Maintenance hemodialysis
72 MHD patients were randomly divided into an observation group and a control group (36 each). Computer-generated block randomisation (block size 6) was used with allocation concealed with sequentially numbered opaque sealed envelopes. Intervention: Dynamic positioning dialysis nursing model guided by relative blood volume monitoring, including passive leg raising during ultrafiltration and sequential tilt/sitting posture adjustment during blood reinfusion, delivered 3 times weekly over 3 months. Comparator: Standard maintenance haemodialysis with fixed supine position and no positional intervention. Using the Fresenius 4008S dialyzer's relative blood volume (RBV) monitoring, the control group stopped ultrafiltration when the RBV curve dropped sharply, while the observation group maintained PLR. If the RBV curve rebounded, ultrafiltration was resumed with an extra 150–500 ml; if it plateaued, the current weight was set as provisional DW. The study compares the overhydration (OH), total body water (TBW), extracellular water (ECW), intracellular water (ICW), as well as the systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) at the start of dialysis, the end of ultrafiltration, and the end of dialysis blood reinfusion between the two groups. Over 3 months, indicators like IDH incidence, ultrafiltration adjustments, overhydration (OH), TBW, ECW, ICW and DW compliance rate were compared.
1. MHD duration of more than 6 months 2. Independent in daily activities 3. Receiving regular HD sessions three times per week
1. Patients with fractures, spinal deformities, or impaired self-care ability 2. History of severe hepatic, pulmonary, or neurological diseases 3. Body mass index (BMI) <18.5 kg/m² (underweight)