不同压力的持续气道正压对单肺通气时肺内分流及氧合的影响

Effects of CPAP with different positive pressures on oxygenation and intrapulmonary shunt during one-lung ventilation

目的观察单肺通气期间非通气侧肺实施不同大小的持续气道正压(CPAP)对肺内分流及氧合的影响。方法60例ASAⅠ-Ⅱ级择期开胸行肺叶切除手术病人,随机分为三组,每组20例。A组,对照组;B组,单肺通气时,非通气侧肺给予5cmH2O的CPAP;C组,单肺通气时,非通气侧肺给予8cmH_2O的CPAP。分别于单肺通气前,单肺通气30min,单肺通气结束,恢复双肺通气30min,测动脉血测血气分析,根据公式计算肺内分流率。结果单肺通气30min及单肺通气结束时,B、C两组PaO2较A组高,Qs/Qt较A组降低(P<0.05)。B、C两组间各时点参数比较差异无显著性。但C组病人术中肺膨胀明显,对手术操作有一定影响。结论单肺通气期间非通气侧肺实施5cmH2O及8cmH2OCPAP可明显提高氧分压,减少肺内分流,5cmH2O的CPAP更有利于手术操作,临床实用价值更高。

Objective To observe the changes of oxygenation and intrapulmonary shunt during one-lung ventilation（OLV） with different CPAPs. Methods Sixty ASA class Ⅰ or Ⅱ patients undergoing pneumonectomy were randomly divided into three groups with 20 cases each. The now ventilated lung was kept open to the air during OLV in group A, 5 crn H2O and 8 cm H2O CPAP were administered to the non-ventilated lung during OLV in group B and group C, respectively. Blood gases of all patients were analyzed before OLV, at 30 min, the end of OLV and 30 rnin after restoring two- lung ventilation. The shunt ratio（Qs/Qt） was calculated. Results Compared with that before OLV, PaO2 was decreased and Qs/Qt was increased significantly（P〈0. 05） during OLV in group A. There were no significant defferences in PaO2 and （Qs/Qt） during OLV between group B and group C. Condusiun Both of 5 cm H2O and 8 cm H2O CPAP added to the non-ventilated lung during OLV can reduce intrapulmonary shunt and prevent hypoxemia. But 5 cm H2O CPAP is more suitable for surgical procedure.