Urgent-start peritoneal dialysis : is it ready for prime time?

Clinical practice guidelines recommend an arteriovenous fistula as the preferred vascular access for hemodialysis, but quantitative associations between vascular access type and various clinical outcomes remain controversial. We performed a systematic review of cohort studies to evaluate the associations between type of vascular access (arteriovenous fistula, arteriovenous graft, and central venous catheter) and risk for death, infection, and major cardiovascular events. We searched MEDLINE, EMBASE, and article reference lists and extracted data describing study design, participants, vascular access type, clinical outcomes, and risk for bias. We identified 3965 citations, of which 67 (62 cohort studies comprising 586,337 participants) met our inclusion criteria. In a random effects meta-analysis, compared with persons with fistulas, those individuals using catheters had higher risks for all-cause mortality (risk ratio=1.53, 95% CI=1.41-1.67), fatal infections (2.12, 1.79-2.52), and cardiovascular events (1.38, 1.24-1.54). Similarly, compared with persons with grafts, those individuals using catheters had higher risks for mortality (1.38, 1.25-1.52), fatal infections (1.49, 1.15-1.93), and cardiovascular events (1.26, 1.11-1.43). Compared with persons with fistulas, those individuals with grafts had increased all-cause mortality (1.18, 1.09-1.27) and fatal infection (1.36, 1.17-1.58), but we did not detect a difference in the risk for cardiovascular events (1.07, 0.95-1.21). The risk for bias, especially selection bias, was high. In conclusion, persons using catheters for hemodialysis seem to have the highest risks for death, infections, and cardiovascular events compared with other vascular access types, and patients with usable fistulas have the lowest risk.

Several comparisons of peritoneal dialysis (PD) and hemodialysis (HD) in incident patients with ESRD demonstrate superior survival in PD-treated patients within the first 1 to 2 years. These survival differences may be due to higher HD-related mortality as a result of high rates of incident central venous catheter (CVC) use or due to an initial survival advantage conferred by PD. We compared the survival of incident PD patients with those who initiated HD with a CVC (HD-CVC) or with a functional arteriovenous fistula or arteriovenous graft (HD-AVF/AVG). We used multivariable piece-wise exponential nonproportional and proportional hazards models to evaluate early (1 year) mortality as well as overall mortality during the period of observation using an intention-to-treat approach. We identified 40,526 incident adult dialysis patients from the Canadian Organ Replacement Register (2001 to 2008). Compared with the 7412 PD patients, 1-year mortality was similar for the 6663 HD-AVF/AVG patients but was 80% higher for the 24,437 HD-CVC patients (adjusted HR, 1.8; 95% confidence intervals [CI], 1.6 to 1.9). During the entire period of follow-up, HD-AVF/AVG patients had a lower risk for death, and HD-CVC patients had a higher risk for death compared with patients on PD. In conclusion, the use of CVCs in incident HD patients largely accounts for the early survival benefit seen with PD.

Microinflammation is linked to cardiovascular disease, and is highly prevalent in dialysis patients. It is logical to postulate that septicemia, a common macroinflammatory occurrence in dialysis patients, contributes to their large burden of cardiovascular disease. The Dialysis Morbidity and Mortality Wave 2 was a randomly selected prospective cohort of incident dialysis patients. Admission claims data were used to define and calculate rates of septicemia or bacteremia and cardiovascular events in those with Medicare as the primary payer. Utilizing Cox proportional hazard models we determined the association between baseline access and the development of bacteremia or sepsis, and also the association between bacteremia or sepsis episodes and subsequent cardiovascular events. The 2358 (59%) patients with Medicare as primary payer were older and more likely to have heart failure than those with other payers, but had similar comorbidity-adjusted mortality hazards. Rates of first septicemia, bacteremia, or either condition, were 7.0, 5.9 and 10.4 events per 100-patient years, respectively. Cox regression identified initial dialysis access as the main antecedent of septicemia or bacteremia. Hazards ratios for hemodialysis with permanent catheters, temporary catheters, and grafts were 1.95 (95% CI 1.47-2.57), 1.76 (95% CI 1.29-2.41), and 1.05 (95% CI 0.82-1.35), respectively, while that for peritoneal dialysis was 0.96 (95% CI 0.75-1.23) (reference arteriovenous fistula). After adjustment for baseline factors, septicemia or bacteremia, as a time-dependent covariate, was associated with subsequent death [hazards ratio (HR) 2.33, 95% CI 1.38-2.28], myocardial infarction (HR 1.78, 95% CI 1.38-2.28), heart failure (HR 1.64, 95% CI 1.39-1.95), peripheral vascular disease (HR 1.64, 95% CI 1.34-2.0), and stroke (HR 2.04, 95% CI 1.27-3.28). Septicemia appears to be an important, potentially preventable, cardiovascular risk factor in dialysis patients.