心脏瓣膜置换手术死亡风险模型与体外膜肺氧合代替体外循环的适应证探讨

目的 建立心脏瓣膜病术前评估的死亡风险模型,并对手术病人进行评估,对体外膜肺氧合(ECMO)代体外循环的适应证进行初步探讨.方法 对4482例心脏瓣膜置换手术病人进行回顾性分析,选取性别,年龄,术前左心室射血分数(EF)、左心室舒张末径、肺动脉压、肾功能和是否合并冠心病7个临床指标作为住院死亡的可能影响因素.利用单因素分析进行筛选,用多因素Logistic回归确立死亡风险模型.根据模型,对此后的瓣膜病病人术前进行死亡风险评估,死亡概率≥10%的病例,随机分别给予常规手术或ECMO代替体外循环、术后转为心肺辅助.比较两种方法的手术病死率.采用SPSS11.5统计软件进行检验(α=0.05).结果 单因素分析除性别之外,其余6个因素均有统计学意义.Logistic回归建立死亡风险模型为Ln(P/1-P)=-4.3742+0.5192肾功能+0.1467年龄+0.3947EF+0.9390冠心病+0.5888肺动脉压+0.3287左室舒末径.此后常规手术52例,ECMO代体外循环术后转心肺辅助22例,两组性别、年龄、预计病死率构成比差异无统计学意义.两组预计病死率分别为(16.35±4.3)%和(16.21±5.19)%,差异无统计学意义(P<0.05).实际病死率分别为30.76%(16/52例)和9.09%(2/22例),差异有统计学意义(Pearson Chi-Square,P=0.047).结论 心脏瓣膜置换术前死亡风险评估,高龄、左心室低EF值、左室舒张末径过大或过小、肺动脉高压、肾功能不良、合并冠心病是危险因素,可以计算预计确切死亡概率.利用心脏瓣膜病死亡风险模型,对高风险(10%以上)病人进行ECMO代体外循环、术后转为心肺辅助,有利于降低手术病死率.

Heart valve replacement surgery mortality risk model and the use of extracorporeal membrane oxygenation as a replacement to cardiopulmonary bypass

Objective To form a scoring model to predict the risk of in-hospital mortality of patients undergoing heart valve replacement. Subsequently, we attempt to assess whether the mortality of patients undergoing heart valve procedure can be decreased by performing earlier ECMO support named replaced extracorporeal circulation of ECMO (REC-ECMO) once patients condition predicted severe by this model preoperatively. Methods We retrospectively reviewed the medical records of 4482 critically ill patients in the database of Anzhen Hospital in Beijing, who underwent cardiac valve replacement from January 1994 to December 2004. Several demographic, clinical, and laboratory variables were retrospectively gathered as predicators of death. A scoring model predicting the risk of postcardiotomy mortality were established, in which variables that were statistically significant (P < 0.05) in the univariate analysis were included in multivariate analysis by applying a multiple logistic regression. The predicted mortality of patients who were going to receive heart valve replacement was calculated using this model. Those whose predicted mortality were more than 10% received valve procedure with normal extracorporeal circulation or REC-ECMO respectively. The difference of the observed mortality were tested by applying Pearson Chi-Square (α = 0.05). Results Six out of seven selected variables that were statistically significant in the univariate analysis were included in multivariate analysis. The risk of mortality according to scoring model was: Ln(P/1-P)=-4.3742+0.5192 renal function + 0.1467 age+ 0.3947 EF+0.9390 CAD +0.5888 PAP+ 0.3287 LVEDD. The predicted mortality of This two groups had no significant difference[(16.35± 4.3) % vs( 16.21 ± 5.19) %, P < 0.05]. While the observed mortality differed significantly(Pearson Chi-Square, P =0.047, P <0.05) and was 30.76%(16/52)and 9.09%(2/22) respectively. Conclusion A risk of postoperative valve replacement mortality can be predicted before the procedure is performed by using our scoring model. Patients with predicted mortality more than 10% by the scoring model gain lower observed mortality if REC-ECMO rather than normal extracorporeal circulation is used.