Early detection of endotracheal tube accidents by monitoring carbon dioxide concentration in respiratory gas

Abstract

Absence of ventilation, which may result during anesthesia from esophageal intubation, accidental tracheal extubation, disconnection of the endotracheal tube from the mechanical ventilator, or obstruction of the endotracheal tube, produces hypoxia rapidly and death if not detected in a timely fashion. Despite conventional monitors, such as high- and low-pressure alarms and precordial or esophageal stethoscopes to detect breath sounds, cases of profound hypoxia, secondary to any of the causes cited, continue to occur. Because equipment to monitor carbon dioxide concentrations in respiratory gases is readily available, we investigated how rapidly such accidents could be detected by changes in carbon dioxide concentration.