Zaluska W T, Schneditz D, Kaufman A M, Morris A T, Levin N W
Department of Medicine, Beth Israel Medical Center, New York, New York, USA.
ASAIO J. 1998 Nov-Dec;44(6):823-7. doi: 10.1097/00002480-199811000-00011.
Whole body bioimpedance is considered helpful in monitoring the removal of excess body water by ultrafiltration in hemodialysis patients. In this study, the cumulative, estimated decrease in extracellular volume (V(est)) modeled from whole body bioimpedance data was compared with measured volume (Vmeas) removed by ultrafiltration (UFR = 1.01 +/- 0.31 L/hr) in 12 patients during 36 high efficiency hemodialysis treatments. In the mean, estimated (V(est) = 3.0 +/- 1.4 L) and measured volumes (Vmeas = 3.4 +/- 1.1 L) correlated linearly: V(est) = 1.05 x Vmeas - 0.60, r2 = 0.68. Patients developed hypotension in half the treatments. Except for a larger decrease in systolic blood pressures in hypotensive (34 +/- 24 mmHg) vs. stable (14 +/- 15 mmHg) treatments, patient and treatment characteristics were not different between groups. However, at the end of hemodialysis, the difference V(est) - Vmeas was -0.8 +/- 0.9 L in hypotensive, and only 0.1 +/- 0.4 L in stable patients (p < 0.05). The difference between V(est) and Vmeas can be explained by a predominant removal of excess body water from central body compartments such as the trunk and the central blood volume during hypotension. These compartments are not adequately measured by whole body bioimpedance techniques. However, this information could be helpful in identifying patients with delayed peripheral fluid removal that may occur when either target weight is too low or UFR rates are too high.
全身生物电阻抗被认为有助于监测血液透析患者通过超滤去除多余身体水分的情况。在本研究中，对12例患者在36次高效血液透析治疗期间，根据全身生物电阻抗数据建模得到的细胞外液体积（V(est)）的累积估计减少量与超滤去除的测量体积（Vmeas）（超滤率=1.01±0.31L/小时）进行了比较。平均而言，估计体积（V(est)=3.0±1.4L）与测量体积（Vmeas=3.4±1.1L）呈线性相关：V(est)=1.05×Vmeas - 0.60，r2=0.68。半数治疗中患者出现低血压。除了低血压治疗组（34±24mmHg）与稳定治疗组（14±15mmHg）的收缩压下降幅度更大外，两组患者及治疗特征无差异。然而，在血液透析结束时，低血压患者的V(est)-Vmeas差值为-0.8±0.9L，而稳定患者仅为0.1±0.4L（p<0.05）。V(est)与Vmeas之间的差异可解释为低血压期间主要从身体中心腔室（如躯干和中心血容量）去除了多余的身体水分。这些腔室无法通过全身生物电阻抗技术进行充分测量。然而，这些信息可能有助于识别那些外周液体清除延迟的患者，这种情况可能发生在目标体重过低或超滤率过高时。
