Adequacy of Alveolar Ventilation During Esophagoscopy Under General Anesthesia Without Endotracheal Intubation

¹ Mayo Graduate School of Medicine (University of Minnesota), Rochester: Resident in Anesthesiology
² Mayo Clinic and Mayo Foundation: Section of Anesthesiology
³ Mayo Clinic and Mayo Foundation: Section of Medicine

During esophagoscopy, an endotracheal tube may be one of the factors contributing to the incidence of esophageal perforation. General anesthesia without an endotracheal tube appears to be advantageous in this regard, providing that adequate alveolar ventilation is maintained. In ten patients undergoing diagnostic esophagoscopy, observations were made periodically throughout the procedure on the changes in arterial blood gases and electrocardiograms. All patients received sufficient oxygen. There was essentially no change in base excess. The maintenance of adequate alveolar ventilation was associated with a depth of anesthesia sufficient to suppress reflexes. Coughing and breath-holding due to insufficient depth of anesthesia caused respiratory acidosis. Larger dosage of gallamine, exceeding 0.4 mg/kg of body weight, caused mild retention of carbon dioxide. Esophagoscopy can be safely performed under general anesthesia and partial myorelaxation without an endotracheal tube.