**3. The need for dialysis**

Given the poor outcomes for patients on HD, every effort should be undertaken to preserve residual renal function, which is associated with improved survival (4). Early nephrology referrals, patient education, and consideration of transplant options may be helpful in decreasing the progression to ESRD. Preparation for dialysis therapy is critical for the

Hemodialysis Principles and Controversies 229

Kidney Foundation (NKF) workgroup in 1997, they recommended that initiation of dialysis be considered when the arithmetic mean of the urea and creatinine clearances fell below approximately 10.5 ml/min/1.73 m2 except in well-nourished, asymptomatic patients (9). In 1999 Obrador *et al.*, observed that 23% of the US ESRD population, between 1995 and 1997, started dialysis at an eGFR less than 5 ml/min/1.73 m2. They opined that this 'late start' of dialysis needed further examination, including studies of the impact on outcomes and cost

In 2006, the NKF work group updated the guidelines for initiation of hemodialysis and stated that 'at CKD Stage 5, when the eGFR is < 15 ml/min/1.73 m2, that nephrologists should evaluate the benefits, risks and disadvantages of beginning renal replacement therapy'. They also suggested that initiation of dialysis therapy before CKD Stage 5 (an eGFR of > 15 ml/min/1.73 m2) may be appropriate in patients who have symptoms believed to be related to both their comorbidities and their level of residual kidney function (11). Only one study has reported the outcomes of patients with CKD who initiated dialysis only after the onset of symptoms due to uremia. In this prospective cohort study of 233 consecutive patients with advanced uremia, 151 were elective starters on dialysis, while 82 initially declined dialysis. Among the initial refusers, 55 percent developed a uremic emergency, while 48 percent were eventually established on maintenance dialysis. In this study, one year mortality was significantly higher among the initial refusers than the elective starters (18 versus 7 percent). However, these results are confounded by lack of randomization and by three deaths among the initial refusers resulting from treatment

Additional published studies have not been able to demonstrate any clear-cut survival benefits for early start of dialysis. The only randomized controlled trial that examined mortality and time of dialysis initiation, the IDEAL study (13), found no difference in survival between early or late initiation of dialysis. In this study, 828 patients with progressive CKD and an estimated GFR between 10.0 and 15.0 mL/min/1.73 m2 (as determined by the Cockcroft-Gault equation) were randomly assigned to dialysis initiation when the estimated GFR was either 10 to 14 mL/min/1.73 m2 or 5 to 7 mL/min/1.73 m2. The median time to the initiation of dialysis was 1.8 and 7.4 months in the early and late start groups, respectively. At a median follow-up period of 3.6 years, the authors noted no significant difference in survival (38 and 37 percent mortality, hazard ratio of 1.05 with early initiation, 95% CI of 0.83 to 1.30) as well as no difference in cardiovascular events, infections,

However, these results do not imply that the initiation of dialysis can be delayed until the GFR is between 5 to 7 mL/min/1.73 m2 in all patients. The design of the IDEAL study permitted clinicians to initiate dialysis based upon the presence of symptoms due to uremia as well as on the estimated GFR. As a result, 76 percent of patients assigned to the late start arm initiated dialysis when the GFR was much greater than 5 to 7 mL/min/1.73 m2. This resulted in a mean GFR of 9.8 mL/min/1.73 m2 at the start of dialysis for the late start group, which was only 2.2 mL/min/1.73 m2 less than the mean start GFR for the early group (12.0 mL/min/1.73 m2). Thus, approximately 88 percent of all enrolled patients had initiated dialysis with an estimated GFR of approximately 10 mL/min/1.73 m2 or more,

A recent study published in *Canadian Medical Association Journal* examined trends in initiation of hemodialysis within Canada and compared the risk of death between patients with early and late initiation of dialysis (14). Using the Canadian Organ Replacement

or dialysis complications between the late start group and early start group.

either because of symptoms or enrollment in the early dialysis arm (13).

of ESRD treatment (10).

withdrawal (12).

smooth transition from CKD care to ESRD. Poor planning for initiation of dialysis is a major cause of increased morbidity and mortality. The use of temporary or tunneled dialysis catheters contributes to dialysis mortality by increasing the incidence of sepsis, acting as a stimulus for chronic inflammation, and damaging the central veins, thereby preventing or shortening the survival of more permanent vascular access once created. The chapter will discuss in detail regarding type of dialysis access.
