Background: Ambulatory blood pressure measurements in haemodialysis patients are relevant in view of the high cardiovascular morbidity and mortality in chronic haemodialysis patients.
Methods: Twelve normotensive patients were studied from the beginning of one dialysis until the end of the next (mean 64 h, SD 19 h) using a Spacelabs oscillometric blood-pressure recorder.
Results: A circadian blood pressure rhythm was present in six of the 12 patients. In seven patients the lowest pressure recorded (including the dialysis sessions) occurred 5-6 h after dialysis (late post-dialysis dip). Blood pressure did not increase sharply in the hours before dialysis although it increased slightly in the interdialytic interval as a whole, at a mean rate of 5.6 mmHg per 24 h (SD 4.1, P < 0.001). We could not find a blood pressure measurement during dialysis (or combination of measurements) which reliably reflects interdialytic blood pressure: the 95% confidence intervals were 25 mmHg or higher.
Conclusion: Ambulatory blood pressure measurements are needed for adequate monitoring of the control of blood pressure in haemodialysis patients.