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, pharmacological and clinical investigations. Effects of arm dominance or arterial cannulation 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 responses to physiological or pharmacological stimuli. Results obtained in 16 volunteers showed that forearm blood flow responses to physiological stimuli are comparable before and after intra-arterial cannulation in either the dominant or the non-dominant forearm. Cannulation of a forearm brachial artery has a small effect on baseline blood flow. Responses to intra-arterially infused noradrenaline (norepinephrine) were not influenced by left or right arm dominance. Intravenous infusion of noradrenaline in eight subjects resulted in small responses in forearm blood flow that were slightly asymmetrical. 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 can be used as the control or intervention arm, and (b) that intra-arterial cannulation does not affect the results of intra-arterial infusion studies.