How to improve survival in geriatric peritoneal dialysis patients.
BACKGROUND
Recently, more elderly patients who are independent or able to live at home with the support of family are opting for continuous ambulatory peritoneal dialysis (CAPD). At the end of 2005, the annual statistical survey conducted by the Japanese Society for Dialysis Therapy indicated that the mean age of patients at initiation of dialysis treatment is 66.2 years. Only 3.6% of the overall end-stage renal disease population were treated with CAPD, and this small number of elderly patients was treated with CAPD despite the many merits of peritoneal dialysis (PD) for the elderly. In the present study, we reviewed our experience with patients 65 years of age and older at the start of PD and the results from two multicenter studies on PD treatment in elderly patients in Japan.


METHODS
Study 1: Of 313 PD patients at Okayama Saiseikai General Hospital between January 1991 and June 2006, 166 patients 65 years of age and older were studied. The characteristics of these elderly PD patients were reviewed to determine which elderly patients can continue PD for more than 5 years, and what the causes of death and the effects of icodextrin were in elderly PD patients. Study 2: A multicenter study of 421 patients introduced to PD from April 2000 to December 2004 in Japan was carried out by the Japanese Society for Elderly Patients on Peritoneal Dialysis to retrospectively analyze patient survival and technique survival and to find factors that have the potential to influence prognosis in these patients. Study 3: A review of the PD management and nursing-care insurance system (long-term care insurance) targeted patients 65 years of age and older who were initiated onto PD from January 2000 to June 2002 at 82 centers in Japan. The review found 765 patients under the age of 65 years (62.6%), and 458 patients 65 years of age and over (37.4%). Data on 409 elderly PD patients from 73 centers were analyzed.


RESULTS
Study 1: In 166 elderly patients, 27 (16.3%; 18 women, 9 men) continued PD for more than 5 years at our hospital. The original disease was chronic glomerulonephritis in 21 patients, diabetic nephropathy in 2 patients, nephrosclerosis in 2 patients, and polycystic kidney disease in 2 patients. The causes of death in the elderly PD patients at our hospital were heart failure (20.3%), cerebrovascular disease (17.7%), myocardial infarction (15.2%), debilitation (12.7%), peritonitis (7.6%), and pneumonia (3.8%). We observed significant differences in ultrafiltration, body weight, sodium, chloride, red blood cells, and hematocrit after using icodextrin in 14 elderly PD patients. Also, use of icodextrin in the daytime helps the family supporting an elderly member on PD by reducing the number of exchanges. Study 2: The average age of 421 patients in 37 hospitals throughout Japan was 76.4 years. Women accounted for 41% of all patients. The average modified (exclusive of factors of aging) Charlson comorbidity index (CCI) was 3.7. The modified CCI was an important factor not only in patient survival but also in technique survival. Patient survival was significantly different for the three modified CCI groups (CCI<3, 3<or=CCI<5, 5<or=CCI). Factors that influenced patient survival included patient choice of modality, modified CCI, exchanges performed by family members, and age at the start of PD. Factors that influenced technique survival included patient choice of modality, modified CCI, and exchanges performed by family members. Age at the start of PD was not a significant factor influencing technique survival. Study 3: Most elderly PD patients were living with family; 7% were living alone. At the start of PD, 24% of elderly PD patients were covered by nursing-care insurance, including 11% of young elderly patients (65-74 years of age), 35% of old elderly patients (75-84 years of age), and 29% of very old elderly patients (85 years of age or older). Patients 75 years of age or older were covered by nursing-care insurance more frequently than were patients under 75 years of age. Nevertheless, at the start of dialysis, fewer than 10% of elderly patients were using nursing-care insurance for PD.


CONCLUSIONS
In elderly patients, PD has good outcomes, especially in nondiabetic patients, in patients with few comorbidities, and in patients managing PD by themselves. In introducing dialysis in elderly patients, PD should be the treatment of choice. A more secure support system should be established to allow the elderly to choose PD treatment.
Hiramatsu
Makoto
M
Department of Nephrology, Okayama Saiseikai General Hospital, Okayama, Japan. m-hirama@saiseidr.jp
D000368:Aged; D015897:Comorbidity; D015314:Dialysis Solutions / Q000494:pharmacology; D005260:Female; D005936:Glucans / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D000077607:Icodextrin; D007564:Japan; D007676:Kidney Failure, Chronic / Q000628:therapy*; D008297:Male; D010531:Peritoneal Dialysis, Continuous Ambulatory / Q000379:methods*; D016016:Proportional Hazards Models; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome
D015314:Dialysis Solutions; D005936:Glucans; D000077607:Icodextrin; D005947:Glucose