Effect of Trendelenburg position and artificial pneumoperitoneum on change of respiratory mechanics in-dexes due to change of preset airway pressure in PCV / 实用医学杂志

ABSTRACT

Objective In pressure controlled ventilation(PCV),a self-control method was used to ob-serve the change of respiration mechanics indexes under Trendelenburg position and pneumoperitoneum versus su-pine position and non-pneumoperitoneum with preset airway pressure.Methods Thirty patients scheduled for lapa-roscopic radical resection of rectal carcinoma were enrolled in this study.ECG,MAP,SpO2,BIS and body temper-ature were routinely detected. After induction of anesthesia,volume controlled ventilation(VCV)was used as ba-sic ventilation,and then switched to PCV after 5 minutes. The airway pressure was the preset airway pressure be-fore pneumoperitoneum,then was lowered 1 cmH2O in proper order,and then restored preset airway pressure and increased 1 cmH2O. 15 minutes after pneumoperitoneum,the airway pressure of PCV was used as preset airway pressure after pneumoperitoneum,and then the above procedure was repeated.The time interval was at least 5 min-utes.The values of MAP,HR,SpO2,VT and Cdyn were recorded at each time;VT,and Cdyn were continuously recorded five times to take the average value. The postoperative recovery in patients was observed. Results After pneumoperitoneum,the values of Cdyn and VT were significantly reduced(P < 0.01),MAP was increased(P <0.05). When the preset airway pressure changed 1 cmH2O,ΔVT was decreased(P < 0.05),and the change of Cdyn was not statistically significant. Conclusions As altering a unit of the preset airway pressure in PCV,the change in VT is significantly reduced but Cdyn does not change markedly in Trendelenburg posture and artificial pneumoperitoneum,as compared with supine position and non-pneumoperitoneum.