Optimising the accuracy of blood pressure monitoring in chronic kidney disease: the utility of BpTRU

Background: Accurate blood pressure monitoring is critical for the management of chronic kidney disease, but changes in management in secondary care clinics may be based on a single blood pressure reading, with a subsequent lack of accuracy. The aim of this study was to evaluate a fully automated sphygmomanometer for optimising the accuracy of blood pressure measurements in the setting of secondary care renal clinics. Methods: Patients had routine blood pressure measurements with a calibrated DINAMAP PRO400 monitor in a clinical assessment room. Patients then underwent repeat assessment with a DINAMAP PRO400 monitor and BpTRU device and subsequent 24 hour ambulatory blood pressure monitoring (ABPM). Results: The BpTRU systolic (+/- SD) reading (117.3 +/- 14.1 mmHg) was significantly lower than the routine clinic mean systolic blood pressure (143.8 +/- 15.5 mmHg; P < 0.001) and the repeat blood pressure taken with a DINAMAP PRO400 monitor in a quiet room (129.9 +/- 19.9 mmHg; P < 0.001). The routine clinic mean diastolic (82.4 +/- 11.2 mmHg) was significantly higher than the BpTRU reading (78.4 +/- 10.0 mmHg; P < 0.001). Clinic BpTRU measurements were not significantly different to the daytime mean or overall mean of 24 hour ABPM. Conclusions: In patients with CKD, routine clinic blood pressure measurements were significantly higher than measurements using a BpTRU machine in a quiet room, but there was no significant difference in this setting between BpTRU readings and 24 hour ABPM. Adjusting clinic protocols to utilise the most accurate blood pressure technique available is a simple manoeuvre that could deliver major improvements in clinical practice.