What medications should be given before performing rapid sequence intubation (RSI) on an adult patient?

Medications for Rapid Sequence Intubation

For rapid sequence intubation in adult patients, 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), with the sedative always given first to prevent awareness during paralysis. 1

Medication Selection Algorithm

Step 1: Choose Your Induction Agent

For hemodynamically unstable patients:

• Etomidate 0.3 mg/kg IV is the preferred first-line agent due to its minimal cardiovascular depression 1, 2
• Onset occurs within seconds, providing rapid unconsciousness with stable blood pressure 2

For hemodynamically stable patients or those with sepsis:

• Ketamine 1-2 mg/kg IV is equally acceptable and may be preferred in septic patients 1, 2
• Ketamine maintains hemodynamic stability through sympathomimetic properties, though it can paradoxically cause hypotension in critically ill patients with depleted catecholamine stores 1
• In pediatric septic shock, ketamine is explicitly preferred over etomidate due to adrenal suppression concerns 1

Critical dosing considerations for etomidate:

• Do not exceed 0.3 mg/kg, especially in patients >55 years, as higher doses significantly increase respiratory depression and oxygen desaturation 1
• In hemodynamically compromised patients, consider reducing to 0.15-0.2 mg/kg 1
• The transient adrenal suppression caused by etomidate does not require corticosteroid administration, as multiple RCTs showed no mortality benefit 1

Step 2: Immediately Follow with Neuromuscular Blockade

The neuromuscular blocking agent must be given after the induction agent to prevent awareness during paralysis—this is a non-negotiable safety requirement. 1, 2

For patients without contraindications:

• Succinylcholine 1-1.5 mg/kg IV is first-line 1, 2
• Provides paralysis in 30-45 seconds with 5-10 minute duration 1
• Use actual body weight, not ideal body weight, for dosing 1

When succinylcholine is contraindicated:

• Rocuronium 0.9-1.2 mg/kg IV (high-dose regimen) 1, 2
• Provides onset comparable to succinylcholine (≈60 seconds) but with 58-67 minute duration 1, 2
• Sugammadex must be immediately available for reversal in "cannot intubate/cannot oxygenate" scenarios 1, 2

Absolute contraindications to succinylcholine:

• Malignant hyperthermia history 1
• Severe burns or crush injury (after first 24 hours) 1, 3
• Spinal cord injury 1
• Hyperkalemia risk, including renal failure after 24 hours 3
• Boys <9 years old (due to undiagnosed muscular dystrophy risk) 1

Step 3: Timing and Administration Sequence

Administration order:

1. Give induction agent (etomidate or ketamine) first 1, 2
2. Immediately follow with neuromuscular blocker 1, 2
3. Wait at least 60 seconds after rocuronium (or 30-45 seconds after succinylcholine) before attempting intubation 1
4. Confirm full neuromuscular blockade before laryngoscopy 1

Special Populations and Modifications

Agitated or Uncooperative Patients (Delayed Sequence Intubation)

For patients who cannot tolerate preoxygenation due to agitation, delirium, or combative behavior:

• Administer ketamine 1-2 mg/kg IV for dissociative sedation 1, 2
• Allow 3 minutes of preoxygenation with high-flow nasal oxygen or NIPPV 1
• Then proceed with neuromuscular blocker and intubation 1
• This approach increases oxygen saturation by approximately 8.9% before paralysis 1, 3

Elderly Patients (≥65 years)

• Ketamine 1-2 mg/kg IV is preferred over etomidate due to better safety profile 3
• Rocuronium 0.9-1.2 mg/kg IV is preferred over succinylcholine 3
• Use semi-Fowler positioning (head elevated 25-30°) 3
• Limit etomidate to ≤0.3 mg/kg to avoid respiratory depression 1, 3

Renal Failure Patients

• Etomidate 0.2-0.3 mg/kg IV requires no dose adjustment 3
• Rocuronium 0.9-1.2 mg/kg IV is the neuromuscular blocker of choice 3
• Avoid succinylcholine after 24 hours of established renal failure due to life-threatening hyperkalemia risk 3
• Ensure sugammadex is immediately available 3

Severe Hypoxemia (PaO₂/FiO₂ <150)

• Use NIPPV for preoxygenation before induction 1, 3
• Consider high-flow nasal oxygen when difficult laryngoscopy is anticipated 1, 3
• Position in semi-Fowler (head-up) 1, 3

Critical Pitfalls and How to Avoid Them

Awareness During Paralysis

The most dangerous error is administering the neuromuscular blocker without adequate sedation. 1, 2

• When using rocuronium, its 30-60 minute duration far exceeds ketamine's sedative effects, creating a high-risk window for awareness 1
• Implement protocolized post-intubation analgosedation immediately after securing the airway 1
• Assign a dedicated team member (ideally a clinical pharmacist) to manage post-intubation sedation timing 1
• The median time to first post-intubation sedation intervention should be ≤7 minutes 4

Hemodynamic Collapse

• All induction agents can cause vasodilation and hypotension by abolishing sympathetic tone 3
• Have vasopressors immediately available before starting RSI 1
• Consider a 500 mL crystalloid bolus before or during induction in non-fluid-overloaded patients 3
• In shock states, etomidate may produce less hypotension than ketamine based on retrospective evidence 5

Inadequate Preoxygenation

• Ensure 3-5 minutes of preoxygenation with a well-fitted mask in cooperative patients 3
• For uncooperative patients, use medication-assisted preoxygenation (delayed sequence intubation) rather than proceeding with inadequate oxygenation 1, 3

Dosing Errors in Obesity

• Use actual body weight, not ideal body weight, for all RSI medications 1
• Patients with BMI >30 kg/m² have twice the risk of intubation complications; those with BMI >40 kg/m² have four times the risk 3

Delayed Intubation Attempt

• Do not attempt laryngoscopy until full neuromuscular blockade is achieved (≥60 seconds after rocuronium, ≥30 seconds after succinylcholine) 1
• Premature attempts increase coughing, aspiration risk, and failed intubation 1

Positioning and Preparation

• Semi-Fowler position (head and torso elevated 25-30°) is recommended to reduce aspiration risk and potentially improve first-pass success 1, 3
• In obese patients, use ramped positioning with reverse Trendelenburg 3
• Confirm functional IV access, continuous capnography, suction, and complete airway cart before starting 3

Post-Intubation Management

• Apply minimum 5 cmH₂O PEEP immediately after intubation in hypoxemic patients 3
• Perform recruitment maneuver in hypoxemic patients 3
• Initiate continuous sedation and analgesia within 7 minutes of intubation when rocuronium was used 1, 4
• Confirm tube placement with waveform capnography 3