Anesthetic Patch for Painful Procedures Such As Minor Operations

Abstract

The anesthetic patch with 30% lidocaine cream can be applied to the intact skin to produce complete skin anesthesia. It has been used for minor operations, intradermal allergen testing, lumbar punctures, bone marrow punctures, and venipunctures in a large series of patients during the past 11 years in both clinic and office practice. There have been no adverse reactions. Utilization of the anesthetic patch may promote more ready acceptance of painful medical diagnostic and therapeutic maneuvers, especially in children.In 1964 Lubens and Sanker1 de¬ scribed the use of an anesthetic patch for the intact skin. It produced satisfactory anesthesia of the skin and was utilized for intradermal al¬ lergen skin testing. No untoward re¬ action, such as contact sensitization or disturbance of the response to al¬ lergen skin testing, was observed. New applications and large scale studies conducted during the past nine years are now reported. Materials and MethodsIn all the studies 30% lidocaine cream was utilized as the anesthetic agent. This was found to be effective, presumably be¬ cause of the high concentration of lido¬ caine and its water solubility, the "occlu¬ sive" aspect, and skin absorption adequate to affect pain receptors.A new use of the anesthetic patch in¬ volves application at home by the patient before visits to the office. The occlusive anesthetic patch is designed to achieve greater penetration of the area to be anesthetized. The patch consists of a gauze square of the appropriate size and shape required for the contemplated procedure (Fig 1). The border of gauze area is marked with a skin marking crayon, thus demarcating the exact anesthetic area. The gauze square is then placed on a larger elastic adhesive strip to form an occlusive dressing. Before application of the patch, the skin is cleansed with acetone and alco¬ hol. The gauze on the anesthetic patch is saturated with the anesthetic cream which is supplied in appropriate quantity in a small disposable, sterile syringe. The patch is then applied to the designated skin area.These instructions are contained in a printed form supplied with the complete patch package. The anesthetized area is then visibly demarcated by a colored im¬ printing on its border. Actually the patient is his own anesthetist. This may permit performance of many procedures, espe¬ cially in children, in a physician's office or clinic, and decrease the requirement for

Dermal patch anaesthesia for venous cannulation with 10% lignocaine gel containing glycyrrhetinic acid monohemiphthalate disodium as an absorption promoter

“…However, the concentration of the uncharged form depends on the pKa, so that only a portion of the local anaesthetic is in a form suitable for tissue penetration. Consequently, to be effective topically the local anaesthetic must be used in high concentrations [2]. Since local anaesthetic bases are freely soluble in various alcoholic solvents, it is possible to obtain a high concentration of the base by dissolving it in, for example, ethanol, as in local anesthetic sprays.…”

Maximum recommended doses of local anesthetics: A multifactorial concept

“…Very slow absorption of local anesthetics occurs from the urinary bladder, 31 and intact skin is almost impermeable to regular concentrations of amide-linked local anesthetics as hydrochlorides. 32,33 Several studies have shown that the blood level of the local anesthetic depends on the total dose and is independent of the the concentration of local anesthetic in the injected solution. 34,35 It is thought that a smaller absorption surface counterbalances a greater concentration so that no alteration in absorbed blood levels occurs.…”

Formulation, Characterization, and Evaluation of Benzocaine Phospholipid-Tagged Lipospheres for Topical Application

“…The response of painlessness was determined in the volunteers over an ordinal scale, the score ranging between 0 and 10. [47][48] The efficacy of the liposphere formulation vis-à-vis conventional emulsion was assessed statistically using nonparametric Mann Whitney test. 49 …”