Brachial artery reactivity: A modified technique with applicability to children

Brachial artery reactivity noninvasively tests endothelial function. Cuff p ressures of 180 to 300 mm Hg have been used. These pressures are ill advise d in neonatal and premature infants. We therefore evaluated the use of subs tantially lower occlusive pressures. Fifteen adult subjects were enrolled. One arm was occluded to 200 mm Hg, and the other arm was occluded to 40 mm Hg above the resting systolic pressure. The occlusion time was 4.5 minutes. The brachial artery was measured at baseline and 1 minute after cuff defla tion. Low pressure occlusions averaged 155.7 +/- 7.8 mm Hg versus 200 mm Hg for high pressure occlusions (P < .0001). One of 15 patients with low pres sure occlusions reported discomfort versus 7 of 15 with high pressure occlu sions (P < .05). Brachial artery reactivity increased by 8.0% +/- 2.5% with low pressure occlusions versus 7.5% +/- 2.7% with high pressure occlusions (P;I not significant). Brachial artery reactivity can be assessed at lower occlusive pressures. This may extend the applicability of the technique to children and neonates.