Comparison of carbon dioxide and room air pneumoperitoneum for day-case diagnostic laparoscopy. 
Laparoscopic examination is useful in the evaluation of infertile women.  To perform this test, pneumoperitoneum is required to distend the abdomen, improve visibility and displace the intestines out of the pelvis.  Several gases have been used to achieve this purpose including nitrous oxide (N2O), carbon dioxide (CO2), helium, xenon and air.  This is a prospective study in a private fertility centre comparing CO2 and room air pneumoperitoneum for diagnostic laparoscopy.  Also the safety of room air was evaluated.  One hundred and forty five patients received CO2 (group 1, n=73) or room air (group 2, n=72) pneumoperitoneum.  Ketamine anaesthesia was used for all the patients and the cost of the procedure was same for the study.  CO2 pneumoperitoneum offered better visibility during laparoscopy and the patients also had a better outcome: Wound infection (CO2-2/73: 2.7% Vs.  Air-11/72: 15.3%); abdominal discomfort (feeling of retained gas in the abdomen) CO2-5/73: 6.9% Vs.  Air-61/72: 84.7%) and shoulder pain (CO2-0/73; 0.0% Vs.  Air-56/72: 77.8%).  Group 1 patients returned to normal activity earlier (1.5 days +/- 1.3 SD Vs.  4.8 days +/- 2.1 SD).  We conclude that CO2 pneumoperitoneum has a better outcome than Air especially for day-case diagnostic laparoscopy.  However, room Air pneumoperitoneum is safe, cheap, and available and may be recommended for low resource settings.