[Detection of esophageal intubation-assessment of several methods in clinical anesthesia].

OBJECTIVE: To evaluate the sensitivity and reliability of several widely used tests for prompt detection of inadvertent esophageal intubation.

METHODS: Both endotracheal and esophageal intubations were made on 40 adult patients undergoing general anesthesia. The tests such as auscultation of bilateral apex of lungs and epigastrium by inexperienced examiners, capnography, SpO2, chest and upper abdomen movements, and airway resistance were evaluated.

RESULTS: 90% and 96.25% cases in esophageal intubation were correctly diagnosed via auscultation of bilateral apex of lungs or epigastrium respectively. During esophageal ventilation, abdominal distension was found in 87.5% of cases, but none of them showed chest movements. Meanwhile, PetCO2 fluctuated between 1-2 mmHg, in association with a quick decline of SpO2 in 156 +/- 11 seconds. The airway mean resistance increased, whereas the period of plateau decreased significantly.

CONCLUSIONS: (1) Auscultation of epigastrium in combination with bilateral apex of lungs is recommended because of the improved accuracy in tube positioning. (2) Capnography is the most reliable technique for the prompt detection of esophageal intubation, whereas other parameters do not seem to be of comparable value.