及时应用经胸超声心动图评估可改善重症监护室患者急性肾损伤发生后的临床预后

Timely utilization of transthoracic echocardiography can improve clinical outcomes after acute kidney injury in intensive care unit patients

目的探讨经胸超声心动图(transthoracic echocardiography,TTE)评估对重症监护室(intensive care unit,ICU)患者发生急性肾损伤(acute kidney injury,AKI)后住院预后的影响。方法回顾性收集美国重症监护医学信息数据库(MIMIC⁃Ⅲv1.4)中AKI患者的临床资料,并根据患者是否在AKI诊断24 h内行TTE分为TTE组和非TTE组(No⁃TTE组,未行TTE检查或首次TTE检查超过24 h),采用倾向性评分匹配法(propensity score matching,PSM)平衡两组患者基本资料的差异,采用Cox回归分析AKI患者住院28 d全因病死(主要终点事件)的独立危险因素。PSM匹配后,分析TTE对患者次要终点事件(第1、2、3天静脉输液量、尿量,28 d内无机械通气、血管加压药和肾脏替代治疗的时间,利尿剂使用,48 h内血肌酐下降幅度,ICU住院时间及住院时间)的影响。结果23945例AKI患者中有3365例(14.1%)在AKI诊断24 h内进行了TTE评估,两组患者按照1∶1匹配后最终各有3361例患者被纳入本研究,匹配后两组患者各指标均衡性较好(标准均数差均<0.1)。PSM匹配前后,TTE组患者住院28 d全因病死率均明显低于No⁃TTE组(10.76%比13.04%,χ^(2)=13.535,P<0.001;10.65%比18.80%,χ^(2)=88.932,P<0.001)。以住院28 d全因病死作为终点事件,Kaplan⁃Meier生存曲线结果显示TTE组患者的累积生存率在匹配前后均明显高于No⁃TTE组(Log⁃rankχ^(2)=15.438,P<0.001和Log⁃rankχ^(2)=75.360,P<0.001)。多因素Cox回归分析结果显示,匹配前后TTE均是患者住院28 d全因病死的独立影响因素(HR=0.80,95%CI 0.73~0.89,P<0.001;HR=0.58,95%CI 0.51~0.65,P<0.001);各亚组分析亦显示,匹配前后TTE均是患者住院28 d全因病死的独立影响因素。PSM匹配后,TTE组患者诊断AKI后第1天及第2天静脉输注量明显高于No⁃TTE组(均P<0.01),第1天及第3天尿量也明显高于No⁃TTE组(均P<0.01),28 d内无机械通气时间及无血管加压药时间均显著低于No⁃TTE组患者(均P<0.01),使用利尿剂比例显著高于No⁃TTE组(54.1%比44.2%,χ^(2)=65.609,P<0.001),48 h内血肌酐下降幅度也显著高于No⁃TTE组[36.6(23.0,97.2)μmol/L比30.1(14.2,61.9)μmol/L,Z=-9.549,P<0.001],ICU住院时间也显著低于No⁃TTE组[5.03(3.40,8.90)d比5.37(3.77,10.00)d,Z=-6.589,P<0.001],其他次要终点事件两组间差异无统计学意义(均P>0.05)。结论ICU患者AKI发病后及时有效的TTE评估可显著改善危重症患者的预后。

Objective To investigate the effect of usage of transthoracic echocardiography(TTE)on the prognosis of patients after acute kidney injury(AKI)in intensive care unit(ICU).Methods The clinical data of patients with AKI in the Medical Information Mart for Intensive Care(MIMIC⁃Ⅲv1.4)database was collected retrospectively,and the patients were divided into TTE group(with TTE within 24 hours of AKI diagnosis)and No⁃TTE group(without TTE examination or first TTE examination was more than 24 hours after AKI diagnosis).Propensity score matching(PSM)was utilized to balance the baseline variables between the two groups and Cox regression analysis was used to evaluate the independent risk factors for 28⁃day all⁃cause mortality(the primary outcome).Moreover,after PSM,the effects of TTE usage on the second outcomes(including the volumes of intravenous fluid and urine output in the first,second and third 24⁃hour after the diagnosis of AKI;the total number of mechanical ventilation⁃free days,renal replacement therapy⁃free days and vasopressor⁃free days within 28 days after ICU admission;use of diuretics after the diagnosis of AKI;reduction in serum creatinine within 48 hours after the diagnosis of AKI;and the length of ICU stay and hospital stay)were also evaluated.Results Among 23945 eligible AKI patients,3365 patients(14.1%)patients received TTE within 24 hours after the diagnosis of AKI and finally there were 3361 patients in TTE group and No⁃TTE group included in this study after PSM based on the ratio of 1∶1.After PSM,all variables in the two groups were well balanced(standardized mean difference<0.1,respectively).Before and after PSM,patients in TTE group had lower 28⁃day all⁃cause mortality compared with patients in No⁃TTE group(10.76%vs 13.04%,χ^(2)=13.535,P<0.001;10.65%vs 18.80%,χ^(2)=88.932,P<0.001),and Kaplan⁃Meier survival curves also revealed that patients in the TTE group had higher cumulative survival rate compared with patients in No⁃TTE group(Log⁃rankχ^(2)=15.438,P<0.001;Log⁃rankχ^(2)=75.360,P<0.001,respectively).Multivariate Cox regression analysis showed that TTE was an independent influencing factor for 28⁃day all⁃cause mortality before and after PSM(HR=0.80,95%CI 0.73-0.89,P<0.001;HR=0.58,95%CI 0.51-0.65,P<0.001).And all subgroup analyses showed the similar results.Compared with patients in the No⁃TTE group,patients in the TTE group had higher volume of intravenous fluid on the first day and the second day after the diagnosis of AKI(both P<0.01).Patients in the TTE group had higher volume of urine output on the first day and the third day after the diagnosis of AKI(both P<0.01).The patients in the TTE group had a significantly lower duration of vasopressor⁃free and mechanical ventilation⁃free(both P<0.01).The usage of diuretic was significantly higher in the TTE group compared with that in the No⁃TTE group(54.1%vs 44.2%,χ^(2)=65.609,P<0.001).With respect to serum creatinine,the reduction in serum creatinine within 48 hours after the diagnosis of AKI was higher in the TTE group than that in the No⁃TTE group[36.6(23.0,97.2)μmol/L vs 30.1(14.2,61.9)μmol/L,Z=-9.549,P<0.001].Moreover,TTE group had shorter ICU stay than that in the No⁃TTE group[5.03(3.40,8.90)d vs 5.37(3.77,10.00)d,Z=-6.589,P<0.001].There were no significant difference between the two groups in other secondary outcomes(all P>0.05).Conclusions Timely TTE utilization after AKI incident is associated with better clinical outcomes for ICU patients.