Articles

Samutsakorn DK, Carius BM 23(3). 36 (Journal Article)

Introduction: Extremity bleeding and subsequent hemorrhagic shock is one of the main causes of preventable battlefield death, leading to mass-fielding of modern tourniquets, such as the Combat Application Tourniquet (CAT; Composite Resources). Numerous look-alike tourniquets, such as the Military Tactical Emergency Tourniquet (MTET; SZCTKlink), flood commercial markets, offering visually near-identical tourniquets for drastically reduced prices. We examined the performance of the MTET compared with that of the CAT. Methods: We undertook a randomized crossover trial to observe self-applied tourniquets to the lower extremity by combat medics, comparing the CAT to the MTET in application time and success rates, proven by loss of distal pulse assessed by Doppler ultrasound in <1 minute. Results: All 50 participants (100%) successfully applied the CAT versus 40 participants (80%) using the MTET (p = .0001). Median application time for the CAT (29.03 seconds; range, 18.63 to 59.50 seconds) was significantly less than those of successful MTET applications (35.27 seconds; range, 17.00 to 58.90 seconds) or failed MTET applications (72.26 seconds; range, 62.84 to 83.96 seconds) (p = .0012). Of 10 MTET failures, three (30%) were from application time >1 minute and seven (70%) from tourniquet mechanical failure. Conclusion: The MTET performed worse than the CAT did in all observed areas. Despite identical appearance, look-alike tourniquets should not be assumed to be equivalent in quality or functionality to robustly tested tourniquets.

Bedolla C, Zilevicius D, Copeland G, Guerra M, Salazar S, April MD, Long B, Naylor JF, De Lorenzo RA, Schauer SG, Hood RL 23(2). 19 (Journal Article)

Introduction: Airway obstruction is the second leading cause of death on the battlefield. The harsh conditions of the military combat setting require that devices be able to withstand extreme circumstances. Military standards (MIL-STD) testing is necessary before devices are fielded. We sought to determine the ability of supraglottic airway (SGA) devices to withstand MIL-STD testing. Methods: We tested 10 SGA models according to nine MIL-STD-810H test methods. We selected these tests by polling five military and civilian emergency-medicine subject matter experts (SMEs), who weighed the relevance of each test. We performed tests on three devices for each model, with operational and visual examinations, to assign a score (1 to 10) for each device after each test. We calculated the final score of each SGA model by averaging the score of each device and multiplying that by the weight for each test, for a possible final score of 2.6 to 26.3. Results: The scores for the SGA models were LMA Classic Airway, 25.9; AuraGain Disposable Laryngeal Mask, 25.5; i-gel Supraglottic Airway, 25.2; Solus Laryngeal Mask Airway, 24.4; LMA Fastrach Airway, 24.4; AuraStraight Disposable Laryngeal Mask, 24.1; King LTS-D Disposable Laryngeal Tube, 22.1; LMA Supreme Airway, 21.0; air-Q Disposable Intubating Laryngeal Airway, 20.1; and Baska Mask Supraglottic Airway, 18.1. The limited (one to three) samples available for testing provide adequate preliminary information but restrict the range of failures that could be discovered. Conclusions: Lower scoring SGA models may not be optimal for military field use. Models scoring sufficiently close to the top performers (LMA Classic, AuraGain, i-gel, Solus, LMA Fastrach, AuraStraight) may be viable for use in the military setting. The findings of our testing should help guide device procurement appropriate for different battlefield conditions.

Schauer SG, Damrow T, Martin SM, Hudson IL, De Lorenzo RA, Blackburn MB, Hofmann LJ, April MD 23(2). 19 (Journal Article)

Background: Airway obstruction is the second leading cause of potentially preventable death on the battlefield. The treatment for airway obstruction is intubation or advanced airway adjunct, which has a known risk of aspiration. We sought to describe the variables associated with aspiration pneumonia after prehospital airway intervention. Methods: This is a sub-analysis of previously described data from the Department of Defense Trauma Registry (DoDTR) from 2007 to 2020. We included casualties that had at least one prehospital airway intervention with documentation of subsequent aspiration pneumonia or pneumonia within three days of the intervention. We used a generalized linear model with Firth bias estimates to test for associations. Results: There were 1,509 casualties that underwent prehospital airway device placement. Of these, 41 (2.7%) met inclusion criteria into the aspiration pneumonia cohort. The demographics had no statistical difference between the groups. The non-aspiration cohort had fewer median ventilator days (2 versus 6, p < 0.001), intensive care unit days (2 versus 7, p < 0.001, and hospital days [3 versus 8, p < 0.001]). Survival was lower in the non-aspiration cohort (74.2% versus 90.2%, p = 0.017). The administration of succinylcholine was higher in the non-aspiration cohort (28.0% versus 12.2%, p = 0.031). In our multivariable model, only the administration of succinylcholine was significant and was associated with lower probability of aspiration pneumonia (odds ratio 0.56). Conclusion: Overall, the incidence of aspiration pneumonia was low in our cohort. The administration of succinylcholine was associated with a lower odds of developing aspiration pneumonia.

Thompson P, Ciarglia A, Handspiker E, Bjerkvig C, Bynum JA, Glassberg E, Gurney J, Hudson AJ, Jenkins DH, Nicholson S, Strandenes G, Braverman MA 23(2). 9 (Journal Article)

Introduction: Tension pneumothorax (TPX) is the third most common cause of preventable death in trauma. Needle decompression at the fifth intercostal space at anterior axillary line (5th ICS AAL) is recommended by Tactical Combat Casualty Care (TCCC) with an 83-mm needle catheter unit (NCU). We sought to determine the risk of cardiac injury at this site. Methods: Institutional data sets from two trauma centers were queried for 200 patients with CT chest. Inclusion criteria include body mass index of ≤30 and age 18-40 years. Measurements were taken at 2nd ICS mid clavicular line (MCL), 5th ICS AAL and distance from the skin to pericardium at 5th ICS AAL. Groups were compared using Mann-Whitney U and chi-squared tests. Results: The median age was 27 years with median BMI of 23.8 kg/m2. The cohort was 69.5% male. Mean chest wall thickness at 2nd ICS MCL was 38-mm (interquartile range (IQR) 32-45). At 5th ICS AAL, the median chest wall thickness was 30-mm (IQR 21-40) and the distance from skin to pericardium was 66-mm (IQR 54-79). Conclusion: The distance from skin to pericardium for 75% of patients falls within the length of the recommended needle catheter unit (83-mm). The current TCCC recommendation to "hub" the 83mm needle catheter unit has potential risk of cardiac injury.

Anderson JL, Kronstedt S, Bergens MA, Johannigman J 99(5). 0 (Journal Article)

Speicher MV, McGowan J, Pruett S, Shurden J, Bianchi W, Kibler A 99(5). 0 (Journal Article)

Trauma casualty care has historically been the cornerstone of special operations military medical training. A recent case of myocardial infarction at a remote base of operations in Africa highlights the importance of foundational medical knowledge and training. A 54-year-old government contractor supporting operations in the AFRICOM area of responsibility (AOR) presented to the Role 1 medic with substernal chest pain with onset during exercise. Abnormal rhythm strips concerning for ischemia were obtained from his monitors. A MEDEVAC to a Role 2 facility was arranged and executed. At the Role 2 a non-ST-elevation myocardial infarction (NSTEMI) was diagnosed. The patient was emergently evacuated on a lengthy flight to a civilian Role 4 treatment facility for definitive care. He was found to have a 99% occlusion of the left anterior descending (LAD) coronary artery, as well as a 75% occlusion of the posterior coronary artery and a chronic 100% occlusion of the circumflex artery. The LAD and posterior arteries were stented, and the patient made a favorable recovery. This case highlights the importance of preparedness for medical emergencies and care of medically critical patients in remote and austere locations.

Johnston LR, Nam JJ, Nissen AP, Sleeter JJ, Aden JK, Mills AF, Sams VG 99(5). 0 (Journal Article)

Background: Patients with rib fractures are at high risk for morbidity and mortality. This study prospectively examines bedside percent predicted forced vital capacity (% pFVC) in predicting complications for patients suffering multiple rib fractures. The authors hypothesize that increased % pFVC is associated with reduced pulmonary complications. Methods: Adult patients with ≥3 rib fractures admitted to a level I trauma center, without cervical spinal cord injury or severe traumatic brain injury, were consecutively enrolled. FVC was measured at admission and % pFVC values were calculated for each patient. Patient were grouped by % pFVC <30% (low), 30-49% (moderate), and ≥50% (high). Results: A total of 79 patients were enrolled. Percent pFVC groups were similar except for pneumothorax being most frequent in the low group (47.8% vs. 13.9% and 20.0%, p = .028). Pulmonary complications were infrequent and did not differ between groups (8.7% vs. 5.6% vs. 0%, p = .198). Discussion: Increased % pFVC was associated with reduced hospital and intensive care unit (ICU) length of stay (LOS) and increased time to discharge to home. Percent pFVC should be used in addition to other factors to risk stratify patients with multiple rib fractures. Bedside spirometry is a simple tool that can help guide management in resource-limited settings, especially in large-scale combat operations. Conclusion: This study prospectively demonstrates that % pFVC at admission represents an objective physiologic assessment that can be used to identify patients likely to require an increased level of hospital care.

Schauer SG, Hudson IL, Fisher AD, Dion G, Long B, Blackburn MB, De Lorenzo RA, Shaw TA, April MD 99(5). 0 (Journal Article)

Background: Airway obstruction is the second leading cause of potentially survivable death on the battlefield. Assessing outcomes associated with airway interventions is important, and temporal trends can reflect the influence of training, technology, the system of care, and other factors. We assessed mortality among casualties undergoing prehospital airway intervention occurring over the course of combat operations during 2007-2019. Methods: This is a retrospective analysis of a previously described dataset from the Department of Defense Trauma Registry (DODTR). We included only casualties with documented placement of an endotracheal tube, cricothyrotomy, or supraglottic airway (SGA) in the prehospital setting. Results: Within the DODTR from January 2007 to December 2019, there were 25,849 adult encounters with documentation of any prehospital activity. Within that group, there were 251 documented cricothyrotomies, 1,147 documented intubations, and 35 documented supraglottic airways placed. Cricothyrotomy recipients had a median age of 25. Within this group, the largest proportion were non-North Atlantic Treaty Organization (NATO) military personnel (35%), were injured by explosives (54%), had a median injury severity score (ISS) of 24, and 60% survived to hospital discharge. Intubation recipients had a median age of 24. Within this group, the largest proportion were non-NATO military personnel (37%), were injured by explosives (57%), had a median ISS of 18, and 76% survived to hospital discharge. SGA recipients had a median age of 28. Within this group, the largest proportion were non-NATO military (37%), were injured by firearms (48%), had a median ISS of 25, and 54% survived to hospital discharge. A downward trend existed in the quantity of all procedures performed during the study period. In both unadjusted and adjusted regression models, we identified no year-to-year differences in survival after prehospital cricothyrotomy or SGA placement. In the unadjusted and adjusted models, we noted a decrease in mortality during the 2007-2008 (odds ratio [OR] for death 0.47, 95% CI 0.26-0.86) and an increase from 2012-2013 (OR 2.10, 95% CI 1.09-4.05) for prehospital intubation. Conclusion: Mortality among combat casualties undergoing prehospital or emergency department airway interventions showed no sustained change during the study period. These findings suggest that advances in airway resuscitation are necessary to achieve mortality improvements in potentially survivable airway injuries in the prehospital setting.

Kamler JJ, Taube S, Koch EJ, Lauria MJ, Kue RC, Rush SC 99(5). 0 (Journal Article)

Mass casualty incidents (MCIs) can rapidly exhaust available resources and demand the prioritization of medical response efforts and materials. Principles of triage (i.e., sorting) from the 18th century have evolved into a number of modern-day triage algorithms designed to systematically train responders managing these chaotic events. We reviewed reports and studies of MCIs to determine the use and efficacy of triage algorithms. Despite efforts to standardize MCI responses and improve the triage process, studies and recent experience demonstrate that these methods have limited accuracy and are infrequently used.

Pajuelo Castro JJ 99(5). 110 - 120 (Journal Article)

Conyers K, Gillies AB, Sibley C, McMullen C, Remley MA, Wence S, Gurney J 99(5). 105 - 108 (Journal Article)

Background: With most combat deaths occurring in prehospital settings, the US Armed Forces focuses on life-threatening conditions at or near the point of injury. Tactical Combat Casualty Care (TCCC) guidelines are required for all US Servicemembers. Multinational militaries lack this requirement, and international partner forces often have limited prehospital medical training. Methods: From November 2019 to March 2020, military members assigned to the Role 2E at the Hamid Kazai International Airport (HKIA) North Atlantic Treaty Organization (NATO) base conducted multinational TCCC training. The standardized Joint Trauma System (JTS) TCCC curriculum consisted of two-day classroom instruction and situational training exercises. Competency was assessed through verbalized and demonstrated knowledge. After Action Reviews (AAR) were completed. Results: Twelve multinational TCCC training courses trained 590 military Servicemembers and civilians from 10 countries, ranging from 16 to 62 participants (avg class size = 35). Portugal and Turkey represented the two largest participating nations with 219 and 133, respectively. Student feedback determined optimal group ratios for instruction. AARs were reviewed to categorize best practices. Conclusion: Multinational TCCC standardization will save lives. Most nations lack TCCC training requirements. Thus, providing opportunities for standardized training for HKIA residents helped established a multinational baseline of medical interoperability. Utilizing this curriculum in multinational environments can replicate these results. International adoption of TCCC is dynamic and ongoing and should be promulgated to reduce preventable deaths.

Knapik JJ, Hoedebecke SS 99(5). 97 - 103 (Journal Article)

Obesity is a worldwide health problem that has reached pandemic proportions. In the military, obesity and overweight are associated with health problems, attrition from military service, and reduced job performance. National and international organizations suggest body mass index (BMI) as a population screening tool to define overweight and obesity. BMI is calculated as weight/height2 (kg/m2). Four categories of adult BMI are underweight (<18.5 kg/m2), healthy weight (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), and obese (≥30.0 kg/m2). This article reports on a systematic review and meta-analysis examining the association between BMI and injury risk among military service members (SMs). Studies were selected for review if they involved military personnel, were prospective or retrospective observational studies, and contained original quantitative data on injury risk at all four BMI levels. Nine studies met the review criteria. Pooled data from these investigations indicated that underweight, overweight, and obese individuals were at 1.17 (95% confidence interval [95%CI]=1.07-1.28), 1.03 (95%CI=1.01-1.06), and 1.15 (95%CI=1.11-1.20) times higher risk of injury than healthy weight individuals, respectively. Compared with healthy weight SMs, military personnel with both low and high BMI are at higher injury risk.

Klucher J, Gonzalez A, Shishido AA 99(5). 94 - 97 (Journal Article)

Crimean-Congo Hemorrhagic Fever (CCHF) is the most widespread tickborne virus causing human disease. CCHF wields a mortality rate up to 30% and was responsible for the death of a US Soldier in 2009. The virus is spread by the Hyalomma species of hard tick found across Central Europe, the Middle East, Africa, and Asia south of the 50° parallel. Infection typically consists of a 1-7-day non-specific viral prodrome, followed by onset of hemorrhagic disease on days 7-10. Severe disease may cause thrombocytopenia, transaminitis, petechial hemorrhage, hematemesis, and death typically by day 10 of illness. Education and insect control are paramount to disease prevention. Treatment is predominantly supportive care, though evidence suggests a benefit of early ribavirin administration. CCHF has caused multiple nosocomial outbreaks, and therefore consideration should be given to safe transport and evacuation of infected and exposed patients. Given the wide area of distribution, transmissibility, innocuous arthropod vectors, and high mortality rate, it is imperative that Special Operations Forces (SOF) providers be aware of CCHF and the existing countermeasures.

Scott J, Linderman JR, Deuster PA 99(5). 89 - 92 (Journal Article)

Full-spectrum Human Performance Optimization (HPO) is essential for Special Operations Forces (SOF). Adequate hydration is essential to all aspects of performance (physical and cognitive) and recovery. Water losses occur as a result of physical activity and can increase further depending on clothing and environmental conditions. Without intentional and appropriate strategic hydration planning, Operators are at increased risk for degradation in performance and exertional heat illness. The purpose of this article is to highlight current best practices for maintaining hydration before, during, and after activity, while considering various environmental conditions. Effective leadership and planning are necessary for preparing Operators for successful military operations.

Dubecq C, Montagnon R, Morand G, De Rocquigny G, Petit L, Peyrefitte S, Dubourg O, Pasquier P, Mahe P 99(5). 85 - 88 (Case Reports)

Optimal pain management is challenging in Tactical Combat Casualty Care (TCCC), particularly in remote and austere settings. In these situations, appropriate treatment for prehospital analgesia can be limited or delayed due to the lack of intravenous access. Several guidelines suggest to implement intranasal (IN) analgesia in French Armed Forces for forward combat casualty care (Sauvetage au Combat), similar to the US TCCC. Four medical teams from the French Medical Military Service were deployed to the Middle East and Sahel from August 2017 to March 2019 and used IN ketamine for analgesia in 76 trauma patients, out of a total of 259 treated casualties. IN administration of ketamine 50mg appeared to be safe and effective, alone or in addition to other opioid analgesics. It also had minimal side effects and led to a reduction in the doses of ketamine and morphine used by the intravenous (IV) route. The French Military Medical Service supports current developments for personal devices delivering individual doses of IN ketamine. However, further studies are needed to analyze its efficacy and safety in combat zones.

Clerkin S, Carlson NT, Long B, Taylor DH, Bridwell R 99(5). 82 - 85 (Case Reports)

As arctic warfare becomes a center focus within Special Operations, cold weather injury looms as both a medical and operational threat. While cold weather injury can range from pernio to hemodynamically unstable systemic hypothermia, the more minor injuries are far more common. However, these present a challenge in austere medical care and can drastically impact mission capability. We present a case of a Special Operations crew chief with cold weather digital injury while at the Arctic Isolation Course in Alaska and his subsequent clinical course. Prevention remains the key for mitigating these injuries, while the decision to rewarm must be made with both medical and tactical factors in mind as refreezing incurs significant morbidity. Other components of prehospital treatment include active rewarming, ibuprofen, aloe vera, and pain control.

Neading R, Scarborough T, O'Connell M, Leasiolagi J, Little M, Burgess J, Hargrove M, Goodfellow A, Scheiber C, Cap AP, Yazer MH 99(5). 76 - 81 (Journal Article)

Special Operations Forces (SOF) medical personnel have been at the forefront of administering blood products in the austere field medicine environment. These far-forward medical providers regularly treat patients and deliver blood transfusions in some of the world's most extreme environments with minimal resources. A multitude of questions have been raised on this topic based on the unique experiences of senior providers in this field. In this paper, we analyze the available literature and present the recommendations of several experts in transfusion medicine for managing atypical field transfusion scenarios.

Baribeau V, Murugappan K, Sharkey A, Lodico DN, Walsh DP, Lin DC, Wong VT, Weinstein J, Matyal R, Mahmood F, Mitchell JD 99(5). 70 - 76 (Journal Article)

Background: Point-of-care ultrasound (POCUS) is commonly employed to image the heart, lungs, and abdomen. Rapid ultrasound for shock and hypotension (RUSH) exams are a critical component of POCUS employed in austere environments by Special Operations Forces (SOF) and tactical medics for triage and diagnosis. Despite its utility, training for POCUS remains largely unstandardized with respect to feedback and markers of proficiency. We hypothesized that motion analysis could objectively identify improvement in medics' performance of RUSH exams. Furthermore, we predicted that motion metrics would correlate with qualitative ratings administered by attending anesthesiologists. Methods: A team of civilian and military attending anesthesiologists trained 24 medics in POCUS during a 5-day course. Each medic performed eight RUSH exams using an ultrasound probe equipped with an electromagnetic motion sensor to track total distance travelled (path length), movements performed (translational motions), degrees rotated (rotational sum), and time. Instructors (experts) observed and rated the exams on the following items: image finding, image fine-tuning, speed, final image accuracy, and global assessment. Motion metrics were used to provide feedback to medics throughout the course. Generalized estimating equations were used to analyze the trends of motion metrics across all trials. Correlations amongst motion metrics and expert ratings were assessed with Pearson correlation coefficients. Results: Participants exhibited a negative trend in all motion metrics (p < 0.001). Pearson correlation coefficients revealed moderate inverse correlations amongst motion metrics and expert ratings. Conclusion: Motion analysis was able to quantify and describe the performance of medics training in POCUS and correlated with expert ratings.

Zink N, Merelman A, Fisher AD, Lauria MJ 99(5). 58 - 62 (Journal Article)

Clinicians involved in the care of critically ill patients are often exposed to demanding and stressful situations that require immediate action. Evidence suggests that human performance can be significantly diminished when multiple stressors and stimuli are present. Humans have developed conscious and unconscious methods of dealing with this type of cognitive overload in various high-risk occupations, but these coping methods have not necessarily been structured and adapted to the provision of emergency medical care. Emergency reflex action drills (ERADs) are derived from available evidence in specific domains (e.g., airway management) and develop automaticity of critical skills which engender quick, effective, and reproducible performance with minimal cognitive load. These are pre-planned, practiced responses to specific, high-demand and time-sensitive situations. This article outlines the psychological, cognitive, and behavioral effects of stress that affect performance and necessitate development of ERADs. It also reviews the scientific underpinnings behind how humans have adapted cognitive behavioral techniques to manage under high-stress situations. Finally, this article recommends the adoption of these cognitive tactics via ERADs to enhance clinical practice and provides an example in the context of airway management.

Mannion E, Pirrallo RG, Dix A, Estes L 99(5). 50 - 57 (Journal Article)

Background: Transfusion of blood products is life-saving and time-sensitive in the setting of acute blood-loss anemia, and is increasingly common in the emergency medical services (EMS) setting. Prehospital blood products are generally "cold-stored" at 4°C, then warmed with a portable fluid-warming system for the purpose of preventing the "lethal triad" of hypothermia, acidosis, and coagulopathy. This study aims to evaluate body temperature changes of EMS patients receiving packed red blood cells (PRBC) and/or fresh frozen plasma (FFP) when using the LifeWarmer Quantum Blood & Fluid Warming System (LifeWarmer, https://www.lifewarmer.com/). Methods: From 1 January 2020 to 31 August 2021, patients who qualified for and received PRBC and/or FFP were retrospectively reviewed. Body-temperature homeostasis pre- and post-transfusion were evaluated with attention given to those who arrived to the emergency department (ED) hypothermic (<36°C). Results: For all 69 patients analyzed, the mean initial prehospital temperature (°C) was 36.5 ± 1.0, and the mean initial ED temperature was 36.7 ± 0.6, demonstrating no statically significant change in value pre- or post-transfusion (0.2 ± 0.8, p = .09). Shock index showed a statistically significant decrease following transfusion: 1.5 ± 0.5 to 0.9 ± 0.4 (p < .001). Conclusion: Use of the Quantum prevents the previously identified risk of hypothermia with respect to unwarmed prehospital transfusions. The data is favorable in that body temperature did not decrease in critically ill patients receiving cold-stored blood warmed during administration with the Quantum.