The effect of arterialization of blood by hand warming on the interpretation of forearm metabolic studies.

Although sampling of arterialized blood is widely used as an alternative to arterial sampling in metabolic studies, the arterialization procedures have been criticized because they may produce metabolic and haemodynamic effects that confound interpretation of results, especially in studies involving arteriovenous exchange of metabolites across the contralateral forearm. This study aimed to assess the effect of warming the hand for 10 or 20 min (a procedure which may be used to arterialize superficial venous blood) on the blood flow to the skin and muscle of the whole of the contralateral forearm. Hand warming, produced by placing the hand in a box kept at 67 +/- 3 degrees C for 10 min (standard errors of mean, SEM), produced no significant change in the blood flow of the whole forearm (4.14 +/- 0.28 versus 4.34 +/- 0.26 ml per 100 ml forearm min-1, measured with the hand circulation occluded), muscle (1.9 +/- 0.12 versus 1.82 +/- 0.15 ml per 100 ml forearm min-1, measured by 133Xe) or skin (5.2 +/- 4.0 versus 4.6 +/- 2.9 arbitrary units, measured by photoplethysmography). After 20 min of hand warming, there was no significant change in the concentration of a variety of metabolites in the deep venous blood draining the contralateral forearm. It is concluded that, unlike other 'arterialization' procedures, that used in this study had no important effect on the blood flow to the contralateral forearm or its distribution between muscular and non-muscular tissues. Therefore, this procedure of arterialization can be employed in arteriovenous studies that aim to assess the exchange of metabolites between blood and forearm tissues.