To the Editor:—
Laparoscopy is commonly used for diagnosis and therapeutic purposes during gynecologic surgery. We recently encountered a case of a life-threatening bilateral pneumothorax that occurred during an anesthetic procedure for the laser treatment of endometriosis. This major adverse event was caused by a misconnection of the laser lens cooling system (Sharplan 1040). Rapid diagnosis and treatment led to an uneventful postoperative course.
A 27-yr-old woman with American Society of Anesthesiologists physical status 1 was scheduled for laparoscopy for exploration of infertility. Shortly after induction of anesthesia, intraperitoneal CO2insufflation was initiated through an optical trocar. Peritoneal endometriosis was diagnosed, laser treatment was decided upon, and an operator trocar was inserted. When the laser started to fire, a sudden decrease in systolic blood pressure (60 mmHg) associated with bradycardia was observed. At that time, intraperitoneal pressure was noted to be 55 mmHg. The patient rapidly developed subcutaneous emphysema, and pneumothorax was suspected. Surgery was resumed immediately, the peritoneal cavity was exsufflated, and bilateral tension pneumothorax was diagnosed on chest radiograph. Bilateral chest tubes were quickly inserted, and rapid restoration of respiratory and hemodynamic stability was obtained. The patient's course was uneventful, and she was discharged from the hospital. Chest tomodensitometry did not show the presence of emphysema blebs.
The peritoneal and pleural cavities develop from a common sac that is separated by the diaphragm, and residual communications such as congenital diaphragmatic defects may persist after birth. 1,2Passage of CO2via the esophageal aortic or Bochdalek gap has been implicated in the development of bilateral pneumothorax occurring during gynecologic laparoscopy. 3,4However, in such circumstances, pneumothorax usually quickly resolves because of the high CO2solubility. In the present case, passage of N2from the peritoneum to the pleura because of intraperitoneal insufflation of N2under high pressure was the more-likely mechanism of the pneumothorax.
The laser machine had a line delivering N2at 3 × 760 mmHg for cooling of the optical lens. In this device, N2flows to cool the lens only when the laser fires, and the N2line must be used only during external treatment (during internal use, the lens is cooled by CO2). Normally, the CO2line, not the N2line, is connected to the operator trocar, and the apparatus delivering the CO2limits the pressure to safe levels. In the present case, the N2line, instead of the CO2line, was inadvertently connected to the trocar (fig. 1).
Consequently, when the laser started to fire, N2was insufflated into the peritoneal cavity under extremely high pressure (instead of the appropriate insufflation pressure of 15 mmHg), resulting in 55-mmHg tension pneumoperitoneum followed immediately by bilateral tension pneumothorax, hypotension, and bradycardia. It can also be speculated that the inadvertent use of N2to cool the laser resulted in longer-lasting pneumothorax than that which would be expected with CO2.
It is important to respect the procedures for the use of laparoscopic devices to prevent the occurrence of such life-threatening events caused by technical errors.