Efficacy of Positive Pressure Ventilation with the ProSeal Versus Classic Laryngeal Mask Airway during Gynecologic Laparoscopic Surgery

Kim, Eun Sung; Kim, Young Hun

Abstract

BACKGORUND: Previous studies have shown that the ProSeal laryngeal mask airway (PLMA) forms a more effective seal than the classic laryngeal mask airway (LMA) during a static oropharyngeal leak test and isolates the respiratory tract from the gastrointestinal tract when correctly positioned, but there is no evidence that it is a better ventilatory device. in the present study, we tested the hypothesis that the PLMA is a more effective ventilatory device than either the LMA or the endotracheal tube (ETT) in healthy anesthetized females undergoing gynecologic laparoscopic surgery at 120 ml/kg minute ventilation volume with the cuff fully inflated.
METHODS
We studied 34 female patients (ASA physical status i, 22-46 yr) undergoing gynecologic laparoscopic surgery. Patients were randomized into three groups according to ventilatory devices; Group 1 (ETT, n = 11), Group 2 (LMA, n = 12) and Group 3 (PLMA, n = 11). After induction of anesthesia, patients were ventilated in the same mode in each group. We measured peak inspiratory pressure (PiP), PaO2, PaCO2, PETCO2 and arterial end-tidal PCO2 difference (PaCO2-PETCO2) at 10 min after induction of anesthesia (stage 1), 10 min after CO2 insufflation (stage 2), 10 min after Trendelenburg (T) position (stage 3) and 30 min after T position (stage 4).
RESULTS
There were no significant differences among the three groups in PaCO2, PETCO2, and PiP. PaCO2 , PETCO2 and PiP increased significantly at stages 2 through 4 compared to stage 1 (P<0.05). PaO2 decreased significantly at stage 4 compared to stage 1 (P<0.05). PaCO2-PETCO2 was maintained within normal range from stage 1 to stage 4.
CONCLUSiONS
This study demonstrates that pulmonary gas exchange is not affected by the choice of ventilatory devices during gynecologic laparoscopic surgery in young female patients under a Trendelenburg position and pneumoperitoneum.