No evidence for decreased incidence of aspiration after rapid sequence induction

The purpose of this structured, evidence-based, clinical update was to determine if rapid sequence induction is a safe or effective technique to decrease the risk of aspiration or other complications of airway management.

In June 2006 a structured search of MEDLINE from 1966 to present using OVID software was undertaken with the assistance of a reference librarian. Medical subject headings and text words describing rapid sequence induction or intubation (RSI), crash induction or intubation, cricoid pressure and emergency airway intubation were employed. OVID's therapy (sensitivity) algorithm was used to maximize the detection of randomized trials while excluding non-randomized research. The bibliographies of eligible publications were hand-searched to identify trials not identified in the electronic search.

A total of 184 clinical trials were identified of which 163 were randomized controlled trials (RCTs). Of these clinical trials, 126 evaluated different drug regimens with 114 being RCTs. Only 21 clinical trials evaluated non-pharmacologic aspects of the RSI with 18 RCTs identified. A parallel search found 52 trials evaluating cricoid pressure (outside of the context of an RSI technique) with 44 classified as RCTs. Definitive outcomes such as prevention of aspiration and mortality benefit could not be evaluated from the trials. Likewise, the impact on adverse outcomes of the different components of RSI could not be ascertained.

An absence of evidence from RCTs suggests that the decision to use RSI during management can neither be supported nor discouraged on the basis of quality evidence.