Introduction: The War in Afghanistan ended in August 2021. Evacuation from the country was a large effort during the last days of the conflict. During evacuation efforts at Kabul Hamid Karzai International Airport, a suicide bombing occurred necessitating emergent medical care for many injured troops and civilians. The U.S. Air Force Critical Care Air Transport Teams (CCATTs) played a role in the medical care provided during the operations in Afghanistan. We report on in-flight events and interventions that took place during the final days of the Afghanistan withdrawal. Materials and Methods: We performed a retrospective chart review of patients requiring aeromedical evacuation from the Afghanistan theater of operations by CCATT from July 1 to August 30, 2021. From the CCATT patient care record, data abstractors collected patient characteristics, flight information, vital signs, laboratory values, in-flight interventions, and in-flight events in a study-specific electronic database. We performed descriptive analyses of patient characteristics and in-flight interventions. This study was approved by the San Antonio Institutional Review Board. Results: Nine patients were included in this analysis. Seven out of nine patients were foreign nationals; the remaining two were U.S. Marines. Five patients suffered penetrating injuries from gunshot wounds and four suffered blast injuries. Six received intravenous narcotic analgesia. Four received intravenous sedatives, and four received antibiotics in flight. Two patients required chest tube management. One patient received blood. Three patients were in acute respiratory distress. Conclusions: Severe injuries were sustained during the withdrawal efforts at the end of the War in Afghanistan. Critical Care Air Transport Teams played a role in the care and evacuation of patients out of theater during this unique and unprecedented time. Even given the limitations associated with retrospective studies and a small sample size, information reported in this study can help inform future decisions, and aid in preparatory efforts for future operations, that may require medical care by CCATT.

Given its availability and lethality, cyanide has potential for weaponization and thus has the attention of several governmental agencies. In large scale exposure scenarios, an effective countermeasure that can be administered quickly and in low volume intramuscularly may prove valuable because IV medications may have limited practical applications in these situations. Sodium tetrathionate, a potential cyanide antidote, is a compound that provides sulfur to rhodanese, the enzyme that detoxifies cyanide endogenously. Additionally, sodium tetrathionate has been reported to directly react with cyanide and is effective when administered intramuscularly. In this study, we assess the efficacy of sodium tetrathionate, when administered intramuscularly for the treatment of acute, oral cyanide poisoning in swine. We conducted a prospective trial approved by the 59th Medical Wing Institutional Animal Care and Use Committee comparing intramuscular sodium tetrathionate (n=6) to no treatment control (n=4) in animals (Sus scrofa) exposed to a lethal dose of oral potassium cyanide. Survival at 120 minutes was the primary outcome. Lactate, a cyanide toxicity biomarker, was measured. At the study end, all animals were euthanized in compliance with the Animal Welfare Act and the American Association for Accreditation of Laboratory Animal Care. Survival between groups was summarized using a Kaplan-Meier survival curve after comparing survival by log-rank, Mantel-Cox analysis. The Mann-Whitney U test was used for comparison of other variables between groups. At baseline animals were similar. There was 100

INTRODUCTION:North American pit viper envenomation occurs over 4,000 times annually in the United States, with polyvalent Fab antivenom being the primary treatment. Fasciotomy is occasionally performed due to concerns about compartment syndrome. We utilized our direct access to Texas Poison Center Network data to create a new snakebite abstraction form and database on relevant available information between 2004 and 2021 and to identify, describe, and estimate the incidence of fasciotomy following pit viper envenomation in Texas. METHODS:We searched the Texas Poison Center Network database for cases during 2004-2021 using keywords such as fasciotomy, surgery, compartment pressure, and compartment syndrome. Descriptive statistics summarized the data. RESULTS:Of 16,911 reported envenomations, 0.69 percent involved fasciotomies (n = 117). Most common bite sites were digits/hands and lower extremities. Patients who underwent fasciotomy were typically male, aged 20-59, and 10 years younger than the total snakebite population. Only 6 percent of reported compartment syndrome cases had a compartment pressure measurement. Antivenom was administered in 101 (86.3 percent) cases, 92 (91.1 percent) of which received only Fab antivenom product. Patients with bites from rattlesnakes (47.9 percent) were associated with most fasciotomies. DISCUSSION:Our findings suggest a potential increase in snakebite exposures, accompanied by a decrease in fasciotomies. Overall, copperheads constituted the majority of snakebites, but most fasciotomies were from rattlesnake envenomations (47.9 percent). In this cohort, compartment syndrome diagnosis and decisions regarding fasciotomy were primarily based on clinical evaluation/surgeon expertise without compartment pressure measurements. Despite the efficacy of antivenom, only 86.3 percent of patients in our study received antivenom. CONCLUSIONS:Fasciotomy after North American pit viper envenomation in Texas is uncommon (0.69 percent) and has decreased over time, possibly due to increased antivenom use or surgeon comfort with nonsurgical management.

ABSTRACT Background Extracorporeal membrane oxygenation (ECMO) is an advanced medical technology that is used to treat respiratory and heart failure. The U.S. military has used ECMO in the care of combat casualties during Operation Enduring Freedom and Operation Iraqi Freedom as well as in the treatment of patients during the recent Coronavirus Disease 2019 pandemic. However, few Military Health System personnel have training and experience in the use of ECMO therapy. To address this dearth of expertise, we developed and evaluated an accelerated ECMO course for military medical personnel. Objectives To compare the efficacy of an accelerated ECMO course for Military Health System critical care teams. Methods Seventeen teams, each consisting of a physician and nurse, underwent a 5-h accelerated ECMO course. Similar to our previous live-tissue ECMO training program (phases I and II), each team watched prerecorded ECMO training lectures. Subjects then practiced priming the ECMO circuit, cannulating ECMO, initiating ECMO, and correcting common complications on an ECMO simulation model. An added component to this phase III project included transportation and telemedicine consultation availability. Training success was evaluated via knowledge and confidence assessments, and observation of each team attempting to initiate ECMO on a Yorkshire swine patient model, transport the patient model, and troubleshoot complications with the support of telemedicine consultation when desired. Results Seventeen teams successfully completed the course. All seventeen teams (100%) successfully placed the swine on veno-arterial ECMO. Of those, 15 teams successfully transitioned to veno-arterial-venous ECMO. The knowledge assessments of physicians and nurses increased by 12.2% from pretest (mean of 62.1%, SD 10.4%) to posttest (mean of 74.4%, SD 8.2%), P < .0001; their confidence assessments increased by 41.1% from pretest (mean of 20.1%, SD 11.8%) to posttest (mean of 61.2%, SD 18.6%). Conclusions An abbreviated 1-day lecture and hands-on task-trainer-based ECMO course resulted in a high rate of successful skill demonstration and improvement of physicians’ and nurses’ knowledge assessments and confidence levels, similar to our previous live-tissue training program. When compared to our previous studies, the addition of telemedicine and patient transportation to this study did not affect the duration or performance of procedures.

INTRODUCTION:Emergent clinical care and patient movements through the military evacuation system improves survival. Patient management differs when transporting from the point-of-injury (POI) to the first medical treatment facility (MTF) versus transporting from the Role 2 to the Role 3 MTF secondary to care rendered within the MTF, including surgery and advanced resuscitation. The objective of this study was to describe care provided to patients during theater inter-facility transports and compare with pre-hospital transports (POI to first MTF). MATERIALS AND METHODS:We performed a retrospective chart review of patients with the Role 2 to the Role 3 transports in Afghanistan and Iraq from 2007 to 2016. Data collected included procedures and events at the MTF and during transport. We compared the intra-theater transport data (Role 2 to Role 3) to data from a previous study evaluating pre-hospiital transports (POI to first MTF). RESULTS:We reviewed the records of 869 Role 2 to Role 3 transport patients. Role 2 to Role 3 transports were longer in duration compared to POI transports (39 minutes vs. 23 minutes) and were more likely to be staffed by advanced personnel (nurses, physician assistants, and physicians) (57% vs. 3%). The sample primarily consisted of military-aged males (mean age 27 years) who suffered from explosive or blunt force injuries. Procedures performed during each phase of care reflected the capabilities of the teams and locations. Pain and cardiac events were more common in POI evacuations compared to the Role 2 to Role 3 transports, but documentation of respiratory events, hemodynamic events, neurologic events, and equipment failure was more common during the Role 2 to Role 3 transports. Survival rates were slightly higher among the Role 2 to Role 3 cohort (98% vs. 95%, difference 3% [95% confidence interval of the difference 1-5%]). CONCLUSIONS:Inter-facility transports (Role 2 to Role 3) are longer in duration, transport more complex patients, and are staffed by more advanced level provider types compared to transports from POI.

INTRODUCTION:Hypocalcemia at hospital presentation is associated with increased mortality in trauma patients with hemorrhagic shock. The 2019 updates to the Joint Trauma System Damage Control Resuscitation (DCR) Clinical Practice Guideline recommend calcium supplementation for ionized calcium (iCa) measurements <1.2 mmol/L. Ionized calcium goals for en route critical care (ERCC) following DCR are less defined, and the impact of in-flight hypocalcemia events among critically injured combat wounded is unknown. This study aimed to describe the association between hypocalcemia and mortality for combat-wounded with brain injury and polytrauma requiring transport by Critical Care Air Transport Teams (CCATT). METHODS:We performed a secondary analysis of a retrospective cohort of patients with moderate-to-severe traumatic brain injury transported by CCATT out of combat theater between January 2007 and May 2014. Additional inclusion criteria included polytrauma and at least one documented in-flight iCa measurement. We categorized exposures based on the minimum in-flight iCa measurement as severe hypocalcemia (iCa <0.9 mmol/L), hypocalcemia (iCa 0.9-1.11 mmol/L), and never hypocalcemic (iCa ≥1.12 mmol/L). The primary outcome measure was mortality. We calculated descriptive statistics and performed multivariate logistic regression to assess the association between hypocalcemia and mortality. RESULTS:We analyzed 190 subjects, with a median age of 24 years (interquartile range [IQR] 21 to 29 years) and 97.7% male gender. Explosive injuries (82.1%) and gunshot wounds (6.3%) were the most common mechanisms of injury. The median injury severity score was 34 (IQR 27 to 43). During the flight, 11.6% of patients had severe hypocalcemia, and 39.5% had hypocalcemia. Among patients with any hypocalcemia measurement in-flight (n = 97), 41.2% had hypocalcemia on pre-flight iCa, 28.9% received blood products in-flight, and 23.7% received in-flight calcium supplementation. Only 32.4% of patients with hypocalcemia or severe hypocalcemia in the setting of vasopressor administration received in-flight calcium supplementation. There was no significant difference in mortality between severe hypocalcemia (9.1%), hypocalcemia (5.3%), and never hypocalcemic (3.2%) patients even after controlling for pre-flight variables. CONCLUSION:In-flight hypocalcemia events were common among critically ill combat-wounded polytrauma patients transported by CCATT but were not associated with differences in mortality. Future training should emphasize the need for calcium correction among ERCC patients requiring vasopressors. Future studies with larger sample sizes of patients receiving ERCC are needed to assess the association between in-flight calcium supplementation with clinical outcomes.

INTRODUCTION:Understanding usage patterns of current paper-based documentation can inform the development of electronic documentation forms for en route care. The primary objective was to analyze the frequency of use of each field within the 3899 L Patient Movement Record documented by en route Critical Care Air Transport Teams. Secondary objectives were to identify rarely utilized form fields and to analyze the proportion of verifiable major events documented within the 3899 L form.MATERIALS AND METHODS:We performed a retrospective review of 3899 L patient movement records for patients transported via Critical Care Air Transport Teams from January 2019 to December 2019. Scanned 3899 L forms were manually transcribed into a Microsoft Access database for evaluation and analysis. Proportions were calculated for completed fields. Major vital sign event frequency was compared for checkbox fields versus the vital sign flow sheet for each patient. We performed descriptive analyses for the proportion of charts with completed documentation in each evaluated field and the proportion of flow sheet events documented in major event fields.RESULTS:We analyzed 130 records. Fourteen of 18 (77.8%) demographic fields had a 75% or greater completion ratio. Sections with the largest proportion of rarely or never utilized fields (<1.5% completed) were procedures (77.8% of fields) and major events (63.9% of fields). Major event checkboxes had low sensitivity for documented events in the flow sheet: Change in heart rate greater than 20% (1 of 28 patients); increase in the fraction of inspired oxygen requirement of greater than 10% (6 of 23 patients); decrease in mean arterial pressure of greater than 20% (1 in 12 patients); and temperature less than 35.6°C (1 in 13 patients).CONCLUSIONS:Many of the current 3899 L fields are highly utilized, but some 3899 L sections contain high proportions of rarely utilized fields. Major event checkboxes did not consistently capture events documented within the in-flight vital sign flow sheet.

BACKGROUND:Critical Care Air Transport Teams (CCATTs) play a vital role in the transport and care of critically ill and injured patients in the combat theater to include mechanically ventilated patients. Previous research has demonstrated improved morbidity and mortality when lung protective ventilation strategies are used. Our previous study of CCATT trauma patients demonstrated frequent non-adherence to the Acute Respiratory Distress Syndrome Network (ARDSNet) protocol and a corresponding association with increased mortality. The goals of our study were to examine CCATT adherence with ARDSNet guidelines in non-trauma patients, compare the findings to our previous publication of CCATT trauma patients, and evaluate adherence before and after the publication of the CCATT Ventilator Management Clinical Practice Guideline (CPG).METHODS:We performed a retrospective chart review of ventilated non-trauma patients who were evacuated out of theater by Critical Care Air Transport Teams (CCATT) between January 2007 and April 2015. Data abstractors collected flight information, oxygenation status, ventilator settings, procedures, and in-flight assessments. We calculated descriptive statistics to determine the frequency of compliance with the ARDSNet protocol before and after the CCATT Ventilator CPG publication and the association between ARDSNet protocol adherence and in-flight events.RESULTS:We reviewed the charts of 124 mechanically ventilated patients transported out of theater via CCATT on volume control settings. Seventy percent (n = 87/124) of records were determined to be Non-Adherent to ARDSNet recommendations predominately due to excessive tidal volume settings and/or high FiO2 settings relative to the patient's positive end-expiratory pressure setting. The Non-Adherent group had a higher proportion of in-flight respiratory events. Compared to our previous study of ventilation guideline adherence in the trauma population, the Non-Trauma population had a higher rate of non-adherence to tidal volume and ARDSNet table recommendations (75.6% vs. 61.5%). After the CPG was rolled out, adherence improved from 24% to 41% (P = 0.0496).CONCLUSIONS:CCATTs had low adherence with the ARDSNet guidelines in non-trauma patients transported out of the combat theater, but implementation of a Ventilator Management CPG was associated with improved adherence.

BACKGROUND Traumatic injury with subsequent hemorrhage is one of the leading causes of mortality among military personnel and civilians alike. Posttraumatic hemorrhage accounts for 40% to 50% of deaths in severe trauma patients occurring secondary to direct vessel injury or the development of trauma-induced coagulopathy (TIC). Hyperfibrinolysis plays a major role in TIC and its presence increases a patient's risk of mortality. Early therapeutic intervention with intravenous (IV) tranexamic acid (TXA) prevents development of hyperfibrinolysis and subsequent TIC leading to decreased mortality. However, obtaining IV access in an austere environment can be challenging. In this study, we evaluated the efficacy of intramuscular (IM) versus IV TXA at preventing hyperfibrinolysis in a hemorrhaged swine. METHODS Yorkshire cross swine were randomized on the day of study to receive IM or IV TXA or no treatment. Swine were sedated, intubated, and determined to be hemodynamically stable before experimentation. Controlled hemorrhaged was induced by the removal of 30% total blood volume. After hemorrhage, swine were treated with 1,000 mg of IM or IV TXA. Control animals received no treatment. Thirty minutes post-TXA treatment, fibrinolysis was induced with a 50-mg bolus of tissue plasminogen activator. Blood samples were collected to evaluate blood TXA concentrations, blood gases, blood chemistry, and fibrinolysis. RESULTS Blood TXA concentrations were significantly different between administration routes at the early time points but were equivalent by 20 minutes after injection, remaining consistently elevated for up to 3 hours postadministration. Induction of fibrinolysis resulted in 87.18 ± 4.63% lysis in control animals, compared with swine treated with IM TXA, 1.96 ± 2.66% and 1.5 ± 0.42% lysis in the IV TXA group. CONCLUSION In the large swine model of hemorrhage with hyperfibrinolysis, IM TXA is bioequivalent and equally efficacious in preventing hyperfibrinolysis as IV TXA administration.

INTRODUCTION:Toxic alcohol ingestion is a rare but serious condition that carries with it a high rate of morbidity and mortality.OBJECTIVE:This review highlights the pearls and pitfalls of toxic alcohol ingestion, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.DISCUSSION:Toxic alcohols include ethylene glycol, methanol, isopropyl alcohol, propylene glycol, and diethylene glycol. These substances can be found in several settings including hospitals, hardware stores, and the household, and ingestion can be accidental or intentional. Toxic alcohol ingestion presents with various degrees of inebriation, acidemia, and end-organ damage depending on the substance. Timely diagnosis is critical to prevent irreversible organ damage or death and is based primarily on clinical history and consideration of this entity. Laboratory evidence of toxic alcohol ingestion includes worsening osmolar gap or anion-gap acidemia and end organ injury. Treatment depends on the ingestion and severity of illness but includes alcohol dehydrogenase blockade with fomepizole or ethanol and special considerations for the initiation of hemodialysis.CONCLUSIONS:An understanding of toxic alcohol ingestion can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

INTRODUCTION:According to the Military Health System Traumatic Brain Injury (TBI) Center of Excellence, 51,261 service members suffered moderate to severe TBI in the last 21 years. Moderate to severe TBI in service members is usually related to blast injury in combat operations, which necessitates medical evacuation to higher levels of care. Prevention of secondary insult, and mitigation of the unique challenges associated with the transport of TBI patients in a combat setting are important in reducing the morbidity and mortality associated with this injury. The primary goal of this study was a secondary analysis comparing the impact of time to transport on clinical outcomes for TBI patients without polytrauma versus TBI patients with polytrauma transported out of the combat theater via Critical Care Air Transport Teams (CCATT). Our secondary objective was to describe the occurrence of in-flight events and interventions for TBI patients without polytrauma versus TBI with polytrauma to assist with mission planning for future transports. MATERIALS AND METHODS:We performed a secondary analysis of a retrospective cohort of 438 patients with TBI who were evacuated out of theater by CCATT from January 2007 to May 2014. Polytrauma was defined as abbreviated injury scale (AIS) of at least three to another region in addition to head/neck. Time to transport was defined as the time (in days) from injury to CCATT evacuation out of combat theater. We calculated descriptive statistics and examined the associations between time to transport and preflight characteristics, in-flight interventions and events, and clinical outcomes for TBI patients with and without polytrauma. RESULTS:We categorized patients into two groups, those who had a TBI without polytrauma (n = 179) and those with polytrauma (n = 259). Within each group, we further divided those that were transported within 1 day of injury, in 2 days, and 3 or more days. Patients with TBI without polytrauma transported in 1 or 2 days were more likely to have a penetrating injury, an open head injury, a preflight Glascow Coma Score (GCS) of 8 or lower, and be mechanically ventilated compared to those transported later. Patients without polytrauma who were evacuated in 1 or 2 days required more in-flight interventions compared to patients without polytrauma evacuated later. Patients with polytrauma who were transported in 2 days were more likely to receive blood products, and patients with polytrauma who were evacuated within 1 day were more likely to have had at least one episode of hypotension en route. Polytrauma patients who were evacuated in 2-3 days had higher hospital days compared to polytrauma with earlier evacuations. There was no significant difference in mortality between any of the groups. CONCLUSIONS:In patients with moderate to severe TBI transported via CCATT, early evacuation was associated with a higher rate of in-flight hypotension in polytrauma patients. Furthermore, those who had TBI without polytrauma that were evacuated in 1-2 days received more in-flight supplementary oxygen, blood products, sedatives, and paralytics. Given the importance of minimizing secondary insults in patients with TBI, recognizing this in this subset of the population may help systematize ways to minimize such events. Traumatic Brain Injury patients with polytrauma may benefit from further treatment and stabilization in theater prior to CCATT evacuation.

Cyanide is a potentially deadly chemical. Its lethality has been demonstrated in suicide, homicide, industrial exposures, iatrogenic, and occupational exposures worldwide. Antidote development has focused on two main therapeutic targets: (1) binding cyanide directly and (2) detoxifying cyanide by converting it to a relatively less toxic compound. The history of antidote development for cyanide is discussed.

OBJECTIVES:Effective and widely available therapies are still needed for outpatients with COVID-19. We aimed to evaluate the efficacy and safety of lopinavir/ritonavir (LPV/r) for early treatment of non-hospitalized individuals diagnosed with COVID-19. METHODS:This randomized, placebo (Plb)-controlled, double-blind, multi-site decentralized clinical trial enrolled non-hospitalized adults with confirmed SARS-CoV-2 infection and six or fewer days of acute respiratory infection symptoms who were randomized to either twice-daily oral LPV/r (400 mg/100 mg) or Plb for 14 days. Daily surveys on study days 1 through 16 and again on study day 28 evaluated symptoms, daily activities, and hospitalization status. The primary outcome was longitudinal change in an ordinal scale based on a combination of symptoms, activity, and hospitalization status through day 15 and was analyzed by use of a Bayesian longitudinal proportional odds logistic regression model for estimating the probability of a superior recovery for LPV/r over Plb (odds ratio >1). RESULTS:Between June 2020 and December 2021, 448 participants were randomized to receive either LPV/r (n = 216) or Plb (n = 221). The mean symptom duration before randomization was 4.3 days (SD 1.3). There were no differences between treatment groups through the first 15 days for the ordinal primary outcome (odds ratio 0.96; 95% credible interval: 0.66 to 1.41). There were 3.2% (n = 7) of LPV/r and 2.7% (n = 6) of Plb participants hospitalized by day 28. Serious adverse events did not differ between groups. CONCLUSION:LPV/r did not significantly improve symptom resolution or reduce hospitalization in non-hospitalized participants with COVID-19. TRIAL REGISTRATION:ClinicalTrials.gov Identifier: NCT04372628.

Extracorporeal membrane oxygenation (ECMO) is an advanced medical technology used to treat respiratory and heart failure. The coronavirus pandemic has resulted in significantly more ECMO patients worldwide. However, the number of hospitals with ECMO capabilities and ECMO‐trained staff are limited. Training of personnel in ECMO could supplement this demand.

BACKGROUND:Exposure to stressors of flight may increase risk of secondary insults among critically injured combat casualties wounded with traumatic brain injury (TBI). The primary objective of this study was to describe the prevalence of hemodynamic events by phase of transport among patients with TBI transported by Critical Care Air Transport Teams (CCATT). METHODS:We performed a secondary analysis of a retrospective cohort of 477 adults with moderate to severe TBI, who required transport by CCATT to Germany from multiple hospitals in the Middle East between January 2007 and May 2014. We abstracted clinical data from handwritten CCATT medical records. Hemodynamic events included systolic blood pressure <100 mm Hg and cerebral perfusion pressure <60 mm Hg. We calculated the proportion of patients experiencing hemodynamic events for each phase of flight. RESULTS:We analyzed 404 subjects after exclusions for catastrophic brain injury (n = 39) and missing timestamps (n = 34). Subjects had high Injury Severity Scores (median, 29; interquartile range [IQR], 21-35) and a median flight time of 423 minutes (IQR, 392.5-442.5 minutes). The median of documented in-flight vital signs was 8 measurements (IQR, 6.5-8 measurements). Documented systolic blood pressure in-flight events occurred in 3% of subjects during ascent, 7.9% during early flight, 7.7% during late flight, and 2.2% during descent, with an overall in-flight prevalence of 13.9%. Among patients with intracranial pressure monitoring (n = 120), documented cerebral perfusion pressure events occurred in 5% of subjects during ascent, 23% during early flight, 17% during late flight, and 5.8% during descent, with an overall in-flight prevalence of 30.8%. CONCLUSION:Documented hemodynamic events occurred during each phase of flight in severely injured combat casualties wounded with TBI, and episodic documentation likely underestimated the actual in-flight frequency of secondary insults. LEVEL OF EVIDENCE:Prognostic and epidemiological; Level IV.

Background Cyanide is a rapid acting, lethal, metabolic poison and remains a significant threat. Current FDA-approved antidotes are not amenable or efficient enough for a mass casualty incident. Objective The objective of this study is to evaluate short and long-term efficacy of intramuscular aqueous dimethyl trisulfide (DMTS) on survival and clinical outcomes in a swine model of cyanide exposure. Methods Anesthetized swine were instrumented and acclimated until breathing spontaneously. Potassium cyanide infusion was initiated and continued until 5 min after the onset of apnea. Subsequently, animals were treated with intramuscular DMTS (n = 11) or saline control (n = 10). Laboratory values and DMTS blood concentrations were assessed at various time points and physiological parameters were monitored continuously until the end of the experiment unless death occurred. A subset of animals treated with DMTS (n = 5) were survived for 7 days to evaluate muscle integrity by repeat biopsy and neurobehavioral outcomes. Results Physiological parameters and time to apnea were similar in both groups at baseline and at time of treatment. Survival in the DMTS-treated group was 90% and 30% in saline controls (p = 0.0034). DMTS-treated animals returned to breathing at 12.0 +/- 10.4 min (mean +/- SD) compared to 22.9 +/- 7.0 min (mean +/- SD) in the 3 surviving controls. Blood collected prior to euthanasia showed improved blood lactate concentrations in the DMTS treatment group; 5.47 +/- 2.65 mmol/L vs. 9.39 +/- 4.51 mmol/L (mean +/- SD) in controls (p = 0.0310). Low concentrations of DMTS were detected in the blood, gradually increasing over time with no elimination phase observed. There was no mortality, histological evidence of muscle trauma, or observed adverse neurobehavioral outcomes, in DMTS-treated animals survived to 7 days. Conclusion Intramuscular administration of aqueous DMTS improves survival following cyanide poisoning with no observed long-term effects on muscle integrity at the injection site or adverse neurobehavioral outcomes.