559 Benzocaine-Lidocaine-Tetracaine (BLT) Cream Adverse Effects in Burn Patients: A Case Report and Literature Review

Abstract

Abstract Introduction Historically, BLT cream has been used at our burn center in laser procedures and tattoo removal with 6–8% lidocaine to improve tolerance of outpatient procedures. Recently, the laser BLT formulation (8%) has been trialed as an opioid-sparing alternative for managing pain during inpatient microneedling procedures. When utilizing this formulation for microneedling, the high percentage of lidocaine absorption may correlate with adverse central nervous system (CNS) effects. Methods A literature evaluation and retrospective chart review of burn patients receiving BLT cream for inpatient microneedling was performed. Results From January to June 2020, two elderly females (77 and 78 years old) received several doses of BLT cream during inpatient microneedling procedures with no documented adverse events attributed to the medication. A 68 year old male with a total body surface area (TBSA) of 8% reported dizziness shortly after he received BLT cream. Vitals were normal, but the patient was unable to focus his eyes or communicate clearly. Neurological exam revealed sluggish, pinpoint pupils. Patient remained disoriented with gargling and tongue thrusting though vitals remained stable. At this time, the remainder of the BLT cream was removed from the wound and his mentation returned to baseline within 90 minutes. No residual neurologic deficits occurred. No other potential causes were identified. Literature review revealed topical lidocaine can be absorbed systemically and cause CNS depression, confusion, and disorientation. Based on limited published data in healthy patients, it is recommended to use no more than 5% of topical lidocaine in large quantities, especially over raw surfaces or blistered areas. The amount of lidocaine systemically absorbed is linked to both the duration of application and the surface area over which it is applied. Using study data from lidocaine/prilocaine 2.5% cream and lidocaine patches, we explored a safer BLT formulation for burn patients as published data do not exist for this group. Conclusions Based on our review, we determined 2% to be the maximum lidocaine concentration to apply to a burn wound, 5% TBSA as the maximum surface area involved, and total exposure time limited to 30 minutes or less to reduce incidence of adverse effects. Specifically, formulations with a higher lidocaine concentration applied to a burn wound have the potential to result in untoward neurological deficits.