A randomized controlled trial to determine the effect of humidified carbondioxide (CO2) insufflation on postoperative pain following thoracoscopic procedures

Background: It has previously been shown that the insufflation of humidifie d gas during laparoscopy results in less postoperative pain than is observe d following the use of dry gas. Experimental evidence also suggests that dr y gas insufflation during thoracoscopy results in greater structural injury to the pleura than occurs with the use of humidified gas. The present stud y was designed to determine the effect of humidified gas insufflation on po stoperative pain following thoracoscopic procedures. Methods: Forty consecutive patients were prospectively randomized. Twenty p atients were insufflated with humidified carbon dioxide (CO2), and 20 contr ol patients received standard dry CO2. Results: The patients' analogue pain score was significantly lower followin g humidified gas insufflation compared to dry gas insufflation when assesse d at 6 h postoperatively, as well as on the 1st, 2nd, 3rd, and 14th postope rative days. The postoperative morphine consumption was lower in the humidi fied group than it was in the control group. The incidence of respiratory c omplications was identical for both groups. Conclusion: The use of humidified gas appears to reduce postoperative pain but not the rate of respiratory complications.