Dialysis-associated hypotension in haemodiafiltration versus conventional haemodialysis

Background: Hypotension in the haemodialysis patient can have a detrimental effect on wellbeing and management of this complication uses a significant proportion of nursing resources to enable the dialysis treatment to be conducted safely. Aims: We sought to establish if there were fewer hypotensive events when using convective therapies such as haemodiafiltration (HDF) in comparison to conventional haemodialysis (HD) therapy. Methods: A prospective observational study in seven SA satellite haemodialysis units of 210 participants receiving HDF or HD for a period of 12 months. A mixed-effect logistic regression model was used to compare the probability of hypotension between the two dialysis modalities with patients as a random effect. Age, sex, coronary artery disease (CAD), type of vascular access, site of dialysis, patient to nurse ratio and diabetes status were examined as fixed effects and the number of dialysis hours per week was examined as a covariate. Results: From August 2012 to July 2013 29,542 dialysis treatments were included in the analysis. The results showed 13.8% (N=4079 patient days) dialysis treatments had at least one episode of hypotension. Pre-existing CAD increased the odds of hypotension by 77% (OR=1.77; 95% CI=1.04-3.02; P=0.04). Age and diabetes did not significantly affect the incidence of hypotension. There was no significant difference in the incidence of hypotension between patients treated with HDF or HD. Implications for clinical practice: The incidence of hypotension in this generally stable cohort may be related to the high prevalence of pre-existing CAD, which continues to represent a considerable challenge for dialysis staff.