Human Health Risks of Conducted Electrical Weapon Exposure: A Systematic Review.

Importance: Conducted electrical weapons (CEWs) are used broadly as a less-lethal force option for police officers. However, there is no clear picture of the possible health risks in humans on the basis of rigorously assessed scientific evidence from the international peer-reviewed literature. Objective: To synthesize and systematically evaluate the strength of published evidence for an association between exposure to different models of CEWs and adverse acute as well as chronic conditions. Evidence Review: Following a preregistered review protocol, the literature search strategy was based on a search of reviews published between January 1, 2000, and April 24, 2020, of PubMed, MEDLINE, EMBASE, Web of Science, PsycINFO, and Cochrane Library, as well as relevant online databases and bibliographic sources, such as reference sections of recent publications. The identified studies were independently assessed in terms of scope, relevance, methodologic bias, and quality. Peer-reviewed publications of human studies were included, using original data and with a focus on the use of taser CEWs in the context of law enforcement. Eligible studies examined clearly defined health outcomes as dependent variables following exposure to a CEW. The review followed the relevant sections of the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline. A meta-analysis could not be conducted. Findings: Of the 1081 unique records screened, 33 relevant studies were identified, all of them of experimental design and conducted in the US. Eleven studies had a low risk of bias and 22 had a higher bias risk. Studies focused on outcomes such as physiologic stress responses, heart rate, blood pressure, arrhythmias, or cognitive performance. Independently of bias risk, the studies reported few or no acute health problems, apart from the wounds caused by the darts. Furthermore, no long-term outcomes were studied. Most of the studies were performed on healthy, physically fit individuals (eg, police officers) in a controlled setting, with short exposure duration (5 seconds). Half of the studies, mainly those with a higher risk of bias, were at least partly funded by the manufacturer. Conclusions and Relevance: Based on the findings of the reviewed studies, the risk for adverse health outcomes due to CEW exposure can be currently estimated as low. However, most of the reviewed studies had methodologic limitations. Considering that recruited participants were not representative of the population that usually encounters a CEW deployment, it is not possible to draw conclusions regarding exposure outcomes in potentially vulnerable populations or high-risk groups, such as those under the influence of substances.

[The topical problems of the application of the TASER electroshock devices]. / Aktual'nye voprosy primeneniia élektroshokovogo ustroistva TASER.

The objective of the present study was the analysis of publications in the foreign medical literature concerning the problems of safety, clinical diagnostics, pathological morphology, and treatment of the patients subjected to the impact by various models of the TASER electroshock devices. The materials for this article were borrowed from the available Internet resources and libraries. The methods of scientific analysis were employed to follow up the dynamics of publication and to determine the number of publications on the issues of interest. The main attention was given to the overview of the subject matter of scientific research and experiments. The review covers 74 foreign articles presenting the discussion of various conditions and circumstances of the action of various types of the TASER electroshock devices (ESD) on the man with special reference to their effectiveness and safety as confirmed by numerous experimental impacts on the volunteers and animals. It is shown that the dynamics of relevant publications in the foreign scientific periodicals gives evidence of the strong interest shown by the specialists in various scientific disciplines to the problem of safety of various models of the TASER electroshock devices. The largest number of the articles (60 or 81.1%) published during the period covered by the present study were submitted by the American authors describing their experiments involving the volunteers, anthropometric dummies, and human corpses (n=38 or 51%). The subject matter of these publications included the forensic medical evaluation of the lethal outcomes of the application of the TASER electroshock devices with the related technical problems and characteristic of various ESD models. Despite the extensive studies on the volunteers and the experimental animals, the authors of the publications failed to present direct and conclusive evidence of the lethal consequences of the application of the TASER electroshock devices (ESD) on the man. Some of them recommend to prohibit (or restrict whenever possible) the targeted application of the electric shock weapons to the thoracic region. Experiments on the animals have demonstrated the possibility of development of cardiovascular and respiratory complications following the application of the TASER X2 electroshock devices operating at a frequency of 40 Hz during 30 minutes. The clinical and laboratory studies with the participation of the volunteers in an alcoholic intoxication condition have confirmed the long-term increase in the blood lactate levels under the influence of the electric shocking weapons. The analogous data suggesting the development of pronounced acidosis under effect of the TASER X2 electroshock devices due to the elevation of the lactate concentration in the venous blood have been obtained in the animal experiments. The studies of humans in a narcotic intoxication condition failed to provide direct evidence of induction of psychic disorders in the form of an acute confusional state (delirium) under the influence of the TASER electroshock devices. The evaluation of changes in the skin cover in the form of the punctured or contused wounds in the victims of the application of the electroshock gun projectiles did not revealed any specific signs of the local electrical action.

Cardiovascular effects of SPARK conducted electrical weapon in healthy subjects.

BACKGROUND: The increasing use of conducted electronic weapons (CEW) cause concern regarding its secure application, specially regarding the implications in the cardiovascular system. METHODS: The objective was to determine Spark CEW safety through cardiovascular parameters analysis of healthy volunteers subjected to its use. RESULTS: Volunteers over 18years without cardiovascular disease or recent use of illegal drugs were submitted, before and after being affected with Spark CEW, to clinical evaluation; blood collection for serum laboratory tests; transthoracic electrocardiography at rest, transthoracic echodopplercardiogram and 24hour Holter. RESULTS: All 71 patients reported being incapable of any voluntary reaction during the shock of the application time. No arrhythmia or myocardial necrosis was related to the use of non-lethal weapon SPARK. Reported adverse events were self-limited, and mostly mild. CONCLUSIONS: SPARK brand CEW is effective in incapacitating individuals by the shock of the application time, without causing.

TASER® conducted electrical weapons: misconceptions in the scientific/medical and other literature.

TASER(®) conducted electrical weapons (CEWs) have become an important law-enforcement tool. Controversial questions are often raised during discussion of some incidents in which the devices have been used. The main purpose of this paper is to point out some misconceptions about CEWs that have been published in the scientific/medical and other literature. This is a narrative review, using a multidisciplinary approach of analyzing reports from scientific/medical and other literature sources. In previous reports, durations of incapacitating effects and possible associations of CEWs with deaths-in-custody have often been overstated or exaggerated. Comparisons of CEW effects with "electrocution" are misleading. Clarification of these misconceptions may be important during policymaker decisions, practitioner operations, expert witness testimonies, and court proceedings. Despite misconceptions in the literature, CEWs can still be a valuable tool for law enforcement activities. Scientists, medical professionals, legal advisors, and investigators of police tactics should be aware of these misconceptions.

Cardiac stimulation with electronic control device application.

BACKGROUND: Electronic control devices (ECDs) are weapons used to incapacitate violent subjects. Subjects have died suddenly after ECD application, but because cardiac dysrhythmias have been inconsistently observed during ECD application in animals, the cause for death is uncertain. OBJECTIVES: The objective was to identify the factors contributing to cardiac stimulation during ECD application detected by transesophageal echocardiography. METHODS: Four Yorkshire pigs were anesthetized, paralyzed with vecuronium, and restrained in a supine position. A GE 6T echo probe was placed in the esophagus to directly visualize left ventricular function. M-mode echocardiography was used to estimate heart rate. Two dart locations, chest and abdomen, were assessed. ECD applications were delivered from one of five commercially available devices (Taser X26, Singer S200 AT, Taser M26, Taser X3, and Taser C2) in random order to each pig, four times in each orientation. RESULTS: Cardiac stimulation, characterized by multiple PVCs or the sudden increase in ventricular contraction rate during application, did not occur with abdominal dart location. With chest dart application in small pigs, cardiac stimulation occurred with all ECDs except with the Taser X3 (p < 0.0001). In large pigs, cardiac stimulation occurred only during chest application of the S200 AT (chest vs. abdomen: 207 beats/min, vs. 91 beats/min, p < 0.0001). CONCLUSION: Cardiac stimulation occurs during ECD application in pigs, and is dependent upon subject size, dart orientation, and ECD. The Taser X3 did not result in cardiac stimulation in small or large pigs.

An evaluation of two conducted electrical weapons using a swine comparative cardiac safety model.

Arrest-related deaths proximate to the use of a conducted electrical weapon (CEW) continue to generate controversy despite a better understanding of the multi-factorial nature of many of these deaths. With the rapid adoption of this technology by law enforcement, and the proliferation of companies entering the marketplace, it is important to have a method to assess the relative safety of these weapons. We had previously developed a model to assess the relative cardiac safety of CEWs. In this study, we use this model to compare the TASER X2 and the Karbon Arms MPID. Our results suggest that the TASER X2 may have an improved cardiac safety margin over the Karbon Arms MPID as determined by a smaller area of cardiac pacing on the anterior chest in our model. This model seems to offer a reproducible means of comparing the cardiac effects of CEWs.

Incapacitation recovery times from a conductive electrical weapon exposure.

PURPOSE: Law enforcement officers expect that a TASER(®) CEW (Conducted Electrical Weapon) broad-spread probe exposure will temporarily incapacitate a subject who will then be able to immediately (~1 s delay) recover motor control in order to comply with commands. However, this recovery time has not been previously reported. METHODS: A total of 32 police academy students were exposed to a very broad-spread 5 s CEW stimulus as part of their training and told to depress a push-button as soon as they sensed the stimulus. A subgroup also depressed the push-button after being alerted by an audio stimulus. RESULTS: The response time after the audio trigger was 1.05 ± 0.25 s; the median was 1.04 s (range 0.69-1.34 s). For the paired CEW triggered group the mean response time was 1.41 ± 0.61 s with a median of 1.06 s (range 0.92-2.18 s), which was not statistically different. Only 2/32 subjects were able to depress the button during the CEW exposure and with delays of 3.09 and 4.70 s from the start. Of the remaining 30 subjects the mean response time to execute the task (once the CEW exposure ended) was 1.27 ± 0.58 s with a median of 1.19 s (range 0.31-2.99 s) (NS vs. the audio trigger). CONCLUSIONS: With a very-broad electrode spread, a CEW exposure could prevent or delay some purposeful movements. Normal reaction times appear to return immediately (~1 s) after the CEW exposure ceases.

The syndrome of excited delirium.

The excited delirium syndrome (EDS) is a life-threatening condition caused by a variety of factors including drug intoxication and psychiatric illness. Fatal instances of excited delirium frequently come to the attention of the medical examiner/coroner due to the circumstances and potential causes. Excited delirium may include paranoid, aggressive, and incoherent behavior which may lead to an encounter with law enforcement. In some instances, the person may die while in the presence of law enforcement. This circumstance further broadens the potential causes of death particularly as EDS has no pathognomonic autopsy finding. Although the syndrome of excited delirium is sufficient to explain death, other intervening causes need to be considered. These include chest or neck compression during restraint, blunt trauma, and underlying natural disease. Since chest/neck compression, natural disease (e.g., atherosclerosis), blunt trauma, and excited delirium are not mutually exclusive, all may be present in one death. The forensic pathologist's role is to determine what caused and/or contributed to the death. When attempting to determine the proximate cause of death in instances with multiple potential causes, determining the mechanism of death often is useful. As not all causes of death have pathologically-demonstrable mechanisms of death, examination of the circumstances of the death often are diagnostically important. The main goal of the autopsy of deaths suspected to be due to EDS is to identify (or exclude) intervening diseases or injuries sufficient to explain the death in the context of the investigated circumstances.

Physiologic effects of a new-generation conducted electrical weapon on human volunteers.

BACKGROUND: Conducted electrical weapons (CEWs) are used by law enforcement to restrain or repel potentially violent persons. The TASER X2 CEW is a next-generation device with new technology, including new electrical waveform and output specifications. It has not previously been studied in humans. OBJECTIVE: The objective of this study was to evaluate the human physiologic effect of a new-generation CEW. METHODS: This was a prospective, observational human study. Volunteers received a 10-s exposure via deployed probes from an X2 CEW in the abdomen and upper thigh. Measured data included vital signs; 12-lead electrocardiograms; and blood serum biomarkers before, immediately after, and 24 h post exposure. Biomarkers measured included pH, lactate, potassium, creatine kinase (CK), and troponin-I. Real-time spirometry and echocardiography were performed before, during, and after the exposure. RESULTS: Ten volunteers completed the study. There were no important changes in vital signs or potassium. Median increase in lactate as a consequence of the exposure was 1.2 mg/dL (range 0.6-2.8 mg/dL). Median change in pH was -0.031 (range -0.011 to -0.067). No subject had a positive troponin. Median change in CK at 24 h was 313 ng/mL (range -40 to 3418 ng/mL). There was no evidence of respiratory impairment. Baseline median minute ventilation was 14.2 L/min, increased to 21.6 L/min intra-exposure (p = 0.05), and remained elevated at 21.6 L/min post exposure (p = 0.01). CONCLUSIONS: There was no evidence of dangerous physiology found in the measured parameters. The physiologic effects of the X2 CEW are similar to older-generation CEWs. We encourage further study to validate these results.

Markers of acidosis and stress in a sprint versus a conducted electrical weapon.

Both profound acidosis and catecholamine excess have been proposed as underlying physiologic derangements in subjects at high risk for arrest related death (ARD). In this study, the objective was to determine a level of physical exertion that is "equivalent" in terms of levels of acidosis and catecholamines to a "standard" TASER X26 exposure. Data were collected on subjects who underwent a 5-s TASER X26 exposure or a sprint of variable distances during a law enforcement training exercise. Our results show that levels of acidosis and catecholamines are less among subjects exposed to the TASER X26 than among subjects who sprinted 20 yards or more.

Blood lactate concentration after exposure to conducted energy weapons (including TASER® devices): is it clinically relevant?

In previous studies, blood lactate concentration (BLac) consistently increased in anesthetized animals and in human subjects after exposures to TASER(®) conducted energy weapons (CEWs). Some have suggested the increased BLac would have detrimental consequences. In the current review, the following are evaluated: (a) the nature of muscle contractions due to CEWs, (b) general aspects of increased BLac, (c) previous studies of conventional neuromuscular electrical stimulation and CEW exposures, and (d) BLac in disease states. On the basis of these analyses, one can conclude that BLac, per se (independent of acidemia), would not be clinically relevant immediately after short-duration CEW applications, due to the short time course of any increase.

Effects of a TASER® conducted energy weapon on the circulating red-blood-cell population and other factors in Sus scrofa.

In previous studies hematocrit has been consistently increased in an anesthetized animal model after exposures to TASER(®) conducted energy weapons (CEWs). In the present study we analyzed changes in blood cell counts and red blood cell membrane proteins following two 30-s applications of a TASER C2 device (which is designed for civilian use). Hematocrit increased significantly from 33.2 ± 2.4 (mean ± SD) to 42.8 ± 4.6 % immediately after CEW exposure of eleven pigs (Sus scrofa). Red blood cell count increased significantly from 6.10 ± 0.55 × 10(12)/L to 7.45 ± 0.94 × 10(12)/L, and mean corpuscular volume increased significantly from 54.5 ± 2.4 fl to 57.8 ± 2.6 fl. Mean corpuscular hemoglobin concentration decreased significantly from 20.5 ± 0.7 to 18.5 ± 0.6 mM. Thirty protein spots (from two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis, selected for detailed comparison) exhibited greater densities 30-min post-exposure compared with pre-exposure values. A greater number of echinocytes were observed following CEW exposure. On the basis of these results it appears that, during the strong muscle contractions produced by TASER CEWs, a specific population of red blood cells (RBCs) may be released from the spleen or other reservoirs within the body. The total time of CEW exposure in the present study was relatively long compared with exposures in common law-enforcement scenarios. Despite statistically significant changes in red blood cell counts (and other measures directly related to RBCs), the alterations were short-lived. The transient nature of the changes would be likely to counteract any potentially detrimental effects.

Use and safety of conducted electronic devices: what is known?

Conductive electronic devices (CED), such as Taser and stun guns, are sold worldwide for use by security services, although they have also been used for self-defence and even for torture. CED are promoted as non-lethal weapons which can potentially save lives. However, there are multiple reports of deaths temporally associated with CED use. These weapons have definite physiological effects in normal volunteers, especially when accompanied by exertion. Medical examiners often report that deaths followed physical encounters which included the use of CED were due to natural causes, excited delirium and/or drug intoxication. These cases present complex situations in which multiple factors potentially contribute to the death, including electric shocks which cause neuromuscular incapacitation, severe pain and anxiety. Public health officials, physicians and hospital personnel need to be aware that individuals controlled with CED are at increased risk of death. We need better recording of incidents worldwide to understand the extent and outcomes of CED use.

Acute pathophysiological influences of conducted electrical weapons in humans: A review of current literature.

Conducted electrical weapons (CEWs) deliver short high-voltage, low current energy pulses to temporarily paralyze a person by causing muscular contraction. The narrative of this article is a methodical analysis on acute pathophysiological changes within the central nervous system, cardiovascular, neuroendocrine, sympatho-adrenergic and muskuloskeletal system which can occur after application of conducted electrical weapons on human subjects. The results are based on wide-ranging literature analysis and source studies. The majority of the recent scientific publications on humans classify the health risks of an appropriate use of the CEWs device as minor. However, there still is an uncertainty about possible side-effects of these devices. Therefore medical supervision with human application is advised.

Cardiac fibrillation risk of TASER X-26 dart mode application.

In view of reported fatalities there are still controversial discussions on whether electronic stun law enforcement weapons can cause cardiac fibrillation. Experimental data are contradictory. Simplified theoretical estimations led to a negligible low risk of 8.10(-7). With a detailed numerical-anatomical model of an adult man (NORMAN) cardiac exposure to Taser X26 high-tension pulses was quantitatively assessed and the fibrillation risk estimated by accounting for its dependence on excited volume based on 3D cardiac exposure patterns. For distance mode and worst case dart hits it could be demonstrated that cardiac exposure can reach the 30% fibrillation risk level. Risk reduces considerably if direct current flow across the heart is prevented. The overall fibrillation risk of Taser application is further reduced by the limited probability of critical hits. However, in agreement with experimental findings it is demonstrated that cardiac fibrillation risk of Taser X26 dart mode application is small, however, not negligible.

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

The syndrome of excited delirium has been implicated in some deaths-in-custody which also involved the use of electronic control devices (ECDs) (including those manufactured by TASER International) on subjects. This review is an update on recent studies of pathophysiologic changes related to these two separate but parallel topics: a) first, the use of ECDs during law-enforcement activities; and b) second, the occurrence of excited delirium during such activities. This is a narrative review of elements that may be of use in generating hypotheses relating to potential similarities or differences between the two topics. Differences between changes in most factors due to excited delirium versus those of ECD applications were not readily apparent in most cases. These factors include: direct and indirect effects on the cardiovascular system, respiration, rhabdomyolysis and muscle enzymes, hyperkalemia, acidosis, hyperglycemia, and increased hematocrit. One factor that may exhibit consistent differences, however, is increased body temperature, which is often evident during excited delirium (versus a lack of increase temperature during ECD exposures). Thus, on the basis of this review, a more detailed delineation of this factor could be a major focus for future forensic investigations of deaths-in-custody involving either excited delirium or ECD exposures.

Absence of electrocardiographic change after prolonged application of a conducted electrical weapon in physically exhausted adults.

BACKGROUND: Conducted electrical weapons (CEWs) are used by law enforcement for control of subjects by causing neuromuscular incapacitation. There has been scrutiny of CEWs and their potential role in the occasional sudden death of subjects in custody. There is a hypothesized causal relationship due to induced cardiac dysrhythmia. Previous work has not shown dysrhythmia induction in resting humans. However, these devices are not often used on resting individuals in the field. OBJECTIVE: We sought to determine if exposure to a CEW in a physically exhausted human sample population caused detectable change in the 12-lead electrocardiogram (ECG). METHODS: Human volunteers were enrolled. All subjects had a baseline ECG obtained and then underwent an exercise regimen until exhaustion. The volunteers then received a continuous 15-s application from a TASER® X26 CEW (TASER International, Scottsdale, AZ). CEW electrodes were placed on random positions of their anterior thoraces. Electrode positions involved at least a 12-inch spread and always encompassed the normal anatomic position of the heart. An ECG was obtained immediately after CEW exposure. ECGs were interpreted by a blinded cardiologist. RESULTS: At baseline, 24/25 ECGs were normal. One baseline ECG was abnormal due to several monomorphic premature ventricular complexes. After CEW exposure, all 25 ECGs were interpreted as normal. CONCLUSIONS: Prolonged CEW application in an exhausted human sample did not cause a detectable change in their 12-lead ECGs. Theories of CEW-induced dysrhythmia in non-rested humans are not supported by our findings.