Intramuscular administration of tranexamic acid in a large swine model of hemorrhage with hyperfibrinolysis

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.

Efficacy of a Single Day Extracorporeal Membrane Oxygenation Training Course for Critical Care Air Transport Team Eligible Personnel

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.

Utilization of the En Route Aeromedical Patient Movement Form by Critical Care Air Transport Teams

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.

Management of Combat Casualties during Aeromedical Evacuation from a Role 2 to a Role 3 Medical Facility

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.

A Descriptive Study of Casualties Evacuated Out of Afghanistan by Critical Care Air Transport Teams During the Withdrawal of U.S. Troops

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.

Lopinavir/ritonavir for treatment of non-hospitalized patients with COVID-19: a randomized clinical trial

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.

High risk and low prevalence diseases: Toxic alcohol ingestion

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.

Improved Adherence to Best Practice Ventilation Management After Implementation of Clinical Practice Guideline (CPG) for United States Military Critical Care Air Transport Teams (CCATTs)

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.

Neonatal mortality in singleton pregnancies: a 20-year retrospective study from a tertiary perinatal unit in Hong Kong

INTRODUCTION

The global neonatal death (NND) rate has been declining in recent decades, but there are no comprehensive data concerning the characteristics of NNDs in Hong Kong. This study investigated the trends and aetiologies of NNDs among singleton pregnancies in Hong Kong.

METHODS

This study included all cases of NND from singleton pregnancies in a tertiary hospital in Hong Kong between 2000 and 2019. The rates, clinical characteristics, and aetiologies of NND were compared between the first (2000-2009) and the second (2010-2019) decades.

RESULTS

The NND rate decreased from 1.66/1000 livebirths (97 cases) in the first decade to 1.32/1000 livebirths (87 cases) in the second decade. Congenital or genetic abnormalities (82 cases) caused 44.6% of all NNDs. There was a significant reduction from 0.82/1000 livebirths in the first decade to 0.52/1000 livebirths in the second decade (P=0.037). Other causes of NND were prematurity (69 cases; 37.5%), sepsis (16 cases; 8.7%), hypoxic-ischaemic encephalopathy (15 cases; 8.2%), and sudden infant death syndrome (2 cases; 1.1%). Gestational age-specific neonatal mortality for moderately preterm neonates (31-33 weeks of gestation) significantly decreased from 34.73/1000 in 2000-2009 to 8.63/1000 in 2010-2019 (P=0.001), but there were no significant changes in neonatal mortality for other gestations.

CONCLUSION

The NND rate in Hong Kong is among the lowest worldwide. Neonatal deaths in our centre declined over the past two decades, mainly because of improvements in the prenatal diagnosis and treatment of congenital or genetic abnormalities, as well as an improved survival rate among moderately preterm neonates.

Association of Hypocalcemia With Mortality of Combat Casualties With Brain Injury and Polytrauma Transported by Critical Care Air Transport Teams

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.

Evacuation Strategies for U.S. Casualties with Traumatic Brain Injury (TBI) with and without Polytrauma

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.

Evaluation of aqueous dimethyl trisulfide as an antidote to a highly lethal cyanide poisoning in a large swine model

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.

Advancing Prehospital Combat Casualty Evacuation: Patients Amenable to Aeromedical Evacuation via Unmanned Aerial Vehicles

INTRODUCTION

The U.S. military currently utilizes unmanned aerial vehicles (UAVs) for reconnaissance and attack missions; however, as combat environment technology advances, there is the increasing likelihood of UAV utilization in prehospital aeromedical evacuation. Although some combat casualties require life-saving interventions (LSIs) during medical evacuation, many do not. Our objective was to describe patients transported from the point of injury to the first level of care and characterize differences between patients who received LSIs en route and those who did not.

MATERIALS AND METHODS

We conducted a retrospective review of the records of traumatically injured patients evacuated between January 2011 and March 2014. We compared patient characteristics, complications, and outcomes based on whether they had an LSI performed en route (LSI vs. No LSI). We also constructed logistic regression models to determine which characteristics predict uneventful flights (no en route LSI or complications).

RESULTS

We examined 1,267 patient records; 47% received an LSI en route. Most patients (72%) sustained a blast injury and injuries to the extremities and head. Over 78% experienced complications en route; the LSI group had higher rates of complications compared to the No LSI group. Logistic regression showed that having a blunt injury or the highest abbreviated injury scale (AIS) severity score in the head/neck region are significant predictors of having an uneventful flight.

CONCLUSION

Approximately half of casualties evaluated in our study did not receive an LSI during transport and may have been transported safely by UAV. Having a blunt injury or the highest AIS severity score in the head/neck region significantly predicted an uneventful flight.

Patients With Traumatic Brain Injury Transported by Critical Care Air Transport Teams: The Influence of Altitude and Oxygenation during Transport

INTRODUCTION

Traumatic brain injuries (TBIs) are life-threatening, and air transport of patients with TBI requires additional considerations. To mitigate the risks of complications associated with altitude, some patients fly with a cabin altitude restriction (CAR) to limit the altitude at which an aircraft's cabin is maintained. The goal of this study was to examine the effects of CARs on patients with TBI transported out of theater via Critical Care Air Transport Teams.

MATERIALS AND METHODS

We conducted a retrospective chart review of patients with moderate-to-severe TBI evacuated out of combat theater to Landstuhl Regional Medical Center via Critical Care Air Transport Teams. We collected demographics, flight and injury information, procedures, oxygenation, and outcomes (discharge disposition and hospital/ICU/ventilator days). We categorized patients as having a CAR if they had a documented CAR or maximum cabin altitude of 5,000 feet or lower in their Critical Care Air Transport Teams record. We calculated descriptive statistics and constructed regression models to evaluate the association between CAR and clinical outcomes.

RESULTS

We reviewed the charts of 435 patients, 31% of which had a documented CAR. Nineteen percent of the sample had a PaO2 lower than 80 mm Hg, and 3% of patients experienced a SpO2 lower than 93% while in flight. When comparing preflight and in-flight events, we found that the percentage of patients who had a SpO2 of 93% or lower increased for the No CAR group, whereas the CAR group did not experience a significant change. However, flying without a CAR was not associated with discharge disposition, mortality, or hospital/ICU/ventilator days. Further, having a CAR was not associated with these outcomes after adjusting for additional flights, injury severity, injury type, or preflight head surgery.

CONCLUSIONS

Patients with TBI who flew with a CAR did not differ in clinical outcomes from those without a CAR.

Pediatric Prehospital Intraosseous Access During Combat Operations in Iraq and Afghanistan

BACKGROUND

Vascular access in critically ill pediatric patients can be challenging with delays potentially leading to worse outcomes. Intraosseous (IO) access has a low rate of complications and can be utilized to administer lifesaving medications. Combat medics are trained to treat adults but may also be required to treat children in the deployed setting. Vascular access in children can be challenging, especially in a hypovolemic state. There are limited data on prehospital lifesaving interventions in children in the combat setting. We sought to characterize the use of IO access in pediatric patients who sustained trauma in the combat setting.

METHODS

We queried the Department of Defense Trauma Registry for all pediatric patients admitted to fixed-facilities and forward surgical teams in Iraq and Afghanistan from January 2007 to January 2016. Within that population, we searched for all subjects with a documented prehospital IO or intravenous (IV) access obtained. Subjects with both an IO and IV documented were placed into the IO category. We separated subjects by age groupings: younger than 1, 1 to 4, 5 to 9, 10 to 14, and 15 to 17 years.

RESULTS

During the study period, there were 3439 subjects 17 years or younger. There were 177 in the IO cohort and 803 in the IV cohort. Most subjects in the IO cohort were in the 10- to 14-year-old age group (35.6%), male (79.1%), located in Afghanistan (95.5%), and injured by explosive (52.0%), with lower survival rates than the IV cohort (68.9% vs 90.7%, P < 0.001). Hemostatic dressing application, tourniquet application, intubation, cardiopulmonary resuscitation, sedative administration, ketamine administration, and paralytic administration were all higher in the IO cohort.

CONCLUSIONS

Pediatric IO placement in the prehospital setting occurred infrequently. Pediatric subjects receiving an IO had higher injury severity scores and higher mortality rates compared with those who received an IV only. Intraosseous use appears to be used more often in critically ill pediatric subjects.

Intramuscular cobinamide as an antidote to methyl mercaptan poisoning

BACKGROUND

Methyl mercaptan occurs naturally in the environment and is found in a variety of occupational settings, including the oil, paper, plastics, and pesticides industries. It is a toxic gas and deaths from methyl mercaptan exposure have occurred. The Department of Homeland Security considers it a high threat chemical agent that could be used by terrorists. Unfortunately, no specific treatment exists for methyl mercaptan poisoning.

METHODS

We conducted a randomized trial in 12 swine comparing no treatment to intramuscular injection of the vitamin B₁₂ analog cobinamide (2.0 mL, 12.5 mg/kg) following acute inhalation of methyl mercaptan gas. Physiological and laboratory parameters were similar in the control and cobinamide-treated groups at baseline and at the time of treatment.

RESULTS

All six cobinamide-treated animals survived, whereas only one of six control animals lived (17% survival) (p = 0.0043). The cobinamide-treated animals returned to a normal breathing pattern by 3.8 ± 1.1 min after treatment (mean ± SD), while all but one animal in the control group had intermittent gasping, never regaining a normal breathing pattern. Blood pressure and arterial oxygen saturation returned to baseline values within 15 minutes of cobinamide-treatment. Plasma lactate concentration increased progressively until death (10.93 ± 6.02 mmol [mean ± SD]) in control animals, and decreased toward baseline (3.79 ± 2.93 mmol [mean ± SD]) by the end of the experiment in cobinamide-treated animals.

CONCLUSION

We conclude that intramuscular administration of cobinamide improves survival and clinical outcomes in a large animal model of acute, high dose methyl mercaptan poisoning.

Are Patients Discharged on the HEART Pathway Following Up?

Introduction

The HEART (history, electrocardiogram [ECG], age, risk factors, troponin) pathway is a useful tool in the emergency department to identify patients that are safe for outpatient evaluation of chest pain. A dedicated HEART Clinic to follow-up versus primary care remains a topic that requires further delineation. We sought to identify how many patients discharged on the HEART pathway specifically followed up with the established HEART Clinic.

Materials and Methods

This is a secondary analysis of a previously published dataset. In an initial validation study of the HEART Pathway, 625 consecutive subjects were identified via chart review, 449 of which were included. We identified subjects for inclusion in this study if they were found to have a HEART score of 3 or less. Subjects were excluded if they were admitted or if their follow-up was beyond 6 weeks.

Results

Of the 449 subjects, 185 met criteria for study inclusion. 125 (67.6%) had follow-up with an average time of 7.94 days (95% CI: 6.54-9.34). Of those, half had additional testing such as ECG, cardiac computed tomography angiography, and treadmill stress testing. The most common clinics for follow-up were the Family Medicine, Internal Medicine, and HEART Clinic representing 35.8, 29, and 18% of the follow-ups, respectively. No subject died, had a myocardial infarction, or required reperfusion.

Conclusions

Of the subjects discharged on the HEART Pathway, 67.6% followed up. Of those subjects that followed up, 18% did so at the HEART Clinic.

Transcriptome visualization and data availability at the Saccharomyces Genome Database

The Saccharomyces Genome Database (SGD; www.yeastgenome.org) maintains the official annotation of all genes in the Saccharomyces cerevisiae reference genome and aims to elucidate the function of these genes and their products by integrating manually curated experimental data. Technological advances have allowed researchers to profile RNA expression and identify transcripts at high resolution. These data can be configured in web-based genome browser applications for display to the general public. Accordingly, SGD has incorporated published transcript isoform data in our instance of JBrowse, a genome visualization platform. This resource will help clarify S. cerevisiae biological processes by furthering studies of transcriptional regulation, untranslated regions, genome engineering, and expression quantification in S. cerevisiae.

Efficacy of Intravenous Hydroxocobalamin for Treatment of Sodium Methanethiolate Exposure in a Swine Model (Sus scrofa) of Severe Methanethiol Toxicity

INTRODUCTION

Methanethiol is a highly toxic chemical present in crude oil and natural gas. At high concentrations, methanethiol causes metabolic acidosis, seizures, myocardial infarction, coma, and death. Occupational Health and Safety Administration lists methanethiol as a potential terrorist weapon. Methanethiol blocks the electron transport chain, resulting in lactic acidosis and acidemia. There is no specific treatment for methanethiol. Our objective was to measure the efficacy of intravenous (IV) hydroxocobalamin (HOC) versus no treatment (control) in methanethiol-induced apnea in a swine model.

METHODS

Sixteen anesthetized swine received IV sodium methanethiolate to apnea and were randomized to receive either IV HOC or no treatment. Physiologic and laboratory parameters were monitored throughout the study. Power analysis indicated that 8 animals per group would be sufficient to find a moderate effect (f = 0.24) with 2 groups, α = 0.05, and 80% power.

RESULTS

Both groups were similar in baseline characteristics. Following treatment, the HOC group had significantly higher heart rate and blood pressure at 5-10 minutes post-apnea, higher systemic vascular resistance at 5 minutes post-apnea, higher tidal volume, higher end-tidal carbon dioxide, and lower end-tidal oxygen 10-15 minutes post-apnea compared with controls. None of the animals survived to the end of the study (60 minutes). The Kaplan-Meier survival curves were significantly different between cohorts (log-rank p = 0.0321), with the HOC group surviving longer than controls (32.4 ± 7.3 vs. 25.8 ± 1.0 minutes).

CONCLUSIONS

In our model of intravenous methanethiolate poisoning, IV HOC administration resulted in a transient improvement in vital signs and prolonged time to death; however, it did not improve survival.

Intramuscular aminotetrazole cobinamide as a treatment for inhaled hydrogen sulfide poisoning in a large swine model

Hydrogen sulfide (H₂ S), a high-threat chemical agent, occurs naturally in a variety of settings. Despite multiple incidents of exposures and deaths, no FDA-approved antidote exists. A rapid-acting, easy to administer antidote is needed. We conducted a randomized control trial in swine comparing intramuscular administration of aminotetrazole cobinamide (2.9 mL, 18 mg/kg) to no treatment following inhalation of H₂ S gas. We found that aminotetrazole cobinamide administered 2 min after the onset of respiratory depression-defined as a tidal volume of less than 3 mL/kg for 2 consecutive minutes-yielded 100% survival, while all control animals died. Respiratory depression resolved in the treatment group within 3.6 ± 1.5 min (mean ± SD) of cobinamide administration, whereas control animals had intermittent gasping until death. Blood pressure and arterial oxygen saturation (SO₂ ) returned to baseline values within 5 and 10 min, respectively, of cobinamide treatment, and plasma lactate concentration decreased to less than 50% of the highest value by the end of the experiment. In control animals, plasma lactate rose continuously until death. We conclude that intramuscular aminotetrazole cobinamide is effective in a large animal, inhalational model of acute, severe H₂ S poisoning.

Chest Pain From Supplement Use in an Active Duty Soldier: A Case Report

In the active duty population, over-the-counter performance enhancing supplements are readily available and consumed, primarily in an unsupervised manner. While some of the active ingredients, such as caffeine and creatine, have been well studied, other sympathomimetic and vasoactive components in these products have minimal data regarding their safety profile. Further potentiating the associated risks of consumption, the quantities and purities of the reported ingredients are often unverified and can vary from serving to serving. We present a case of the deleterious side effect profiles of these lesser studied components in overconsumption in an active duty soldier. Although improvements are being made regarding product safety, the paucity of ingredient regulation and quality assurance can result in warfighter morbidity and mortality, especially when these supplements are abused or combined with other products.

The Development of an Emergency Medicine Resident Research Program in the United States Military

INTRODUCTION

The Accreditation Council for Graduate Medical Education stipulates that residents should participate in scholarly activity. As of 2019 that verbiage will be changed to, "Residents must participate in scholarship." However, scholarly activity is not clearly defined. We set out to define our graduation research requirement in a measurable way and structure a research curriculum that better prepared residents to conduct scholarly activity.

MATERIALS AND METHODS

This study compares resident scholarly output in several categories before and after the initiation of a revised research curriculum and graduation requirement. Scholarly activity was measured by comparing the production of Pubmed Indexed (PMID) publications, online publications, and conference presentations of two Emergency Medicine Residency classes. The intervention class was represented by the class of 2018 which exposed 16 residents to the new curriculum and graduation requirement for the full three years of their residency. The comparison class was represented by the class of 2015 which exposed 16 residents to the old curriculum and old graduation requirement. The old graduation requirement and curriculum were undefined. The new requirement involved two options, participate in original research starting from the process of question formulation and carried through manuscript drafting or publishing at first author PMID of any kind. The new curriculum involved monthly journal clubs, two annual deep dives, and an 8-day Intern Research Course modeled after the Emergency Medicine Basic Research Skills workshop sponsored by the American College of Emergency Physicians. In addition to the new curriculum, several new leadership positions were created at both the staff and resident level that solely focused on the promotion of scholarly activity. In addition to creating a culture within the department that encouraged scholarship, these overlapping leadership positions also helped create continuity in a program that could easily be hampered by frequent staff turnover due to new military assignments and military deployments.

RESULTS

Resident scholarly activity in the form of PMIDs increased from 4 to 22. The production of online publications was 0 and 12, respectively. There were 2 and 11 conference presentations, respectively.

CONCLUSION

Resident scholarly activity increased following the institution of a new research curriculum and graduation requirement.

Acetaminophen poisoning-induced heart injury: a case-based review

PURPOSE

Acetaminophen (Paracetamol, APAP) poisoning is frequently implicated in self-harm. Cases of acetaminophen-associated cardiotoxicity are rare in relation to the number of patients with acetaminophen poisoning. A review of acetaminophen cardiotoxicity in 1996 concluded that there was no decisive evidence demonstrating that acetaminophen overdose has a cardiotoxic effect. This review study aimed to determine whether acetaminophen could induce heart injury.

METHODS

We searched for keywords of acetaminophen, paracetamol, cardiotoxicity, heart injury, heart damage, myocarditis, pericarditis, myocardial infarction, and myocardial ischemia in Web of Science, PubMed, Scopus, Embase, Google Scholar, and Persian databases. The search included articles published from January 1950 to October 2018 with no language restrictions.

RESULTS

The search yielded 64 citations in English; 36 of the articles were excluded as they were not relevant; 5 articles were excluded since they were duplicates, leaving 23 articles. Full-text articles of the 23 citations were obtained and reviewed. Myocardial infarction, heart dysfunction and failure, cardiac arrhythmias, pericarditis, heart cell necrosis, and sudden cardiac death were reported in acetaminophen overdose.

CONCLUSIONS

Ddysrhythmias, heart failure, and various other cardiac effects could occur following acetaminophen induced hepatic failure. However, the evidence for direct injury on cardiac tissue is weak. Graphical abstract Potential mechanisms for cardiotoxicity of acetaminophen.

Digoxin Toxicity in a Patient with Pacemaker: A Case Report

Digoxin is a cardiac myocyte sodium/potassium ATPase inhibitor with a narrow therapeutic index used to treat patients with conditions such as heart failure with reduced ejection fraction and atrial fibrillation. Currently, digoxin-specific antibody fragments serve as a therapeutic option in patients with digoxin toxicity; however, the indications for digoxin-specific antibody fragments are inconsistent, and some sources report a serum digoxin concentration of >12 ng/mL as a treatment indication. We discuss a case of an asymptomatic elevated digoxin level of 13.5 ng/mL secondary to a dosing error, who was managed without digoxin-specific antibody fragments as well as a brief retrospective chart review for patients with a pacemaker presenting with a high digoxin concentration managed with and without digoxin-specific antibody fragments, with equivocal findings.

Adolescent exposures to traditional and novel psychoactive drugs, reported to National Poison Data System (NPDS), 2007-2017

BACKGROUND

Survey data on adolescent drug use trends have limitations evaluating the impact of drug use on health and may lag current trends. The objective was to describe National Poison Data System (NPDS) trends, medical outcomes, and healthcare encounters from adolescent exposures of traditional and novel psychoactive drugs.

METHODS

Retrospective review of adolescent (10-18 years of age) exposure calls to all U.S. poison centers, from January 1, 2007 through December 31, 2017, using generic codes for traditional and novel psychoactive drugs. Descriptive statistics and univariate Poisson regression modeling were used for analysis.

RESULTS

There were 49,757 exposure calls for the included psychoactive drugs. The median age was 16 years (IQR 15,17), 64% were male, and the majority were evaluated in a healthcare facility (92%). Marijuana had the most exposure calls (36.6%), followed by synthetic cannabinoids (e.g., spice; 21.3%). There were 181 (<1%) deaths; the highest fatality rates were from fentanyl, 2C drugs (phenylethylamine derivatives), and heroin. LSD exposure calls have had the most significant increase over the past 10 years.

CONCLUSION

U.S. Poison Centers reported almost 50,000 exposure calls and 181 deaths over 10 years for adolescent exposures of both traditional and novel psychoactive drugs, demonstrating the significant health impact on this vulnerable population. Opioids and 2C drugs contributed to the highest mortality rates, moderate/major symptoms and healthcare utilization, and LSD had the most significant increase in calls. Multi-source surveillance methodology is critical in understanding the public health impact on drug abuse in the adolescent population.

Idiopathic acute eosinophilic pneumonia: A rare cause of hypoxic respiratory failure

Idiopathic Acute Eosinophilic Pneumonia (IAEP) is a life-threatening cause of hypoxic respiratory failure. IAEP is challenging to diagnose as it may mimic infectious pneumonia or acute respiratory distress syndrome. Distinguishing IAEP from these alternatives is important; the mainstay of treatment for IAEP is corticosteroids, a therapy which might not otherwise be indicated. Patients treated appropriately usually experience a full recovery. In this case report we describe the presentation, evaluation, and management of a 19-year old male who presented to the emergency department (ED) in respiratory failure from IAEP. The patient was a military trainee who recently moved to the United States from Saudi Arabia. He also recently began smoking cigarettes for the first time, a known risk factor for IAEP. Upon initial presentation, the patient was in respiratory distress and had an oxygen saturation of 82% on room air. His ED diagnostic workup included chest X-ray showing diffuse interstitial thickening and chest computed tomography that demonstrated diffuse nodular opacification of pulmonary parenchyma. The patient was admitted to the intensive care unit (ICU) where bronchoscopy yielded cytology with 30% eosinophilia. The patient ultimately required 3 days of extra corporeal membrane oxygenation (ECMO) due to worsening hypoxic respiratory failure. After both intravenous and outpatient oral steroid treatments, the patient went on to have a full recovery with no ongoing respiratory issues. To our knowledge, this is the first case of IAEP requiring ECMO reported in the emergency medicine literature.

Efficacy of Oral Administration of Sodium Thiosulfate and Glycine in a Large, Swine Model of Oral Cyanide Toxicity

STUDY OBJECTIVE

Cyanide is a deadly poison, particularly with oral exposure, in which larger doses can occur before any symptoms develop. Multiple governmental agencies highlight oral cyanide as an agent that can be used in a terrorist attack because it can be easily weaponized and is readily available. Currently, there are no Food and Drug Administration-approved antidotes specifically for oral cyanide. An oral countermeasure that can neutralize and prevent absorption of cyanide from the gastrointestinal tract after oral exposure is needed. The objective of this study is to determine if the combination of glycine and sodium thiosulfate administered orally is effective in reducing mortality in a large, swine model of oral cyanide toxicity.

METHODS

Nine swine (45 to 55 kg) were instrumented, sedated, and stabilized. Potassium cyanide (at 8 mg/kg) in saline solution was delivered as a onetime bolus through an orogastric tube. Three minutes after cyanide administration, animals that were randomized to the treatment group received sodium thiosulfate (508.2 mg/kg, 3.25-M solution) and glycine (30 mg/kg, 3.5-M solution) through an orogastric tube. Survival at 60 minutes was the primary outcome. We compared survival between groups by log-rank Mantel-Cox analysis and trended laboratory results and vital signs.

RESULTS

At baseline and treatment, all animals were similar. Survival at 60 minutes was 100% in treated animals compared with 0% in the control group (P=.003). By the study end, defined as death or 60 minutes after cyanide administration, there was a significant difference in the lactate concentration between the treatment and control groups (control 9.43 mmol/L [SD 4.08]; treatment 1.66 mmol/L [SD 0.82]; difference between means 7.69 mmol/L [SD 2.07]; 95% confidence interval difference -14.05 to -1.32). Mean arterial pressure was significantly different between the treatment and control groups at study end (control 26 mm Hg [SD 6.7]; treatment 81 mm Hg [SD 14]; difference between means 55.2 mm Hg [SD 7.1]; 95% confidence interval difference 37.8 to 72.6). pH and oxygen saturation were also significantly different between the treatment and control groups at study end.

CONCLUSION

The combination of oral sodium thiosulfate and glycine significantly improved survival and physiologic parameters in a large-animal model of oral cyanide toxicity.

Hydrogen Sulfide Toxicity: Mechanism of Action, Clinical Presentation, and Countermeasure Development

INTRODUCTION

Hydrogen sulfide (H₂S) is found in various settings. Reports of chemical suicide, where individuals have combined readily available household chemicals to produce lethal concentrations of H₂S, have demonstrated that H₂S is easily produced. Governmental agencies have warned of potential threats of use of H₂S for a chemical attack, but currently there are no FDA-approved antidotes for H₂S. An ideal antidote would be one that is effective in small volume, readily available, safe, and chemically stable. In this paper we performed a review of the available literature on the mechanism of toxicity, clinical presentation, and development of countermeasures for H₂S toxicity.

DISCUSSION

In vivo, H₂S undergoes an incomplete oxidation after an exposure. The remaining non-oxidized H₂S is found in dissolved and combined forms. Dissolved forms such as H₂S gas and sulfhydryl anion can diffuse between blood and tissue. The combined non-soluble forms are found as acid-labile sulfides and sulfhydrated proteins, which play a role in toxicity. Recent countermeasure development takes into account the toxicokinetics of H₂S. Some countermeasures focus on binding free hydrogen sulfide (hydroxocobalamin, cobinamide); some have direct effects on the mitochondria (methylene blue), while others work by mitigating end organ damage by generating other substances such as nitric oxide (NaNO2).

CONCLUSION

H₂S exists in two main pools in vivo after exposure. While several countermeasures are being studied for H₂S intoxication, a need exists for a small-volume, safe, highly effective antidote with a long shelf life to treat acute toxicity as well as prevent long-term effects of exposure.

Intramuscular sodium tetrathionate as an antidote in a clinically relevant swine model of acute cyanide toxicity

Background: Cyanide is a metabolic poison used in multiple industries and is a high threat chemical agent. Current antidotes require intravenous administration, limiting their usefulness in a mass casualty scenario. Sodium tetrathionate reacts directly with cyanide yielding thiosulfate and the non-toxic compound thiocyanate. Thiosulfate, in turn, neutralizes a second molecule of cyanide, thus, per mole, sodium tetrathionate neutralizes two moles of cyanide. Historical studies examined its efficacy as a cyanide antidote, but it has not been evaluated in a clinically relevant, large animal model, nor has it previously been administered by intramuscular injection.Objective: The objective of this study is to evaluate the efficacy of intramuscular sodium tetrathionate on survival and clinical outcomes in a large, swine model of severe cyanide toxicity.Methods: Anesthetized swine were instrumented for continuous monitoring of hemodynamics, then acclimated and breathing spontaneously prior to potassium cyanide infusion (0.17 mg/kg/min). At 6-min post-apnea (no breaths for 20 s), the cyanide infusion was terminated, and animals were treated with sodium tetrathionate (∼18 mg/kg) or normal saline control. Clinical parameters and laboratory values were evaluated at various time points until death or termination of the experiment (90 min post-treatment).Results: Laboratory values, vital signs, and time to apnea were similar in both groups at baseline and treatment. Survival in the sodium tetrathionate treated group was 100% and 17% in controls (p = 0.0043). All animals treated with sodium tetrathionate returned to breathing at a mean time of 10.85 min after antidote, and all but one control remained apneic through end of the experiment. Animals treated with tetrathionate showed improvement in blood lactate (p ≤ 0.002) starting at 30 min post-treatment. The average time to death in the control group is 63.3 ± 23.2 min. No systemic or localized adverse effects of intramuscular administration of sodium tetrathionate were observed.Conclusion: Sodium tetrathionate significantly improves survival and clinical outcomes in a large, swine model of acute cyanide poisoning.

Lacosamide Overdose: A Case of QRS Prolongation and Seizure

BACKGROUND

Lacosamide is a third-generation antiepileptic drug. Its likely mechanism of action is via neuronal sodium channel blockade, via a unique manner compared with other antiepileptic drugs that block sodium channels. A paucity of information exists regarding lacosamide overdosage. Lacosamide overdosage is thought to cause QRS prolongation and seizures, due to its effect of sodium channel blockade. The potential efficacy of sodium bicarbonate to reverse the effects of lacosamide has not been well studied. Furthermore, prior reports of lacosamide toxicity have occurred in the setting of concomitant polypharmacy. Thus, the isolated toxic effects of the drug have not been well elucidated.

CASE REPORT

We report a case of a suspected, single-ingestion overdose on lacosamide. The patient developed signs of cardiotoxicity and seizure. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: After lacosamide overdosage, the emergency physician must be capable of acute management of subsequent lacosamide toxicity. Understanding the mechanisms of action causing toxicity due to this drug can help the clinician to anticipate the interventions that may be needed or useful to treat this potentially toxic ingestion.

Acetaminophen and Acetylsalicylic Acid Exposure in a Preterm Infant after Maternal Overdose

Here, we review the case of a 26 1/7 weeks' gestation premature female infant born to a mother who intentionally ingested a large quantity of Tylenol, aspirin, quetiapine, and prenatal vitamins. The neonate subsequently had markedly elevated levels of both Tylenol and aspirin when checked on the first day of life. While overall clinically stable, the neonate did demonstrate coagulopathy as evidenced by abnormal coagulation studies. Both poison control and a pediatric gastroenterologist/hepatologist were consulted. She successfully tolerated a course of N-acetylcysteine; her subsequent Tylenol level was markedly decreased and the neonate exhibited no further effects of toxicity. The salicylate level decreased on its own accord. To our knowledge, this is the first report of a neonate at 26 weeks' gestation that has been successfully managed for supratherapeutic concentrations of acetaminophen and acetylsalicylic acid secondary to maternal ingestion. While rare, this case may serve as a reference for the effectiveness of N-acetylcysteine in premature infants in such instances.

A Review on Ingested Cyanide: Risks, Clinical Presentation, Diagnostics, and Treatment Challenges

Cyanide, a metabolic poison, is a rising chemial threat and ingestion is the most common route of exposure. Terrorist organizations have threatened to attack the USA and international food and water supplies. The toxicokinetics and toxicodynamics of oral cyanide are unique, resulting in high-dose exposures, severe symptoms, and slower onset of symptoms. There are no FDA-approved therapies tested for oral cyanide ingestions and no approved intramuscular or oral therapies, which would be valuable in mass casualty settings. The aim of this review is to evaluate the risks of oral cyanide and its unique toxicokinetics, as well as address the lack of available rapid diagnostics and treatments for mass casualty events. We will also review current strategies for developing new therapies. A review of the literature using the PRISMA checklist detected 7284 articles, screened 1091, and included 59 articles or other reports. Articles referenced in this review were specific to risk, clinical presentation, diagnostics, current treatments, and developing therapies. Current diagnostics of cyanide exposure can take hours or days, which can delay treatment. Moreover, current therapies for cyanide poisoning are administered intravenously and are not specifically tested for oral exposures, which can result in higher cyanide doses and unique toxicodynamics. New therapies developed for oral cyanide exposures that are easily delivered, safe, and can be administered quickly by first responders in a mass casualty event are needed. Current research is aimed at identifying an antidote that is safe, effective, easy to administer, and has a rapid onset of action.

Intramuscular cobinamide versus saline for treatment of severe hydrogen sulfide toxicity in swine

INTRODUCTION

Hydrogen sulfide (H₂S) is found in petroleum, natural gas, and decaying organic matter. Terrorist groups have attempted to use it in enclosed spaces as a chemical weapon. Mass casualty scenarios have occurred from industrial accidents and release from oil field sites. There is no FDA approved antidote for sulfide poisoning. We have previously reported that intravenous cobinamide is effective for sulfide poisoning. A rapid-acting antidote that is easy to administer intramuscularly (IM) would be ideal for use in a prehospital setting. In this study, we assessed survival in sulfide-poisoned swine treated with IM cobinamide.

METHODS

Eleven swine (45-55 kg) were anesthetized, intubated, and instrumented with continuous femoral and pulmonary artery pressure monitoring. After stabilization, anesthesia was adjusted such that animals ventilated spontaneously with a FiO₂ of 0.21. Sodium hydrosulfide (NaHS, 8 mg/mL) was infused intravenously at 0.9 mg/kg.min until apnea or severe hypotension. Animals were randomly assigned to receive cobinamide (4 mg/kg), or no treatment at the apnea/hypotension trigger. The NaHS infusion rate was sustained for 1.5 min post trigger, decreased to 0.2 mg/kg.min for 10 min, and then discontinued.

RESULTS

The amount of NaHS required to produce apnea or hypotension was not statistically different in both groups (cobinamide: 9.0 mg/kg ±6.1; saline: 5.9 mg/kg ±5.5; mean difference: -3.1, 95% CI: -11.3, 5.0). All of the cobinamide treated animals survived (5/5), none of the control (0/6) animals survived (p < .01). Mean time to return to spontaneous ventilation in the cobinamide treated animals was 3.2 (±1.1) min. Time to return to baseline systolic blood pressure (±5%) in cobinamide-treated animals was 5 min.

CONCLUSION

Intramuscular cobinamide was effective in improving survival in this large swine model of severe hydrogen sulfide toxicity.

Intramuscular dimethyl trisulfide: efficacy in a large swine model of acute severe cyanide toxicity

BACKGROUND

Cyanide is a deadly compound used as a terrorist agent. Current FDA approved antidotes require intravenous administration, limiting their utility in a mass casualty scenario. Dimethyl trisulfide (DMTS), a sulfur-based molecule, binds cyanide converting it to the less toxic by-product thiocyanate. Studies evaluating efficacy in rodents have been performed, but a large, clinically relevant animal model has not been reported.

OBJECTIVE

This study evaluates the efficacy of intramuscular DMTS on survival and clinical outcomes in a swine model of acute, severe cyanide toxicity.

METHODS

Anesthetized swine were instrumented for continuous monitoring of hemodynamics. Prior to potassium cyanide infusion animals were acclimated and breathing spontaneously. At 5-minutes post-apnea animals were treated with DMTS or saline. Vital signs, hemodynamics, and laboratory values were evaluated at various time points.

RESULTS

Baseline values and time to apnea were similar in both groups. Survival in the DMTS treated group was 83.3% and 0% in saline controls (p = .005). The DMTS group returned to breathing at a mean time of 19.3 ± 10 min after antidote, control animals did not return to breathing (CI difference 8.8, 29.8). At the end of the experiment or time of death, mean lactate was 9.41 mmol/L vs. 4.35 mmol/L (CI difference -10.94,0.82) in the saline and DMTS groups, respectively and pH was 7.20 vs. 7.37 (CI difference -0.04, 0.38). No adverse effects were observed at the injection site.

CONCLUSION

Intramuscular administration of DMTS improves survival and clinical outcomes in our large animal swine model of acute cyanide toxicity.

Epidemiological and clinical profiles of acute poisoning in patients admitted to the intensive care unit in eastern Iran (2010 to 2017)

BACKGROUND

Acute poisoning is a common chief complaint leading to emergency department visits and hospital admissions in developing countries such as Iran. Data describing the epidemiology of different poisonings, characteristics of the clinical presentations, and the predictors of outcome are lacking. Such data can help develop more efficient preventative and management strategies to decrease morbidity and mortality related to these poisonings. This manuscript describes the epidemiology of acute poisoning among patients admitted to the intensive care unit (ICU) in Birjand, Iran.

METHODS

This retrospective, cross-sectional study was conducted to characterize acute poisonings managed in the ICU during a 7-year period from March 2010 to March 2017 in a single center in Birjand, Iran. Patient characteristics, suspected exposure, the route of exposure, and outcome data were collected from hospital medical records.

RESULTS

During the study period, 267 (64% male and 36% female) patients met inclusion criteria. Pharmaceutical medication (36.6%), opioids (26.2%) followed by pesticides (13.9%) were the most common exposures 38.2% of these cases were identified as suicide attempts. There were different frequencies in terms of xenobiotic exposure in relation to gender (p = 0.04) and the survival (p = 0.001). There was a significant difference between various xenobiotics identified as the cause of poisoning (p = 0.001). Mortality rate in our study was 19.5%. The incidence of outcomes was significantly higher in patients poisoned with opioids, pesticides, benzodiazepines, and tricyclic antidepressants (p < 0.05). The median length of hospital stay was higher in pesticide-poisoned patients (p = 0.04).

CONCLUSION

Opioids and pesticides were the most common exposures. The mortality rate of the poisoned patients in the ICU was proportionately high. The mortality rate due to opioid poisoning is a major concern and the most significant cause death due to poisoning in the region. Further monitoring and characterization of acute poisoning in Birjand, Iran is needed. These data can help develop educational and preventative programs to reduce these exposures and improve management of exposures in the prehospital and hospital settings.

Characterization of a Swine (Sus scrofa) Model of Oral Potassium Cyanide Intoxication

Cyanide is a readily available and potentially lethal substance. Oral exposure can result in larger doses, compared with other routes. Currently, there are no antidotes specific for use in the treatment of oral cyanide poisoning, and studies cannot be done in humans. We report on a new large animal model of oral cyanide toxicity to evaluate potential antidotes. Six female swine (Sus scrofa; weight, 45 to 55 kg) were anesthetized, intubated, and instrumented. Animals received a KCN bolus of either 5 or 8 mg/kg delivered via orogastric tube. Time to apnea was recorded; parameters monitored included heart rate, respiratory rate, blood pressure, pulse oximetry, end-tidal CO2, arterial blood gasses, and lactate concentrations. The Welch t test was used to calculate confidence intervals, mean, and standard deviation, and a Kaplan-Meier survival curve was used to compare survival between the 2 groups. At baseline, all animals in both groups were similar. Animals in the 5-mg/kg group had a more rapid time to apnea (5.1 ± 2.1 min), longer time to death (48.5 ± 38.1 min), and a greater rate of survival than the 8-mg/kg group (apnea, 10.6 ± 10.7 min; death, 26.1 ± 5.8 min). All animals displayed signs of toxicity (acidemia, hyperlactatemia, hypotension, apnea). We here report a large animal (swine) model of oral cyanide poisoning with dose-dependent effects in regard to time to death and survival rate. This model likely will be valuable for the development of medical countermeasures for oral cyanide poisoning.

Aromatherapy Versus Oral Ondansetron for Antiemetic Therapy Among Adult Emergency Department Patients: A Randomized Controlled Trial

STUDY OBJECTIVE

We compare aromatherapy with inhaled isopropyl alcohol versus oral ondansetron for treating nausea among emergency department (ED) patients not requiring immediate intravenous access.

METHODS

In a randomized, blinded, placebo-controlled trial, we enrolled a convenience sample of adults presenting to an urban tertiary care ED with chief complaints including nausea or vomiting. We randomized subjects to 1 of 3 arms: inhaled isopropyl alcohol and 4 mg oral ondansetron, inhaled isopropyl alcohol and oral placebo, and inhaled saline solution placebo and 4 mg oral ondansetron. The primary outcome was mean nausea reduction measured by a 0- to 100-mm visual analog scale from enrollment to 30 minutes postintervention. Secondary outcomes included receipt of rescue antiemetic medications and adverse events.

RESULTS

We enrolled 122 subjects, of whom 120 (98.3%) completed the study. Of randomized subjects, 40 received inhaled isopropyl alcohol and oral ondansetron, 41 received inhaled isopropyl alcohol and oral placebo, and 41 received inhaled saline solution placebo and oral ondansetron. The mean decrease in nausea visual analog scale score in each arm was 30 mm (95% confidence interval [CI] 22 to 37 mm), 32 mm (95% CI 25 to 39 mm), and 9 mm (95% CI 5 to 14 mm), respectively. The proportions of subjects who received rescue antiemetic therapy in each arm were 27.5% (95% CI 14.6% to 43.9%), 25.0% (95% CI 12.7% to 41.2%), and 45.0% (95% CI 29.3% to 61.5%), respectively. There were no adverse events.

CONCLUSION

Among ED patients with acute nausea and not requiring immediate intravenous access, aromatherapy with or without oral ondansetron provides greater nausea relief than oral ondansetron alone.

A Prospective Observation Study of Medical Toxicology Consultation in a U.S. Combat Theater

OBJECTIVES

Since 2001, U.S. military personnel and active duty, uniformed physicians providing medical support have been deployed to Afghanistan. Medical toxicologists are among the physicians deployed. There is a paucity of information present in the literature that has documented cases treated by toxicologists in theater. This prospective observational study describes 15 male patients treated in theater by a military medical toxicologist.

METHODS

We performed a prospective observational study in which a medical toxicologist consulted and reported on deployed toxicology cases occurring during a 5-month deployment to Bagram, Afghanistan.

RESULTS

Fifteen toxicology cases were collected during the 5-month period. The patients included three Afghan civilians, three U.S. civilians, and nine U.S. military personnel. Eight cases were attempts at recreational euphoria, two were self-harm attempts, two were from performance-enhancing supplements, two were accidental occupational exposures and one was alcohol withdrawal. Methanol was the most common exposure followed by dextromethorphan, supplements, opiates, and chlorine gas.

CONCLUSION

In our study, we found that toxic alcohols and nonprescription medications were the most common exposures. In addition, this is the first study to describe bedside toxicology consults for U.S. combat forces in theater and the use of an observation unit for critically ill patients.

Using Pill Identification Calls to Poison Centers as a Marker of Drug Abuse at Three Texas Military Bases

OBJECTIVES

Opioid abuse is a growing problem in civilian communities, and it has developed in the military as well. Telephone calls to poison centers requesting pill identification (ID) is a marker of drug abuse. This study identifies the number of pill ID calls made to the poison centers from areas containing and surrounding three Texas military bases during an 8-year period.

METHODS

We performed a retrospective observational study identifying calls to certified poison centers in Texas from 2002 to 2009 that identified hydrocodone tablets and other pain medications. We noted the calls made from ZIP codes containing and surrounding the three largest military bases in Texas.

RESULTS

We reviewed 75,537 drug ID calls for any drug from the ZIP codes of interest. Total drug ID calls increased 105% and the number of calls for hydrocodone increased 463%.

CONCLUSIONS

In our study most of the drug ID calls from military communities in Texas were for hydrocodone. The rate of calls for hydrocodone increased more than the rate of calls for other analgesics from 2002 to 2009. Using drug ID calls as a surrogate of drug abuse, our results suggest that hydrocodone abuse has increased within military communities and that poison center data can be a reliable surrogate for prescription drug abuse near military bases. Future studies are needed to further understand the extent of this problem in military and civilian communities. We can use this information to heighten awareness, influence prescription practices, establish practice guidelines, and develop educational programs to mitigate the increasing rate of prescription analgesic abuse in the United States.

Self-reported dietary supplement use in deployed United States service members pre-deployment vs. during deployment, Afghanistan, 2013-2014

BACKGROUND

Dietary supplement use (protein/amino acids, weight-loss supplements, performance enhancers) is common among U.S. military members. Reported dietary supplement use in deployed troops is limited and is of concern in settings where troops are exposed to high ambient temperatures, increased physical demands, and dehydration. Our objective was to describe dietary supplement use and adverse events (AEs) among deployed U.S. service members compared with their pre-deployment use.

METHODS

We conducted an institutional review board (IRB) approved, descriptive study in Afghanistan using a written questionnaire and collected demographic information, dietary supplement use before and during deployment, AEs associated with supplement use, and physical workout routines. Participants were U.S. military personnel of all branches of service deployed to Afghanistan. They were recruited in high-traffic areas in the combat theater. We analyzed the data with descriptive statistics. Paired t-test/Wilcoxon signed-rank test was conducted to examine the before/during deployment changes for continuous data, and McNemar's chi-square test was conducted for categorical data. We constructed separate logistic regression models to determine the best predictors of increases or decreases in dietary supplement use, with demographic information, reasons for using supplements, and education requested/received as covariates in each model. All statistical tests were two-sided at a significance level of 5% (P < 0.05).

RESULTS

Data were collected on 1685 participants. Ninety-seven of the participants were in the Army or Air Force. The participants were more likely to work out daily or more than once a day during deployment. Thirty-five percent of the participants reported no supplement use before or during deployment. The remaining 65% of participants reported increased use and increased frequency of use of supplements (e.g., daily) during deployment compared with pre-deployment. Additionally, more people followed label instructions strictly during deployment vs. pre-deployment. Overall, the frequency of self-reported AEs among supplement users remained consistent before and during deployment. The only significant difference noted was in problems falling or staying asleep, which increased during deployment. In the adjusted logistic regression models, the level of formal education, military branch, occupational specialty, education about dietary supplements, and certain reasons for using supplements (to boost energy, lose weight, gain muscle strength and mass, and as a meal replacement) were significant predictors of changes in supplement use.

CONCLUSION

Deployed U.S. service members were more likely to use dietary supplements, use more than one supplement and use supplements more frequently during deployment than pre-deployment. No serious AEs were reported, but problems falling or staying asleep increased during deployment.

A 12-month descriptive analysis of emergency intubations at Brooke Army Medical Center: a National Emergency Airway Registry study

Emergency airway management is a critical skill for military healthcare providers. Our goal was to describe the Emergency Department (ED) intubations at Brooke Army Medical Center (BAMC) over a 12-month period.

MATERIAL AND METHODS

Physicians performing endotracheal intubations in the BAMC ED complete data collection forms for each intubation event as part of the National Emergency Airway Registry, including patient demographics, intubation techniques, success and failure rates, adverse events, and patient disposition. We cross-referenced these forms against the numbers of intubation events reported in the ED nursing daily reports to ensure capture of all intubations. Providers completed forms for every intubation within 6 weeks of the procedure. We analyzed data from March 28, 2016, to March 27, 2017.

RESULTS

During the study period, providers performed 259 intubations in the BAMC ED. Reasons for intubation were related to trauma for 184 patients (71.0%) and medical conditions for 75 patients (29.0%). Overall, first-attempt success was 83.0%. Emergency medicine residents performed a majority of first attempts (95.0%). Most common devices chosen on first attempt were a video laryngoscope for 143 patients (55.2%) and a direct laryngoscope for 115 patients (44.4%). One patient underwent cricothyrotomy. The 2 most common induction agents were ketamine (59.8%; 95% CI, 55.2%-67.4%) and etomidate (19.3%; 95% CI, 14.7%-24.7%). The most common neuromuscular blocking agents were rocuronium (62.9%; 95% CI, 56.7%-68.8%) and succinylcholine (18.9%; 95% CI, 14.3%-24.2%).

CONCLUSION

In the BAMC ED, emergency intubation most commonly occurred for trauma indications using video laryngoscopy with a high first-pass success.

Cervical Ectopic Pregnancy in a 23 Year Old with Uterus Didelphys

Ectopic pregnancy remains an important diagnosis for the emergency physician to recognize, accounting for up to 2% of all pregnancies and associated with significant morbidity and mortality. Ectopic pregnancies can implant in various sites outside of the uterus, one of the rarest of which is in the cervix. Cervical ectopics account for less than 1% of ectopic pregnancies, but are associated with higher rates of significant bleeding than others.1–2 Uterine anomalies are a predisposing factor for ectopic pregnancies. This case highlights the management of a cervical ectopic pregnancy in a 23 year old with a history of uterine didelphys.