The negative-pressure test using a self-inflating bulb (SIB) during emergency intubation was studied to determine its reliability and predictive value in this setting.Methods
The endotracheal tube (ETT) position was tested in 300 consecutive patients undergoing in-hospital emergency endotracheal intubation. Immediately after intubation and before ETT cuff inflation, the following protocol was strictly followed: (1) an SIB was compressed, connected to the ETT, and released. A 10-s period was allowed for the bulb to inflate. (2) The ETT cuff was inflated, and the ETT position was confirmed using colorimetric or infrared carbon dioxide detection, or both, combined with clinical evaluation.Results
There were 19 esophageal intubations (6% incidence). The SIB correctly identified all patients with esophageal intubation (sensitivity, 100%) and correctly identified all but three ETTs placed in the trachea (specificity, 99%). The three tracheally placed tubes that were misidentified by the bulb syringe occurred during one case each of chronic obstructive pulmonary disease, copious secretions, and obesity; of note were three tracheally placed tubes that were misidentified by the carbon dioxide analyzers during cardiopulmonary resuscitation.Conclusions
The SIB proved to be a sensitive and specific test for esophageal intubation in the emergency setting when used according to the protocol described, and it is complementary to carbon dioxide detection. The predictive value of the bulb syringe appears to be improved when a prolonged period for reinflation is allowed. It holds particular promise because of its low cost and portability.