The effects of ventilation mo des of pressure and volume on respiratory function of obese patients undergoing gynecologic laparoscopic surgery

Abstract

Objective To investigate the effects of pressure -controlled ventilation (PCV) and volume -controlled ventilation (VCV) on obese patients undergoing gynecologic laparoscopic surgery by evaluating hemodynamics and respiratory parameters, and arterial oxygenation. Methods Forty obese patients undergoing gynecological laparoscopic surgery were randomly divided into PCV and VCV group (n=20). Patients were all implemented into the program of total intravenous anesthesia, and ventilated with different modes.End-tidal carbon dioxide partial pressure (PETCO2) was maintained between(35-45 ) mm Hg. Arterial blood was collected respectively to analyze blood gas at 5 min before anesthesia (T0), 5 min before the start of pneumoperitoneum (T1),30 min after the start of pneumoperitoneum(T2), 5 min after the end of pneumoperitoneum(T3) and at extubation(T4). Meanwhile, parameters of hemodynamics and respiratory mechanics were monitored and calculated. Results 1 、At T1,T2 and T3, PaO2 and OI (460±78,453±83,463±95)were significantly higher in PCV group (P<0.05), A-aDO2(74±25,80±30,82±26) and RI (0.32±0.08,0.33±0. 10,0.34±0.13 ) was significantly lower (P<0.05) in PCV group. 2. Compared with T0, PaCO2 at T2,T3,T4 in both groups increased significantly and PH decreased significantly (P<0.05); Compared with VCV group, PCV group had no significant difference at each time point. 3. Compared with VCV group, Ppeak(27.8±1.6)in PCV group at T2 was significantly lower(P<0.05). Conclusion The ventilation/perfusion ratio was improved and gas exchange was promoted in obese patients undergoing gynecologic laparoscopic surgery with PCV model. Key words: Laparoscopy; Gynecology; Obesity; Ventilation; Respiratory mechanics