Determining minimum cuff pressure required to reduce arterial blood flow at rest.

The aim of our study was to determine the minimum cuff pressure to induce alterations in the brachial and popliteal blood flow (BF). Forty-two healthy men underwent an incremental cuff pressure protocol at rest. The cuff was positioned at the proximal part of the right arm (9 cm width, brachial artery) and thigh (13 cm width, superficial femoral artery) in a randomized order. Pressure increments started at 0 mmHg, increased by 20 mmHg up to 100 mmHg, and then by 10 mmHg until total occlusion of BF. Each pressure was held for 30 s to stabilize BF and measurements were carried out on brachial (BA) and popliteal (PA) arteries using a 2-D B-mode ultrasound. Mean arterial occlusion pressure (AOP) was 161 ± 18 mmHg in BA and 150 ± 15 mmHg for the PA. At 20-100 mmHg, the mean BF changes were 4% (BA) and 11% (PA), without significant BF reductions compared to baseline values. Reductions in BF vs. baseline (p < 0.05) were found from 120 mmHg (BA) and 110 mmHg (PA) cuff pressures. Calculations of the minimal clinically important differences showed meaningful changes beginning at 110 mmHg for BA and 100 mmHg for PA. Experimental approaches requiring BF restriction should use cuff pressures greater than 69% (BA) and 67% (PA) of AOP to promote significant reductions in blood flow.