Factors associated with sudden death in peritoneal dialysis patients

Relatively little is known of the epidemiology and predictors of sudden death in peritoneal dialysis (PD) populations. We aimed to identify the risk factors of sudden death among PD subjects.

To explore clinical correlates of sudden death in PD patients, we conducted a population-based case-control study using data from a single dialysis unit. Cases (n=24) were defined as all PD patients that met the criteria for sudden death during January 2003 through December 2006. We also selected 48 control subjects that were selected from the prevalent PD patient name list compiled in alphabetical order. Data on the hemoglobin, potassium, and calcium levels, residual renal function, dialysis adequacy, cardiovascular risks, comorbid conditions, concurrent use of aspirin, beta-blockers, angiotensin-converting enzyme inhibitors, and erythropoietin, electrocardiographic and echocardiographic findings were extracted from case notes and computer records. Confounders were controlled by logistic regression.

Over a period of 4 years, 24 PD patients (mean age 61.4+/-9.5 years, median duration of dialysis 3.1 years) experienced sudden death. Univariate analyses showed that patients that died suddenly were more likely to be male and to have diabetes mellitus, a history of smoking, and a lower small solute clearance as measured by Kt/V. Cases of sudden death were also more likely to have received blood transfusion within the previous 1 year. There were no significant differences between patients and controls for residual renal function, serum potassium levels, control of blood pressure and mineral metabolism, or hemoglobin levels. Multivariate regression analysis confirmed independent association between recent blood transfusion and increased odds of sudden death [adjusted odds ratio (OR) 5.18, 95% confidence interval (CI) 1.44-18.6]. Two other factors significantly associated with risk of sudden death were male gender (adjusted OR 4.16, 95% CI 1.14-15.2) and diabetes mellitus (adjusted OR 5.33, 95% CI 1.53-18.6).

This study shows that recent blood transfusion is associated with an increased likelihood of sudden death in PD patients. The mechanisms that underlie this observation are unclear.