A new study by Cambridge researchers has identified a physical cause for inaccurate cuff-based blood pressure readings. The familiar auscultatory method can cause systolic pressure readings to register lower than they really are, potentially missing thousands of cases of high blood pressure.
The issue lies in the way the cuff inflates around the upper arm, stopping blood flow and causing the artery’s reopening as it deflates. This delay leads to a steady, low-pressure state in the vessels downstream, resulting in underestimation of systolic pressure. The team found that this error can be up to 6 mmHg on average, missing roughly one in three cases of systolic hypertension.
To address this issue, researchers propose simple fixes such as raising the patient’s arm before inflating the cuff, which reduces venous pressure and creates a more predictable downstream pressure. This technique could be combined with short rest periods or integrated into new blood pressure devices to estimate downstream pressure and adjust systolic readings in real-time.
The study’s findings highlight the importance of accurate blood pressure readings, particularly for patients with high blood pressure who may not show symptoms until serious complications strike. By improving diagnosis rates, researchers hope to reduce the risk of premature death associated with this leading risk factor.
Source: https://www.medicaleconomics.com/view/cambridge-study-reveals-critical-flaw-in-blood-pressure-readings-and-how-to-fix-it