呼吸末二氧化碳在危重病患者代谢性紊乱中预测价值

目的:探讨呼吸末二氧化碳(ETCO2)在急危重患者代谢性紊乱中的预测价值。方法:分析2011-06-2011-09急诊入住武汉大学人民医院重症医学科的100例患者,入院后使用碳酸波形图监测初始ETCO2值,ETCO2监测完毕以后迅速抽血做血气分析监测HCO3值。统计数据并分析ETCO2和HCO3值的关系,同时比较分析存活组和死亡组以及HCO3≤21mmol/L和HCO3>21mmol/L的病例ETCO2和HCO3值的关系。结果:ETCO2和HCO3中度相关(R=0.593),死亡组ETCO2和HCO3值较存活组均明显减低,HCO3≤21mmol/L组ETCO2较HCO3>21mmol/L组低,差异有统计学意义。ETCO2可反映HCO3的水平,ROC曲线下面积是0.754(95%CI:0.659～0.850),ETCO2=32.5mmHg时,灵敏度=0.65,特异度=0.85,Youden指数=0.5,阳性似然比=4.3,阴性似然比=0.5,ETCO236.5mmHg时,特异度均在95%以上,甚至等于1。结论:碳酸波形图监测的ETCO2值作为一种无创的诊断工具,可有效预测危重症患者代谢性紊乱的发生,为临床评估患者的危重程度提供有力的证据,并为临床治疗的时机提供及时性的指导。

ETCO2:The predicative value of metabolic disturbances in critical patients

Objective:To discuss ETCO2’s predictive value of metabolic disturbances in critical patients.Method:100 patients admitted in ICU of People’s Hospital of Wuhan University from 2011-6 to 2011-9 were analyzed in this study.After admission,every critical patient had a simultaneous ETCO2 measurement using capnography.Then,blood gas analysis monitoring HCO3 value was taken quickly.The relationship between ETCO2 and HCO3 in survival and dead group,HCO3≤21 mmol/l and HCO3>21 mmol/l group was comparative analyzed.Result:There was a moderate correlation between the value of ETCO2 and HCO3 levels(r=0.593).The mean ETCO2 and HCO3 level were significantly lower in patients who died.The value of ETCO2 measurement for detecting low bicarbonate level was found to be significant.The area under the receiver operating characteristic curve was 0.754(95% CI,0.659~0.850).When ETCO2=32.5 mmHg,Sensitivity=0.65,Specificity=0.85,Youden index=0.5,LR(+)=4.3,LR(-)=0.5.When ETCO2 36.5 mmHg,all specificity are more than 95% and even reached 1.Conclusion:As a noninvasive diagnostic tool,ETCO can effectively predict the occurrence of metabolic disorders in critical patients,and can provide powerful evidence for evaluating the severity of patients.ETCO can provide timeliness guidance for clinical treatment.