[Peritoneal dialysis in the aged].

INTRODUCTION: Patients older than 65 years represent the group of patients affected by end-stage renal failure characterized by the most rapid growth. The prevalent causes of end-stage renal disease (ESRD) in the elderly are diabetes mellitus and nephrosclerosis due to long-term arterial hypertension. There are a number of physiologic changes which occur with aging that might have an impact on the choice of renal replacement modality for an elderly patient: clinical or subclinical diminished cardiovascular reserve due to atherosclerosis or impaired baroreceptor function, slow deterioration of pulmonary function, impaired immunity, increased susceptibility to infection, metabolic disturbances, bone loss from osteoporosis, altered metabolism of protein and a variety of drugs, high rate of malnutrition, tendency to carbohydrate intolerance.

MATERIAL AND METHODS: When choosing a dialysis regimen for an elderly patient, physiologic changes that occur with aging, specific medical conditions that are common in this period of life, medical and psychosocial advantages and disadvantages of the single mode need to be taken into consideration.

DISCUSSION: Continuous ambulatory peritoneal dialysis (CAPD) is the predominant mode of therapy for elderly patients. Medical advantages of CAPD in elderly patients are easier control of hypertension and anemia, slower and sustained ultrafiltration, avoidance of cardiac arrhythmias, improvement of nutritional status, better correction of cognitive functions. Psychosocial benefits are home dialysis program, improvement of quality of life and avoidance of co-morbid diseases. There are contraindications to peritoneal dialysis which apply to elderly as well as to younger patients: inadequate peritoneal membrane function, hernias that cannot be repaired, inability to insert a chronic peritoneal access. Relative contraindications include recurrent pancreatitis, chronic back pain, recent aortic prosthesis placement, severe periferal vascular disease and recurrent diverticulitis. Further potential disadvantages of peritoneal dialysis in the elderly are depression and physical and intellectual incapability of self-performing dialysis in the absence of an adequate assistant. Besides, pain, malnutrition and in-hospitalization time associated with peritonitis may be less well tolerated in the elderly than in younger patients. Finally, anorexia, nausea and protein losses in dialysate may aggravate malnutrition. Food intake in the elderly is lower than in younger patients because of the financial situation, loneliness, habits, inertia, depression, bad teeth, impairment of sense of smell and taste, nausea, impeded moving, use of a variety of drugs and many other reasons. Renal failure aggravates malnutrition in the elderly, while peritoneal dialysis is characterized by significant protein losses in the dialysate. It is advisable to make an individual plan of nutrition for elderly patients on peritoneal dialysis in order to provide adequate intake of proteins, energy, vitamins and minerals. Survival rates are the same in patients on peritoneal dialysis and on hemodialysis, but the number of co-morbid conditions is higher in the first group. Age of course is a major death risk factor. Many complications of peritoneal dialysis occur no more frequently in the elderly than in younger patients. The rate of hospitalization is higher and its duration is longer in elderly patients, due to higher incidence of Staphyloccocus epidermidis peritonitis and vascular disease. Urea removal normalized to urea volume of distribution (Kt/Vurea) and weekly creatinine clearance are used as methods of assessing adequacy of peritoneal dialysis in the elderly. Creatinine production declines significantly in older patients and serum creatinine is a poor measure of level of renal function or dialysis adequacy. Assessment of quality of life is quite subjective. Only 15-30% of elderly patients on peritoneal dialysis relate their health worse t