Clinical scenario: You are working in the emergency department when a car pulls up, dropping off an otherwise healthy male who has suffered a gun shot wound (GSW) to left shoulder. He says that he was in the rear passenger seat driving around with friends and "minding his own business" when he heard multiple gun shots. He felt immediate pain in his left shoulder. A full exam reveals two wounds to the left shoulder and nowhere else. The patient has bilateral breath sounds and his left arm is neurovascularly intact. X-rays demonstrate no pneumothorax, but the patient has a comminuted left scapular fracture:
You update the patient's tetanus, administer pain control, and call Orthopedics. The orthopedist on call asks that the patient receive prophylactic antibiotics. An ardent defender of antibiotic stewardship, you wonder if antibiotics are necessary. Is it possible that the heat exposure that comes with firearm discharge sterilizes a contaminated bullet? Do prophylactic antibiotics decrease the chance of infection?
Literature Review:
Question 1: Does the heat of firearm discharge sterilize a contaminated bullet?
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A study by Thoresby and Darlow from 1967 simulated GSWs using a series of gelatin models, contaminated bullets, and contaminated overlying “clothes”[1]. There were 3 “series” of testing. The first fired bullets contaminated with
Serratia marcescens into a gelatin block. The second fired sterile bullets shot through pieces of military fatigues inoculated with
Serratia overlying the entrance or exits side of the gelatin (with a piece of foil in between the cloth and gelatin to avoid direct transmission). The third fired bullets through an aerosolized cloud of
Serratia in front of the gelatin block. Significantly, there was bacterial growth along the bullet track in the gelatin in all three series (except for their respective controls). This suggests that bullets are
not sterilized by heat upon discharge of the gun. Furthermore, it demonstrates that bacteria were drawn into the cavitation space via vaccum forces in series in which inoculated cloth was placed on the exit site.
