British Journal
of Anaesthesia. 70(2): 167-72, 1993 Feb.
Effects of intradermal lignocaine
and mepivacaine on human cutaneous circulation in areas with histamine-induced neurogenic
inflammation.
H. Fruhstorfer, G. Wagener
Abstract
The vasoconstrictive potencies of
lignocaine and mepivacaine were studied in human skin. Lignocaine 0.5%, 0.25% mepivacaine
(both plain and mixed with adrenaline or ornipressin), and saline (control) were injected
intradermally into skin areas with enhanced perfusion (1% histamine prick). Flux was
determined by scanning laser Doppler flowmetry and the size of any eventual pallor was
measured. The artificially enhanced flux was increased further by saline, but not altered
by the local anaesthetics. Mepivacaine produced a small pallor. Both vasoconstrictors
reduced flux significantly and produced a larger pallor. We conclude that both local
anaesthetics have only a mild constrictive effect on precapillary vessels. Mepivacaine
has, additionally, a constrictor effect on the postcapillary vascular bed, causing pallor.
An effective precapillary constriction which reduces the capillary clearance of both local
anaesthetics can be achieved only by addition of a vasoconstrictor.
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