Sudden Increase in EtCO2 During Upper Endoscopy Under General Endotracheal Anesthesia Suggests the Presence of Tracheoesophageal Fistula: A Case Report.

Acquired tracheoesophageal fistula is a rare and devastating complication of lung cancer. The diagnosis is typically confirmed on barium esophagram. We report a case of a patient with lung cancer status after palliative chemoradiotherapy and esophageal stenting for malignant stenosis who presented with signs and symptoms suggestive of tracheoesophageal fistula; however, no evidence of fistula was found on barium esophagram. During subsequent esophagogastroduodenoscopy, the presence of a fistula was verified by capnography, given extreme elevations in end-tidal CO2 concentrations during endoscopic CO2 insufflation.