Carbon dioxide for obstetric pneumoperitoneum.

To the Editor-Dr. Rosen’ provides a comprehensive review of anes thesia for the pregnant surgical patient, including some recommendations for the increasingly frequent procedure of laparoscopy during pregnancy. One of his recommendations is the use of nitrous oxide in place of carbon dioxide for establishing pneumoperitoneum. This is a major departure from current clinical practice and deserves better supporting evidence than any provided in Dr. Rosen’s review. His sole reference regarding obstetric laparoscopy is a study of the Swedish Health Registry from 1973-1993,’ which compares complications of laparotomy with complications of laparoscopy. That article does not describe details of laparoscopic technique. However, one of the same authors’ published a 1997 survey of 16,329 laparoscopic surgeons that reported details of 413 laparoscopic cases during pregnancy, and 100% of those cases used carbon dioxide for pneumoperitoneum. During pregnancy, special care should be taken to keep the intraabdominal pressure low (less than 15 mmHg) and maintain maternal normocapnia. Using these precautions, for several important reasons, including noncombustibility and easy, rapid elimination, carbon dioxide is the gas of choice for creating pneumoperitoneum.