Variables associated with lung congestion as assessed by chest ultrasound in diabetics undergoing hemodialysis

Abstract Introduction: Ultrasound is an emerging method for assessing lung congestion but is still seldom used. Lung congestion is an important risk of cardiac events and death in end-stage renal disease (ESRD) patients on hemodialysis (HD). Objective: We investigated possible variables associated with lung congestion among diabetics with ESRD on HD, using chest ultrasound to detect extracellular lung water. Methods: We studied 73 patients with diabetes as the primary cause of ESRD, undergoing regular HD. Lung congestion was assessed by counting the number of B lines detected by chest ultrasound. Hydration status was assessed by bioimpedance analysis and cardiac function by echocardiography. The collapse index of the inferior vena cava (IVC) was measured by ultrasonography. All patients were classified according to NYHA score. Correlations of the number of B lines with continuous variables and comparisons regarding the number of B lines according to categorical variables were performed. Multivariate linear regression was used to test the variables as independent predictors of the number of B lines. Results: None of the variables related to hydration status and cardiac function were associated with the number of B lines. In the multivariate analysis, only the IVC collapse index (b = 45.038; p < 0.001) and NYHA classes (b = 13.995; p = 0.006) were independent predictors of the number of B lines. Conclusion: Clinical evaluation based on NYHA score and measurement of the collapsed IVC index were found to be more reliable than bioimpedance analysis to predict lung congestion.

摘要：超声是评估肺淤血的新兴检测手段，但目前仍未得到广泛应用。肺淤血是接受血液透析（Hemodialysis, HD）的终末期肾病（End-stage renal disease, ESRD）患者发生心脏事件及死亡的重要危险因素。
研究目的：本研究通过胸部超声检测肺细胞外水含量，探讨接受血液透析的糖尿病型终末期肾病患者的肺淤血相关影响因素。
研究方法：本研究纳入73例以糖尿病为终末期肾病首要病因、接受规律性血液透析的患者。采用胸部超声计数B线（B lines）数量以评估肺淤血程度；通过生物电阻抗分析（bioimpedance analysis）评估患者水合状态，经超声心动图（echocardiography）评估心功能；超声测量下腔静脉（Inferior vena cava, IVC）塌陷指数，并依据纽约心脏协会（New York Heart Association, NYHA）心功能分级对所有患者进行分组。分析B线数量与连续型变量的相关性，并按分类变量比较B线数量的组间差异；采用多元线性回归检验各变量作为B线数量独立预测因素的效能。
研究结果：本研究中，所有与水合状态及心功能相关的变量均与B线数量无显著关联。多元线性回归分析结果显示，仅下腔静脉塌陷指数（b=45.038；p<0.001）与NYHA心功能分级（b=13.995；p=0.006）为B线数量的独立预测因素。
研究结论：本研究结果表明，基于NYHA心功能分级与下腔静脉塌陷指数的临床评估，在预测肺淤血方面较生物电阻抗分析更为可靠。