不同通气模式对Trendelenburg体位腹腔镜手术患者PaO_2和PaCO_2的影响

目的探讨压力控制通气(PCV)联合呼气末正压(PEEP)在Trendelenburg体位腹腔镜手术中对PaO_2和PaCO_2的影响。方法腹腔镜直肠癌根治术患者40例,年龄35~55岁,随机分为两组,每组20例。A组采用容量控制通气模式(VCV)通气VT=体重(kg)×10ml]20min后,改用PCV模式通气20min,返回VCV模式继续通气20min后,采用PCV+低PEEP(5cm H_2O)模式通气20min。B组则将PCV与PCV+PEEP的顺序调换。在切换通气模式时行动脉血气分析。结果两组VCV模式时PaO_2均明显低于PCV模式及PCV+PEEP模式(P0.05)。PCV模式时PaO_2明显低于PCV+PEEP模式(P0.05);VCV模式时PaCO_2明显高于PCV模式和PCV+PEEP模式(P0.05),而PCV模式和PCV+PEEP模式时PaCO_2差异无统计学意义。VCV模式时动脉血pH值明显低于PCV和PCV+PEEP模式(P0.05),PCV和PCV+PEEP模式时动脉血pH值差异无统计学意义。结论 Trendelenburg体位腹腔镜手术时采用PCV+PEEP通气模式,与单纯VCV或单纯PCV模式比较,在提高PaO_2以及降低PaCO_2方面更具优势。

Effect of different modes of ventilation on PaO2 and PaCO2 in laparoscopic surgery in the Trendelenburg position

Objective To investigate the effects of different ventilation modes on PaCO 2 and PaO 2 during laparoscopic surgery in the Trendelenburg position.Methods Forty cases of laparoscopic resection of rectal cancer were randomly divided into group A (n =20)and group B (n =20).Under general anesthesia,all the cases were in volume-controlled ventilation mode (VCV,tidal volume=10 ml/kg)before pneumoperitoneum.After ventilating in VCV mode for 20 minutes with a lower tidal volume (8 ml/kg),group A was converted to PCV mode for 20 minutes and then back to the VCV mode for 20 minutes again.Next we switched to PCV combined with PEEP (5 cm H 2 O)mode (PCV+PEEP)for 20 minutes.In group B,we only alternated PCV with PCV combined with PEEP.Arte-rial blood-gas analysis was obtained at each time when ventilating mode changed.Results In both group A and B,PaO 2 in VCV mode was less than that in PCV mode and PCV+PEEP mode (P <0.05),PaO 2 in PCV mode was also less than that in mode PCV+PEEP mode (P <0.05).PaCO 2 in PCV and PCV combined with PEEP mode was less than that in VCV mode (P <0.05 ),and there was no difference of PaCO 2 in PCV mode and PCV+PEEP mode.The pH value in VCV mode was less than that in PCV mode and PCV+PEEP mode (P < 0.05).There was no difference in pH value between PCV mode and PCV+PEEP mode.Conclusion PCV combined PEEP mode is beneficial ei-ther in increasing or decreasing of PaCO 2 during laparoscopic surgery in the Trendelenburg position comparing with single VCV mode or PCV mode.