What are the considerations for Rapid Sequence Intubation (RSI) in a 127 kg male?

Rapid Sequence Intubation for a 127 kg Male

For this 127 kg male, dose rocuronium at 1.0-1.2 mg/kg based on actual body weight (127-152 mg total) combined with ketamine 1-2 mg/kg (127-254 mg total) as your induction agent, as this provides optimal intubating conditions while maintaining hemodynamic stability. 1, 2

Weight-Based Dosing Considerations

Critical: Use actual body weight, not ideal body weight, for RSI medications in this patient. 3, 2

• Succinylcholine specifically requires dosing based on actual body weight rather than ideal body weight for non-resuscitation medications 3
• FDA labeling for rocuronium confirms that dosing according to actual body weight in obese patients (those ≥30% above ideal body weight) provides superior intubating conditions compared to ideal body weight dosing 2
• Patients dosed by ideal body weight had longer time to maximum block, shorter clinical duration (25 vs 33 minutes), and failed to achieve comparable intubating conditions 2

Recommended Medication Regimen

Induction Agent: Ketamine

• Dose: 1-2 mg/kg IV based on actual body weight (127-254 mg total) 1
• Ketamine is preferred as first-line due to sympathomimetic properties that maintain hemodynamic stability 1, 4
• For patients with potential cardiovascular compromise, use the lower end of the dosing range (1 mg/kg = 127 mg) 1

Alternative: Etomidate if ketamine is contraindicated 1, 4

• Dose: 0.2-0.3 mg/kg IV (25-38 mg total) 1
• In hemodynamically compromised patients, consider reducing to 0.15 mg/kg (19 mg) 1
• Caution: Doses >0.3 mg/kg increase respiratory depression risk, particularly in older patients 1

Neuromuscular Blocking Agent: Rocuronium

• Dose: 1.0-1.2 mg/kg IV based on actual body weight (127-152 mg total) 1, 5, 2
• This high-dose rocuronium provides rapid onset comparable to succinylcholine 1, 5
• Provides 58-67 minutes of clinical relaxation 2
• Essential: Have sugammadex immediately available for reversal 1, 5

Alternative: Succinylcholine if no contraindications exist 1, 5

• Dose: 1.5 mg/kg IV based on actual body weight (190 mg total) 3, 4, 5
• Faster onset but may cause earlier desaturation due to increased oxygen consumption 5

Critical Timing and Sequence

1. Administer ketamine FIRST, then rocuronium immediately after 1, 4
2. Wait at least 60 seconds after rocuronium before attempting intubation 1
3. Failure to provide sedation before paralysis causes awareness during paralysis in approximately 2.6% of emergency intubations 4

Positioning and Preoxygenation

• Position in semi-Fowler (head and trunk inclined) during RSI to reduce aspiration risk and improve first-pass success 1, 5
• Use high-flow nasal oxygen if challenging laryngoscopy is anticipated 1, 5
• For severe hypoxemia (PaO2/FiO2 <150), use noninvasive positive pressure ventilation for preoxygenation 1, 5

Common Pitfalls to Avoid

Dosing Error: Do not use ideal body weight calculations—this will result in underdosing and poor intubating conditions 2

Hemodynamic Instability: Have vasopressors immediately available, as both ketamine and rocuronium can cause hypotension despite ketamine's sympathomimetic properties, particularly in critically ill patients with depleted catecholamine stores 1

Premature Intubation Attempt: Attempting intubation before full neuromuscular blockade increases aspiration risk and can cause patient coughing or movement 1

Inadequate Preoxygenation: In a patient of this size with potentially reduced functional residual capacity, ensure thorough preoxygenation to prevent rapid desaturation 5

Post-Intubation Management

• Apply PEEP of at least 5 cmH2O after intubation if hypoxemic 5
• Consider recruitment maneuver in hypoxemic patients 4, 5
• Be aware that rocuronium's longer duration (58-67 minutes) may delay post-intubation analgosedation 5