Abstract: Objective: To evaluate the diversity of thoracic fluid content (TFC) in dialysis patients before and after HD using the noninvasive hemodynamic monitor and to investigate its clinical application in modulating a suitable dry weight (DW). Methods: Thirty-seven patients were selected and divided into two groups based on their blood pressure: 18 patients with controlled hypertension (group A) and 19 patients with hypertension that was difficult to control (Group B). Sixteen healthy volunteers were enrolled in the control group (group C). A noninvasive hemodynamic monitor was utilized to determine the variation of thoracic fluid content (TFC), weight, systolic blood pressure (SBP), diastolic blood pressure (DBP) and ultra-filtration volume in patients before and after HD. The dry weight and volume of ultra-filtration were gradually modulated when TFC levels were above normal. Patients were re-evaluated with a noninvasive hemodynamic monitor 4 weeks after the initial assessment. SPSS software was used to analyze the data. Results: (1) The TFC level was significantly higher in groups A and B than in group C before HD (P＜0.05), and was dramatically reduced following HD in groups A and B. The TEC level in group B was still significantly higher than in group C. However, it decreased to normal after the dry weight and ultrafiltration volume were modified. The DBP/SBP were significantly reduced (P＜0.05) after the initial HD and eventually returned to a normal range 4 weeks after HD. (2) The post-HD TFC level in group B correlated well with the reduced mean arterial pressure (P＜0.01). The difference of the reduced TFC levels between the initial post-HD and post-HD after modification correlated well with the decreased BP post-HD (P＜0.01). Conclusion: The noninvasive hemodynamic monitoring method can be effectively used to evaluate the volume state in patients requiring HD, and has a significant clinical value in determining a suitable dry weight for these patients.

Key words: Hemodynamics, Dry weight, Hemodiafiltration