Comparison of Carbon Dioxide Absorption Rates in Gynecologic Laparoscopy with a Valveless versus Standard Insufflation System: Randomized Controlled Trial

STUDY OBJECTIVE: The primary objective was to compare carbon dioxide (CO2) absorption rates in patients undergoing gynecologic laparoscopy with a standard versus valveless insufflation system (AirSeal; ConMed, Utica, NY) at intra-abdominal pressures (IAPs) of 10 and 15 mm Hg. Secondary objectives were assessment of surgeons\u27 visualization of the operative field, anesthesiologists\u27 ability to maintain adequate end-tidal CO2 (etCO2), and patients\u27 report of postoperative shoulder pain. DESIGN: A randomized controlled trial using an equal allocation ratio into 4 arms: standard insufflation/IAP 10 mm Hg, standard insufflation/IAP 15 mm Hg, valveless insufflation/IAP 10 mm Hg, and valveless insufflation/IAP 15 mm Hg. SETTING: Single tertiary care academic institution. PATIENTS: Women \u3e/= 18 years old undergoing nonemergent conventional or robotic gynecologic laparoscopic surgery. INTERVENTIONS: A standard or valveless insufflation system at IAPs of 10 or 15 mm Hg. MEASUREMENTS AND MAIN RESULTS: One hundred thirty-two patients were enrolled and randomized with 33 patients per group. There were 84 robotic cases and 47 conventional laparoscopic cases. CO2 absorption rates (mL/kg*min) did not differ across groups with mean rates of 4.00 +/- 1.3 in the valveless insufflation groups and 4.00 +/- 1.1 in the standard insufflation groups. The surgeons\u27 rating of overall visualization of the operative field on a 10-point Likert scale favored the valveless insufflation system (median visualization, 9.0 +/- 2.0 cm and 9.5 +/- 1.8 cm at 10 and 15 mm Hg, respectively) over standard insufflation (7.0 +/- 3.0 cm and 7.0 +/- 2.0 cm at 10 and 15 mm Hg, respectively; p .05). CONCLUSION: CO2 absorption rates, anesthesiologists\u27 ability to maintain adequate etCO2, and postoperative shoulder pain did not differ based on insufflation system type or IAP. Surgeons\u27 rating of visualization of the operative field was significantly improved when using the valveless over the standard insufflation system