Accuracy and performance of the Terumo ES-H51, a new portable blood pressure monitor

Sources of inaccuracy in the measurement of adult patients' resting blood pressure in clinical settings: a systematic review

BACKGROUND

To interpret blood pressure (BP) data appropriately, healthcare providers need to be knowledgeable of the factors that can potentially impact the accuracy of BP measurement and contribute to variability between measurements.

METHODS

A systematic review of studies quantifying BP measurement inaccuracy. Medline and CINAHL databases were searched for empirical articles and systematic reviews published up to June 2015. Empirical articles were included if they reported a study that was relevant to the measurement of adult patients' resting BP at the upper arm in a clinical setting (e.g. ward or office); identified a specific source of inaccuracy; and quantified its effect. Reference lists and reviews were searched for additional articles.

RESULTS

A total of 328 empirical studies were included. They investigated 29 potential sources of inaccuracy, categorized as relating to the patient, device, procedure or observer. Significant directional effects were found for 27; however, for some, the effects were inconsistent in direction. Compared with true resting BP, significant effects of individual sources ranged from -23.6 to +33 mmHg SBP and -14 to +23 mmHg DBP.

CONCLUSION

A single BP value outside the expected range should be interpreted with caution and not taken as a definitive indicator of clinical deterioration. Where a measurement is abnormally high or low, further measurements should be taken and averaged. Wherever possible, BP values should be recorded graphically within ranges. This may reduce the impact of sources of inaccuracy and reduce the scope for misinterpretations based on small, likely erroneous or misleading, changes.

How accurate are automated blood pressure monitors?

Increasingly, automated blood pressure devices are replacing mercury sphygmomanometers to monitor blood pressure in primary care settings. Practitioners have raised questions about the accuracy of these new devices, so a mini-review was undertaken to examine the evidence. A systematic search of the Medline database identified seven studies that were of sufficient quality. Eight devices were examined, all of which had passed validation procedures, achieving A or B grades according to current protocols. All were 'recommended for clinical use', despite the tendency of the devices to produce inaccurate measurements in high blood pressure ranges. The review demonstrates that 'accuracy' of the new devices does not equate to the accustomed accuracy of the mercury sphygmomanometer.