To evaluate the reliability of capnography in identifying esophageal intubation in the presence of a carbonated beverage in the stomach, we first investigated the amount of CO2 released from different carbonated beverages and antacids in a simulated stomach; next we measured the end-expired CO2 level during esophageal ventilation with a carbonated beverage in the stomachs of six swine. CO2 levels of approximately 20% were consistently observed in all carbonated beverages. The CO2 levels obtained with sodium bicarbonate, Maalox, and sodium citrate were 19.3%, 2.0%, and 0%, respectively. CO2 waveforms were observed during esophageal ventilation in five of six animals after intragastric administration of a carbonated beverage. An end-expired CO2 level of 2.5% or more was observed in two swine. The highest end-expired CO2, level measured was 5.3%. We conclude that although capnography is convenient and effective, it lacks all the attributes of an ideal monitor for detecting esophageal intubation.
|Original language||English (US)|
|Number of pages||5|
|Journal||Anesthesia and analgesia|
|State||Published - Jan 1 1991|
ASJC Scopus subject areas
- Anesthesiology and Pain Medicine