不同压力呼气末正压对单肺通气时肺内分流及氧合的影响

目的观察单肺通气(OLV)期间通气侧肺实施不同大小的呼气末正压通气(PEEP)对肺内分流及氧合的影响。方法45例ASAⅠ～Ⅱ级择期在全麻下行肺叶切除手术病人,随机分为3组,每组15例。A组为不采用PEEP的OLV对照组;B组为OLV PEEP(5cmH2O)组;C组为OLV PEEP(8cmH2O)组。各组病例于OLV前、OLV后30min、OVL结束、恢复双肺通气后30min进行动脉血气分析,根据公式计算肺内分流率(QS/QT)。结果OVL30min及OVL结束时,B、C两组的PaO2较A组高,QS/QT较A组低(P<0.05);B、C两组各时点参数比较差异无统计学意义(P>0.05)。结论OVL期间通气侧肺实施5cmH2O及8cmH2O的PEEP可明显提高PaO2,减少肺内分流;5cmH2O的PEEP有利于手术操作,临床实用价值更高。

Observation of the effects of pulmonary shunt fraction and oxygenation in one lung ventilation with different pressure PEEP

Objective To observe the effects of pulmonary shunt fraction and oxygenation in one lung ventilation(OLV)with different positive end-expiratory pressure(PEEP)during pulmonary lobectomy.Methods Forty five adult patients proceeding pulmonary lobectomy were performed under three modes of ventilation:OLV with PEEP 0 cmH2O(group A),5 cmH2O(group B) and 8cmH2O(group C).The arterial blood gas analysis was monitored at different time before and after OVL,30 min after OVL and recovery two-lung ventilation respectively.Accoerding to the formula we calculated pulmonary shunt fracion(QS/QT).Results At the end of OVL and 30 min after OVL,PaO2 were increased in group B and C,while QS/QT were decreased(P<0.05),there were no differences between group B and C.Conclusion OLV with PEEP 5 or 8 cmH2O could improve the arterial oxygenation,dcrease the pulmonary shunt fracion;PEEP 5 cmH2O is benificial to operative procedure,it is more effective in clinical practicing.