肾脏替代治疗时机对急性肾损伤患者病死率的影响——两项随机对照研究的再分析

The timing of renal replacement therapy on mortality in patients with acute renal injury： a reanalysis of two recently published randomized control trials

探讨两项关于急性肾损伤（AKI）患者接受肾脏替代治疗（RRT）时机的临床研究（AKIKI研究和ELAIN研究）出现不同结局的原因。AKIKI研究入选了620例符合AKI 3期、需要机械通气/升压药物治疗的无危及生命并发症的AKI患者，随机分为RRT早期组和RRT延迟组，RRT早期组患者在入组后即刻行RRT，RRT延迟组待患者出现高钾血症、严重代谢性酸中毒、肺水肿或入组后少尿持续超过72 h方开始行RRT。研究终点为60 d全因病死率。ELAIN研究入选了231例AKI 2期患者，随机分为RRT早期组和RRT延迟组，RRT早期组患者在诊断AKI 2期后8 h内开始RRT，RRT延迟组患者在诊断AKI 3期后12 h内开始RRT。研究终点为90 d全因病死率。对比2项研究患者的疾病特征、病情严重程度、肾功能水平等。结果显示，AKIKI研究入组的多为内科患者（约占80%），而ELAIN研究入组的均来自外科，ELAIN研究患者合并高血压、充血性心力衰竭的比例及序贯器官衰竭评分（SOFA）显著高于AKIKI研究。尽管ELAIN研究RRT早期组患者病死率较RRT延迟组显著降低（39.3%比54.7%），但ELAIN研究RRT延迟组28 d、60 d病死率（40.3%、50.4%）与AKIKI研究RRT早期组、延迟组28 d和60 d病死率（41.6%、43.5%和48.5%、49.7%）比差异无统计学意义（P〉0.05）。两项研究结局不同的关键因素是研究群体的异质性，包括研究对象的疾病特征和肾损伤程度（AKI分期）。

To investigate the sources of inconsistent findings between two randomized control trials[＂initiation strategies for renal-replacement therapy in the intensive care unit＂（AKIKI trial） vs＂effect of early vs delayed initiation of renal replacement therapy on mortality in critically ill patients with acute kidney injury＂（ELAIN trial） ], regarding＂timing of renal replacement therapy （RRT） on mortality in patients with acute kidney injury （AKI）. By reanalysis of the published data, it was found that demographics, severity of primary disease and stage of AKI before initiation of RRT were quite different between AKIKI and ELAIN trials. Interestingly, similar mortalities were demonstrated in late group of ELAIN trial, both of early and late groups of AKIKI trial [all patients were classified at Kidney Disease： Improving Global Outcomes （KDIGO） classification stage 3 of AKI, P〉0.05] although a significant reduction of mortality was determined in early group of ELAIN trial （KDIGO stage 2 of AKI）.Therefore, it was concluded that inconsistent results were largely attributable to the heterogeneity of enrolled patients between ELAIN vs AKIKI trials, including demographics and severity of AKI（AKI stage） before initiation of RRT.