What is the induction of Rapid Sequence Intubation (RSI)?

From the Guidelines

Rapid sequence induction (RSI) is best performed using a combination of a sedative and a neuromuscular blocking agent, with etomidate or ketamine being suitable options for sedation, as they have been shown to have no significant difference in mortality or incidence of hypotension compared to other induction agents 1.

Key Considerations for RSI

• Pre-oxygenate the patient for 3-5 minutes with 100% oxygen before induction to minimize the risk of hypoxia.
• Administer the sedative first, followed immediately by the paralytic agent, then proceed to laryngoscopy and intubation within 45-60 seconds without bag-mask ventilation (unless oxygen saturation drops critically).
• Have backup airway equipment readily available, including a video laryngoscope if possible.
• Consider hemodynamic support with fluids or vasopressors for hypotension-prone patients, as peri-intubation hypotension is a common event in critically ill patients and can be associated with organ dysfunction and increased mortality 1.

Choice of Sedative

• Etomidate (0.2-0.3 mg/kg IV) is a reasonable option for RSI due to its favorable hemodynamic profile, although concerns about adrenal enzyme inhibition exist 1.
• Ketamine (1-2 mg/kg IV) may also be used, particularly in patients with depleted catecholamine stores, as it has sympathomimetic properties that can help maintain blood pressure 1.

Important Evidence

• A recent meta-analysis found no significant difference in mortality between etomidate and other induction agents, including ketamine and propofol 1.
• Studies have shown that etomidate and ketamine have similar effects on peri-intubation hemodynamics, with no significant difference in the incidence of hypotension or vasopressor use 1.
• The choice of sedative should be based on individual patient factors, including hemodynamic stability and potential for adrenal insufficiency 1.

From the FDA Drug Label

Rapid Sequence Intubation Intubating conditions were assessed in 230 patients in six clinical studies where anesthesia was induced with either thiopental (3 to 6 mg/kg) or propofol (1.5 to 2. 5 mg/kg) in combination with either fentanyl (2 to 5 mcg/kg) or alfentanil (1 mg). Most patients also received a premedication such as midazolam or temazepam. Most patients had intubation attempted within 60 to 90 seconds of administration of rocuronium bromide 0.6 mg/kg or succinylcholine 1 to 1. 5 mg/kg.

The induction of Rapid Sequence Intubation (RSI) typically involves the administration of a sedative (such as thiopental or propofol) in combination with a neuromuscular blocking agent (such as rocuronium bromide or succinylcholine), often with an opioid (like fentanyl or alfentanil) and a premedication (like midazolam or temazepam).

• The dose of thiopental is usually between 3 to 6 mg/kg.
• The dose of propofol is usually between 1.5 to 2.5 mg/kg.
• The dose of rocuronium bromide is usually 0.6 mg/kg.
• The dose of succinylcholine is usually between 1 to 1.5 mg/kg.
• Intubation is typically attempted within 60 to 90 seconds after administration of the neuromuscular blocking agent 2.

From the Research

Induction of Rapid Sequence Intubation (RSI)

The induction of RSI is a critical step in the process, and several medications can be used for this purpose.

• Etomidate and ketamine are the most commonly used induction agents due to their favorable hemodynamic profiles 3.
• Ketamine may produce more hypotension than etomidate in patients presenting with shock or sepsis, according to retrospective evidence 3.
• Other options for induction agents include propofol, thiopental, and midazolam, but the choice of agent depends on the patient's specific condition and the physician's preference 4, 5.
• The use of fentanyl, ketamine, and rocuronium for RSI has been shown to produce superior intubating conditions and a more favorable hemodynamic response to laryngoscopy and tracheal intubation 6.
• The selection of induction agents is crucial for the success of RSI, and the choice of agent should be based on the patient's individual needs and the physician's expertise 3, 4, 5, 6.

Medications Used for Induction

Several medications can be used for induction in RSI, including:

• Etomidate: a commonly used induction agent with a favorable hemodynamic profile 3, 5.
• Ketamine: a commonly used induction agent with a favorable hemodynamic profile, but may produce more hypotension than etomidate in patients with shock or sepsis 3, 5, 6.
• Propofol: an induction agent that can be used for RSI, but may not be suitable for all patients due to its potential for hypotension 5.
• Fentanyl: an opioid that can be used in combination with other agents for RSI, and has been shown to produce superior intubating conditions and a more favorable hemodynamic response to laryngoscopy and tracheal intubation 6.
• Rocuronium: a neuromuscular blocking agent that can be used for RSI, and has been shown to produce comparable intubating conditions to succinylcholine 7.