Effects of arm dominance and brachial artery cannulation on forearm blood flow measured by strain-gauge plethysmography

The human forearm model is used extensively in physiological, pharmacologic al and clinical investigations. Effects of arm dominance or arterial cannul ation on forearm flow measurements have never been tested formally. In the present study we tested the hypotheses that left or right arm dominance or cannulation of the brachial artery do not affect forearm haemodynamic respo nses to physiological or pharmacological stimuli. Results obtained in 16 vo lunteers showed that forearm blood flow responses to physiological sti mu i i are com parable before and after intraarterial cannulation in either the dominant or the non-dominant forearm. Cannulation of a forearm brachial art ery has a small effect on baseline blood flow. Responses to intra-arteriall y infused noradrenaline (norepinephrine) were not influenced by left or rig ht arm dominance. Intravenous infusion of noradrenaline in eight subjects r esulted in small responses in forearm blood flow that were slightly asymmet rical. During the intravenous infusion of noradrenaline, forearm blood flow or the forearm blood flow ratio did not reflect the marked increase in FVR that occurred. These results support our hypotheses (a) that either arm ca n be used as the control or intervention arm, and (b) that intra-arterial c annulation does not affect the results of intra-arterial infusion studies.