Two is better than one

A recent BBC headline, « Measuring blood pressure in both arms should be routine »(1) had the potential to send shockwaves through nursing practice. It was prompted by a Lancet research review of hypertension literature(2), which suggests that a large difference in systolic blood pressure (SBP) between left and right arms could be an indicator of peripheral vascular disease (PVD), cerebrovascular disease (CVD) and death.

The Lancet study reviewed 20 meta-analyses and concluded that an average interarm SBP difference of 10 mm Hg could indicate a high risk of asymptomatic peripheral vascular disease (PVD) including subclavian stenosis. A difference of 15 mm Hg or more could indicate an increased risk of cerebrovascular disease or death : an increased risk of 70 % for cardiovascular mortality and 60 % risk of death from all causes. Readings from both arms could therefore become a useful prognostic tool(3).

Current UK NICE guidelines(4) recommend bilateral brachial measurements at an initial hypertension-screening test, proposed to all over-40s. D^r J. Mant, of Oxford University, wrote in the Lancet editorial that this practice « should become part of routine care, as opposed to a guideline recommendation that is mostly ignored. »(5)

Future research may focus on data collection methods (type of equipment ; sequential, simultaneous readings ; using ankle brachial readings…) and the trigger point for aggressive risk-factor management.