Risk factors for hypercarbia, subcutaneous emphysema, pneumothorax, and pneumomediastinum during laparoscopy

Objective: To determine independent predictors for the development of hypercarbia, subcutaneous emphysema, pneumothorax, and pneumomediastinum during laparoscopy. Methods: We reviewed 968 laparoscopic cases between January 1, 1997, and December 31, 1998. Patients who had hypercarbia (end-tidal carbon dioxide of 50 mmHg or greater), pneumothorax/pneumomediastinum, and subcutaneous emphysema were compared with controls according to age, operative time, type of surgery, extraperitoneal or intraperitoneal approach, preexisting medical conditions, body mass index, sex, use of Hasson technique, and number of surgical ports. Maximum positive end-tidal CO2 (PETCO2) was added as an independent variable for subcutaneous emphysema, pneumothorax, and pneumomediastinum. Data were analyzed using univariate analysis and then subjected to multivariate analysis using multiple logistic regression analysis. Results: Incidence rates were 5.5% for hypercarbia, 2.3% for subcutaneous emphysema, and 1.9% for pneumothorax/ pneumomediastinum. Independent risk factors for development of hypercarbia were operative time greater than 200 minutes (odds ratio [OR] 2.02), patient age greater than 65 years (OR 2.19), and Nissen fundoplication surgery (OR 3.18). Predictors of the development of subcutaneous emphysema were PETCO2 greater than 50 mmHg (OR 3.49), operative time greater than 200 minutes (OR 5.27), and the use of six or more surgical ports (OR 3.06). Variables that predicted the development of pneumothorax and/or pneumomediastinum were PETCO2 greater than 50 mmHg (OR 4.15) and operative time greater than 200 minutes (OR 20.49). Conclusion: Longer operative times, higher maximum measured end-tidal CO2, greater number of surgical ports, older patient age, and Nissen fundoplication surgery predispose patients to hypercarbia-related complications during laparoscopy. (Obstet Gynecol 2000;95:704-9. (C) 2000 by The American College of Obstetricians and Gynecologists.).