体外循环术后患者早期液体平衡及其相关因素的回顾性研究

A retrospective study about the factors of early postoperative fluid balance of patients undergoing cardiopulmonary bypass

目的探讨体外循环术后早期液体平衡的影响因素及其对患者早期预后的影响。方法采用便利抽样法收集2012年1月至2015年12月在中山大学孙逸仙纪念医院心脏外科体外循环下行心血管手术180例患者的资料。采用SPSS17．0统计软件进行数据录入及统计分析。结果体外循环术后早期液体平衡为（540．94±135．86）ml；应用ROC曲线预测体外循环术后液体平衡与临床转归的定量关系，液体平衡[（总人量-总出量）／体质量]ROC曲线下面积为0．850（95％C10．736-0．965，P〈0．01），其敏感度为80．0％，特异度为84．6％，提示预测效果良好。根据最大Youden指数得出最佳临界点为28．63ml/kg，即体外循环术后早期液体平衡为28．63ml／kg时，患者预后良好的可能性最大；体外循环术后早期液体平衡水平与患者术后混合静脉血氧饱和度、机械通气时间、ICU停留时间及临床转归有关（P〈0．05）。欧洲心脏手术风险评估系统Ⅱ（EuroSCOREⅡ）评分、其他（多种方式混合）手术类型、体质量指数、术后早期尿量、术后引流量是体外循环术后早期液体平衡的独立影响因素。结论体外循环术后早期液体平衡对于预测患者预后情况具有重要意义；体外循环术后早期液体平衡与术后早期混合静脉血氧饱和度水平、术后机械通气时间、急性肾损伤的发生率、ICU停留时间及临床转归有关；其最佳临界值为28．63ml／kg，高于该值提示出现预后不良的可能性增加；体质量指数、EuroSCOREⅡ评分、其他手术类型、术后早期尿量，术后早期引流量是体外循环术后液体平衡的独立影响因素。

Objective To explore the possible factors of early postoperative fluid balance and the influence of early postoperative fluid balance on the prognosis of patients undergoing cardiopuhnonary bypass. Methods A retrospective study was conducted on the clinical data of 180 adult patients undergoing cardiopulmonary bypass from January 2012 to December 2015.All the patients were from Sun Yat-sen Memorial Hospital, Sun Yat-Sen University. The data were input and analyzed by SPSS 17.0 software. Results The early postoperative fluid balance of cardiovascular surgery with cardiopulmonary bypass was （540.94±135.86） ml. The value of the early postoperative fluid balance （the difference of the total input amount and the total output amount/body quality） in predicting the major clinical outcome was analyzed by ROC curve. The area under the ROC curve from fluid balance was 0.850 （95% CI 0.736- 0.965, P 〈 0.01） and it had the sensitivity of 80.0%, and the specificity was 84.6%. The result showed that the cut off values had a good prediction ability for outcome. The cut off values determined by the biggest Youden index were 28.63 ml/kg, indicated that patients may had better outcome when they had the fluid balance of 28.63 ml/kg. The level of early postoperative fluid balance of patients undergoing cardiopulmonary bypass was correlated with mechanical ventilation time, ICU length of stay, higher risk of acute kidney injury, mixed venous oxygen saturation and clinical outcome （P 〈 0.05）. Multivariate analysis indicated that European System for Cardiac Operative Risk Evaluation Ⅱ （EuroSCORE Ⅱ）, other types of surgery, body mass index, early postoperative urine output and early postoperative drainage flow were independently associated with postoperative fluid balance of patients undergoing cardiopulmonary bypass. Conclusions Early postoperative fluid balance has a good prediction ability for prognosis of patients undergoing cardiopulmonary bypass. Compared with patients having lower level of fluid balance, the patients with a higher level would be more likely to have longer mechanical ventilation time, longer ICU length of stay, higher risk of acute kidney injury and lower level of mixed venous oxygen saturation. By analysis of ROC curves, the cut-off value for early postoperative fluid balance is 28.63 ml/kg, worse prognosis may be predicted if fluid balance is above 28.63 ml/kg. EuroSCORE 1I, other types of surgery, body mass index, early postoperative urine output and early postoperative drainage flow are independently associated with the postoperative fluid balance of patients undergoing cardiopulmonary bypass.