Respiratory and Cardiovascular Response during Electronic Control Device Exposure in Law Enforcement Trainees

Abstract

Objective: Law enforcement represents a large population of workers who may be exposed to electronic control devices (ECDs). Little is known about the potential effect of exposure to these devices on respiration or cardiovascular response during current discharge.

Methods: Participants (N = 23) were trainees exposed to 5 s of an ECD (Taser X26(®)) as a component of training. Trainees were asked to volitionally inhale during exposure. Respiratory recordings involved a continuous waveform recorded throughout the session including during the exposure period. Heart rate was calculated from a continuous pulse oximetry recording.

Results: The exposure period resulted in the cessation of normal breathing patterns in all participants and in particular a decrease in inspiratory activity. No significant changes in heart rate during ECD exposure were found.

Conclusion: This is the first study to examine breathing patterns during ECD exposure with the resolution to detect changes over this discrete period of time. In contrast to reports suggesting respiration is unaffected by ECDs, present evidence suggests that voluntary inspiration is severely compromised. There is no evidence of cardiac disruption during ECD exposure.

Keywords: TASER X26®; electronic control device; heart rate; respiration.

Figure 1

Subject A – respiratory flow pre, during and post-ECD exposure. Subject A is an example of a participant who showed both inspiratory and expiratory activity during the ECD exposure period. Only a few of the subjects showed this pattern of respiratory activity during ECD exposure. The vertical lines indicate the onset and offset of ECD exposure. Negative values represent inspiratory flow.

Figure 2

Subject B – respiratory flow pre, during and post-ECD exposure. Subject B is an ex ample of a participant who showed a substantial inspiratory volume displacement from the pre-ECD to the exposure period. Most subjects showed this pattern of little or no inspiratory activity during the 5-s exposure. The vertical lines indicate the onset and offset of EC D exposure. Negative values represent inspiratory flow.

Figure 3

(A) Subject C – blood flow pre, during, and post-ECD exposure. (B) Subject C-heart rate pre, during, and post-ECD exposure. Blood flow (A): example of the processed PPG waveform for 10-sprior to ECD exposure, through the 5-s exposure, and for 10-s following exposure. Note that dramatic flow artifact is evident immediately upon ECD exposure and immediately upon the cessation of exposure; this artifact is evident to a similar degree in all participants. Heart rate (B): despite the artifact noted above, heart rate was reliably obtained for approximately the 1ast 3-s of ECD exposure. This same time window (3-s) was applied to the data that immediately preceded ECD onset and the data that immediately followed the dissipation of the post-ECD artifact.

Figure 4

Example of ECD exposure locations.

Figure 5

Evidence of sniff behavior during ECD exposure. Subjects C and D showed evidence of sniff behavior during the ECD exposure period. Subject C self-reported trying to sniff during exposure, but was unsure of their success. Subject D was unsure in self-report about trying to sniff during exposure. Negative values represent inspiratory flow.

Figure 6

Inspiratory and expiratory volume. Shows inspiratory and expiratory volumes for each of the 5-s periods of time measured: pre-ECD, during ECD, and post-ECD. Both inspiration and expiration significantly decreased during ECD exposure.

Figure 7

Individual differences in inspiratory and expiratory volume. Shows individual inspiratory and expiratory volumes for each of the 5-s periods of time measured: pre-ECD, during ECD, and post-ECD. For the vast majority of subjects there was a dramatic decrease in inspiratory volume from pre-ECD to during ECD exposure and a greater increase from during ECD to post-ECD.

Figure 8

Change in inspiratory and expiratory volume during ECD and after ECD. Due to the variability of the percentages the above figures are presented on different scales. A = Both exposure locations were above the bottom of the spine. S = Exposure locations spanned the bottom of the spine.