The Effect Of Two Types Of Mechanical Ventilation Modes On Obese Patients Undergoing Gynecologic Laparoscopic Surgery In Respiratory Function

Objective To investigate the effect of two types of mechanical ventilation modes on obese patients undergoing gynecologic laparoscopic surgery on patients hemodynamics, respiratory mechanics, arterial oxygenation.Method 40 obese patients undergoing gynecological laparoscopic surgery were randomly divided into pressure-controlled ventilation group (PCV) and volume-controlled ventilation group (VCV), 20 cases in each group.Two groups of patients were all implemented a standardlized program of total intravenous anesthesia, and ventilationed respectively with different programs. End-tidal carbon dioxide partial pressure PetCO2 should maintained at between 35-45mmHg, airway pressure as low as possible.At 5 min before anesthesia (T0), 5 min prior to the start of pneumoperitoneum(T1), 30min after pneumoperitoneum (T2), 5 min after pneumoperitoneum lifting (T3), 5 min prior to removal of endotracheal tube (T4), arterial blood was respectively collected to analysis blood gas,and parameters were monitored and calculated,including hemodynamic parameter:systolic pressure,diastolic pressure,mean arterial pressure,central venous pressure , heart rate ; blood gas analysis parameter: pH value,pressure of arterial carbon dioxide,pressure of arterial oxygen,alveolar arterial oxygen difference, Oxygenation index ; respiratory mechanic parameter:peak airway pressure,airway plateau pressure,the average airway pressure,peak flow rate,end-tidal carbon dioxide partial pressure, total respiratory dynamic compliance, Vd/Vt.Results 1. There were no significant differences in patient characteristics in the two groups (p>0.05).2. Compared with T0, both groups after pneumoperitoneum at 30min (T2) BP, HR, CVP was significantly increased (p<0.05); Compared with the VCV group, BP, HR, CVP in PCV group had no statistically significant difference at each time point (p> 0.05 ).3. Compared with the VCV group, PaO2, OI in PCV group at T1, T2, T3 were higher (p<0.05); A-aDO2, RI in PCV group at T1, T2, T3 was significantly lower than VCV group (p<0.05).4. Compared with T0, at (T2) 30min after pneumoperitoneum, (T3) 5 min after pneumoperitoneum lifting, and (T4)5 min prior to removal of endotracheal tube in both groups, PaCO2 increased significantly and pH value decreased significantly (p<0.05); Compared with the VCV group, PCV group had no statistically significant difference at each time point (p>0.05).5.Compared with the VCV group, Ppeak in PCV group at (T2) period after pneumoperitoneum was lower (p<0.05).6. Compared with the VCV group, Pplateau, Pmean, Cdyn in PCV group at each time point had no significant difference (p> 0.05).7. Compared with the VCV group, peak flow in PCV group at the time point T1, T2, T3 were higher (p<0.05).Conclusion 1.Compared with VCV, PCV in obese patients undergoing laparoscopic surgery improved the ratio of ventilation flow, and promoted gas exchange. 2.The use of PCV ventilation mode did not increase stress, not cause hemodynamic side-effect, and not affect the CO2 emission.