Rapid Sequence Intubation of Critically Ill Patients: Guidelines From the Society of Critical Care Medicine

Emergency airway management is high-risk and involves multiple decisions. Rapid sequence intubation, which usually occurs after administration of a sedative-hypnotic agent and a neuromuscular blocking agent in rapid succession, should optimize the chance of successful intubation while reducing peri-intubation risks such as aspiration or hypotension. The Society of Critical Care Medicine developed guidelines to optimize rapid sequence intubation.

Simulation studies suggest that sitting a patient up from the traditional supine position to a semi-Fowler position (ie, head and trunk raised) before intubation decreases aspiration risk, increases lung volumes, and improves intubation success through better views. The guideline suggests semi-Fowler positioning based on very low-quality evidence from conflicting studies. Although simulation and observational studies clearly demonstrate improved first-pass intubation success with semi-Fowler positioning compared with the supine position, the few randomized trials demonstrated no difference between the two positions.

Based on low-quality evidence, preoxygenation with 100% oxygen before intubation is suggested to prevent desaturation from apnea during the intubation attempt. Preoxygenation can be performed using noninvasive positive pressure ventilation (NIPPV), oxygen by face mask, or high-flow nasal oxygen.

Based on low-quality evidence, using high-flow nasal oxygen for preoxygenation when laryngoscopy is expected to be challenging may be more beneficial than using oxygen by face mask. Limited evidence suggests that using high-flow nasal oxygen reduces desaturations without increasing aspirations. Unlike face mask or NIPPV, high-flow nasal oxygen can be used for preoxygenation throughout intubation attempts.

With severe hypoxemia, a ratio of partial pressure of oxygen to fraction of inspired oxygen concentration less than 200, NIPPV is suggested because preoxygenation with high-flow nasal oxygen may lead to increased desaturation risk.

If patients cannot tolerate preoxygenation due to confusion, using ketamine is suggested for sedation during preoxygenation based on very low-quality evidence. Using sedation during preoxygenation is sometimes referred to as delayed sequence intubation. A fixed infusion dose of 1.5 mg/kg or titrating up from an initial dose of 1.0 mg/kg to reach the goal of dissociation is recommended.

The guidelines suggest etomidate (Amidate), ketamine, midazolam, or propofol (Diprivan) for induction before rapid sequence intubation. Although one meta-analysis suggests slightly higher mortality when using etomidate compared with ketamine, there is no difference when considering only randomized controlled trials.

Although some physicians choose to avoid paralysis to prevent the risk of inability to intubate and inability to ventilate, the guideline strongly recommends using neuromuscular blocking agents despite the low quality of evidence. Using these agents reduces vomiting and aspiration risk during intubation. Administering succinylcholine or rocuronium before intubation is suggested to paralyze a sedated patient. Even though intubation success rates vary, the most robust study demonstrated first-pass intubation in 81% of patients with paralysis compared with 70% without paralysis and higher first-pass success if a paralytic agent is used.