Chronic kidney disease may progress to end-stage renal disease, a stage in which the kidneys will no longer be able to adequately remove extra fluid and waste products from the body. Many patients with end-stage renal disease will require regular dialysis to survive. Conventional hemodialysis is the most commonly used dialysis technique and will mainly remove waste products through diffusion. Hemodiafiltration is another dialysis technique that will combine diffusion with convection and may help remove a wider range of waste substances from the blood.

This randomized clinical trial will compare hemodiafiltration with conventional hemodialysis in adult patients with end-stage renal disease who are already receiving maintenance dialysis. Eligible participants will be assigned by random allocation to either conventional hemodialysis or hemodiafiltration. Both treatments will be provided as part of routine dialysis care, and no experimental drug will be used.

The main purpose of the study will be to determine whether hemodiafiltration will lead to better fluid control compared with conventional hemodialysis. Fluid control will be assessed by measuring the average weight gained between dialysis sessions over a four-week period. The study will also compare selected blood test parameters between the two groups after one month, including hemoglobin, C-reactive protein, serum albumin, total cholesterol, serum calcium, serum phosphate, and intact parathyroid hormone.

Inclusion Criteria:

• Adult patients aged 18-70 years.
• Both male or female.
• End-stage kidney disease as per operational definition.
• On a stable dialysis prescription for at least 3 months, with thrice-weekly sessions (or unit-standard schedule) and stable dry weight assessment.
• Clinically stable over the preceding 4 weeks, with no hospitalization or acute intercurrent illness.

Exclusion Criteria:

• Cardiovascular instability: recurrent intradialytic hypotension (≥30% of sessions in the prior month requiring saline or early termination), uncontrolled hypertension (SBP >180 mmHg or DBP >110 mmHg despite therapy), recent acute coronary syndrome, stroke, or decompensated heart failure within 3 months.
• Advanced hepatic disease (decompensated cirrhosis or refractory ascites), active systemic infection, chronic inflammatory disease flare, or active malignancy under treatment likely to confound fluid status or survival.
• Recent blood transfusion within the preceding 4 weeks, or active bleeding, as these may distort hemoglobin and inflammatory indices.
• Advanced chronic liver disease, nephrotic-range protein loss, or other conditions likely to substantially alter serum albumin independent of dialysis modality.
• Parathyroidectomy history or current use of intravenous calcimimetics initiation/change within the preceding 4 weeks, if expected to markedly alter intact parathyroid hormone.
• Adherence concerns: documented inability to follow fluid/salt advice or to attend scheduled treatments during the screening period; anticipated surgery or hospitalization within the study window.