Two Cases of Pneumothorax Occurring during Laparoscopy

We report two cases of pneumothorax which occurred during laparoscopy under general anesthesia. The trachea was intubated and anesthesia was maintained with nitrous oxide, oxygen and isoflurane in both cases. Right pneumothorax occurred immediately after pneumoperitoneum in a 25-year-old woman who underwent laparoscope for inspection of endometriosis. Left pneumothorax occurred 45 minutes after carbon dioxide insufflation into the abdominal cavity of a 70-year-old man who underwent laparoscopic cholecystectomy. In both patients, an emergent chest drainage was established and they recovered uneventfully. No air leakage from the chest drain was seen after re-expansion of the lung. There was no evidence of iatrogenic damage to the diaphragm in either case. Chest CT was normal in the former case, and carbon dioxide pneumothorax was revealed in the latter case because PCO2 of the sealed water in the chest drainage bag was 722 mmHg. The existence of some pleuroperitoneal communication (for example, via congenital defect of the diaphragm) was thought to be a possible cause of the pneumothorax.