9-1.2 mg/kg IV) should be used when succinylcholine is contraindicated (hyperkalemia, burns >24 hours old, crush injuries, neuromuscular disease, malignant hyperthermia history). 1, 2 At doses of 1.0-1.2 mg/kg, rocuronium provides intubating conditions comparable to succinylcholine within 60-90 seconds. 3, 8 Sugammadex must be immediately available when using rocuronium for potential reversal in "can't intubate, can't ventilate" scenarios. 1, 4
Pretreatment Medications
Pediatric Patients (<8 years)
Atropine 0.01-0.02 mg/kg IV (maximum 0.5 mg) must be administered to children aged 28 days to 8 years before intubation, particularly when using succinylcholine or in patients with septic shock or hypovolemia. 1, 3 This prevents clinically significant bradycardia that commonly occurs with laryngoscopy in young children. 1
Optional Adjuncts
Lidocaine 1-2 mg/kg IV may be given 30 seconds to 5 minutes before intubation in patients with increased intracranial pressure, though evidence is limited. 1
Fentanyl 1-2 mcg/kg IV can be used to blunt the sympathetic response to laryngoscopy, but increases apnea risk when combined with sedatives. 3, 6
Medication Sequencing
The sedative-hypnotic agent should be administered first, followed immediately by the neuromuscular blocking agent. 2, 9 However, administering the paralytic first may reduce intubation time by approximately 6 seconds without apparent harm, though this remains controversial. 9 The critical principle is that both medications must be given within 30 seconds of each other to prevent awareness during paralysis, which occurs in 2.6% of emergency intubations when sedation is inadequate. 2
Population-Specific Considerations
Pediatric Dosing
- Succinylcholine: 2 mg/kg IV for infants and small children; 1 mg/kg for older children/adolescents 1, 7
- Ketamine: 1-2 mg/kg IV (preferred in children) 1
- Etomidate: 0.2-0.4 mg/kg IV for children >2 years (avoid in sepsis) 3
- Rocuronium: 0.9-1.2 mg/kg IV when succinylcholine contraindicated 3, 1
Obese Patients
Dose all RSI medications based on actual body weight, not ideal body weight. 8 Dosing based on ideal body weight results in inadequate intubating conditions and shorter duration of action. 8
Geriatric Patients
Standard adult dosing of rocuronium 0.6 mg/kg provides adequate intubating conditions without prolonged recovery times in patients 65-80 years old. 8
Critical Pitfalls to Avoid
Do not use succinylcholine in patients with hyperkalemia, burns >24 hours old, crush injuries, prolonged immobilization, or neuromuscular disease due to risk of fatal hyperkalemic cardiac arrest. 1, 7 Despite this, 13% of patients in one study received succinylcholine despite contraindications. 10
Do not use rocuronium without immediately available sugammadex, as the prolonged paralysis (45-70 minutes) creates dangerous situations if intubation fails. 1, 4
Do not use etomidate in septic patients without considering adrenal suppression, though clinical significance remains debated. 3 In practice, 58% of septic patients received etomidate without documented adrenal insufficiency in one large study. 10
Do not administer succinylcholine to patients with baseline bradycardia without atropine pretreatment, as it significantly increases post-intubation bradycardia risk (RR 1.81). 10 Yet 67% of bradycardic patients received succinylcholine in one multicenter study. 10
Do not forget post-intubation sedation and analgesia after using non-depolarizing paralytics, as most patients in observational studies did not receive adequate sedation following RSI. 10, 11