人体成分分析对接受连续性肾脏替代治疗的急性肾损伤患者预后的预测价值

目的探讨人体成分分析测定的营养及液体负荷指标对住院需行连续性肾脏替代治疗(CRRT)的急性肾损伤(AKI)患者预后的预测价值。方法连续纳入自2016年9月至2018年9月在江苏省人民医院住院的严重AKI患者,行CRRT前、CRRT治疗后第7天常规测定人体成分。按照CRRT后28d是否存活分为死亡组和生存组,使用Cox回归分析28d生存与瘦体重指数(LTI)、脂肪组织指数(FTI)、细胞外液(ECW)与体细胞质量(BCM)比值(ECW/BCM)、水分过多(OH)的关系。结果共纳入156例患者,其中男性101例,年龄(62.7±15.4)岁,序贯器官衰竭估计评分(SOFA)9.9±3.9,28d病死率为46.2%。28d生存组和死亡组CRRT前OH值分别为2.95(1.80,5.50)L和4.20(2.95,5.70)L(P=0.016),ECW/BCM值分别为1.00(0.76,1.18)和1.07(0.88,1.25)(P=0.033),两组间差异均有统计学意义。单因素Cox回归分析结果显示,CRRT前高OH值(HR=1.08,95%CI1.00~1.17,P=0.040)、CRRT前高ECW/BCM比值(HR=3.02,95%CI1.46~6.22,P=0.003)与28d死亡显著相关;开始CRRT后第7天的OH值和首次CRRT治疗前OH的差值(HR=0.83,95%CI0.72~0.95,P=0.008)以及对应时间点的ECW/BCM差值(HR=6.79,95%CI1.72~26.82,P=0.006)与CRRT治疗7d内生存患者的28d死亡显著相关。经校正年龄、性别、SOFA评分,多因素Cox回归分析结果提示CRRT前高OH值(HR=1.16,95%CI1.06~1.27,P=0.002)、CRRT前高ECW/BCM比值(HR=2.80,95%CI1.30~6.06,P=0.009)、CRRT第7天与CRRT前OH差值(HR=0.82,95%CI0.72~0.95,P=0.008)、CRRT第7天与CRRT前ECW/BCM差值(HR=2.79,95%CI1.30~5.98,P=0.009)均与28d死亡相关,而CRRT前LTI(HR=0.93,95%CI0.86~1.02,P=0.113)、FTI(HR=0.98,95%CI0.92~1.04,P=0.475)与28d死亡无明显相关。结论开始CRRT前人体成分分析测定的高OH、高ECW/BCM与AKI患者28d死亡相关,而营养指标LTI、FTI与AKI患者28d死亡相关不明显。在7d内通过CRRT纠正液体超负荷状态可减少28d死亡风险。

Assessment of fluid and nutritional status using bioelectrical impedance methods in acute kidney injury patients requiring continuous renal replacement therapy

Objective To investigate the predictive value of nutritional and fluid status measured by bioelectrical impedance methods for the prognosis of acute kidney injury (AKI) patients undergoing continuous renal replacement therapy (CRRT). Methods Patients with severe AKI received CRRT in the First Affiliated Hospital of Nanjing Medical University from September 2016 to September 2018 were enrolled, and divided into death group and survival group according to 28-day survival. Cox regression was used to analyze the association between 28-day survival and lean tissue index (LTI), fat tissue index (FTI), the ratio of extracellular water (ECW) and body cell mass (BCM) (ECW/BCM), and overhydration (OH), respectively. Results A total of 156 patients were included, including 101 males and 55 females. The age was (62.7±15.4) years, with sequential organ failure assessment (SOFA) score of 9.9±3.9. The 28-day mortality rate was 46.2%. The pre-CRRT OH values in the 28-day survival group and death group were 2.95(1.80, 5.50) L and 4.20(2.95, 5.70) L(P=0.016), and ECW/BCM values were 1.00(0.76, 1.18) and 1.07(0.88, 1.25) (P=0.033), respectively. Univariate Cox regression analysis showed that pre-CRRT high OH values (HR=1.08, 95%CI 1.00-1.17, P=0.040) and high ECW/BCM values (HR=3.02, 95%CI 1.46-6.22, P=0.003) were associated with 28-day death. The changes of OH values (HR=0.83, 95%CI 0.72-0.95, P=0.008) and ECW/BCM values (HR=6.79, 95%CI 1.72-26.82, P=0.006) between pre-CRRT and the 7th day after CRRT initiation were significantly associated with 28-day mortality in patients who survived 7 days after CRRT initiation. After adjusting for age, gender, and SOFA scores, multivariate Cox regression analysis showed that the high OH value (HR=1.16, 95%CI 1.06-1.27, P=0.002) and the high ECW/BCM value (HR=2.80, 95%CI 1.30-6.06, P=0.003) before CRRT, the change of OH value (HR=0.82, 95%CI 0.72-0.95, P=0.008) and ECW/BCM value (HR=2.79, 95%CI 1.30-5.98, P=0.009) between the 7th day after CRRT initiation and pre-CRRT, were independently associated with 28-day death, while LTI (HR=0.93, 95%CI 0.86-1.02, P=0.113) and FTI (HR=0.98, 95%CI 0.92-1.04, P=0.475) before CRRT were uncorrelated with 28-day death. Conclusions In bioelectrical impedance analysis, the high OH value and high ECW/BCM value before CRRT are associated with 28-day mortality in patients with AKI, while the nutritional indicators LTI and FTI before CRRT are not significantly related. The correction of fluid overload by CRRT within 7 days may reduce the risk of 28-day mortality.