The cardiovascular, respiratory, and metabolic effects of a long duration electronic control device exposure in human volunteers

Abstract

Electronic control devices (ECD) have become popular in law enforcement because they have filled a gap left by other law enforcement devices, tactics, or tools and have been shown to reduce officer and suspect injuries. Civilians are using the same technology for defensive purposes. TASER C2 is the latest generation civilian-marketed device from the manufacturer. Unlike the law enforcement devices, the device discharges for 30 s continuously. This study is the first to look at the cardiovascular, respiratory, and metabolic effects of this device on human subjects. This was a prospective, observational study of human subjects involved in a training course. Subjects were exposed for 30 s on the anterior thorax. Vital signs, ECG, troponin I, pH, lactate, and creatine kinase (CK) were measured before and immediately after the exposure. Troponin I, pH, lactate, and CK were measured again 24 h after the exposure. Continuous spirometry was used to evaluate the respiratory effects. Echocardiography was also performed before, during, and immediately after the exposure to determine heart rate and rhythm. Eleven subjects completed the study. There were no clinically important electrocardiogram changes and no positive troponins. Spirometry showed an increase in minute ventilation during the exposure. There was no important change in CK at 24 h. Lactate was slightly higher and pH was slightly lower after the exposure, but similar to the effects of physical exertion. Echocardiography was performed in 6 subjects. In half of these subjects, the rhythm was determined to be "sinus" and in the other half the rhythm was indeterminant. In our study, the civilian device caused a mild lactic acidosis. No other important physiologic effects were found.

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

“…Moreover, respiration did not appreciable change in the post-ECD period. For Dawes et al (2010a,b, 2011)), respiration as measured by respiratory rate, tidal volume, and minute volume were not significantly affected. A weakness of the breath-by-breath analysis used in previous studies is that it is intended to examine normal breathing patterns.…”

“…Ventilation rates increased slightly for both types of exposure. Dawes et al (2010a,b, 2011) published a series of papers that examined respiration (e.g., respiration rate, tidal volume, minute volume) using a breath-by-breath analyzer for various ECD exposures (either two or three consecutive 5-s exposures to TASER X26, 10-s exposures to TASER X3, and 30-s exposure to TASER C2, respectively). The breath-by-breath analyzer that was implemented in these studies has the same limitations as that used in the aforementioned study (Ho et al, 2007) with respect to resolution and synchronization with ECD exposure.…”

“…A number of studies have assessed 12-lead ECGs for morphology and found little impact from baseline to immediately post exposure (Vilke et al, 2008) and 24-h post exposure (Ho et al, 2006), although there is suggestive evidence that exposure to ECD in those with pre-existing 12-lead abnormalities worsen (VanMeenen et al, 2010). Currently, the cardiovascular impact of the ECD during its application has been confined to a few studies using echocardiography (Ho et al, 2008; Dawes et al, 2010a,b,c). Advances in pulse oximetry offered the promise of obtaining heart rate from a measure unaffected by the ECD itself.…”

Pathophysiologic changes due to TASER® devices versus excited delirium: Potential relevance to deaths-in-custody?

“…The investigators noted that their data may not apply to situations of ECD applications of longer durations or repetitive discharges. Lactic acidosis resulted from exposures to an ECD marketed for civilians ("TASER C2") in experiments of both human 79 and animal 14 subjects. Although some investigators may consider acidosis to be "a life-threatening condition regardless of the underlying condition," 80 short ECD applications may cause only very transient decreases in blood pH.…”

Civilian use of a conducted electrical weapon

“…Studies using the C2 Taser, for example, demonstrate long periods of apnea, with resultant hypoxia, hypercarbia, and lactic acidosis [9,10]. Despite this potential increased risk, civilian purchase and use of CEWs do not require training or education thought to be critical to proper and safe law enforcement use.…”