Anesthetic management of an extremely obese patient

We present the case of a morbidly obese woman, with a body mass index (BMI) of 73.7 kg.m(-2), who had a gynecological operation under combined general and epidural anesthesia. The patient's trachea was intubated, using a fiberscope, while she was breathing spontaneously after the intravenous injection of fentanyl and propofol as sedatives. Anesthesia was maintained with intravenous propofol and epidural mepivacaine. When the gynecologist placed a sponge in the abdominal cavity to retract the bowel, the patient experienced severe arterial deoxygenation and mild hypotension, due to massive atelectasis of the left lung. Both oxygenation and perfusion were corrected by the removal of the sponge and with the placement of a pillow under the patient's left shoulder. The atelectasis resulted from compression of the left lung by the fatty mediastinum and by the diaphragm being pushed up by the sponge. The hypotension resulted from impaired venous return and hypoxia. The patient suffered no perioperative complications other than atelectasis and a surgical-site infection. Key factors that contributed to the favorable outcome of this patient included a careful tracheal intubation technique, the choice and dose of anesthetic agents, immediate correction of the factors leading to atelectasis, early ambulation, and prophylaxis for deep vein thrombosis.