Role of Renal Replacement Therapy in the Elderly

Chronic kidney disease is predominantly a disease of older adults — its incidence rises steadily with age and it is at least 10 times commoner at 75 and over than at 15–45.

The commonest causes of end-stage renal disease in old age are hypertension, nephrosclerosis, diabetes mellitus and obstructive uropathy; in up to one-third of cases no specific cause is identifiable.

Age itself does not constitute a contraindication to dialysis or transplantation.

When GFR falls below about 10 mL/min with uraemic features, replacement therapy becomes necessary — but the modern approach is to start on symptoms and clinical state rather than on an eGFR threshold alone.

Haemodialysis (HD) — in-centre, satellite or home; requires vascular access and haemodynamic tolerance.

Peritoneal dialysis (PD) — home-based, continuous, gentler; elderly patients on PD and HD have similar survival.

Kidney transplantation — the best modality for survival and quality of life in selected older patients.

Conservative kidney management (CKM) — active, planned, non-dialytic care focused on symptom control, quality of life and advance care planning; not “no treatment”.

Practical problems during HD in the aged: difficulty creating an arteriovenous fistula, permanent catheter or graft infection, gastrointestinal bleeding, intradialytic hypotension, headaches, vomiting, cramps, angina, arrhythmias and cardiovascular instability.

Older patients are more vulnerable to dialysis-related complications — haemodynamic instability, bleeding and disequilibrium syndrome.

Malnutrition is frequent; provide more than 1 g/kg body weight of protein daily on HD. Bone disease is more severe than in the young.

Very elderly patients on haemodialysis have a poor life expectancy: median survival is 15.6 months from age 80–84 and 11.6 months from age 85–89.

The leading causes of death in the oldest dialysis patients are elective withdrawal (38%), cardiovascular events (24%) and infection (22%) — withdrawal being the single commonest, which makes advance care planning essential from the outset.

Predictors of poor outcome on dialysis in older adults are: poor nutritional status, dementia, gait disorders, impaired activities of daily living and instrumental ADLs, and late referral to nephrology services.

Comprehensive geriatric assessment — not chronological age — should drive the decision; frailty, cognition, functional status and social support predict outcome better than any laboratory value.

Transplantation: with improved patient selection, newer immunosuppressants and lower corticosteroid doses, one-year patient and graft survival of 85% and 75% is achievable; for patients over 60–65 the five-year functional graft survival is 55–60%.

Older recipients have fewer rejection episodes; graft loss is mainly due to death with a functioning graft, and the commonest causes of death are cardiovascular disease and infection related to peaks of immunosuppression.

Donor age is the greatest adverse factor in cadaveric transplantation; kidneys from older donors are “marginal” but can be used, singly or as a pair, in a subgroup of older recipients.

Drug dosing must be individualised — bioavailability, volume of distribution, renal excretion and half-life all change with age; use low, slowly increasing doses and avoid polypharmacy.

CKM is a legitimate, active pathway comprising symptom control (pruritus, nausea, restless legs, breathlessness, pain), anaemia and acidosis management, blood-pressure and volume control, dietary support, advance care planning and palliative care linkage.

The survival advantage of dialysis is attenuated in the oldest and frailest patients; survival is broadly similar regardless of modality among those aged 80 and over with high comorbidity, particularly ischaemic heart disease, while dialysis imposes far greater treatment burden.

Use structured aids for prognostication and communication — the “surprise question” (“would I be surprised if this patient died within a year?”), validated mortality prediction models, and frailty measures — and frame the discussion around quality of life, hospital-free days and patient goals, not survival alone.

Withdrawal from dialysis should be discussed openly and revisited; it is a recognised, ethical decision and the commonest immediate cause of death in the very old on dialysis.