Wann G L, Tsai C S, Lin S H, Huang W D, Chu P, Chen G S, Lin Y F
Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China.
ASAIO J. 1998 Sep-Oct;44(5):M569-73. doi: 10.1097/00002480-199809000-00052.
Dry weight evaluation is generally made from clinical observation of body weight (BW) changes, edema, blood pressure, and chest radiograph. In fact, 25-50% of patients on chronic hemodialysis had an incorrectly determined dry weight. To predict dry weight, twenty stable patients on regular hemodialysis were enrolled to investigate the correlation among dry weight, hematocrit, blood volume (BV), and vasoactive hormones including plasma renin activity (PRA), aldosterone (PA), and cyclic 3',5'-guanosine monophosphate (cGMP) values. BV was estimated by an infrared light reflection method. PRA, PA, and plasma cGMP were determined by commercial radioimmunoassay kits. The results showed significantly decreasing plasma cGMP values toward the end of hemodialysis compared with before hemodialysis (15.76 +/- 3.56 pmol/ml vs 33.57 +/- 3.98 pmol/ml; p < 0.05). A significant correlation exists between changes in plasma cGMP values and BV (p < 0.05). In addition, no significant correlation exists between changes in plasma cGMP and BW. A good correlation was found between changes in BV and hematocrit throughout dialysis (r = -0.774; p < 0.001). PRA and PA values predict neither BV nor BW changes. All patients were treated to attain a further ultrafiltration of 0.5 to 1.0 L after reaching dry weight, and we found that the critical point in blood pressure drop occurred when BV decreased by 8% or when plasma cGMP values decreased by 50% from their initial values. Continuous BV monitoring with infrared light reflection and detecting of cGMP throughout hemodialysis could help predict dry weight and avoid dialysis hypotension.
干体重评估通常通过对体重（BW）变化、水肿、血压和胸部X光片的临床观察来进行。事实上，25%-50%的慢性血液透析患者的干体重被错误判定。为了预测干体重，招募了20名接受定期血液透析的稳定患者，以研究干体重、血细胞比容、血容量（BV）以及血管活性激素（包括血浆肾素活性（PRA）、醛固酮（PA）和环磷酸鸟苷（cGMP）值）之间的相关性。BV通过红外光反射法估算。PRA、PA和血浆cGMP通过商用放射免疫分析试剂盒测定。结果显示，与血液透析前相比，血液透析结束时血浆cGMP值显著下降（15.76±3.56 pmol/ml对33.57±3.98 pmol/ml；p<0.05）。血浆cGMP值的变化与BV之间存在显著相关性（p<0.05）。此外，血浆cGMP的变化与BW之间不存在显著相关性。在整个透析过程中，BV变化与血细胞比容之间存在良好的相关性（r=-0.774；p<0.001）。PRA和PA值既不能预测BV变化，也不能预测BW变化。所有患者在达到干体重后接受进一步超滤0.5至1.0 L的治疗，我们发现当BV从初始值下降8%或血浆cGMP值从初始值下降50%时，血压下降的临界点出现。在整个血液透析过程中，通过红外光反射连续监测BV并检测cGMP，有助于预测干体重并避免透析低血压。
