Randomized clinical trial of the effect of supplemental opioids in procedural sedation with propofol on serum catecholamines

OBJECTIVES

The objective was to assess the effect on stress biomarkers of supplemental opioid to a standard propofol dosing protocol for emergency department (ED) procedural sedation (PS). The hypothesis was that there is no difference in the change in serum catecholamines between PS using propofol with or without supplemental alfentanil.

METHODS

This was a randomized, nonblinded pilot study of adult patients undergoing PS in the ED for the reduction of fractures and dislocations. Patients with pain before the procedure were treated with intravenous (IV) morphine sulfate until their pain was adequately treated for at least 20 minutes before starting the procedure. Patients were randomized to receive either 10 μg/kg alfentanil followed by 1 mg/kg propofol, followed by 0.5 mg/kg every 3 minutes as needed, or propofol only, dosed in similar fashion without supplemental alfentanil. Doses, vital signs, nasal end-tidal CO2 (ETCO2), pulse oximetry, and bispectral electroencephalogram (EEG) analysis scores were recorded. Subclinical respiratory depression was defined as a change in ETCO2 > 10 mm Hg, an oxygen saturation of < 92% at any time, or an absent ETCO2 waveform at any time. Clinical events related to respiratory depression were noted during the procedure, including the addition of or increase in the flow rate of supplemental oxygen, the use of a bag-valve-mask apparatus, airway repositioning, or stimulation to induce breathing. Blood was drawn 1 minute prior to the administration of the medications for PS and again 1 minute after completion of the procedure for which the patient was sedated. Serum was tested for total catecholamines, epinephrine, norepinephrine, and dopamine. Postprocedure, patients were asked to report any pain perceived during the procedure. Data were analyzed using descriptive statistics, Wilcoxon rank sum tests, and chi-square tests, as appropriate.

RESULTS

Twenty patients were enrolled; 10 received propofol and 10 received propofol with alfentanil. No clinically significant complications were noted. Subclinical respiratory depression was seen in four of 10 (40%) patients in the propofol group and five of 10 (50%) patients in the propofol/alfentanil group (effect size = -10%, 95% confidence interval [CI] = -53% to 33%). There was no difference in the rate of clinical signs of respiratory depression between the two groups. Pain during the procedure was reported by two of 10 (20%) patients in the propofol group and five of 10 (50%) patients in the propofol/alfentanil group (effect size = -30%, 95% CI = -70% to 10%). Recall of some part of the procedure was reported by 0 of 10 (0%) patients in the propofol group and five of 10 (50%) of patients in the propofol/alfentanil group (effect size = -50%, 95% CI = -81% to -19%). There was no difference in the baseline or postprocedure catecholamine levels between the groups.

CONCLUSIONS

No difference in serum catecholamines was detected immediately after PS between patients who receive propofol with and without supplemental opioid in this small pilot study. PS using propofol only without supplemental opioid did not appear to induce markers of physiologic stress in this small pilot study.

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.