Literature Review: Injuries to Taser Subjects

     Bozeman WP, Hauda WE 2nd, Heck JJ, et al. Safety and injury profile of conducted electrical weapons used by law enforcement officers against criminal suspects. Ann Emerg Med, Jan 19, 2009 [e-pub ahead of print].

Abstract

     This prospective multicenter observational trial tracked a consecutive case series of all conducted electrical weapon uses against criminal suspects at six U.S. law enforcement agencies. Mandatory review of each use incorporated physician review of police and medical records. Injuries were classified as mild, moderate or severe according to a priori definitions. The primary outcome was a composite of moderate and severe injuries, termed significant injuries. Results—Conducted electrical weapons were used against 1,201 subjects during 36 months. Of these subjects, 1,125 (94%) were men; the median age was 30 years (range 13–80 years). Mild or no injuries were observed after conducted electrical weapon use in 1,198 subjects (99.75%; 95% CI, 99.3%–99.9%). Of mild injuries, 83% were superficial puncture wounds from conducted electrical weapon probes. Significant injuries occurred in three subjects (0.25%; 95% CI, 0.07%–0.7%), including two intracranial injuries from falls and one case of rhabdomyolysis. Two subjects died in police custody; medical examiners did not find conducted electrical weapon use to be causal or contributory in either case. Conclusion—To [the authors'] knowledge, these findings represent the first large, independent multicenter study of conducted electrical weapon injury epidemiology. They suggest that more than 99% of subjects do not experience significant injuries after conducted electrical weapon use.

Comment

     This study looked at the outcomes of patients after receiving one or more electrical shocks from a Taser X26 or M26 device. Tasers have become increasingly popular, and are now used by more than 60% of law enforcement agencies, who report that use of these devices has been associated with reductions in suspect injuries, officer injuries and the use of firearms.

     Tasers work by delivering a high-voltage but very low-amperage electrical charge. This interferes with the body's normal electrical signals and causes involuntary muscle contractions. Smaller studies in both animals and humans have concluded that Tasers are safe, but this study is larger than previous ones. Of the more than 1,200 subjects, 78% had no injuries, and 21% had minor injuries (e.g., puncture wounds from the probes and contusions/abrasions from falls). Only three subjects had more severe injuries; none required surgery, and all recovered.

     EMS will continue to see patients on whom Tasers have been used, and although serious injuries are very uncommon, these patients must be carefully evaluated. Although there is no good evidence that Tasers cause cardiac dysrhythmias in humans, animal studies suggest this may be a concern, and more research is needed. Other issues to keep in mind are occult injuries from falls (often in patients who are intoxicated, belligerent or otherwise difficult to assess) and puncture wounds to dangerous areas, such as the eyes. EMS systems should be sure that all personnel know what to look for in a patient on whom a Taser has been used.

     Angelo Salvucci, Jr., MD, FACEP, is an emergency physician and medical director for the Santa Barbara County and Ventura County (CA) EMS agencies.