title: Topical anaesthesia does not affect cutaneous vasomotor or sudomotor responses in human skin.
abstract: (1) The effects of local sensory blockade (topical anaesthesia) on eccrine sweat glands and cutaneous circulation are not well understood. This study aimed to determine whether topical lidocaine/prilocaine alters eccrine sweat gland and cutaneous blood vessel responses. (2) Sweating (capacitance hygrometry) was induced via forearm intradermal microdialysis of five acetylcholine (ACh) doses (1 × 10(-4) to 1 × 10(0) m, 10-fold increments) in control and treated forearm sites in six healthy subjects. Nitric oxide-mediated vasodilatory (sodium nitroprusside) and adrenergic vasoconstrictor (noradrenaline) agonists were iontophoresed in lidocaine/prilocaine-treated and control forearm skin in nine healthy subjects during blood flow assessment (laser Doppler flowmetry, expressed as% from baseline cutaneous vascular conductance; CVC; flux/mean arterial pressure). (3) Non-linear regression curve fitting identified no change in the ED50 of ACh-induced sweating after sensory blockade (-1.42 ± 0.23 logM) compared to control (-1.27 ± 0.23 logM; P > .05) or in Emax (0.43 ± 0.08 with, 0.53 ± 0.16 mg cm(-2) min(-1) without lidocaine/prilocaine; P > .05). Sensory blockade did not alter the vasodilator response to sodium nitroprusside (1280 ± 548% change from baseline CVC with, 1204 ± 247% without lidocaine/prilocaine) or vasoconstrictor response to noradrenaline (-14 ± 4% change from baseline CVC with, -22 ± 14% without lidocaine/prilocaine; P > 0.05). (4) Cutaneous sensory blockade does not appear to alter nitric oxide-mediated vasodilation, adrenergic vasoconstriction, or cholinergic eccrine sweating dose-response sensitivity or responsiveness to maximal dose. Thus, lidocaine/prilocaine treatment should not affect sweat gland function or have blood flow implications for subsequent research protocols or clinical procedures.
authors.affiliation: Ohio Musculoskeletal and Neurological Institute, Irvine Hall, Ohio University, Athens, OH, 45701, USA; Department of Physical Therapy, Lebanon Valley College, 101 N College Ave, Annville, PA, 17003, USA.
authors.forename: K
authors.initials: K
authors.lastname: Metzler-Wilson
authors.forename: T E
authors.initials: TE
authors.lastname: Wilson
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000279:Administration, Cutaneous; D000322:Adrenergic Agonists / Q000494:pharmacology; D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000494:pharmacology*; D018679:Cholinergic Agonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005542:Forearm / Q000502:physiology; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage / Q000494:pharmacology*; D000077442:Lidocaine, Prilocaine Drug Combination; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D011318:Prilocaine / Q000008:administration & dosage / Q000494:pharmacology*; D012039:Regional Blood Flow / Q000187:drug effects* / Q000502:physiology; D012867:Skin / Q000098:blood supply / Q000187:drug effects*; D013545:Sweat Glands / Q000187:drug effects* / Q000502:physiology; D013546:Sweating / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D000322:Adrenergic Agonists; D000779:Anesthetics, Local; D018679:Cholinergic Agonists; D000077442:Lidocaine, Prilocaine Drug Combination; D014665:Vasodilator Agents; D011318:Prilocaine; D009599:Nitroprusside; D008012:Lidocaine; D000109:Acetylcholine
keywords: EMLA®; eccrine sweating; intradermal microdialysis; iontophoresis; skin blood flow