A comparison of three conducted electrical weapons in a surrogate swine cardiac safety model

We used a previously described methodology in a swine model to compare the relative cardiac safety of the Axon T7 Conducted Electrical Weapon (CEW), released in October of 2018, to two prior generations of Axon CEWs to include the X2 and the X26E. A total of 5 swine (252 total CEW exposures) were tested by alternating the three weapons at each chest exposure location. Our testing, using systemic hypotension as the quantitative surrogate for cardiac capture, demonstrated that the T7 and X2 were not statistically different. Both were superior, in terms of reduced hypotension during exposure, to the X26E. This study is important as it demonstrates that the newly released weapon is non-inferior to the X2 and superior to the X26E using this surrogate safety model. It is also important because it is the first study to examine the cardiac effects of simultaneous multi-bay exposures. Our prior study compared the X2 to the X26E but examined only single bay exposures from the X2. Lastly, we feel we have improved the methodology for studying the comparative cardiac effects of CEWs.

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.

Acidosis and catecholamine evaluation following simulated law enforcement "use of force" encounters

OBJECTIVES

Law enforcement authorities are often charged with controlling resisting suspects. These encounters sometimes result in the sudden and unexpected death of the suspect. Drug intoxication, excited delirium syndrome, or excessive uses of force are factors that are often blamed, but sometimes the mechanism of these deaths is not fully understood. It is possible that worsening acidosis or excessive catecholamine release play a part. The objective of this study was to determine the effect on markers of acidosis and catecholamines of various tasks intended to simulate common arrest-related situations.

METHODS

Subjects were assigned to one of five task groups: 1) a 150-meter sprint and wall hurdle (simulated flight from arrest); 2) 45 seconds of striking a heavy bag (simulated physical resistance); 3) a 10-second TASER X26 electronic control device exposure; 4) a fleeing and resistance exercise involving a law enforcement dog (K-9); or 5) an oleoresin capsicum (OC) exposure to the face and neck. Baseline serum pH, lactate, potassium, troponin I, catecholamines, and creatine kinase (CK) were evaluated. Serum catecholamines, pH, lactate, and potassium were sampled immediately after the task and every 2 minutes for 10 minutes posttask. Vital signs were repeated immediately after the task. Serum CK and troponin I were evaluated again at 24 hours posttask.

RESULTS

Sixty-six subjects were enrolled; four did not complete their assigned task. One subject lost the intravenous (IV) access after completing the task and did not have data collected, and one subject only received a 5-second TASER device exposure and was excluded from the study, leaving 12 subjects in each task group. The greatest changes in acidosis markers occurred in the sprint and heavy bag groups. Catecholamines increased the most in the heavy bag group and the sprint group and increased to a lesser degree in the TASER, OC, and K-9 groups. Only the sprint group showed an increase in CK at 24 hours. There were no elevations in troponin I in any group, nor any clinically important changes in potassium.

CONCLUSIONS

The simulations of physical resistance and fleeing on foot led to the greatest changes in markers of acidosis and catecholamines. These changes may be contributing or causal mechanisms in sudden custodial arrest-related deaths (ARDs). This initial work may have implications in guiding applications of force for law enforcement authorities (LEAs) when apprehending resisting subjects.

Effect of an electronic control device exposure on a methamphetamine-intoxicated animal model

OBJECTIVES

Because of the prevalence of methamphetamine abuse worldwide, it is not uncommon for subjects in law enforcement encounters to be methamphetamine-intoxicated. Methamphetamine has been present in arrest-related death cases in which an electronic control device (ECD) was used. The primary purpose of this study was to determine the cardiac effects of an ECD in a methamphetamine intoxication model.

METHODS

Sixteen anesthetized Dorset sheep (26-78 kg) received 0.0 mg/kg (control animals, n = 4), 0.5 mg/kg (n = 4), 1.0 mg/kg (n = 4), or 1.5 mg/kg (n = 4) of methamphetamine hydrochloride as a slow intravenous (IV) bolus during continuous cardiac monitoring. The animals received the following exposures in sequence from a TASER X26 ECD beginning at 30 minutes after the administration of the drug: 1) 5-second continuous exposure, 2) 15-second intermittent exposure, 3) 30-second intermittent exposure, and 4) 40-second intermittent exposure. Darts were inserted at the sternal notch and the cardiac apex, to a depth of 9 mm. Cardiac motion was determined by thoracotomy (smaller animals, < or = 32 kg) or echocardiography (larger animals, > 68 kg). Data were analyzed using descriptive statistics and chi-square tests.

RESULTS

Animals given methamphetamine demonstrated signs of methamphetamine toxicity with tachycardia, hypertension, and atrial and ventricular ectopy in the 30-minute period immediately after administration of the drug. Smaller animals (n = 8, < or = 32 kg, mean = 29.4 kg) had supraventricular dysrhythmias immediately after the ECD exposures. Larger animals (n = 8, > 68 kg, mean = 72.4) had only sinus tachycardia after the exposures. One of the smaller animals had frequent episodes of ventricular ectopy after two exposures, including runs of delayed onset, nonsustained six- to eight-beat unifocal and multifocal ventricular tachycardia that spontaneously resolved. This animal had significant ectopy prior to the exposures as well. Thoracotomy performed on three smaller animals demonstrated cardiac capture during ECD exposure consistent with previous animal studies. In the larger animals, none of the methamphetamine-intoxicated animals demonstrated cardiac capture. Two control sheep showed evidence of capture similar to the smaller animals. No ventricular fibrillation occurred after the exposure in any animal.

CONCLUSIONS

In smaller animals (32 kg or less), ECD exposure exacerbated atrial and ventricular irritability induced by methamphetamine intoxication, but this effect was not seen in larger, adult-sized animals. There were no episodes of ventricular fibrillation after exposure associated with ECD exposure in methamphetamine-intoxicated sheep.

The physiologic effects of multiple simultaneous electronic control device discharges

OBJECTIVES

Law enforcement and military personnel use electronic control devices to control non-compliant and actively resistive subjects. The TASER((R)) Shockwave is a new electronic control device designed specifically as an area denial device capable of delivering multiple simultaneous discharges. This is the first study to examine the effects of multiple simultaneous device discharges in humans.

METHODS

Volunteers were exposed to multiple (two to three), simultaneous 5-second discharges from the Shockwave device to the chest, back, chest to abdomen, or thighs. Blood was analyzed before and after discharge for pH, lactate, potassium, creatine kinase (CK), and troponin. Continuous spirometry was performed before, during, and after the discharge. In addition, electrocardiograms (ECGs) before and after discharge were recorded, and echocardiography was used to determine the rhythm during discharge.

RESULTS

Small elevations of lactate occurred. Moderate increases in CK at 24 hours occurred and appeared to be related to the number of simultaneous discharges. There was a trend to a decrease in minute ventilation in the volunteers exposed to two simultaneous discharges, but it did not reach statistical significance. ECG changes only reflected an increase in vagal tone, and there was no evidence of capture by echocardiography. Five-second, simultaneous, multiple exposures to the TASER Shockwave device were reasonably tolerated by our human volunteers.

CONCLUSION

Our study suggests that this device may have a reasonable risk/benefit ratio when used to protect an area from a threat.

Prolonged TASER use on exhausted humans does not worsen markers of acidosis

OBJECTIVE

There are safety concerns about TASER conducted electrical weapon (CEW) use on humans, and there have been media reports of adverse human outcomes after CEW exposure. Conducted electrical weapons are often used on physically exhausted subjects. A single CEW application of a CEW is generally accepted to be 5 seconds of exposure. Some exposures in reality involve more than 5 seconds. We sought to determine if a prolonged (15 seconds) CEW exposure on exhausted humans caused acidosis, hyperkalemia, serum lactate change, or troponin change.

METHODS

This was a prospective study of generally healthy human volunteers. Medical histories and baseline serum values were obtained, and several of the volunteers did have acute or chronic medical problems. Subjects underwent an exercise protocol until subjective exhaustion. Exhaustion was defined by the volunteer no longer being able to perform the exercise at a given pace. Blood was drawn immediately (defined as within 20 seconds) after exercise and was immediately followed by a 15-second CEW exposure. Blood was drawn immediately after exposure and again at 16 to 24 hours after exposure. Blood was analyzed for pH, pco(2), potassium, lactate, and troponin. Data were compared using Wilcoxon signed rank tests.

RESULTS

There were 38 subjects enrolled with an average age of 39 years. The following health conditions were reported among the volunteers: hypertension (2), gastritis/reflux (2), active respiratory tract infections (3), asthma (2), chronic muscular pain conditions (4), pituitary adenoma (1) and glaucoma (1). Sixteen volunteers reported use of prescription medication at the time of their participation. The median initial pH of 7.38 (interquartile range [IQR], 7.35-7.40) decreased to 7.23 (IQR, 7.19-7.31) immediately after exercise. Immediately after exposure, median pH was 7.22 (IQR, 7.18-7.25). It was 7.39 (IQR, 7.37-7.43) at 24 hours. The pCO2 increased from 46.3 (IQR, 43.0-54.5) to 57.4 (IQR, 49.9-67.7) immediately after exercise, decreased to 51.3 (IQR, 44.4-65.0) immediately after exposure, and was 46.3 (IQR, 42.7-51.7) at 24 hours. Lactate increased from a median of 1.65 (IQR, 1.14-2.55) to 8.39 (IQR, 6.98-11.66) immediately after exercise, increased to 9.85 (IQR, 7.70-12.87) immediately after exposure, and was 1.02 (IQR, 0.91-1.57) at 24 hours. Serum potassium increased from 3.9 (IQR, 3.8-4.4) to 4.2 (IQR, 4.0-4.9) immediately after exercise, decreased to 3.8 (IQR, 3.7-4.4) immediately after exposure, and was 4.1 (IQR, 3.9-4.6) at 24 hours. No troponin elevations were detected.

CONCLUSION

Prolonged CEW application on exhausted humans was not associated with worsening change in pH or troponin. Decreases in pCO2 and potassium and a small increase in lactate were found. Worsening acidosis theories due to CEW use in this population are not supported by these data.

Unexpected arrest-related deaths in america: 12 months of open source surveillance

INTRODUCTION

Sudden, unexpected arrest-related death (ARD) has been associated with drug abuse, extreme delirium or certain police practices. There is insufficient surveillance and causation data available. We report 12 months of surveillance data using a novel data collection methodology.

METHODS

We used an open-source, prospective method to collect 12 consecutive months of data, including demographics, behavior, illicit substance use, control methods used, and time of collapse after law enforcement contact. Descriptive analysis and chi-square testing were applied.

RESULTS

There were 162 ARD events reported that met inclusion criteria. The majority were male with mean age 36 years, and involved bizarre, agitated behavior and reports of drug abuse just prior to death. Law enforcement control techniques included none (14%); empty-hand techniques (69%); intermediate weapons such as TASER((R)) device, impact weapon or chemical irritant spray (52%); and deadly force (12%). Time from contact to subject collapse included instantaneous (13%), within the first hour (53%) and 1-48 hours (35%). Significant collapse time associations occurred with the use of certain intermediate weapons.

CONCLUSION

This surveillance report can be a foundation for discussing ARD. These data support the premise that ARDs primarily occur in persons with a certain demographic and behavior profile that includes middle-aged males exhibiting agitated, bizarre behavior generally following illicit drug abuse. Collapse time associations were demonstrated with the use of TASER devices and impact weapons. We recommend further study in this area to validate our data collection method and findings.

Human research review of the TASER electronic control device

TASER Electronic Control Devices have become mainstream methods of applying electricity to control unruly suspects. There has been speculation that they may be associated with worsening human physiology or death. The lay impressions that these devices are unsafe are not founded on known human research findings. This presentation briefly reviews the most pertinent human research on this subject.

Echocardiographic evaluation of a TASER-X26 application in the ideal human cardiac axis

OBJECTIVES

TASER electronic control devices (ECDs) are used by law enforcement to subdue aggressive persons. Some deaths temporally proximate to their use have occurred. There is speculation that these devices can cause dangerous cardiac rhythms. Swine research supports this hypothesis and has reported significant tachyarrhythmias. It is not known if this occurs in humans. The objective of this study was to determine the occurrence of tachyarrhythmias in human subjects subjected to an ECD application.

METHODS

This was a prospective, nonblinded study. Human volunteers underwent limited echocardiography before, during, and after a 10-second TASER X26 ECD application with preplaced thoracic electrodes positioned in the upper right sternal border and the cardiac apex. Images were analyzed using M-mode through the anterior leaflet of the mitral valve for evidence of arrhythmia. Heart rate (HR) and the presence of sinus rhythm were determined. Data were analyzed using descriptive statistics.

RESULTS

A total of 34 subjects were enrolled. There were no adverse events reported. The mean HR prior to starting the event was 108.7 beats/min (range 65 to 146 beats/min, 95% CI = 101.0 to 116.4 beats/min). During the ECD exposure, the mean HR was 120.1 beats/min (range 70 to 158 beats/min, 95% CI = 112.2 to 128.0 beats/min) and a mean of 94.1 beats/min (range 55 to 121 beats/min, 95% CI = 88.4 to 99.7 beats/min) at 1 minute after ECD exposure. Sinus rhythm was clearly demonstrated in 21 (61.7%) subjects during ECD exposure (mean HR 121.4 beats/min; range 75 to 158 beats/min, 95% CI = 111.5 to 131.4). Sinus rhythm was not clearly demonstrated in 12 subjects due to movement artifact (mean HR 117.8 beats/min, range 70 to 152 beats/min, 95% CI = 102.8 to 132.8 beats/min).

CONCLUSIONS

A 10-second ECD exposure in an ideal cardiac axis application did not demonstrate concerning tachyarrhythmias using human models. The swine model may have limitations when evaluating ECD technology.

Impact of conducted electrical weapons in a mentally ill population: a brief report

INTRODUCTION

Conducted electrical weapons (CEWs) are used by some law enforcement agencies to subdue mentally ill subjects who are combative, violent, or suicidal. The use of CEWs in this population is controversial. Proponents advocate CEW use to avoid other forms of escalated force. Opponents advocate against CEW use because of the potential for abuse. What is lacking in the medical literature is documentation of the impact on outcome that this technology may have when used in this population. This project represents an initial report in this area.

METHODS

A database of CEW use has been maintained since 1999 to which law enforcement agencies voluntarily report. This database was reviewed for occurrences of CEW use on mentally ill and suicidal subjects. Situation outcome and potential for law enforcement use of deadly force as an alternative were recorded. Data analysis was performed using descriptive statistics.

RESULTS

There were 10,608 reports of CEW use over a 72-month period. Of these, there were 2452 uses on mentally ill subjects; and of these, 1111 (45.3%) were in situations where lethal force by the law enforcement agency would have been justified or where the subject represented an imminent life threat to himself.

CONCLUSION

The mentally ill represents a significant portion of subjects upon whom CEWs are used. These data suggest frequent use of CEWs in situations where deadly force would otherwise be justified and in situations where subjects exhibit imminent danger to themselves. These data also suggest that escalation to deadly force was avoided in many mental illness and suicidal situations by the presence of a CEW.

Respiratory effect of prolonged electrical weapon application on human volunteers

BACKGROUND

Conducted electrical weapons (CEWs) are used by law enforcement to subdue combative subjects. Occasionally, subjects will die after a CEW has been used on them. It is theorized that CEWs may contribute to these deaths by impairing respiration.

OBJECTIVES

To examine the respiratory effects of CEWs.

METHODS

Human volunteers received a 15-second application of electrical current from a CEW while wearing a respiratory measurement device. Common respiratory parameters were collected before, during, and after exposure. Health histories and demographic information were also collected.

RESULTS

Fifty-two subjects were analyzed. Thirty-four underwent a 15-second continuous exposure, and 18 underwent three 5-second burst exposures. In the continuous application group, the baseline mean tidal volume of 1.1 L increased to 1.8 L during application, the baseline end-tidal CO2 level went from 40.5 mm Hg to 37.3 mm Hg after exposure, the baseline end-tidal oxygen level went from 118.7 mm Hg to 121.3 mm Hg after exposure, and the baseline respiratory rate went from 15.9 breaths/min to 16.4 breaths/min after exposure. In the 5-second burst group, the baseline mean tidal volume increased to 1.85 L during application, the baseline end-tidal CO2 level went from 40.9 mm Hg to 39.1 mm Hg after exposure, the baseline end-tidal oxygen level went from 123.1 mm Hg to 127.0 mm Hg after exposure, and the baseline respiratory rate went from 13.8 breaths/min to 14.6 breaths/min after exposure.

CONCLUSIONS

Prolonged CEW application did not impair respiratory parameters in this population of volunteers. Further study is recommended to validate these findings in other populations.

Molecular genetic aspects of oligodendrogliomas including analysis by comparative genomic hybridization

Oligodendroglial neoplasms are a subgroup of gliomas with distinctive morphological characteristics. In the present study we have evaluated a series of these tumors to define their molecular profiles and to determine whether there is a relationship between molecular genetic parameters and histological pattern in this tumor type. Loss of heterozygosity (LOH) for 1p and 19q was seen in 17/23 (74%) well-differentiated oligodendrogliomas, in 18/23 (83%) anaplastic oligodendrogliomas, and in 3/8 (38%) oligoastrocytomas grades II and III. LOH for 17p and/or mutations of the TP53 gene occurred in 14 of these 55 tumors. Only one of the 14 cases with 17p LOH/TP53 gene mutation also had LOH for 1p and 19q, and significant astrocytic elements were seen histologically in the majority of these 14 tumors. LOH for 9p and/or deletion of the CDKN2A gene occurred in 15 of these 55 tumors, and 11 of these cases were among the 24 (42%) anaplastic oligodendrogliomas. Comparative genomic hybridization (CGH) identified the majority of cases with 1p and 19q loss and, in addition, showed frequent loss of chromosomes 4, 14, 15, and 18. These findings demonstrate that oligodendroglial neoplasms usually have loss of 1p and 19q whereas astrocytomas of the progressive type frequently contain mutations of the TP53 gene, and that 9p loss and CDKN2A deletions are associated with progression from well-differentiated to anaplastic oligodendrogliomas.