Investigation of the vascular effect of newer local anesthetics and vasoconstrictors.

Changes in blood flow can be measured with the aid of infrared thermography and make possible a comparative assessment of the vascular effect of vasoconstrictors and local anesthetics. With Adrenalin, vasoconstriction sets in immediately following infiltration; with POR-8, a sufficient vasoconstriction is observed only after 10 to 15 minutes. In both products, ischemia subsides after 60 minutes. Adrenalin then reverses the reaction in reactive hyperemia after 150 minutes, while the tissue infiltrated with POR-8 returns to normal ater 120 minutes. When combining a local anesthetic with a vasoconstrictor, the intrinsic vascular effect has to be considered. We experimentally proved that Novocain (procaine), Hostacain (butanilicaine), and on a lower scale Xylocaine (lignocaine) have a vasodilator effect. Citanest (prilocaine) demonstrates no vasodilatory effect. Carbocaine (mepivacaine) produces a mild vasoconstriction.