3700m高原地区体外循环围术期肺功能变化的研究

PERIOPERATIVE ALTERATIONS OF PULMONARY FUNCTION AFTER CARDIOPULMONARY BYPASSAT AN ALTITUDE OF 3700 METERS

目的 :观察高原地区体外循环 (CPB)围术期呼吸指数 (RI)、肺顺应性等肺功能指标的动态变化 ,探讨肺动脉高压与CPB后肺功能变化的关系 ;方法 :选择 2 0 0 1年 6月至 2 0 0 1年 7月在海拔 370 0m高原地区开展的CPB心内直视手术患者 1 0例 ,根据术前肺动脉平均压 (MPAP) ,将患者分成肺动脉高压组 (n =5,术前MPAP >2 .6 6kPa)和对照组 (n =5,术前MPAP≤ 2 .6 6kPa)。各组均分别于CPB前、主动脉开放后 5分钟、CPB结束时以及CPB后 6 0分钟、1 2 0分钟、1 80分钟 ,测定气道平台压 (PPLATEAU)、气道峰压 (PPEAK)、胸肺顺应性 (Cs)、动态肺顺应性 (Cd)和RI的变化 ;结果 :无早期死亡。与CPB前相比 ,肺动脉高压组在主动脉开放后 5分钟至CPB后1 80分钟 ,其PPLATEAU、PPEAK和RI均显著升高 (P <0 .0 5) ,Cs、Cd均明显降低 (P <0 .0 5) ;对照组在主动脉开放后 5分钟至CPB后 1 2 0分钟 ,其PPLATEAU、PPEAK和RI亦较CPB前显著增加 ,Cs、Cd明显降低 ,但在CPB后 1 80分钟上述各指标均恢复至CPB前水平 (P >0 .0 5) ;与对照组相比 ,主动脉开放后 5分钟、CPB结束时以及CPB后 6 0分钟、1 2 0分钟、1 80分钟 ,肺动脉高压组PPLATEAU、PPEAK和RI均明显升高 (P <0 .0 5) ,而Cs、Cd明显降低 (P <0 .0 5) ;结论

Objectives:To evaluate the effect of cardiopulmonary bypass (CPB) on perioperative pulmonary compliance and respiratory index (RI) and to elucidate the influence of pulmonary hypertension (PH) on pulmonary function after CPB in children at high altitude.Methods:Ten patients of congenital heart defect (CHD), who underwent operative repair under CPB between June 2001 and July 2001 in Lhasa at an altitude of 3 700 meters, were prospectively classified into two groups according to preoperative mean pulmonary arterial pressure (MPAP): PH group(n=5) with the preoperative MPAP>2.26kPammHg and control group (n=5) with the MPAP≤2.26kPa.There were 6 Tibetan and 4 Tibetan-born Hans with a mean age of 4.4 years (2～12 years).Plateau airway pressure (P PLATEAU ), peak airway pressure (P PEAK ), RI, static pulmonary compliance (Cs) and dynamic pulmonary compliance (Cd) were respectively measured or calculated after induction of anesthesia, 5minutes after aortic unclamping,and 5,60,120,180 minutes after weaning CPB. Results:There was no operative death. P PLATEAU , P PEAK as well as RI were statistically elevated (P<0.05) and Cs and Cd significantly reduced (P<0.05) during and 120 min after CPB in either group when compared before CPB. However, in control group the P PLATEAU , P PEAK , RI, Cs and Cd were recovered 180 min after CPB while in PH group these parameters did not improved.Moreover,the changes of P PLATEAU ,P PEAK , RI,Cs and Cd in PH group were significantly greater than those in control group (P<0.05).Conclusion:CPB conducted at the high altitude can result in a significant acute lung injury. Pulmonary hypertension may exaggerate the post-CPB pulmonary dysfunction.