血动态乳酸预测重症监护患者预后的临床价值

Clinical value of serial blood lactic acid monitoring in prognostic prediction for ICU patients

目的探索血动态乳酸测定在重症监护室（ICU）患者病情预后预测中的价值。方法2004年1月至2005年12月因呼吸衰竭、急性心肌梗死、感染性休克等原因入住ICU者110例，对其住院24h内各项生理参数和实验室检查结果的最差值进行急性生理及慢性健康状况评估系统（APACHEⅡ）评分，同时测定动脉血乳酸。此后，每24h复查一次，动态观察血乳酸水平和APACHEⅡ评分，分析乳酸清除率与APACHEⅡ评分的相关性，比较乳酸水平和APACHEⅡ评分预测预后的准确性。结果死亡48例，病死率43．6％；入院后乳酸增高组、不变组、进行性下降组病死率分别为89．7％（26／29）、66．7％（18／27）和7．4％（4／54）；乳酸清除率与相应时段的APACHEⅡ分值差相关（r=0．836，P=0．000）；乳酸清除率较APACHEⅡ变化值对预后的贡献大，其OR值分别为2．21和1．26；APACHEⅡ、乳酸的受试者工作特征曲线（ROC曲线）下面积分别为0．863和0．900。结论血乳酸清除率和APACHEⅡ均能够灵敏反映患者的预后，两者的相关性好；由于APACHEⅡ需要评估的指标多，不方便临床运用。血乳酸动态检测简单、快速，更具有实用性。

Objective To investigate the clinical value of serial blood lactic acid monitoring in predicting prognosis for ICU patients. Method Physiological parameters and arterial blood lactate level of 110 patients suffered from respiratory failure （RF）, acute myocardial infarction （AMI）, infectious shock, and so on admitted to ICU of the 12th Hospital, Guangzhou during January 2004 to December 2005 were measured 24 h within admission, as well as their acute physiology and chronic health evaluation Ⅱ （APACHE Ⅱ）score was evaluated according to their worst physiological parameters or results of laboratory examinations at the same time. Those measurements were repeated every 24 h. Relationship between lactate clearance rate and APACHE Ⅱ scores was evaluated for predicting prognosis of the patients. Results Forty-eight of 110 patients died during hospitalization, with a case-fatality of 43.6%. There were 89. 7% （26/29）, 66.7% （18/27） and 7. 4% （4/54） fatalities for those with progressive increasing, stable and progressive reducing blood lactate levels, respectively. Lactic acid clearance rate correlated with difference of APACHE Ⅱ scores at the same times （r =0. 836, P =0. 000）. Lactate clearance contributed more than APACHE Ⅱ scores in predicting the patients＇prognosis, with ORs of 2.21 and 1.26, respectively, and with areas under the ROC curve of 0. 863 and 0. 900 for the APACHE Ⅱ score and blood lactic acid level, respectively. Conclusions Both serial blood lactic acid monitoring and APACHE Ⅱ scoring can reflect the prognosis of ICU patients sensitively. And, they correlate each other well in evaluating patients＇ prognosis. But, APACHE Ⅱ scoring system is not so convenient and too complicated for clinical use because too many variables are needed in evaluation. Serial blood lactic acid monitoring is simple, easy and practical to use in predicting prognosis of ICU patients sensitively.