Haemodialysis

The kidneys, when functioning normally, filter roughly 180 litres of blood every 24 hours through millions of tiny filtering units called glomeruli. When this capacity is lost, waste products like urea and creatinine accumulate in the blood, fluid builds up in the lungs and around the ankles, and potassium rises to dangerous levels.

Haemodialysis replicates this filtering process outside the body. Blood is drawn from the patient, passed through a dialyser, which is a machine containing a semipermeable membrane, and returned cleaned. The membrane allows waste and excess fluid to pass into a dialysis solution called dialysate, while keeping blood cells and essential proteins where they belong.

Each session begins with access to the bloodstream. Most patients undergoing regular haemodialysis have a surgically created arteriovenous fistula, typically in the forearm near the wrist or just below the elbow, where an artery and vein are joined to create a larger, higher-flow vessel. Two needles are inserted into this fistula at the start of each session. For patients who are new to dialysis or awaiting fistula maturation, a temporary catheter placed in the internal jugular vein in the neck may be used.

Blood flows out through one needle at approximately 200 to 400 millilitres per minute, passes through the dialyser, and returns through the second needle. The machine simultaneously monitors blood pressure, flow rate, and the composition of fluid being removed.

Sessions typically run three to four hours and are required three times per week in most cases. Some patients with residual kidney function may initially manage with two sessions, but this is assessed individually and adjusted over time.

Many patients tolerate sessions reasonably well once they are established on a routine. That said, certain symptoms are common and worth knowing about in advance.

• Muscle cramps, particularly in the calves and feet, occur when fluid is removed too quickly toward the end of a session
• A drop in blood pressure, felt as dizziness, nausea, or lightheadedness, is one of the most frequent issues and is managed by adjusting the fluid removal rate
• Fatigue in the hours immediately after dialysis is very common and tends to improve as the body adapts over weeks
• Headache and a general feeling of heaviness may occur, particularly in the first few weeks of starting treatment
• Itching, sometimes persistent, is related to phosphate accumulation and usually improves with dietary changes and phosphate binders

Haemodialysis is life-sustaining but not without consequences when continued long-term.

• Fistula-related problems, including clotting, narrowing, or infection at the access site, are among the most common reasons sessions are disrupted
• Infection risk is elevated, particularly with catheter-based access, and requires strict hygiene protocols at the insertion site
• Anaemia develops because damaged kidneys produce less erythropoietin, the hormone that stimulates red blood cell production. Injectable erythropoietin is often prescribed alongside dialysis
• Bone disease from impaired phosphate and calcium regulation may develop gradually and requires monitoring of parathyroid hormone levels
• Cardiovascular complications remain the leading cause of mortality in dialysis patients, making blood pressure control and lipid management central to long-term care

This is the part of dialysis life that patients find most challenging, and understandably so. Between sessions, the kidneys are not clearing fluid or electrolytes, so what you consume accumulates. Fluid intake is typically restricted to 500 to 700 millilitres per day above urine output, if any urine is still being produced. Patients are advised to limit potassium-rich foods, including bananas, oranges, tomatoes, potatoes, and most dals. Phosphate restriction means reducing dairy, nuts, and cola drinks. Sodium restriction helps control thirst and fluid retention between sessions. A renal dietitian works closely with our dialysis team to personalize these recommendations rather than handing patients a generic list.

Regular blood tests are done monthly to track urea, creatinine, potassium, phosphate, calcium, haemoglobin, and parathyroid hormone. Blood pressure is monitored at every session at our Department of Nephrology. Fistula function is assessed periodically. Annual cardiac evaluation is recommended, given the cardiovascular burden that comes with long-term dialysis.

Our dialysis unit at the best haemodialysis hospital in Navi Mumbai – UMC Hospitals has dedicated sessions with trained nephrology nurses and continuous machine monitoring throughout each session. Patients are reviewed regularly by our nephrology team, and care plans are adjusted based on monthly investigations rather than fixed protocols. For patients who are transplant eligible, dialysis is managed as a bridge rather than a permanent solution, with evaluation running in parallel wherever appropriate.