Topical anaesthesia for minor lacerations: MAC versus TAC.

OBJECTIVE

To determine whether a solution of bupivacaine Marcain [Astra]), adrenaline and cocaine (MAC) is as safe and effective as tetracaine, adrenaline and cocaine (TAC) as topical anaesthesia for wound suturing.

DESIGN

Double-blind, randomised, prospective trial.

SETTING

Emergency departments of two tertiary referral hospitals (one specialising in paediatric care) in Adelaide, South Australia, between February 1992 and April 1994.

PARTICIPANTS

181 patients, aged six or older, with simple dermal lacerations less than 5mm deep, not involving mucous membranes or areas with end-arterial blood supply.

INTERVENTIONS: Patients received a weight-adjusted dose of either MAC or TAC.

OUTCOME MEASURES: Needle-prick testing of wound for pain before suturing, pain ratings by patients and physicians during suturing, signs and symptoms of cocaine toxicity, wound complications and patient preference for topical anaesthesia.

RESULTS

Topical anaesthesia was adequate for suturing in 73% of patients (83% or those with head wounds and 56% of those with extremity wounds). MAC and TAC did not differ significantly in efficacy overall or by wound location. Pain ratings from patients treated with MAC and TAC were comparable, as was patients acceptance of topical anesthesia (77%, MAC; 81%, TAC) and the incidence of adverse effects (4% infection rate overall).

CONCLUSIONS

Topical anesthesia is a safe and effective means of anaesthetising selected lacerations for suturing. As we found no significant differences in either the efficacy or safety of the two solutions, we believe that MAC can be substituted for the less readily available TAC whenever expedient.