Patients with end-stage renal disease (ESRD) who convert to hemodialysis (HD) after failing treatment with peritoneal dialysis (PD) may be at higher death risk in the first year than ESRD patients who used HD as their primary treatment, but researchers caution that the association may not be causal.
Cheuk-Chun Szeto, MD, and collaborators at Prince of Wales Hospital, Chinese University of Hong Kong reviewed data from 197 patients who received long-term HD after failed PD (PD-first group) and 140 patients who received long-term HD at their initial treatment (primary-HD group). In Hong Kong, PD is the first-line renal replacement therapy for all ESRD patients, the authors noted.
At five years, the actuarial survival of the PD-first group was 39.9% compared with 59.7% of the primary-HD group even though technique survival was similar (30.4% and 30.1%), according to a report in Nephron Clinical Practice (2010;116:c300-c306).
When the investigators analyzed actuarial survival for patients who survived the first 12 months on HD, the five-year survival became similar (65.2% vs. 68.8%).
The researchers noted that the finding of excess mortality during on during the first 12 months of conversion to HD is consistent with previous studies. They speculate that this excess mortality might be an indirect consequence of PD, such as inadequate dialysis and malnutrition as a result of peritonitis.
Vascular access was a common problem for patients who failed PD, the authors noted. Compared with Western standards, they observed, the prevalence of using an arteriovenous fistula (AVF) for permanent vascular access is low in Hong Kong “largely because of the small body build of Chinese patients and technical difficulties in creating a usable fistula.” Although the percentage of patients in the present study who could have an AVF as permanent vascular access was similar between the groups, “patients who failed PD required twice as many temporary dialysis catheter insertions.”
The authors noted that their study had limitations, most importantly, the absence of a PD-only group as a control. Consequently, the prognosis of patients who converted to HD and those who remained on PD could not be compared. In addition, the study was not randomized, so the PD-first and primary-HD groups are not directly comparable. “Although the baseline demographic data were similar between the groups, three were likely important differences between them,” the researchers noted. For examine, patients who received HD as their primary therapy were mostly self-funded and came from the upper social class. With Hong Kong’s PD-first policy, most new dialysis patients with government funding were placed on PD.