Clin Nephrol. 2021;96(1):74-79. doi: 10.5414/CNP96S13.
Arterial stiffness represents an independent risk factor for cardiovascular mortality in dialysis patients and is strongly connected to hypervolemia. The aim of the study was to evaluate different methods for fluid status assessment and their association with arterial stiffness parameters in peritoneal dialysis patients.
In 16 peritoneal dialysis patients (53 ± 18 years, 9/16 men) fluid status was determined by clinical examination, lung ultrasound (number of B-lines, normal up to 4), overhydration degree by bioimpedance monitor device, estimation of central venous pressure by ultrasound measurement of vena cava inferior, measurement of serum N-terminal pro b-type natriuretic peptide (NT-proBNP), and albumin level. Pulse wave velocity and augmentation index were measured non-invasively with an oscillometric device to indirectly assess arterial stiffness, blood pressure (BP) was obtained by the same device.
Clinical evaluation (BP 136 ± 15/93 ± 15 mmHg, edema in 2/16 patients) and lung ultrasound (on average 3 ± 6 B-lines) showed mostly normal fluid status of patients. Patients had slightly lower albumin values (37 ± 4 g/L), slightly elevated central venous pressure (10 ± 4 mmHg), and elevated NT-proBNP (11,596 ± 13,635 ng/L). Body composition evaluation showed mild overhydration (1.5 ± 2 L), which significantly correlated with central venous pressure (p = 0.046) and NT-proBNP (p = 0.004). Lung ultrasound significantly negatively correlated with albumin (r = -0.82, p < 0.001) and positively with NT-proBNP (r = 0.62, p = 0.011). Augmentation index (22 ± 11%) and augmentation pressure correlated with lung ultrasound (r = 0.54, p = 0.032 and r = 0.67, p = 0.004, respectively), although pulse wave velocity (8.4 ± 2.5 m/s) showed no significant correlation with fluid status parameters. The multivariate model showed that lung ultrasound B-lines were an independent determinant of augmentation pressure (β = 0.58, p = 0.043).
Fluid status evaluated with lung ultrasound showed good correlation with augmentation index and augmentation pressure, which are markers of arterial stiffness. The lung ultrasound B-lines were found to be an independent determinant of augmentation pressure. Overall arterial stiffness evaluated with pulse wave velocity and augmentation index was not markedly elevated in our patients, which could be due to a good euvolemic status. We conclude that different methods for fluid status evaluation are complementary, with lung ultrasound as a beneficial tool in routine clinical practice in peritoneal dialysis patients.
动脉僵硬是透析患者心血管死亡率的独立危险因素，与血容量过多密切相关。本研究的目的是评估不同的液体状态评估方法及其与腹膜透析患者动脉僵硬参数的关系。
在 16 名腹膜透析患者（53 ± 18 岁，9/16 名男性）中，通过临床检查、肺部超声（B 线数量，正常<4 条）、生物电阻抗监测仪评估的超滤液量、超声测量下腔静脉评估中心静脉压、测量血清 N 末端 pro B 型利钠肽（NT-proBNP）和白蛋白水平来确定液体状态。使用振荡测量仪无创性地测量脉搏波速度和增强指数，间接评估动脉僵硬，使用相同的设备测量血压（BP）。
临床评估（BP 136 ± 15/93 ± 15mmHg，16 例患者中有 2 例出现水肿）和肺部超声（平均 3 ± 6 条 B 线）显示患者的液体状态基本正常。患者的白蛋白值略低（37 ± 4g/L），中心静脉压略高（10 ± 4mmHg），NT-proBNP 升高（11596 ± 13635ng/L）。身体成分评估显示轻度血容量过多（1.5 ± 2L），与中心静脉压（p=0.046）和 NT-proBNP（p=0.004）显著相关。肺部超声与白蛋白呈显著负相关（r=-0.82，p<0.001），与 NT-proBNP 呈显著正相关（r=0.62，p=0.011）。增强指数（22 ± 11%）和增强压与肺部超声呈正相关（r=0.54，p=0.032 和 r=0.67，p=0.004），而脉搏波速度（8.4 ± 2.5m/s）与液体状态参数无显著相关性。多元模型显示，肺部超声 B 线是增强压的独立决定因素（β=0.58，p=0.043）。
使用肺部超声评估的液体状态与增强指数和增强压具有良好的相关性，而增强指数和增强压是动脉僵硬的标志物。肺部超声 B 线被发现是增强压的独立决定因素。我们的患者整体动脉僵硬程度（通过脉搏波速度和增强指数评估）没有明显升高，这可能是由于患者处于良好的血容量状态。我们得出结论，不同的液体状态评估方法是互补的，肺部超声是腹膜透析患者常规临床实践中的有益工具。
