Use of an Apnea Monitor to Verify Endotracheal Intubation

Abstract

Unrecognized esophageal intubation comprises a significant proportion of anesthesia-related mishaps, leading to patient morbidity and mortality. The literature amply documents the observation that clinical signs commonly used to assess endotracheal intubation (breath sounds, chest excursion, exhaled air) can be inaccurate. In an attempt to prevent the sometimes catastrophic consequences of this inaccuracy, we investigated the practical application of a portable capnometer (Tri Med 510 Respiration Monitor) in the qualitative detection of exhaled CO2 to verify endotracheal tube placement. During a 6-month period the capnometer was used to monitor 41 intubation attempts in our adult intensive care unit. Esophageal intubation, as indicated by the absence of exhaled CO2 from the endotracheal tube, was detected on three occasions (7%). In one of these three patients, clinical signs had failed to detect the misplacement of the endotracheal tube into the esophagus. Esophageal intubation can be difficult to detect clinically and can lead to fatalities. This technique can improve the clinician's ability to detect and promptly correct esophageal intubation. (Respir Care 1985;30:974-976.)