Vikhyat S. Bebarta

Unified treatment algorithm for the management of crotaline snakebite in the United States: results of an evidence-informed consensus workshop

BackgroundEnvenomation by crotaline snakes (rattlesnake, cottonmouth, copperhead) is a complex, potentially lethal condition affecting thousands of people in the United States each year. Treatment of crotaline envenomation is not standardized, and significant variation in practice exists.MethodsA geographically diverse panel of experts was convened for the purpose of deriving an evidence-informed unified treatment algorithm. Research staff analyzed the extant medical literature and performed targeted analyses of existing databases to inform specific clinical decisions. A trained external facilitator used modified Delphi and structured consensus methodology to achieve consensus on the final treatment algorithm.ResultsA unified treatment algorithm was produced and endorsed by all nine expert panel members. This algorithm provides guidance about clinical and laboratory observations, indications for and dosing of antivenom, adjunctive therapies, post-stabilization care, and management of complications from envenomation and therapy.ConclusionsClinical manifestations and ideal treatment of crotaline snakebite differ greatly, and can result in severe complications. Using a modified Delphi method, we provide evidence-informed treatment guidelines in an attempt to reduce variation in care and possibly improve clinical outcomes.

Expert Consensus Guidelines for Stocking of Antidotes in Hospitals That Provide Emergency Care

STUDY OBJECTIVE We developed recommendations for antidote stocking at hospitals that provide emergency care. METHODS An expert panel representing diverse perspectives (clinical pharmacology, clinical toxicology, critical care medicine, clinical pharmacy, emergency medicine, internal medicine, pediatrics, poison centers, pulmonary medicine, and hospital accreditation) was formed to create recommendations for antidote stocking. Using a standardized summary of the medical literature, the primary reviewer for each antidote proposed guidelines for antidote stocking to the full panel. The panel used a formal iterative process to reach their recommendation for the quantity of an antidote that should be stocked and the acceptable period for delivery of each antidote. RESULTS The panel recommended consideration of 24 antidotes for stocking. The panel recommended that 12 of the antidotes be available for immediate administration on patient arrival. In most hospitals, this period requires that the antidote be stocked in the emergency department. Another 9 antidotes were recommended for availability within 1 hour of the decision to administer, allowing the antidote to be stocked in the hospital pharmacy if the hospital has a mechanism for prompt delivery of antidotes. The panel identified additional antidotes that should be stocked by the hospital but are not usually needed within the first hour of treatment. The panel recommended that each hospital perform a formal antidote hazard vulnerability assessment to determine the need for antidote stocking in that hospital. CONCLUSION The antidote expert recommendations provide a tool to be used in creating practices for appropriate and adequate antidote stocking in hospitals that provide emergency care.

Tranexamic Acid and Trauma: Current Status and Knowledge Gaps with Recommended Research Priorities

ABSTRACT A recent large civilian randomized controlled trial on the use of tranexamic acid (TXA) for trauma reported important survival benefits. Subsequently, successful use of TXA for combat casualties in Afghanistan was also reported. As a result of these promising studies, there has been growing interest in the use of TXA for trauma. Potential adverse effects of TXA have also been reported. A US Department of Defense committee conducted a review and assessment of knowledge gaps and research requirements regarding the use of TXA for the treatment of casualties that have experienced traumatic hemorrhage. We present identified knowledge gaps and associated research priorities. We believe that important knowledge gaps exist and that a targeted, prioritized research effort will contribute to the refinement of practice guidelines over time.

Prehospital Interventions Performed in a Combat Zone: A Prospective Multicenter Study of 1,003 Combat Wounded

BACKGROUND Battlefield care given to a casualty before hospital arrival impacts clinical outcomes. To date, the published data regarding care given in the prehospital setting of a combat zone are limited. The purpose of this study was to describe the incidence and efficacy of specific prehospital lifesaving interventions (LSIs; interventions that could affect the outcome of the casualty), consistent with the Tactical Combat Casualty Care paradigm, performed during the resuscitation of casualties in a combat zone. METHODS We performed a prospective observational study between November 2009 and November 2011. Casualties were enrolled as they were treated at six US surgical facilities in Afghanistan. Descriptive data were collected on a standardized data collection form and included mechanism of injury, airway management, chest and hemorrhage interventions, vascular access, type of fluid administered, and hypothermia prevention. On arrival to the military hospital, the treating physician determined whether an intervention was performed correctly and whether an intervention was not performed that should have been performed (missed LSI). RESULTS A total of 1,003 patients met the inclusion criteria. Their mean (SD) age was 25 (8.5) years and 97% were male. The mechanism of injury was explosion in 60% of patients, penetrating in 24% of patients, blunt in 15% of patients, and burn in 0.8% of patients. The most commonly performed LSIs included hemorrhage control (n = 599), hypothermia prevention (n = 429), and vascular access (n = 388). Of the missed LSIs, 252 were identified with the highest percentage of missed opportunities being composed of endotracheal intubation, chest needle decompression, and hypotensive resuscitation. In contrast, tourniquet application had the lowest percentage of missed opportunities. CONCLUSIONS In our prospective study of prehospital LSIs performed in a combat zone, we observed a higher rate of incorrectly performed and missed LSIs in airway and chest (breathing) interventions than hemorrhage control interventions. The most commonly performed LSIs had lower incorrect and missed LSI rates. LEVEL OF EVIDENCE Prognostic study, level III.

Six Years of Epinephrine Digital Injections: Absence of Significant Local or Systemic Effects

STUDY OBJECTIVE Epinephrine autoinjectors are known to result in accidental digital injections. Treatment recommendations and adverse outcomes are based on case reports. The objective of our study is to determine the frequency of digit ischemia after epinephrine autoinjector digital injections. In addition, we describe the frequency of epinephrine digital injections, treatments used, adverse local effects, and systemic effects. METHODS We performed a retrospective cohort study on cases reported to 6 poison centers during 6 years, using a search of the Texas Poison Center Network database. Patients who had an epinephrine injection of the hand were reviewed, and digital injections were included. Variables collected included demographics, local and systemic effects, symptom duration, treatments used, comorbidities, and whether admission, surgery, or hand surgery consultation was used. One trained abstractor used a standard electronic data collection form. RESULTS There were 365 epinephrine injections to the hand identified for the 6-year period. Of these, 213 were digital injections, and 127 had follow-up. All patients had complete resolution of symptoms. None of the patients were hospitalized or received hand surgery consultation or surgical care. Significant systemic effects were not reported. Pharmacologic vasodilatory treatment was used in 23% (29/127) of patients. Ischemic effects were documented for 4 patients, and 2 of these had symptom resolution within 2 hours. All 4 patients received vasodilatory therapy and were discharged home, with complete resolution of symptoms. CONCLUSION In our series of patients using poison center calls about digital epinephrine autoinjections, there were no cases in which clinically apparent systemic effects were recorded and few patients had ischemia. No patient was admitted or had surgery. Most clinicians did not use vasodilation medications or techniques.

Hydroxocobalamin and sodium thiosulfate versus sodium nitrite and sodium thiosulfate in the treatment of acute cyanide toxicity in a swine (Sus scrofa) model.

STUDY OBJECTIVE Cyanide can cause severe hypotension with acute toxicity. To our knowledge, no study has directly compared hydroxocobalamin and sodium nitrite with sodium thiosulfate in an acute cyanide toxicity model. Our objective is to compare the return to baseline of mean arterial blood pressure between 2 groups of swine with acute cyanide toxicity and treated with hydroxocobalamin with sodium thiosulfate or sodium nitrite with sodium thiosulfate. METHODS Twenty-four swine were intubated, anesthetized, and instrumented (continuous arterial and cardiac output monitoring) and then intoxicated with a continuous cyanide infusion until severe hypotension. The animals were divided into 2 arms of 12 each and then randomly assigned to intravenous hydroxocobalamin (150 mg/kg)+sodium thiosulfate (413 mg/kg) or sodium nitrite (10 mg/kg)+sodium thiosulfate (413 mg/kg) and monitored for 40 minutes after start of antidotal infusion. Twenty animals were needed for 80% power to detect a significant difference in outcomes (alpha 0.05). Repeated measures of analysis of covariance and post hoc t test were used for determining significance. RESULTS Baseline mean weights, time to hypotension (31 minutes 3 seconds versus 28 minutes 6 seconds), and cyanide dose at hypotension (5.6 versus 5.9 mg/kg) were similar. One animal in the hydroxocobalamin group and 2 animals in the sodium nitrite group died during antidote infusion and were excluded from analysis. Hydroxocobalamin resulted in a faster return to baseline mean arterial pressure, with improvement beginning at 5 minutes and lasting through the conclusion of the study (P<.05). No statistically significant difference was detected between groups for cardiac output, pulse rate, systemic vascular resistance, or mortality at 40 minutes post intoxication. Mean cyanide blood levels (4.03 versus 4.05 microg/mL) and lactate levels (peak 7.9 versus 8.1 mmol/L) at hypotension were similar. Lactate levels (5.1 versus 4.48 mmol/L), pH (7.40 versus 7.37), and base excess (-0.75 versus 1.27) at 40 minutes were also similar. CONCLUSION Hydroxocobalamin with sodium thiosulfate led to a faster return to baseline mean arterial pressure compared with sodium nitrite with sodium thiosulfate; however, there was no difference between the antidote combinations in mortality, serum acidosis, or serum lactate.

A multicenter comparison of the safety of oral versus intravenous acetylcysteine for treatment of acetaminophen overdose

Oral and intravenous (IV) N-acetylcysteine (NAC) are used for the treatment of acetaminophen poisoning. The objective of this multicenter study was to compare the safety of these two routes of administration. Methods. We conducted a multicenter chart review of all patients treated with NAC for acetaminophen poisoning. The primary safety outcome was the percentage of patients with NAC-related adverse events. Results. A total of 503 subjects were included in the safety analysis (306 IV-only, 145 oral-only, and 52 both routes). There were no serious adverse events related to NAC for either route. Nausea and vomiting were the most common related adverse events and were more common with oral treatment (23 vs. 9%). Anaphylactoid reactions were more common with IV administration (6 vs. 2%). Conclusions. IV and oral NAC are generally mild adverse drug reactions.

Tympanic membrane perforation after combat blast exposure in Iraq: a poor biomarker of primary blast injury.

OBJECTIVE The US military has reported over 10,000 improvised explosive device attacks attributing to over 400 deaths in Iraq in 2005. Otologic blast injury and tympanic membrane (TM) perforation have traditionally been used as a predictor, or biomarker, of serious or occult primary blast injury (PBI). Although combat injuries from the US-Iraq conflict have been described, the utility of TM perforation as a marker of PBI has not. The objective of this study is to determine the incidence of tympanic perforation in patients subject to blast exposures and describe its utility as a biomarker of more serious primary barotrauma, as observed at a US military hospital in Iraq. METHODS In our institutional review board-approved study, all patients during a 30-day period who arrived at a tertiary US military hospital in Iraq were evaluated. All patients with blast injures were identified on arrival to the hospital emergency department and were followed up through their hospital course and evacuation to the United States to assure they received proper otolaryngology evaluation and follow-up. Demographic data and manifestations of PBI (TM perforation, pneumothorax, pulmonary contusion, nonpenetrating facial sinus injury, and bowel perforation) and other combat injuries were recorded. The diagnostic tests and clinical examination findings used to identify these complications were also recorded. RESULTS One hundred sixty-seven patients were enrolled over 30 days. All blast exposures resulted from primary or secondary explosions from munitions used in combat. This included both combatants and civilians. All patients were men. The mean patient age was 28 years (range, 12-55 years). Sixteen percent (27 of 167) of blast-exposed patients had TM perforation. Thirteen of 27 patients with perforations had bilateral perforations. Twelve of 167 patients (7%) had PBI. Six of 12 patients (50%) with PBI had TM perforation. The use of TM perforation as a biomarker for PBI resulted in a sensitivity of 50% (95% CI, 22-78%) and specificity of 87% (95% CI, 81-92%). CONCLUSIONS Both TM perforation and PBI are rare with improvised explosive devices and other explosive devices in the current Iraqi-US conflict. Contrary to previous belief and management guidelines, TM perforation had low sensitivity for serious or occult PBI and was not a good biomarker. On the basis of the findings of this study, the absence of TM perforation does not appear to exclude other serious PBI.

Reliability of the Glasgow Coma Scale for the emergency department evaluation of poisoned patients

The Glasgow Coma Scale (GCS) was developed for monitoring the mental status of head-injured patients in the intensive care unit. The purpose of this study is to determine the inter-rater reliability of the GCS for poisoning patients in the emergency department. Methods: This was a prospective, observational study. Two observers used a standard assessment checklist to determine the GCS of suspected poisoning patients. Inter-rater reliability was assessed with a weighted Kappa score. Results: A total of 39 patients were enrolled. Weighted kappa for the total GCS demonstrated excellent agreement. Agreement was also good for each component of the score. Conclusion: The GCS is a reliable tool for the evaluation of mental status of poisoning patients in the emergency department.

Low-dose ketamine vs morphine for acute pain in the ED: a randomized controlled trial☆ , ☆☆

OBJECTIVES To compare the maximum change in numeric rating scale (NRS) pain scores, in patients receiving low-dose ketamine (LDK) or morphine (MOR) for acute pain in the emergency department. METHODS We performed an institutional review board-approved, randomized, prospective, double-blinded trial at a tertiary, level 1 trauma center. A convenience sample of patients aged 18 to 59 years with acute abdominal, flank, low back, or extremity pain were enrolled. Subjects were consented and randomized to intravenous LDK (0.3mg/kg) or intravenous MOR (0.1mg/kg). Our primary outcome was the maximum change in NRS scores. A sample size of 20 subjects per group was calculated based on an 80% power to detect a 2-point change in NRS scores between treatment groups with estimated SDs of 2 and an α of .05, using a repeated-measures linear model. RESULTS Forty-five subjects were enrolled (MOR 21, LDK 24). Demographic variables and baseline NRS scores (7.1 vs 7.1) were similar. Ketamine was not superior to MOR in the maximum change of NRS pain scores, MOR=5 (confidence interval, 6.6-3.5) and LDK=4.9 (confidence interval, 5.8-4). The time to achieve maximum reduction in NRS pain scores was at 5 minutes for LDK and 100 minutes for MOR. Vital signs, adverse events, provider, and nurse satisfaction scores were similar between groups. CONCLUSION Low-dose ketamine did not produce a greater reduction in NRS pain scores compared with MOR for acute pain in the emergency department. However, LDK induced a significant analgesic effect within 5 minutes and provided a moderate reduction in pain for 2 hours.