Increased Hematocrit Due to Electrical-Waveform Exposures in Splenectomized Sus scrofa.

In laboratory studies of the pig Sus scrofa, hematocrit has consistently increased after conducted-electrical-weapon (CEW) exposures, possibly due to contraction of the spleen. Splenectomized animals and intact sham control animals were exposed, each for 30 sec, to a benchtop-produced electrical waveform of net charge levels similar to those of some CEWs. Changes in the blood were compared statistically. Hematocrit increased significantly in both splenectomized and sham animals. There were no significant main-effect differences between values of hematocrit from the two groups. There were, however, significant interactive effects of time and splenectomy for hematocrit, red blood cell count, and hemoglobin. After peak values were reached for these variables, values returned toward baseline levels more slowly in splenectomized animals. This may have been due to the lack of a spleen to sequester red blood cells (thereby resulting in more cells remaining in the general circulation), unlike sham animals with intact spleens.

Pathophysiological alterations induced by sustained 35-GHz radio-frequency energy heating.

BACKGROUND: Exposure to radio-frequency energy (RFE) of millimeter wavelengths results in a relatively high skin-heating rate, with only a moderate rate of core heating. Yet, prolonged RFE exposure eventuates in severe hypotension and death. In this study, we characterized pathophysiological changes associated with prolonged RFE sufficient to induce hypotension. METHODS: Anesthetized rats were exposed to 35-GHz RFE with a power density of 75 mW/cm2. Cardiovascular and temperature parameters were continuously recorded. Blood factors and histopathology were compared between sham (n=6) and exposed (n=12) animals. RESULTS AND CONCLUSIONS: Using infrared thermography, we confirmed a relatively high temperature (>46 °C) at the skin surface of the irradiated site. Histopathological results included hemorrhage and congestion of blood vessels in the dermis and subcutis of irradiated skin without induction of burn. As in environmental heating, significantly greater levels of serum glucose, creatinine, uric acid, and anion gap were observed in rats exposed to longer-duration RFE (approx. 38-min exposures) than in shorter-duration (approx. 19-min exposures) or sham (time control) animals. However, changes in blood electrolytes or liver enzymes (often seen during heatstroke) were not observed after the RFE exposures. Even without major tissue injury or serum/plasma enzyme and electrolyte changes, rapid cutaneous heating via RFE induced profound hypotension that eventuated in death.

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.

Exposures to conducted electrical weapons (including TASER® devices): how many and for how long are acceptable?

TASER(®) conducted electrical weapons (CEWs) are an important law-enforcement tool. The purposes of this study are a) to review recent literature regarding potential pathophysiological responses to applications of CEWs, and other related issues and b) to evaluate whether enough data exist to determine the acceptability of longer-duration (or repeated) exposures. This is a narrative review, using a multidisciplinary approach of analyzing reports from physiological, legal-medical, and police-strategy literature sources. In general, short-duration exposures to CEWs result in limited effects. Longer-duration or repeated exposures may be utilized with caution, although there are currently not enough data to determine the acceptability of all types of exposures. Data examined in the literature have inherent limitations. Appropriateness of specific types of CEW usage may be determined by individual police agencies, applying risk/benefit analyses unique to each organization. While more research is recommended, initial concepts of potential future long-duration or repeated CEW applications are presented.

Exposures of Sus scrofa to a TASER(®) conducted electrical weapon: no effects on 2-dimensional gel electrophoresis patterns of plasma proteins.

In an earlier study, we found significant changes in red-blood-cell, leukocyte, and platelet counts, and in red-blood-cell membrane proteins, following exposures of anesthetized pigs to a conducted electrical weapon. In the current study, we examined potential changes in plasma proteins [analyzed via two-dimensional gel electrophoresis (2-DGE)] following two 30 s exposures of anesthetized pigs (Sus scrofa) to a TASER (®) C2 conducted electrical weapon. Patterns of proteins, separated by 2-DGE, were consistent and reproducible between animals and between times of sampling. We determined that the blood plasma collection, handling, storage, and processing techniques we used are suitable for swine blood. There were no statistically significant changes in plasma proteins following the conducted-electrical-weapon exposures. Overall gel patterns of fibrinogen were similar to results of other studies of both pigs and humans (in control settings, not exposed to conducted electrical weapons). The lack of significant changes in plasma proteins may be added to the body of evidence regarding relative safety of TASER C2 device exposures.

40-Hz square-wave stimulation requires less energy to produce muscle contraction: compared with the TASER® X26 conducted energy weapon.

Conducted energy weapons (CEWs) (including the Advanced TASER(®) X26 model produced by TASER International, Inc.) incapacitate individuals by causing muscle contractions. In this study using anesthetized swine, the potential incapacitating effect of primarily monophasic, 19-Hz voltage imposed by the commercial CEW was compared with the effect of voltages imposed by a laboratory device that created 40-Hz square waves. Forces of muscle contraction were measured with the use of strain gauges. Stimulation with 40-Hz square waves required less pulse energy than stimulation with the commercial CEW to produce similar muscle contraction. The square-pulse stimulation, at the higher repetition rate, caused a more complete tetanus at a lower energy. Use of such a simple shape of waveform may be used to make future nonlethal weapon devices more efficient.

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.

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.

Survival of anesthetized Sus scrofa after cycling (7-second on/3-second off) exposures to an electronic control device for 3 minutes.

Electronic control devices (ECDs) may eventually be deployed by the military in a manner resulting in longer exposures than those encountered during law-enforcement operations. In a previous study, 18 repeated cycling (5-second on/5-second off) exposures (within a 3-minute period) of anesthetized swine to an ECD (TASER International's Advanced TASER X26 device) resulted in leg muscle contraction, acidosis, and increases in blood electrolytes. In the current study, experiments were performed to examine effects of exposures to a different cycling rate (7-second on/3-second off), from a modified X26 ECD, on 10 swine (Sus scrofa), maintained on propofol anesthesia. In contrast with the previous study, a large number of animals (6/10) died immediately after the exposures. There were no major differences in pre-exposure blood factors from survivors versus nonsurvivors, with the exception of hematocrit and 2 isoenzymes of lactate dehydrogenase. It is doubtful that these factors would be useful in predicting survival after ECD exposure. Blood pH was significantly decreased after exposure, but (in animals that survived) subsequently returned to baseline levels. On the basis of the overall survival rate, further development of useful ECDs (for long-term incapacitation during military operations) may require consideration of longer pauses between repeated exposures over a 3-minute period.

Increased hematocrit after applications of conducted energy weapons (including TASER(®) devices) to Sus scrofa.

Conducted energy weapons (CEWs) are used by law enforcement personnel to incapacitate individuals quickly and effectively, without intending to cause lethality. CEWs have been deployed for relatively long or repeated exposures in some cases. In laboratory animal models, central venous hematocrit has increased significantly after CEW exposure. Even limited applications (e.g., three 5-sec applications) resulted in statistically significant increases in hematocrit. Preexposure hematocrit was significantly higher in nonsurvivors versus survivors after more extreme CEW applications. The purpose of this technical note is to address specific questions that may be generated when examining these results. Comparisons among results of CEW applications, other electrical muscle stimulation, and exercise/voluntary muscle contraction are included. The anesthetized swine appears to be an acceptable animal model for studying changes in hematocrit and associated red blood cell changes. Potential detrimental effects of increased hematocrit, and considerations during law enforcement use, are discussed.

Muscle contraction during electro-muscular incapacitation: A comparison between square-wave pulses and the TASER(®) X26 Electronic control device.

Electronic control devices (including the Advanced TASER(®) X26 model produced by TASER International) incapacitate individuals by causing muscle contractions. To provide information relevant to development of future potential devices, effects of monophasic square waves with different parameters were compared with those of the X26 electronic control device, using two animal models (frogs and swine). Pulse power, electrical pulse charge, pulse duration, and pulse repetition frequency affected muscle contraction. There was no difference in the charge required, between the square waveform and the X26 waveform, to cause approximately the same muscle-contraction response (in terms of the strength-duration curve). Thus, on the basis of these initial studies, the detailed shape of a waveform may not be important in terms of generating electro-muscular incapacitation. More detailed studies, however, may be required to thoroughly test all potential waveforms to be considered for future use in ECDs.

An animal model to investigate effectiveness and safety of conducted energy weapons (including TASER devices).

Conducted energy weapons (CEWs) are used by law-enforcement personnel to incapacitate individuals quickly and effectively, without causing lethality. CEWs have been deployed for relatively long or repeated exposures during law-enforcement operations. The purpose of this technical note is to describe, in detail, some aspects of an anesthetized swine model used in our laboratory and to answer specific questions related to the model. In particular, tiletamine/zolazepam-induced, propofol-maintained anesthesia appears to be a useful technique for studying effects of CEW applications on muscle contraction and blood factors such as muscle enzymes. Because effects of CEWs on breathing have not been fully elucidated, a spontaneously breathing model is preferable to one in which mechanical ventilation is supplied. Placement of the swine in a supine position may facilitate measurement of muscle contractions, without compromising other physiological parameters.

Deaths in custody: are some due to electronic control devices (including TASER devices) or excited delirium?

Deaths have occurred after law-enforcement incidents involving applications of electronic control devices (ECDs) (including TASER devices). An "excited delirium" syndrome (reported in the literature prior to the development of ECDs currently in use), however, includes several factors that may be related to such deaths in custody. In this review, potential detrimental effects of ECDs are compared with possible changes due to excited delirium. Although extreme (i.e., long-duration or repeated) exposures to ECDs can result in significant hyperkalaemia, acidaemia, and myoglobinemia in animal models, limited applications (such as those normally used in law-enforcement situations) would appear to have only transient effects. In addition, the hyperthermia observed in patients with excited delirium does not seem to be directly exacerbated by ECD applications. ECD use is unlikely to be a common cause of ventricular fibrillation, but other events that are generally associated with excited delirium (e.g., drug use) may be related to subsequent ventricular fibrillation or asystole. Metabolic or respiratory acidosis may only be serious consequences of long-duration or repeated ECD applications. On the basis of current available information, factors other than ECDs themselves may be more important when death occurs after the use of ECDs.

Repeated or long-duration TASER electronic control device exposures: acidemia and lack of respiration.

Conducted energy weapons (CEWs), such as TASER devices, may be applied to subjects in repeated or long-duration modes. Such applications may result in more potentially harmful effects (as reflected in blood factor changes) than shorter exposures. In this review, results from a number of studies of repeated and long-duration CEW exposures in an animal model are examined. Additionally, a few limited investigations of shorter CEW applications to human subjects are considered. Specifically, in anesthetized swine, increased blood acidity (acidemia) and lack of effective respiration were found to be common during or immediately after CEW exposure. The acidemia could have been due to both metabolic and respiratory acidosis. A relatively rapid recovery toward baseline pH levels occurred. The lack of effective respiration has not been verified in experiments of CEW applications to human subjects; however, in some incidents of human deaths after CEW exposures subjects have been reported to stop breathing immediately after the exposure. It is not known if all human subjects exposed to CEW applications in the field (often "on drugs" or "in excited delirium") would be able to maintain adequate breathing. Since a limited number of short CEW applications would be less likely to cause adverse effects, however, CEWs can still be a valuable tool for law enforcement activities.

Pulse variations of a conducted energy weapon (similar to the TASER X26 device): effects on muscle contraction and threshold for ventricular fibrillation*.

Conducted energy weapons (such as the Advanced TASER X26 model produced by TASER International), incapacitate individuals by causing muscle contractions. To provide information relevant to development of future potential devices, a "Modifiable Electronic Stimulator" was used to evaluate the effects of changing various parameters of the stimulating pulse. Muscle contraction was affected by pulse power, net/gross charge, pulse duration, and pulse repetition frequency. The contraction force increased linearly as each of these factors was increased. Elimination of a precursor pulse from X26-like pulses did not have a significant effect on the normalized force measured. Muscle-contraction force increased as the spacing increased from 5 to 20 cm, with no further change in force above 20 cm of spacing. Therefore, it is suggested that any future developments of new conducted energy weapons should include placement of electrodes a minimum of 20 cm apart so that efficiency of the system is not degraded. In the current study, the 50% probability of fibrillation level of X26-like pulses ranged from 4 to 5 times higher than the X26 itself. Relatively large variations about the X26 operating level were found not to result in fibrillation or asystole. Therefore, it should be possible to design and build an X26-type device that operates efficiently at levels higher than the X26.

Physiological effects of the TASER C2 conducted energy weapon.

In previous studies, exposure to conducted energy weapons (CEWs) (such as TASER International's Advanced TASER X26 device) resulted in leg muscle contraction, acidosis, increased blood electrolytes, and other biochemical and physiological changes. In the current study, experiments were performed to examine the effects of exposures to TASER International's "C2" CEW, which is specifically marketed to civilian rather than law-enforcement users. Ten pigs (Sus scrofa) were sedated with an intramuscular injection of Telezol (tiletamine HCl and zolazepam HCl) and intubated. General anesthesia was maintained with an IV propofol infusion. Applications of the C2 device for 30 s resulted in extensive muscle contraction and significant increases in heart rate and hematocrit, and in blood levels of pCO2, lactate, glucose, and potassium, sodium, and calcium ions. Significant decreases were observed in blood oxygen saturation, pO2, and pH. Qualitatively, many of these changes were consistent with previous reports in the literature dealing with studies of muscle stimulation or exercise. The changes in blood pCO2, pO2, electrolytes, lactate, and pH, however, were greater than in a previous study of three repeated 5-s exposures to the X26 CEW commonly used by law-enforcement personnel. On the basis of the results, potential detrimental effects due to use of the "citizen-version" TASER C2 CEW may be more likely than limited intermittent applications of the X26 CEW.

Effects of low-level radio-frequency (3kHz to 300GHz) energy on human cardiovascular, reproductive, immune, and other systems: a review of the recent literature.

OBJECTIVES: Occupational or residential exposures to radio-frequency energy (RFE), including microwaves, have been alleged to result in health problems. A review of recent epidemiological studies and studies of humans as subjects in laboratory investigations would be useful. METHODS: This paper is a narrative review of the recent medical and scientific literature (from mid-1998 through early 2006) dealing with possible effects of RFE on humans, relating to topics other than cancer, tumors, and central nervous system effects (areas covered in a previous review). Subject areas in this review include effects on cardiovascular, reproductive, and immune systems. RESULTS: A large number of studies were related to exposures from cellular telephones. Although both positive and negative findings were reported in some studies, in a majority of instances no significant health effects were found. Most studies had some methodological limitations. Although some cardiovascular effects due to RFE were reported in epidemiological studies (e.g., lower 24-h heart rate, blunted circadian rhythm of heart rate), there were no major effects on a large number of cardiovascular parameters in laboratory studies of volunteers during exposure to cell-phone RFE. In population-based studies of a wide range of RFE frequencies, findings were equivocal for effects on birth defects, fertility, neuroblastoma in offspring, and reproductive hormones. Some changes in immunoglobulin levels and in peripheral blood lymphocytes were reported in different studies of radar and radio/television-transmission workers. Due to variations in results and difficulties in comparing presumably exposed subjects with controls, however, it is difficult to propose a unifying hypothesis of immune-system effects. Although subjective symptoms may be produced in some sensitive individuals exposed to RFE, there were no straightforward differences in such symptoms between exposed and control subjects in most epidemiological and laboratory studies. Consistent, strong associations were not found for RFE exposure and adverse health effects. The majority of changes relating to each of the diseases or conditions were small and not significant. CONCLUSIONS: On the basis of previous reviews of older literature and the current review of recent literature, there is only weak evidence for a relationship between RFE and any endpoint studied (related to the topics above), thus providing at present no sufficient foundation for establishing RFE as a health hazard.

Blood factors of Sus scrofa following a series of three TASER electronic control device exposures.

In a previous study, 18 repeated exposures of anaesthetized swine to an electro-muscular incapacitating device (TASER International's ADVANCED TASER X26 electronic control device) resulted in acidosis and increases in blood electrolytes. In the current study, experiments were performed to investigate effects of a more typical scenario of repeated exposures of the device on muscle contraction and changes in blood factors. Ten swine were exposed for 5s, followed by a 5-s period of no exposure, three times. Selected blood factors were monitored for 3h following exposure. Transient increases in blood glucose, lactate, sodium, potassium, calcium, and pCO(2) were consistent with previous reports in the literature dealing with studies of muscle stimulation or exercise. Blood pH was decreased immediately following exposure, but subsequently returned toward a normal level. Oxygen saturation (measured by pulse oximetry) was not changed significantly. In conclusion, three repeated TASER device exposures had only transient effects on blood factors, which all returned to pre-exposure levels, with the exception of hematocrit (which remained elevated after 3h). Since the increase in this factor was less than that which may occur after short periods of exercise, it is unlikely that this would be an indicator of any serious harm.