A Potential Role of Peritoneal Dialysis as ‘a Bridging Therapy’ to Other Renal Replacement Therapies

Sudden and cardiac death (including death from congestive heart failure, myocardial infarction, and sudden death) are common occurrences in hemodialysis patients. The intermittent nature of hemodialysis may lead to an uneven distribution of sudden and cardiac death throughout the week. The purpose of this study was to assess the septadian rhythm of sudden and cardiac death in hemodialysis patients. Data from the United States Renal Data System (USRDS) were obtained to examine the day of death for United States hemodialysis and peritoneal dialysis patients from 1977 through 1997. The days of death were also determined for patients in the Case Mix Adequacy Study of the USRDS. There was an even distribution of sudden and cardiac deaths for patients on peritoneal dialysis, and hemodialysis patients dying of noncardiac deaths also had an even distribution. For all hemodialysis patients, Monday and Tuesday were the most common days of sudden and cardiac death. For patients in the Case Mix Adequacy Study designated as Monday, Wednesday, and Friday dialysis patients, 20.8% of sudden deaths occurred on Monday compared with the 14.3% expected (P = 0.002). Similarly, 20.2% of cardiac deaths occurred on Monday compared with the 14.3% expected (P = 0.0005). Similar trends were found on Tuesday for Tuesday, Thursday, and Saturday dialysis patients. The intermittent nature of hemodialysis may contribute to an increased sudden and cardiac death rate on Monday and Tuesday for patients enrolled in the USRDS.

Recent evidence suggests that the cost as well as the morbidity associated with the maintenance of hemodialysis access is increasing rapidly; currently, the cost exceeds 1 billion dollars and access related hospitalization accounts for 25% of all hospital admissions in the U.S.A. This increase in cost and morbidity has been associated with several epidemiological trends that may contribute to access failure. These include late patient referral to nephrologists and surgeons, late planning of vascular access as well as a shift from A-V fistulaes to PTFE grafts and temporary catheters, which have a higher failure rate. The reasons for this shift in the types of access is multifactorial and is not explained by changes in the co-morbidities of patients presenting to dialysis. Surgical preference and training also appear to play an important role in the large regional variation and patency rate of these PTFE grafts. We propose a program for early placement of A-V fistulae, a continuous quality improvement, multidisciplinary program to monitor access outcome, the development of new biomaterials, and a research plan to investigate pharmacological intervention to reduce development of stenosis and clinical interventions to treat those that do develop, prior to thrombosis.

The role of peritoneal dialysis (PD) in renal replacement therapy (RRT) remains unclear. There are no controlled trials to provide hard evidence of its efficacy. Comparative studies with haemodialysis from different centres and countries have given conflicting results even when allowing for case mix. Data from the United States on patients starting or receiving treatment in the late 1980s suggested a worse prognosis for older patients, particularly diabetics receiving PD as compared to HD. Analysis of the USRDS data base for patients starting in the early 1990s shows an improvement in outcome but with no difference in overall mortality. The Canadian registry has recently published data showing a better survival with PD than with HD in the first two years of RRT. Morbidity is similar with both therapies, although hospitalization is increased with PD. Unfortunately long-term technique survival is not as good with PD. However, PD has certain medical advantages, particularly the maintenance of residual renal function that contributes to solute and fluid removal. It may also postpone the onset of amyloidosis. Patients transplanted after previous PD have a decreased risk of early acute renal failure and equally good long-term results when compared to those patients who were on HD before transplantation. The quality of life is as good with PD as with center HD, and there are social advantages to PD including an increased chance of employment, more flexible holidays and avoidance of thrice weekly travel to a dialysis center. PD also has logistical advantages and can be utilized by the majority of new patients. We therefore conclude that PD has potential advantages early in the course of RRT, and should therefore be offered as a first option to all suitable new patients. Whether PD has a major or minor role in later years (> 5) remains unclear.