What is the recommended procedure for rapid sequence intubation (RSI) in emergency situations?

Rapid Sequence Intubation in Emergency Situations

Rapid sequence intubation (RSI) involves administering a sedative-hypnotic agent followed immediately by a neuromuscular blocking agent (NMBA) in rapid succession, with endotracheal tube placement before any assisted ventilation, specifically designed for critically ill adult patients requiring emergency airway management. 1

Core Definition and Indications

RSI is indicated for critically ill adult patients in emergency departments, ICUs, or other locations outside the operating room who require emergency airway management, particularly those at risk for aspiration (full stomach, ileus, bowel obstruction, gastroesophageal reflux disease, or increased intra-abdominal pressure). 1, 2

Positioning

Position the patient in semi-Fowler position (head and torso inclined) during RSI to reduce aspiration risk and potentially improve first-pass intubation success. 1, 2 This represents a conditional recommendation based on very low quality evidence, but the benefits clearly outweigh risks. 1

Preoxygenation Strategy

The preoxygenation approach depends on patient cooperation and severity of hypoxemia:

For Cooperative Patients

• Use high-flow nasal oxygen (HFNO) when laryngoscopy is expected to be challenging. 1, 2
• For patients with severe hypoxemia (PaO2/FiO2 < 150), use noninvasive positive pressure ventilation (NIPPV) for preoxygenation. 1, 2

For Agitated/Uncooperative Patients

• Use medication-assisted preoxygenation (also called delayed sequence intubation) with ketamine (1-1.5 mg/kg IV) for agitated, delirious, or combative patients who cannot tolerate preoxygenation devices. 1, 2 This approach increases oxygen saturation by approximately 8.9% before NMBA administration. 1
• Administer ketamine to achieve dissociative state, allow 3 minutes of preoxygenation, then proceed with NMBA and intubation. 1

Gastric Decompression

Place a nasogastric tube for gastric decompression when the benefit outweighs the risk in patients at high risk of regurgitation of gastric contents. 1 This is a best practice statement based on aspiration risk reduction principles. 1

Pharmacologic Management

Sedative-Hypnotic Induction Agents

A sedative-hypnotic induction agent MUST be administered when an NMBA is used for intubation to prevent awareness during paralysis. 1, 3, 2 This is a best practice statement with universal applicability. 1

Agent Selection Algorithm:

For hemodynamically unstable patients:

• Use etomidate (0.2-0.3 mg/kg) as the preferred induction agent due to minimal cardiovascular depression. 3, 2 The Society of Critical Care Medicine found no significant difference between etomidate and other induction agents (ketamine, midazolam, propofol) with respect to mortality or hypotension, but etomidate remains most favorable for unstable patients. 1, 3

For hemodynamically stable patients:

• Either etomidate or ketamine (1-2 mg/kg) can be used. 3
• Be aware that ketamine may cause paradoxical hypotension in critically ill patients with depleted catecholamine stores despite its typical sympathomimetic effects. 3

For agitated patients requiring medication-assisted preoxygenation:

• Use ketamine (1-2 mg/kg) before the paralytic to facilitate preoxygenation. 1, 3

Neuromuscular Blocking Agents

The Society of Critical Care Medicine strongly recommends administering an NMBA when a sedative-hypnotic induction agent is used for intubation. 1, 3, 2 This is a strong recommendation despite low quality evidence. 4, 1

NMBA Selection:

Either succinylcholine (1-1.5 mg/kg) or rocuronium (0.9-1.2 mg/kg) is recommended when there are no contraindications to succinylcholine. 1, 2

For standard RSI dosing:

• Rocuronium 0.6 mg/kg provides intubating conditions in median 1 minute with 31 minutes clinical duration. 5
• Higher doses of rocuronium (0.9-1.2 mg/kg) provide more rapid onset comparable to succinylcholine but with longer duration (58-67 minutes). 5

Critical safety requirement: Sugammadex MUST be immediately available when rocuronium is used for potential "cannot intubate/cannot oxygenate" scenarios. 3, 2

Key Distinction Between Agents:

• Succinylcholine: Rapid onset, short duration (preferred for hemodynamically stable patients) 3
• Rocuronium: Rapid onset at high doses, intermediate duration (31-67 minutes depending on dose), requires sugammadex availability 3, 5

Critical Timing

Administer the sedative-hypnotic agent and NMBA in rapid succession with immediate endotracheal tube placement before assisted ventilation begins. 3, 2 This minimizes aspiration risk and ensures optimal intubating conditions. 3

Special Population Considerations

Obese Patients

Dose rocuronium based on actual body weight (ABW), not ideal body weight (IBW). 5 Dosing based on IBW results in longer time to maximum block, shorter clinical duration, and inadequate intubating conditions. 5

Obstetric Patients

Rocuronium is NOT recommended for rapid sequence induction in Cesarean section patients. 5 When rocuronium 0.6 mg/kg was used with thiopental 3-4 mg/kg, intubating conditions were poor or inadequate in 5 of 13 women when intubation was attempted at 60 seconds. 5

Geriatric Patients

Rocuronium 0.6 mg/kg provides excellent to good intubating conditions in median 2.3 minutes, with recovery times not prolonged compared to younger adults. 5

Common Pitfalls and How to Avoid Them

Inadequate preoxygenation increases desaturation risk:

• Ensure proper preoxygenation technique for at least 3 minutes 1
• Consider medication-assisted preoxygenation for uncooperative patients 1, 2

Administering NMBA without sedative-hypnotic agent:

• This causes awareness during paralysis and is never acceptable 1, 3
• Always administer sedative-hypnotic BEFORE or simultaneously with NMBA 3

Failure to have backup airway equipment immediately available:

• Can lead to "cannot intubate/cannot oxygenate" scenarios 2
• Ensure sugammadex is immediately available when using rocuronium 3, 2

Delayed post-intubation analgosedation:

• Rocuronium's longer duration (compared to succinylcholine) may delay provision of post-intubation analgosedation, potentially increasing awareness risk 1, 2
• Plan for immediate post-intubation sedation and analgesia 1

Inappropriate medication selection causing hemodynamic instability:

• Use etomidate for hemodynamically unstable patients 3, 2
• Be cautious with ketamine in critically ill patients with depleted catecholamine stores 3