Characterization and analysis of exhaust pipe (muffler) contact burns: An unsuspecting culprit

Abstract

Introduction Thermal injury due to contact with engine exhaust systems represents a distinct subgroup of acute contact burns. Temperatures generated by motor vehicle, radiator, and lawn mower engines can exceed 250℃, at which point relatively deep tissue loss occurs with less than 0.06 seconds of cutaneous exposure. While prior studies have helped elucidate the demographic characteristics of exhaust pipe contact burns, our analysis was aimed at both demographics and burn severity, as indicated by rate of full-thickness injury and requirement for tangential excision and skin grafting. Methods Data were obtained from a retrospective review of admissions at a regional burn center between 1 July 2012 and 30 August 2016. Patients of all ages with muffler, exhaust, motorcycle, lawn mower, and radiator burn injuries were included. Extensive demographic information, percent total body surface area burned (TBSA), burn etiology and location, third-degree and fourth-degree burn percentage, and subsequent operative information were analyzed for patients who sustained exhaust pipe contact burns. These data were then compared with all contact burn injuries from the same time period, matched for %TBSA range, using Fisher exact and unpaired t-tests. Results A total of 110 patients suffered exhaust pipe contact burns during the study period; 65 (59%) were males, and mean age was 30. Nearly two thirds of the muffler burns were sustained from motorcycles with TBSA ranging from 0.05% to 3.14%; at least 61% had some third-degree burn. The average number of operating room visits per patient was 0.54, though this varied significantly, with 38 patients (35%) requiring 59 total surgeries (range 1–6). Muffler burn patients were older than the matched control group. The most common location of burn injury was the lower leg with no difference between adults and children. Pediatric patients understandably had smaller burn surface area but similar TBSA compared to adults. The majority of injuries occurred in May, June, and July. Conclusions Exhaust pipe contact burns comprise a specific subset of low %TBSA contact burns with relatively high morbidity, evidenced by a significantly higher proportion of full-thickness tissue loss and eventual need for skin grafting when compared with nonexhaust burn controls. Awareness of the increased severity of exhaust pipe contact burns may lead to more expedient surgical intervention as well as further education regarding preventative measures.