Abstract
BACKGROUND: Hypertension in patients with haemodialysis is mainly characterised by high pre-dialysis blood pressure (BP) due to body fluid retention before dialysis, and the BP tends to decrease after dialysis due to removal of water during dialysis. Intervals between haemodialysis treatments vary and a long inter-dialytic interval dialysis is associated with increased mortality. OBJECTIVE: To examine variations in BP; how ambulatory BP vary during a dialysis treatment performed after the long inter-dialytic interval, that is, the first treatment of the week, compared to dialysis after a short inter-dialytic interval, and in the interval between the two dialysis sessions. DESIGN: Exploratory non-interventional observational. PARTICIPANTS: Eleven patients with chronic kidney disease Stage 5 treated with haemodialysis were enroled. The mean age was 69 years (range 48-87) and mean dialysis duration 65 months (range 4-128). MEASUREMENTS: Ambulatory BP was recorded for 52 h including two haemodialysis treatments and one inter-dialytic interval. For statistical analyses the Wilcoxon signed ranks test was used. RESULTS: Significant differences in systolic and diastolic BPs were observed between dialyses after long inter-dialytic interval and short inter-dialytic interval, respectively (systolic 122 mmHg vs. 114 mmHg, p = 0.012 and diastolic 62 mmHg vs. 61 mmHg, p = 0.036). In addition, the BP declined during the first 90 min during dialysis in both settings. CONCLUSIONS: Measuring ambulatory BP for 52 h in patient with chronic kidney disease and haemodialysis is feasible and show that both systolic and diastolic BP differ between dialysis treatments following inter-dialytic intervals of diverse length. These findings should be replicated in larger studies.