Cannabis in combat sports: position statement of the Association of Ringside Physicians.

and ARP Position Statement: Based on the available body of scientific evidence and with the goals of promoting safety of combat sports athletes and striving for the advancement of clean sport, the Association of Ringside Physicians recommends the following regarding cannabis:• Use of marijuana or synthetic cannabinoids by combat sports athletes is discouraged due to unproven benefits and many known adverse effects. Acute use can impair cognition and complex motor function, which likely leads to reduced performance in combat sports. Chronic use can increase risk for heart and lung disease, several cancers, schizophrenia, and can reduce testosterone in men and impair fertility. Benefits from cannabis in most contexts, including athletic performance, have not been proven.• Use of topical purified CBD is neither encouraged nor discouraged.• Since acute cannabis intoxication can impair complex cognitive and motor function, any athlete suspected of acute intoxication at the time of competition - based on clinical judgment - should be banned from that competition.• Wide-scale regulation of cannabis based on quantitative testing has limited usefulness in combat sports, for the following reasons:∘ Cannabis is not ergogenic and is likely ergolytic.∘ Concentrations in body fluids correlate poorly with clinical effects and timing of use.∘ Access to testing resources varies widely across sporting organizations.

Impact of repeated sportive chokes on carotid intima media thickness and brain injury biomarkers in grappling athletes.

PURPOSE: Vascular neck compression techniques, referred to as 'chokes' in combat sports, reduce cerebral perfusion, causing loss of consciousness or voluntary submission by the choked athlete. Despite these chokes happening millions of times yearly around the world, there is scant research on their long-term effects. This pilot study evaluated whether repeated choking in submission grappling impacts the carotid intima media thickness (CIMT) and brain injury biomarkers (NFL, hGFAP, t-Tau, and UCH-L1). METHODS: Participants (n = 39, 29 male; ages 27-60 years) were assigned to one of two study arms: Grapplers (n = 20, 15 male) and 19 age/sex/body size matched controls. Grapplers had been exposed to >500 choke events while training for >5 years in a choke-inclusive sport. Exclusion criteria were recent TBI or deficits from a past TBI or stroke. Bilateral ultrasound measurement of the CIMT was performed, and blood was collected for quantitative analysis of four brain injury markers. Subgroup analyses were performed within the Grappler group to account for blunt head trauma as a possible confounder. RESULTS: There was no overall difference in CIMT measurements between Grapplers (mean 0.55 mm, SD 0.07) and Controls (mean 0.57 mm, SD 0.10) p = 0.498 [95% CI -0.04-0.08], nor were there CIMT differences between Grappler subgroups of blunt Trauma and No-Trauma. There were no significant differences in any biomarkers comparing Grapplers and Controls or comparing Grappler subgroups of Trauma and No-Trauma. CONCLUSION: This study found no significant difference in CIMT and serum brain injury biomarkers between controls and grapplers with extensive transient choke experience, nor between grapplers with extensive past blunt head trauma and those without.

Cervical Artery Dissections and Ischemic Strokes Associated with Vascular Neck Compression Techniques (Sportive Chokes).

BACKGROUND: Strangulation as a fight-finishing maneuver in combat sports, termed "choking" in that context, occurs worldwide millions of times yearly. This activity can be trained safely, but devastating injuries can occur. OBJECTIVE: Our aim was to present a case series of cervical artery dissections and ischemic strokes associated with sportive choking. Sharing these cases is meant to draw awareness, to assist emergency physicians in caring for these athletes, and to provide a platform for further research. METHODS: Institutional Review Board approval was obtained. Participants consented for medical information transfer and anonymous academic reproduction. The minimum medical record information necessary for inclusion was a report of diagnosis-confirming advanced imaging. Participants were contacted for primary information in addition to what the medical records could provide and to confirm some information in the record (e.g., pertinent medical history, demographic characteristics, choking event description, medical care, and commentary on their current health). Medical records and additional first-hand information were reviewed and participants were included if they had a diagnosed dissection or stroke likely associated with a sportive choke. RESULTS: Ten cases met all criteria for inclusion. There were 5 cases of carotid artery dissection, 3 cases of vertebral artery dissection, and 2 cases of ischemic stroke without dissection. Nine of 10 participants survived and 3 of 10 have returned to submission grappling training. CONCLUSIONS: Cervical artery dissections and ischemic strokes can occur in association with sportive choking. Emergency physicians must be aware of the widespread nature of this activity and must be vigilant in approaching management of patients with symptoms consistent with these injuries.

Approach considerations for the management of strangulation in the emergency department.

Patients with a history of strangulation present to the emergency department with a variety of different circumstances and injury patterns. We review the terminology, pathophysiology, evaluation, management, and special considerations for strangulation injuries, including an overview of forensic considerations and legal framework for strangulation events.

Analysis of a Consecutive Retrospective Cohort of Strangulation Victims Evaluated by a Sexual Assault Nurse Examiner Consult Service.

OBJECTIVE: The purpose of this study was to review the evaluation of strangulation victims assessed by a sexual assault nurse examiner (SANE) service. The primary objective was to produce observational results on documented injury frequency and secondarily to explore advanced imaging use, outcomes, signs/symptoms, and documentation. METHODS: This was a retrospective analysis of a cohort of 130 consecutive strangled patients over a 42-month period evaluated by a SANE consult service in a metropolitan area. A single investigator extracted medical records for demographics, history, imaging, injuries, disposition, and both presence and documentation of a number of signs/symptoms. A second investigator independently extracted greater than 30% of the total charts with universal agreement. Data were analyzed with descriptive statistics. RESULTS: Patients were primarily female (129:1) and their age averaged 30.6 years. Time from event to presentation varied. There were no major brain or neck injuries detected (0%; 95 confidence interval, 0-2.31), and all patients were discharged in stable condition. Imaging was used in 23 patients (17.7%). Certain signs and symptoms were more common than others, and documentation frequency of signs and symptoms varied. CONCLUSION: In this retrospective cohort of 130 consecutive nonfatally strangled awake patients seen as SANE consults in a single emergency department, there were no major injuries documented. The most common signs or symptoms were neck pain, neck markings, and loss of consciousness. Imaging was used in 17.7% of the patients. Presence or absence of neck pain, neck markings, and altered mental status were most consistently documented. Seizure, subcutaneous emphysema, and carotid bruit were least consistently documented.

Analysis of the fight-ending chokes in the history of the Ultimate Fighting Championship™ mixed martial arts promotion.

OBJECTIVE: Knowledge of sportive chokes is vital to the practice of Sports Medicine when providing care at mixed martial arts and submission grappling events. This is a descriptive analysis of fight-ending chokes to help provide data on the topic not previously presented. METHODS: An analysis was done on every fight-ending choke in the history of the UFC™ mixed martial arts promotion. Investigators focused on the frequency of chokes, types of chokes, handedness of the chokes, and whether chokes resulted in loss of consciousness. This analysis was done using existing fight outcome reports and video analysis of every choke that ended a fight in UFC™ history. RESULTS: During the study period there were 904 such chokes, comprising 15.5% of fight outcomes and 76.2% of grappling submissions. The makeup of right (50.1%) and left (49.9%) handedness of the chokes has been essentially identical (χ2 [1] = 0.0011, p =.947, phi =.00). Most of the fight-ending chokes culminated in voluntary submission; however, 11% resulted in loss of consciousness. The rear naked choke (RNC) was significantly more frequent than other chokes, comprising 49.1% of the total choke finishes; 19 other choke types accounted for the remaining 50.9%. CONCLUSION: Fight-ending chokes have been common in MMA. Many types of chokes have successfully ended UFC™ fights, with the RNC accounting for almost half of fight-ending chokes. Loss of consciousness occurred in 11% of fight-ending chokes. Right and left handed chokes were utilized equally.

Electrocardiographic Diagnosis of Acute Coronary Occlusion Myocardial Infarction in Ventricular Paced Rhythm Using the Modified Sgarbossa Criteria.

STUDY OBJECTIVE: Ventricular paced rhythm is thought to obscure the electrocardiographic diagnosis of acute coronary occlusion myocardial infarction. Our primary aim was to compare the sensitivity of the modified Sgarbossa criteria (MSC) to that of the original Sgarbossa criteria for the diagnosis of occlusion myocardial infarction in patients with ventricular paced rhythm. METHODS: In this retrospective case-control investigation, we studied adult patients with ventricular paced rhythm and symptoms of acute coronary syndrome who presented in an emergency manner to 16 international cardiac referral centers between January 2008 and January 2018. The occlusion myocardial infarction group was defined angiographically as thrombolysis in myocardial infarction grade 0 to 1 flow or angiographic evidence of coronary thrombosis and peak cardiac troponin I ≥10.0 ng/mL or troponin T ≥1.0 ng/mL. There were 2 control groups: the "non-occlusion myocardial infarction-angio" group consisted of patients who underwent coronary angiography for presumed type I myocardial infarction but did not meet the definition of occlusion myocardial infarction; the "no occlusion myocardial infarction" control group consisted of randomly selected emergency department patients without occlusion myocardial infarction. RESULTS: There were 59 occlusion myocardial infarction, 90 non-occlusion myocardial infarction-angio, and 102 no occlusion myocardial infarction subjects (mean age, 72.0 years; 168 [66.9%] men). For the diagnosis of occlusion myocardial infarction, the MSC were more sensitive than the original Sgarbossa criteria (sensitivity 81% [95% confidence interval [CI] 69 to 90] versus 56% [95% CI 42 to 69]). Adding concordant ST-depression in V4 to V6 to the MSC yielded 86% (95% CI 75 to 94) sensitivity. For the no occlusion myocardial infarction control group of ED patients, additional test characteristics of MSC and original Sgarbossa criteria, respectively, were as follows: specificity 96% (95% CI 90 to 99) versus 97% (95% CI 92 to 99); negative likelihood ratio (LR) 0.19 (95% CI 0.11 to 0.33) versus 0.45 (95% CI 0.34 to 0.65); and positive LR 21 (95% CI 7.9 to 55) versus 19 (95% CI 6.1 to 59). For the non-occlusion myocardial infarction-angio control group, additional test characteristics of MSC and original Sgarbossa criteria, respectively, were as follows: specificity 84% (95% CI 76 to 91) versus 90% (95% CI 82 to 95); negative LR 0.22 (95% CI 0.13 to 0.38) versus 0.49 (95% CI 0.35 to 0.66); and positive LR 5.2 (95% CI 3.2 to 8.6) versus 5.6 (95% CI 2.9 to 11). CONCLUSION: For the diagnosis of occlusion myocardial infarction in the presence of ventricular paced rhythm, the MSC were more sensitive than the original Sgarbossa criteria; specificity was high for both rules. The MSC may contribute to clinical decisionmaking for patients with ventricular paced rhythm.

Intravenous Fat Emulsion Does Not Significantly Alter Clotting Markers in Dabigatran-Treated Blood.

Dabigatran etexilate is an oral direct thrombin (Factor IIa) inhibitor approved for patients with atrial fibrillation and for management of risk of deep vein thrombosis and pulmonary embolism. Dabigatran offers advantages over treatment with warfarin, including limited laboratory monitoring. It is equivalent in prevention of stroke and deep vein thrombosis with essentially equivalent complication rates. In contrast to warfarin, reversal of the anticoagulation is less well established. Idarucizumab is available for reversal, however supporting research is mixed; the agent also happens to be quite expensive making availability difficult. Hemodialysis has been proposed as a method of reversal, but this is difficult in patients with life threatening hemorrhage, and is not available at many hospitals. Intravenous fat emulsion (IFE) has been used for treatment of overdose of lipophilic drugs. Most toxicologists only recommend IFE for patients in extremis after ingestion of a lipid soluble substance. Dabigatran is lipid soluble, although the pro-drug more so than the active metabolite. The authors sought to see if dabigatran-induced coagulopathy of human in vitro blood samples could be reversed with IFE. Blood samples were spiked with dabigatran or dabigatran plus IFE. Values for Ecarin clot time (ECT-primary outcome), PT/INR, and aPTT, were compared across both study arms. A total of 18 healthy volunteers were included in our study. There were no significant differences in the ECT, PT/INR, and aPTT between the dabigatran arm and the dabigatran plus IFE arm. Based on these methods, IFE does not reverse dabigatran-induced coagulopathy.

Delayed peaks of acetaminophen in overdose patients with concomitant abdominal trauma.

OBJECTIVE: To present two cases of delayed acetaminophen absorption in abdominal trauma patients with concomitant acetaminophen overdose. CASES: Case 1. A 25-year-old female arrived to the emergency department with multiple stab wounds. She had ingested an unknown amount of acetaminophen and was then stabbed by her boyfriend in a suicide pact. Initial acetaminophen concentration was 211.7 mcg/mL and the patient was started on N-Acetylcysteine (NAC) therapy. She was found to have injuries and was taken for operative repair. Acetaminophen concentrations were down trending and nearly undetectable until 58 h post-presentation when concentrations began to rise again. CASE 2: A 41-year-old female ingested approximately 500 tablets of acetaminophen prior to jumping from a four-story building in a suicide attempt. She was found to have multiple traumatic injuries as well as an initial acetaminophen concentration of 225 mcg/mL and was started on NAC therapy. The patient underwent multiple interventions to treat her traumatic injuries. Despite receiving no acetaminophen while inpatient, the patient's acetaminophen concentrations peaked a second time on her third hospital day. CONCLUSIONS: In this case series, two patients with abdominal trauma and coexistent massive acetaminophen ingestions were described. Both cases demonstrated a delayed rise in serum acetaminophen concentrations and required extended NAC therapy.

Urine Drug Screens in the Emergency Department: The Best Test May Be No Test at All.

The manuscript purpose is to provide a resource for clinicians on the functionality and pitfalls of the rapid urine drug screen for clinical decision making. Many providers remain under-informed about the inherent inaccuracies. The rapid urine drug screen is the first, and often only, step of drug testing. In the majority of emergency departments the urine drug screen is a collection of immunoassays reliant on an interaction between the structure of a particular drug or metabolite and an antibody. Drugs in separate pharmacologic classes often have enough structural similarity to cause false positives. Conversely, drugs within the same pharmacologic class often have different enough structures that they may result in inappropriate negatives. This lack of sensitivity and specificity significantly reduces the test utility, and may cause decision-making confusion. The timing of the drug screen relative to the drug exposure also limits accuracy, as does detection threshold. Confirmatory steps following the initial immunoassay include chromatography and/or mass spectrometry. These are unavailable at many institutions and results rarely return while the patient is in the emergency department. In addition, institutional capabilities vary, even with confirmatory testing. Confirmation accuracy depends on a number of factors, including the extent of the catalog of drugs/metabolites that the facility is calibrated to detect and report. In summary, the standard emergency department urine drug screen is a test with extremely limited clinical utility with multiple properties contributing to poor sensitivity, specificity, and accuracy. The test should be used rarely, if ever, for clinical decision making.

Effect of Methylene Blue on a Porcine Model of Amlodipine Toxicity.

INTRODUCTION: Calcium channel blocker (CCB) overdoses cause significant morbidity and mortality. Dihydropyridine CCBs cause peripheral vascular dilation and at high doses cardiac dysfunction. Amlodipine, a dihydropyridine, causes peripheral vasodilation from release of nitric oxide (NO) in addition to calcium channel blockade; NO scavenging is a potential treatment. Methylene blue (MB) inhibits NO directly and inhibits NO production. We compared the effects of MB versus norepinephrine (NE), with time to death as the primary outcome, in a porcine amlodipine toxicity model. METHODS: Animals were anesthetized and instrumented, and an amlodipine infusion was administered to mimic oral overdose. After 70 minutes, each group was resuscitated with normal saline. Animals in each group were then randomized to receive either MB or NE. Hemodynamic parameters, including mean arterial pressure and cardiac output, were recorded every 10 minutes. The primary outcome was survival time (Kaplan-Meier analysis and log-rank test). RESULTS: Interim analysis after 15 animals (7 MB, 8 NE) revealed that MB was clearly not superior to NE. Overall, 1 of 7 animals in the MB group survived to 300 minutes compared with 2 of 8 animals in the NE group. The median survival time was 100 minutes for the MB group and 177 minutes for the NE group. Survival time did not differ by group (log-rank test p = 0.29). CONCLUSION: In this porcine model of amlodipine toxicity, methylene blue did not improve survival time compared with norepinephrine. Whether methylene blue is beneficial in combatting distributive shock in amlodipine toxicity remains unclear and requires further study.

Oral nitroglycerin solution for oesophageal food impaction: a prospective single-arm pilot study.

BACKGROUND: Thirteen episodes of oesophageal food impaction (EFI) per 100 000 people present to a medical setting each year. Several pharmacological interventions meant to relieve such impactions have been explored; none have proven superior. OBJECTIVES: Perform a single-arm feasibility study of oral nitroglycerin solution for EFI. METHODS: Twenty adult patients presenting to a single urban tertiary medical centre thought to have EFI were given up to three doses of 0.4 mg nitroglycerin solution orally and evaluated for resolution of symptoms, new symptoms and vital signs. Patients with intractable vomiting, haemodynamic instability, airway compromise, oesophageal perforation, coronary ischaemia or presentation delayed greater than 12 hours were excluded. RESULTS: 17 of 20 enrolled subjects received the intervention. The average duration of symptoms prior to intervention was 285 min (SD=187). Four subjects did not tolerate the intervention (inability to swallow or headache). Two of 17 (11.8%) subjects obtained temporally proximal symptom resolution: 11 min after the second dose, and 7 min after the third dose. Seven also received glucagon during their visit, with 0% temporally proximal symptom resolution. Fifteen underwent endoscopy, with food bolus identified in 12. One subject had brief and mild hypotension with spontaneous resolution. Two subjects developed a headache after nitroglycerin administration. The median length of stay for those who found relief without endoscopy was 195 min (range 129-261) vs 374 min (range 122-525) among those with endoscopy. CONCLUSION: The observed rate of relief after oral nitroglycerin solution for EFI is disappointing but comparable to previous glucagon, benzodiazepines and effervescent beverage studies, and that of placebo. Oral nitroglycerin solution appears to be well tolerated among those able to swallow, although in our sample several subjects were unable to tolerate swallowing entirely.

The safety of sportive chokes: a cross-sectional survey-based study.

Objectives: Sportive choking or strangling, known as a 'choke' in the combat sports community, is the practice of compressing the jugular veins and carotid arteries to threaten unconsciousness by lowering cerebral perfusion pressure. This is commonly practiced within combat sports and police/military combatives. The safety profile of sportive choking is underrepresented in the literature. The authors sought to explore the safety of sportive chokes. Methods: A convenience sample of visitors to two combat sports internet forums completed an anonymous web-based survey on choking experience and related symptoms. Descriptive statistics were used to describe the obtained data. Bivariate analysis was performed to elaborate on relationships between grappling experience and the number of times choked, between the number of times choked with pre-syncope/syncope, and between the duration of symptoms and the number of times choked with pre-syncope/syncope. Results: Overall, 4421 individuals completed the survey. One hundred and fourteen were excluded, leaving 4307 analyzed respondents. Ninety-four percent were male, 89.2% were ages 18-44 years. Seventy-nine percent had >1 year of grappling experience and 30% had >5 years. Of the 4307, 1443 (33.5%) reported being choked >500 times, 3257 (75.7%) have been choked to near-syncope, and 1198 (27.8%) have been choked unconscious. Two of the 4307 (0.05%) reported ongoing symptoms from chokes. Of the respondents, 94.3% felt applying a choke would be a safe and effective way to control a street fight; 83.6% felt that vascular neck restraint, the police combative equivalent of sportive choking, would be appropriate as an alternative escalation of force option. Conclusion: Based on a convenience sample of 4307 respondents' self-reported data, sportive choking appears to be safe. Only 0.05% experienced ongoing symptoms, which were likely not related to brain ischemia.

Use of a Porcine Model to Evaluate the Risks and Benefits of Vasopressors in Propranolol Poisoning.

INTRODUCTION: Vasopressors are a commonly used treatment in beta-blocker poisoning despite evidence they may be ineffective or harmful. The primary objective of the present study is to use previously collected data from two prior studies (high-dose insulin (HDI) versus vasopressin + epinephrine and a placebo-controlled HDI study) to compare survival between vasopressin + epinephrine and placebo. Secondary outcomes included a comparison with HDI as well as comparisons with hemodynamic parameters, including mean arterial pressure (MAP), cardiac output (CO), heart rate (HR), and systemic vascular resistance (SVR). METHODS: Cardiogenic shock was induced in healthy pigs with a bolus of 0.5 mg/kg of intravenous propranolol followed by an infusion of 0.25 mg/kg/minute until the point of toxicity, defined as (0.75 × initial HR × initial MAP), at which point the infusion was reduced to 0.125 mg/kg/minute for 240 (vasopressin + epinephrine or HDI) or 360 minutes (placebo) or until death. RESULTS: Survival was significantly lower in pigs receiving vasopressin + epinephrine (0%, 0/5) than in pigs receiving placebo (50%, 2/4) (p < 0.01). Survival was significantly higher with HDI compared with both groups (100%, 5/5) (p < 0.01). All vasopressin + epinephrine pigs died within 100 minutes after reaching toxicity. Over the course of the resuscitation, we observed a statistically significant steady decrease in CO and HR in the vasopressin + epinephrine group compared with placebo (p < 0.01). In contrast, we observed a statistically significant change in MAP and SVR that followed a parabolic arc, with MAP and SVR rising significantly initially in the vasopressin + epinephrine group then rapidly falling until death (p < 0.01). CONCLUSIONS: Mortality was higher with vasopressors compared with placebo in this porcine model of propranolol poisoning. Further studies are warranted to define the optimal timing and role of vasopressors in beta-blocker poisoning.

Development and Feasibility of a Porcine Model of Amlodipine Toxicity.

INTRODUCTION: Toxicity related to calcium-channel blockers remains a significant cause of morbidity and mortality. Amlodipine-induced shock is unique in that its mechanism of action is thought to occur in part via the release of nitric oxide (NO) in the peripheral vasculature. Specific therapeutic interventions, including methylene blue (an NO scavenger), have been suggested, but efficacy studies are severely limited. To facilitate a larger porcine study into the effect of various interventions on amlodipine toxicity, we undertook this model development and feasibility study. METHODS: Intravenous amlodipine was prepared by dissolving commercially obtained amlodipine tablets in dimethylsulfoxide. The concentration of the drug was verified using ultraviolet spectroscopy. We administered this solution to three animals in order to determine a toxic dose, capable of facilitating a two-arm study of amlodipine toxicity. RESULTS: The first pig died rapidly after the bolus infusion. The second pig developed mild toxicity, but the dissolution of the plastic tubing by the solvent and subsequent leakage limited the interpretability of the result. The third animal developed expected toxicity with an infusion rate between 2.0  and 5.5 mg/kg/h. CONCLUSION: This study demonstrates a potentially repeatable model of amlodipine-induced toxic shock using intravenous administration of amlodipine and several methodological considerations for researchers undertaking similar work.

There is more to the mechanism of unconsciousness from vascular neck restraint than simply carotid compression.

Vascular neck restraint (VNR), an effective technique practiced within police and military combatives and in mixed martial arts and grappling sports, is of both interest and controversy. In any context the goal of VNR (referred to as a choke within combat sports) is to restrict brain blood flow enough to threaten or result in unconsciousness. The physiologic basis for the resultant unconsciousness has been depicted as being solely because of restriction of carotid blood flow due to direct external compression. This view is likely simpler than what is actually going on, but it's an area not well explored in the medical literature. Brain blood flow is maintained through mechanisms that allow for a relatively wide acceptable cerebral perfusion pressure (CPP). If CPP drops below the threshold of this auto-regulation, blood flow and brain oxygen delivery begin to decline. CPP is the difference of the mean arterial pressure (MAP) coming into the brain and the intracranial pressure (ICP). Lowering the MAP and/or raising the ICP reduce the CPP. The best literature-established physiologic component of VNR is carotid compression and resultant reduction in functional carotid MAP, thus lowering the CPP. Most studies have looked at this essentially to the exclusion of two other contributing entities: jugular compression resulting in increased ICP from reduction of outflow, and reduction of actual whole body MAP due to reduced cardiac output from vagal stimulation coming from a pressure affected carotid body. This article fleshes out some of these physiologic variables and discusses the related available literature.

Chokes in mixed martial arts. Comment on Hubbard et al. Brain Injury (2019; 33: 349-354).

This letter to the editor is in response to "The King-Devick test in mixed martial arts: the immediate consequences of knock-outs, technical knock-outs, and chokes on brain functions" by authors Hubbard et al., published in Brain Injury (2019; 33: 349-354). This study explored the impact of events significant enough to end mixed martial arts training sessions or matches, with "event" meaning a knock-out, technical knock-out, or event without head trauma; the measuring stick was the King-Devick test (K-D). This communication clarifies the portion of their study and manuscript focusing on "events without observed head trauma." These events without head trauma were choke-outs, near choke-outs, and non-choke submissions. Fourteen athletes sustained these types of events; nine had worse post-event K-D times, one had no change, and five had post-event improvement. Despite this non-significant result, the authors frame an argument that these non-traumatic events cause anoxic brain injury resulting in similar cerebral changes that occur in concussive injuries. This is not founded on the results in their study, nor in the literature available on the topic, which is also misrepresented in this manuscript.

A Comparison of Resource Utilization in the Management of Anticholinergic Delirium Between Physostigmine and Nonantidote Therapy.

Background: Antimuscarinic delirium is associated with significant morbidity, and its management requires substantial resource allocation, including intubation, restraint, and intensive care unit (ICU) placement. There is controversy over the management of these patients. Physostigmine can rapidly reverse antimuscarinic delirium but has been associated with adverse effects. Objective: This study aims to assess the effect of physostigmine use on resource allocation and adverse events. Methods: This is a retrospective chart review of patients with an antimuscarinic toxidrome at a single hospital approved by the local institutional review board. A blinded abstractor recorded data from patient charts. Whether the patient was given physostigmine, intubated, restrained, or admitting to critical care was recorded. We recorded instances of seizure, vomiting, or bradycardia. The primary aim was to compare frequency of intubation as a function of physostigmine administration. Results: A total of 141 patients were identified. We found no difference between the groups in age, gender, or initial heart rate; 65 (46%) were given physostigmine, 45 (32%) were admitted to the ICU, and 29 (20%) were intubated. Patients who received physostigmine in the first 24 hours were less likely to be intubated and less likely to be admitted to an ICU. The instance of bradycardia (n = 16), vomiting (n = 27), and seizures (n = 7) was limited, and there were no significant differences between the groups. There were no associations noted between physostigmine administration and adverse effects. Conclusion and Relevance: This study demonstrated that physostigmine use is associated with decreased resource utilization (including intubation and ICU placement) without increasing rates of bradycardia, vomiting, or seizures.

A Swine Model of Severe Propranolol Toxicity Permitting Direct Measurement of Brain Tissue Oxygenation.

INTRODUCTION: High-dose insulin (HDI) therapy has been used successfully for beta-blocker toxicity, but needs further study when hypotension persists despite HDI. The objective was to develop a model of propranolol toxicity with persistent hypotension despite HDI and to develop means to measure cerebral oxygen tension (PbrO2). METHODS: Eight anesthetized Yorkshire pigs were instrumented with a tracheostomy, Swan-Ganz catheter, arterial catheter, and intra-cerebral pressure and oxygen monitor. Intravenous propranolol was given until the initial point of toxicity (POT); 25% reduction from baseline mean arterial pressure (MAP) × heart rate (HR). At the initial POT, normal saline (NS) bolus and infusion along with HDI infusion were started. The propranolol infusion was titrated up slowly to induce hypotension. Group 2 pigs received a norepinephrine (NE) infusion after a secondary POT defined as a MAP < 50 mmHg. NE was titrated to maintain subsequent MAPs > 50 mmHg. Cardiac output, HR, MAP, PbrO2, and intracranial pressure were then recorded every 5 min until death or 4 h. Systemic vascular resistance, potassium, and glucose were also measured. Surviving pigs were euthanized. RESULTS: Two pigs received unique doses for protocol development. One pig developed a tachyarrhythmia prior to protocol, one failed to reach secondary POT, leaving 2 pigs in each group reaching secondary POT. The range of PbrO2 recordings for group 1 was 12.7-48.5 mmHg and 9.2-26.2 mmHg for group 2. CONCLUSION: We report a pilot study swine model of propranolol toxicity with hypotension despite HDI, in which physiologic measures including PbrO2 are achieved. Our toxicity model can be used in the future, and the hemodynamic and brain monitoring model may prove important for subsequent research in various contexts.

Ten Years of Robotripping: Evidence of Tolerance to Dextromethorphan Hydrobromide in a Long-Term User.

INTRODUCTION: Dextromethorphan hydrobromide is widely available as an over-the-counter cough suppressant. A semi-synthetic opioid displaying N-methyl-D-aspartate receptor antagonism, it is commonly abused for recreational purposes. Spuriously elevated serum chloride concentrations are a well-described phenomenon in the setting of dextromethorphan hydrobromide toxicity, but evidence to suggest the development of tolerance is limited to case reports. CASE: A 32-year-old male known to chronically ingest dextromethorphan hydrobromide for recreational purposes presented to regional hospitals on 179 occasions over 110 months and was treated for dextromethorphan toxicity on 163/174 (93.7%) of these visits. He reported a subjective need to increase his dosing over time to achieve the same degree of intoxication. Measured serum chloride over this period (n = 217) ranged from 98 to 138 mEq/L (median 115 mEq/L, IQR 110-123 mEq/L). Measured concentrations over the 110-month period progressively rose, with a fitted plot of 111.15 + 0.00232x describing the rise in measured chloride. Though not formally assessed, anion gaps tended to become progressively more negative over the observed period. DISCUSSION: We report a patient with persistent dextromethorphan hydrobromide abuse at escalating doses whose mean serum chloride concentration increased, on average, by 0.00232 mEq/L every day over a 110-month period. This case demonstrates progressive spurious hyperchloremia secondary to bromide interference in hospital-based chloride assays, supporting the patient's reported need to dose escalate to the same desired effect. Although this artefactual laboratory finding is a well-documented result of bromide ingestion, it may be useful in identifying patterns of dextromethorphan hydrobromide use that suggest tolerance.