双瓣膜置换患者围术期心排血量与呼出气二氧化碳的关系

Relationship Between Cardiac Output and End-tidal Carbon Dioxide Tension in Patients During and after Mitral and Aortic Double Valve Replacement

目的 探讨双瓣膜置换术患者围术期心排血量监测 ,提高手术安全性和预测患者预后 ,及时调整治疗方案。 方法 根据 Fick原理将呼出气二氧化碳 (ETCO2 )监测用于估计患者围术期心排血量 (CO) ,并与有创性温度稀释法进行比较。将 1991年 10月以来随机选择 2 0例双瓣膜置换患者分为两组 ,对照组 :使用常规心肌保护液 ;用药组 :常规心肌保护液中加入山莨菪碱 ,30 mg/L。常规体外循环 ,冠状窦逆行灌注 ,分别于麻醉前、转流前、转流结束、手术结束、术后 2小时、4小时、8小时、12小时和 2 4小时测定心脏指数 (CI)、左心室收缩做功指数 (L VSWI)、右心室收缩做功指数 (RVSWI)、肺血管阻力 (PVR)、全身血管阻力 (SVR)、ETCO2 、动脉血二氧化碳分压 (Pa CO2 )。 结果 对照组恢复心脏灌注后 CO的增加与 ETCO2 变化无相关关系 ,用药组 CO增加较对照组显著 ,且与 ETCO2 密切相关 ,CO的变化与 ETCO2 在各时点的变化呈正相关 (P<0 .0 5 ) ;同时对照组在心脏复跳后 Pa CO2 持续增加与术前及同时间用药组相比有差异 (P<0 .0 5 )。 结论 山莨菪碱可改善肺循环 ,减少分流 ,可使 ETCO2 正确地反映 CO变化 ,是一种既无创 ,又方便、经济并能连续进行 CO监测的方法。

Objective\ In order to improve quality of perioperative care and to predict the outcome for patients undergoing mitral and aortic double valve replacement(DVR), we tried to utilize end tidal carbon dioxide (ETCO 2), according to Fick's principle to estimate cardiac output(CO) with comparsion by conventional invasive thermodilution method.\ Methods\ Since Oct. 1991, 20 patients with DVR were selected randomly.Control group( n=10) conventional cardioplegia and medicative group( n=10) with anisodamine 30mg/L in cardioplegic solution. Cardiopulmonary bypass(CPB) was carried out routinely. Swan Ganz catheter was inserted into pulmonary artery and retrograde coronary sinus perfusion was used in all patients. Cardiac index(CI),left ventricular stroke work index (LVSWI),right ventricular stroke work index(RVSWI),systemic vascular resistance (SVR),pulmonary vascular resistance(PVR), ETCO 2, arterial partial pressure of arterial carbon dioxide (PaCO 2) were measured at preanaesthetic, prebypass, end of bypass, end of operation, postoperative 2 hours, 4 hours, 8 hours, 12 hours and 24 hours.\ Results Using anisodamine in cardioplegic solution, correlation between ETCO 2 and CO was found consistent and positive, while in the control group intrapulmonary shunt might play an important role in interferring this correlationship.\ Conclusion\ Anisodamine can improve the pulmonary circulation, reduce intrapulmonary blood shunt and render ETCO 2 to reflect CO change more correctly.