Dialysis

Dialysis is a life-sustaining kidney replacement therapy used in patients with advanced chronic kidney disease (CKD) or acute kidney injury (AKI) when the kidneys are no longer able to adequately remove waste products, excess fluid, and electrolytes or maintain acid-base balance. Dialysis improves survival, relieves symptoms of uraemia, corrects metabolic abnormalities, and serves as a bridge to kidney transplantation or as long-term therapy for patients with end-stage kidney disease (ESKD).

The two principal forms of dialysis are haemodialysis and peritoneal dialysis, both of which require careful patient selection, regular monitoring, and multidisciplinary care.

Epidemiology

The global demand for dialysis continues to increase because of the rising prevalence of chronic kidney disease, diabetes mellitus, hypertension, and aging populations. End-stage kidney disease affects millions of people worldwide, although access to dialysis remains limited in many low- and middle-income countries. In Tanzania, dialysis services are available in selected referral hospitals and specialized centres, with haemodialysis being the most commonly available modality.

Indications

Dialysis should be considered in patients with acute kidney injury or chronic kidney disease who develop life-threatening complications that cannot be adequately managed with conservative therapy.

Common indications include:

• End-stage kidney disease (CKD Stage 5).

• Severe uraemic symptoms.

• Refractory fluid overload or pulmonary oedema.

• Persistent hyperkalaemia not responding to medical treatment.

• Severe metabolic acidosis refractory to medical therapy.

• Uraemic pericarditis.

• Uraemic encephalopathy.

• Progressive deterioration of kidney function requiring kidney replacement therapy.

• Certain drug intoxications where dialysis is indicated.

Types of dialysis

Haemodialysis

Haemodialysis removes waste products, electrolytes, and excess fluid by circulating the patient's blood through a dialysis machine across a semipermeable membrane before returning it to the circulation.

Peritoneal dialysis

Peritoneal dialysis utilizes the patient's peritoneal membrane as a natural semipermeable membrane through which solute and fluid exchange occur after instillation of dialysis solution into the peritoneal cavity.

The choice of dialysis modality should be individualized based on the patient's clinical condition, comorbidities, availability of services, and patient preference where appropriate.

Clinical assessment before dialysis

Patients should undergo comprehensive evaluation including:

• Assessment of volume status.

• Blood pressure measurement.

• Evaluation for uraemic symptoms.

• Review of medications.

• Nutritional assessment.

• Assessment of dialysis access.

• Evaluation for potential kidney transplantation where appropriate.

Investigations

Recommended investigations include:

• Serum creatinine.

• Blood urea nitrogen (BUN).

• Estimated glomerular filtration rate (eGFR).

• Serum electrolytes.

• Serum bicarbonate.

• Calcium and phosphate.

• Full blood count.

• Serum albumin.

• Hepatitis B screening.

• Hepatitis C screening.

• HIV testing according to national guidelines.

• Chest X-ray where indicated.

• Electrocardiogram (ECG).

• Additional investigations guided by the patient's clinical condition.

Management

Management aims to:

• Correct fluid overload.

• Remove uraemic toxins.

• Correct electrolyte abnormalities.

• Restore acid-base balance.

• Improve quality of life.

• Prepare suitable patients for kidney transplantation.

Non-pharmacological treatment

General measures include:

• Individualize dialysis prescription according to patient needs.

• Restrict dietary sodium, potassium, phosphate, and fluid intake as appropriate.

• Provide nutritional counselling.

• Monitor body weight and fluid balance.

• Educate patients regarding dialysis access care.

• Screen regularly for dialysis-related complications.

• Assess suitability for kidney transplantation where appropriate.

Pharmacological treatment

Drug therapy should be individualized according to the patient's clinical condition and may include:

• Antihypertensive medications.

• Erythropoiesis-stimulating agents for anaemia.

• Iron supplementation where indicated.

• Phosphate binders.

• Vitamin D supplementation.

• Treatment of mineral and bone disorders.

• Management of cardiovascular risk factors.

• Dose adjustment of medications according to kidney function and dialysis modality.

Referral

All patients requiring dialysis should be referred promptly to a nephrologist or a health facility with established dialysis services.

Patients should also be referred for:

• Creation and maintenance of permanent dialysis access.

• Evaluation for kidney transplantation.

• Management of dialysis-related complications.

• Multidisciplinary long-term follow-up.

Complications

Potential complications include:

• Hypotension during dialysis.

• Vascular access infection.

• Catheter-related bloodstream infection.

• Peritonitis (peritoneal dialysis).

• Electrolyte disturbances.

• Muscle cramps.

• Dialysis disequilibrium syndrome.

• Anaemia.

• Cardiovascular disease.

• Malnutrition.

• Vascular access thrombosis.

Prognosis

The prognosis depends on the underlying cause of kidney failure, age, associated comorbidities, dialysis adequacy, nutritional status, and adherence to treatment. Early initiation of appropriate kidney replacement therapy, effective management of complications, and consideration for kidney transplantation improve long-term survival and quality of life.

Prevention

Preventive measures include:

• Early detection and treatment of chronic kidney disease.

• Optimal control of hypertension and diabetes mellitus.

• Prevention of acute kidney injury.

• Avoidance of nephrotoxic medications.

• Timely referral to nephrology services.

• Early planning for kidney replacement therapy before end-stage kidney disease develops.

• Appropriate care of dialysis access to prevent infection and thrombosis.

National recommendation

Detailed indications, patient selection, dialysis procedures, infection prevention measures, monitoring protocols, and management of patients undergoing haemodialysis or peritoneal dialysis should follow the National Guidelines for Dialysis Services issued by the Ministry of Health, Community Development, Gender, Elderly and Children (MOHCDGEC), Tanzania.