The Effect of Critical Task Auto-failure Criteria on Medical Evaluation Methods in the Pararescue Schoolhouse.

BACKGROUND: Medical training and evaluation are important for mission readiness in the pararescue career field. Because evaluation methods are not standardized, evaluation methods must align with training objectives. We propose an alternative evaluation method and discuss relevant factors when designing military medical evaluation metrics. METHODS: We compared two evaluation methods, the traditional checklist (TC) method used in the pararescue apprentice course and an alternative weighted checklist (AWC) method like that used at the U.S. Army static line jumpmaster course. The AWC allows up to two minor errors, while critical task errors result in autofailure. We recorded 168 medical scenarios during two Apprentice course classes and retroactively compared the two evaluation methods. RESULTS: Despite the possibility of auto-failure with the AWC, there was no significant difference between the two evaluation methods, and both showed similar overall pass rates (TC=50% pass, AWC=48.8% pass, p=.41). The two evaluation methods yielded the same result for 147 out of 168 scenarios (87.5%). CONCLUSIONS: The AWC method strongly emphasizes critical tasks without significantly increasing failures. It may provide additional benefits by being more closely aligned with our training objectives while providing quantifiable data for a longitudinal review of student performance.

Effectiveness of and Adherence to Triage Algorithms During Prehospital Response to Mass Casualty Incidents.

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.

Threat Appraisal, Recovery Operations, and PTSD Symptoms Among US Air Force Rescue Personnel.

BACKGROUND: Research among military personnel and veterans indicates that subjective appraisal of warzone stressors explains the relation of combat exposure to posttraumatic stress disorder (PTSD), but not the relation of exposure to injury and death to PTSD. Studies have primarily been limited to conventional forces using aggregate measures of warzone stressor exposure. Threat appraisal may play a different role in the emergence of PTSD among military personnel for whom dangerous deployment experiences are more closely associated with exposure to injury and death, such as US Air Force Pararescuemen and Combat Rescue officers. MATERIALS AND METHODS: In a sample of 207 rescue personnel, correlations among various types of warzone stressor exposure, threat appraisal, and postdeployment PTSD symptoms were examined. RESULTS: The relative strongest correlates of threat appraisal were stressors related to injury, death, and human remains. Although exposure to these stressors was also correlated with PTSD symptom severity, partial correlations of stressor exposure and PTSD symptoms were no longer significant when adjusting for threat appraisal. CONCLUSION: Results support the contributing role of threat appraisal to PTSD among military personnel whose primary duties entail exposure to injury and death under hostile and dangerous conditions.

Prehospital Iliac Crest Intraosseous Whole Blood Infusion.

Low-titer cold-stored O-positive whole blood (LTCSO+WB) resuscitation therapy is the cornerstone of military hemorrhagic shock resuscitation. During the past 19 years, improved patient outcomes have shown the importance of this intervention in shock treatment. Iliac crest intraosseous (IO) placement is an alternative when peripheral sites such as the humeral head and tibia are not available options. To date, no study has explored the administration of LTCSO+WB through an iliac crest IO in the military prehospital setting. Contingency procedures for vascular access are necessary for casualties with severe trauma to all four extremities, and the iliac crest is a viable option. The literature supports situational advantages over other peripheral IO sites.

Safety and Efficacy of 23.4% Sodium Chloride Administered via Peripheral Venous Access for the Treatment of Cerebral Herniation and Intracranial Pressure Elevation.

BACKGROUND: Sodium chloride (NaCl) 23.4% solution has been shown to reduce intracranial pressure (ICP) and reverse transtentorial herniation. A limitation of 23.4% NaCl is its high osmolarity (8008 mOsm/l) and the concern for tissue injury or necrosis following extravasation when administered via peripheral venous access. The use of this agent is therefore often limited to central venous or intraosseous routes of administration. Our objective was to evaluate the safety and efficacy of administration of 23.4% NaCl via peripheral venous access compared with administration via central venous access. METHODS: We reviewed pharmacy records to identify all administrations of 23.4% NaCl at our institution between December 2017 and February 2020. Medical records were then reviewed to identify complications, such as extravasation, soft tissue injury or necrosis, hypotension (mean arterial pressure less than 65 mm Hg), pulmonary edema, hemolysis, and osmotic demyelination. We also compared the change in physiological variables, such as ICP, mean arterial pressure, cerebral perfusion pressure, and heart rate, as well as laboratory values, such as sodium, chloride, bicarbonate, creatinine, and hemoglobin, following administration of 23.4% NaCl via the peripheral and central venous routes. RESULTS: We identified 299 administrations of 23.4% NaCl (242 central and 57 peripheral) in 141 patients during the study period. There was no documented occurrence of soft tissue injury or necrosis in any patient. One patient developed hypotension following central administration. Among the 38 patients with ICP monitoring at the time of drug administration, there was no significant difference in median ICP reduction (- 13 mm Hg [central] vs. - 24 mm Hg [peripheral], p = 0.21) or cerebral perfusion pressure augmentation (16 mm Hg [central] vs. 15 mm Hg [peripheral], p = 0.87) based on route of administration. CONCLUSIONS: Peripheral venous administration of 23.4% NaCl is safe and achieves a reduction in ICP equivalent to that achieved by administration via central venous access.

23.4% Hypertonic Saline: A Tactical Option for the Management of Severe Traumatic Brain Injury With Impending or Ongoing Herniation.

There are limited options available to the combat medic for management of traumatic brain injury (TBI) with impending or ongoing herniation. Current pararescue and Tactical Combat Casualty Care (TCCC) guidelines prescribe a bolus of 3% or 5% hypertonic saline. However, this fluid bears a tactical burden of weight (~570g) and pack volume (~500cm3). Thus, 23.4% hypertonic saline is an attractive option, because it has a lighter weight (80g) and pack volume (55cm3), and it provides a similar osmotic load per dose. Current literature supports the use of 23.4% hypertonic saline in the management of acute TBI, and evidence indicates that it is safe to administer via peripheral and intraosseous cannulas. Current combat medic TBI treatment algorithms should be updated to include the use of 23.4% hypertonic saline as an alternative to 3% and 5% solutions, given its effectiveness and tactical advantages.

Rationale and Implementation of a Novel Special Operations Medical Officer Course.

BACKGROUND: The Air Force Special Warfare Medical Officer Course was created to address the lack of operationally focused, job-specific clinical training for medical officers (MOs). This course addresses the gap in knowledge, skill, and application of operational medicine, as well as the behavioral health, human performance, education, and medical oversight of Operators. METHODS: The course was designed around the senior author's decade of experience piecing together training for his own role as a pararescue flight surgeon and informed by 5 years of flight surgeon courses, lessons learned from case studies of ill-prepared deployed physicians, and input from prehospital medicine subject matter experts. RESULTS: Air Force pararescue and special tactics flight surgeons, physician assistants, and an independent duty medical technician (IDMT) attended. The course consisted of 10 full weekdays of didactics and skills sessions covering theory and application of operational medicine, human performance optimization, behavioral health for Operators, adult education theory, principles of prehospital clinical oversight, and other expeditionary concepts. The course culminated with combat casualty care scenario-based exercises, in which the providers performed operational medicine in full kit with weapons and simulation rounds. DISCUSSION: For many logistical and practical reasons, civilian medical experience, traditional military medical training, existing special operations medical courses, and "merit badge" card classes are not adequate preparation for this specialized role. Focused, job-specific training should be provided to Special Operations Forces Medical Officers (SOFMO) and, ultimately, to any MO deploying in support of medics or combatants. The goal is to maximize the success of military medical operations while reducing the morbidity and mortality of combat and training casualties. CONCLUSION: This operationally focused MO course can serve as a model for the future training of SOFMO and has stimulated discussion for consideration of a joint approach to prehospital medical training.

Commercial and Improvised Pelvic Compression Devices: Applied Force and Implications for Hemorrhage Control.

Uncontrolled hemorrhage secondary to unstable pelvic fractures is a preventable cause of prehospital death in the military and civilian sectors. Because the mortality rate associated with unstable pelvic ring injuries exceeds 50%, the use of external compression devices for associated hemorrhage control is paramount. During mass casualty incidents and in austere settings, the need for multiple external compression devices may arise. In assessing the efficacy of these devices, the magnitude of applied force has been offered as a surrogate measure of pubic symphysis diastasis reduction and subsequent hemostasis. This study offers a sensor-circuit assessment of applied force for a convenience sample of pelvic compression devices. The SAM® (structural aluminum malleable) Pelvic Sling II (SAM Medical) and improvised compression devices, including a SAM Splint tightened by a Combat Application Tourniquet® (C-A-T; North American Rescue) and a SAM® Splint tightened by a cravat, as well as two joined cravats and a standard-issue military belt, were assessed in male and female subjects. As hypothesized, compressive forces applied to the pelvis did not vary significantly based on device operator, subject sex, and subject body fat percentage. The use of the military belt as an improvised method to obtain pelvic stabilization is not advised.

Ketamine Administration by Special Operations Medical Personnel During Training Mishaps.

BACKGROUND: Opioids can have adverse effects on casualties in hemorrhagic shock. In 2014, the Committee on Tactical Combat Casualty Care (CoTCCC) recommended the use of ketamine at the point of injury (POI). Despite these recommendations the adherence is moderate at best. Poor use may stem from a lack of access to use ketamine during training. The United States Special Operations Command (USSOCOM) is often in a unique position, they maintain narcotics for use during all training events and operations. The goal of this work is to demonstrate that ketamine is safe and effective in both training and operational environments. METHODS: This was a retrospective, observational performance improvement project within United States Special Operations Command and Air Combat Command that included the US Army's 75th Ranger Regiment, 160th Special Operations Aviation Regiment, and US Air Force Pararescue. Descriptive statistics were used to calculate the doses per administration to include the interquartile range (IQR), standard deviation (SD) and the range of likely doses using a 95% confidence interval (CI). A Wilcoxon signed-rank test was used to compare the mean pre-ketamine pain scores to the mean post-ketamine on a 0-to-10 pain scale. RESULTS: From July 2010 to October 2017, there was a total of 34 patients; all were male. A total of 22 (64.7%) received intravenous ketamine and 12 (35.3%) received intramuscular ketamine and 8 (23.5%) received intranasal ketamine. The mean number of ketamine doses via all routes administered to patients was 1.88 (SD 1.094) and the mean total dose of all ketamine administration was 90.29mg (95% CI, 70.09-110.49). The mean initial dose of all ketamine administration was 47.35mg (95% CI, 38.52-56.18). The median preketamine pain scale for casualties was noted to be 8.0 (IQR 3) and the median post-ketamine pain scale was 0.0 (IQR 3). CONCLUSION: Ketamine appears to be safe and effective for use during military training accidents. Military units should consider allowing their medics to carry and use as needed.

A Case Series of Air Force Pararescue Long-Range Ocean Rescues.

BACKGROUND: US Air Force (USAF) pararescuemen (PJs) perform long-range ocean rescue missions for ill or injured civilians when advanced care and transport are not available. The purpose of this case series is to examine the details of these missions, review patient treatments and outcomes, and describe common tactics, techniques, and procedures for these missions. METHODS: Cases in which the USAF PJs preformed long-range ocean rescue for critically ill or injured civilians between 2011 and 2018 were identified. Case information was obtained, including patient demographics, location, infiltration/exfiltration methods, diagnoses, treatments, duration of patient care, patient outcome, and lessons learned. RESULTS: A total of 14 pararescue missions involving 22 civilians were identified for analysis. Of the 22 patients, 10 (45%) suffered burns, six (27%) had abdominal issues, four (18%) had musculoskeletal injuries, one had a traumatic brain injury, and one had a necrotizing soft-tissue infection. Medical care of these patients included intravenous fluid and blood product resuscitation, antibiotics, analgesics, airway management, and escharotomy. The median duration of patient care was 51 hours. CONCLUSION: This case series illustrates the complex transportation requirements, patient and gear logistical challenges, austere medicine, and prolonged field care (PFC) unique to USAF PJ open-water response.

Management of Critically Injured Burn Patients During an Open Ocean Parachute Rescue Mission.

Best practices and training for prolonged field care (PFC) are evolving. The New York Pararescue Team has used part task training, cadaver labs, clinical rotations, and a complicated sim lab to prepare for PFC missions including critical care. This report details an Atlantic Ocean nighttime parachute insertion to provide advanced burn care to two sailors with 50% and 60% body surface area burns. Medical mission planning included pack-out of ventilators, video laryngoscopes, medications, and 50 L of lactated Ringer's (LR). Over the course of 37 hours, the patients required high-volume resuscitation, analgesia, wound care, escharotomies, advanced airway and ventilator management, continuous sedation, telemedicine consultation, and complicated patient movement during evacuation. A debrief survey was obtained from the Operators highlighting recommendation for more clinical rotations and labs, missionspecific pack-outs, and tactical adjustments. This historic mission represents the most sophisticated PFC ever performed by PJs and serves to validate and share our approach to PFC.

The Role of Magnetic Resonance Imaging in Optimizing Injury Management in Air Force Pararescuemen, Combat Rescue Officers, and Survival Specialists.

Operators perform physically demanding jobs associated with a variety of overuse and acute musculoskeletal injuries. The current management of musculoskeletal complaints in the Air Force includes plane radiographs and 6 weeks of physical therapy (PT) before consideration of orthopedic consultation and magnetic resonance imaging (MRI); however, MRI shows a clear advantage compared with plane radiographs. We conducted a performance improvement project and conclude that (1) MRI allowed for definitive diagnosis as well as definitive triage for care in a timely manner, (2) guidelines for ordering lumbosacral MRIs should be followed and not ordered for pain that is not progressive and severe or not associated with a neurological finding, and (3) because of the risk of X-ray exposure in patients in their 20 and 30s, X-rays should be avoided in this setting unless definitely indicated.

Successful Use of Ketamine as a Prehospital Analgesic by Pararescuemen During Operation Enduring Freedom.

Effective analgesia is a crucial part of the care and resuscitation of a traumatically injured patient. These secondary effects of pain may increase morbidity and mortality in the acutely injured patient. When ketamine is administered appropriately in the clinical setting, it can provide analgesia, anxiolysis, and amnesia for patients with less respiratory depression and hypotension than equivalent doses of opioid analgesics.

Efficacy of the Mnemonic Device "MARCH PAWS" as a Checklist for Pararescuemen During Tactical Field Care and Tactical Evacuation.

BACKGROUND: The application of Tactical Combat Casualty Care (TCCC) represents evidence-based medicine to improve survival in combat. Over the past several years, US Air Force Pararescuemen (PJs) have expanded the mnemonic device "MARCH" to "MARCH PAWS" for use during tactical field care and tactical evacuation (TACEVAC). The mnemonic stands for massive bleeding, airway, respiration, circulation, head and hypothermia, pain, antibiotics, wounds, and splinting. We undertook this performance improvement project to determine the efficacy of this device as a treatment checklist. METHODS: The mission reports of a 16-PJ combat rescue deployment to Operation Enduring Freedom (OEF) from January through June 2012 were reviewed. The triage category, mechanism of injury, injury, and treatments were noted. The treatments were then categorized to determine if they were included in MARCH PAWS. RESULTS: The recorded data for missions involving 465 patients show that 45%, 48%, and 7%, were in category A, B, and C, respectively (urgent, priority, routine); 55% were battle injuries (BIs) and 45% were nonbattle injuries (NBIs). All treatments for BI were accounted for in MARCH PAWS. Only 9 patients' treatments with NBI were not in MARCH PAWS. CONCLUSION: This simple mnemonic device is a reliable checklist for PJs, corpsmen, and medics to perform TACEVAC during combat Operations, as well as care for noncombat trauma patients.

Optimization of Simulation and Moulage in Military-Related Medical Training.

Preparation of Special Operations Forces (SOF) Medics as first responders for the battle space and austere environments is critical to optimize survival and quality of life for our Operators who may sustain serious and complex wounding patterns and illnesses. In the absence of constant clinical exposure for these medics, it is necessary to maximize all available training opportunities. The incorporation of scenario-based training helps weave together teamwork and the ability to practice treatment protocols in a tactical, controlled training environment to reproduce, to some degree, the environment in and stressors under which care will need to be delivered. We reviewed the evolution of training scenarios within one Pararescue (PJ) team since 2008 and codified various tools used to simulate physical findings and drive medical exercises as part of scenario-based training. We also surveyed other SOF Medic training resources.

Review of 54 Cases of Prolonged Field Care.

BACKGROUND: Prolonged field care (PFC) is field medical care applied beyond doctrinal planning time-lines. As current and future medical operations must include deliberate and contingency planning for such events, data are lacking to support efforts. A case review was conducted to define the epidemiology, environment, and operational factors that affect PFC outcomes. METHODS: A survey distributed to US military medical providers solicited details of PFC encounters lasting more than 4 hours and included patient demographics, environmental descriptors, provider training, modes of transportation, injuries, mechanism of injury, vital signs, treatments, equipment and resources used, duration of PFC, and morbidity and mortality status on delivery to the next level of care. Descriptive statistics were used to analyze survey responses. RESULTS: Surveys from 54 patients treated during 41 missions were analyzed. The PFC provider was on scene at time of injury or illness for 40.7% (22/54) of cases. The environment was described as remote or austere for 96.3% (52/54) of cases. Enemy activity or weather also contributed to need for PFC in 37.0% (20/54) of cases. Care was provided primarily outdoors (37.0%; 20/54) and in hardened nonmedical structures (37.0%; 20/54) with 42.6% (23/54) of cases managed in two or more locations or transport platforms. Teleconsultation was obtained in 14.8% (8/54) of cases. The prehospital time of care ranged from 4 to 120 hours (median 10 hours), and five (9.3%) patients died prior to transport to next level of care. CONCLUSION: PFC in the prehospital setting is a vital area of military medicine about which data are sparse. This review was a novel initial analysis of recent US military PFC experiences, with descriptive findings that should prove helpful for future efforts to include defining unique skillsets and capabilities needed to effectively respond to a variety of PFC contingencies.

Preliminary Comparison of New and Established Tactical Tourniquets in a Manikin Hemorrhage Model.

BACKGROUND: Emergency tourniquet use has been associated with hemorrhage control and improved survival during the wars since 2001. The purpose of the present study is to compare the differential performance of two new tactical tourniquets with the standard-issue tourniquet to provide preliminary evidence to guide decisions on device development. METHODS: A laboratory experiment was designed to test the effectiveness of tourniquets on a manikin thigh. Three models of tourniquets were assessed. The Rapid Application Tourniquet System (RATS) and the Tactical Mechanical Tourniquet (TMT) were compared with the standard-issue Combat Application Tourniquet(®) (C-A-T). Two users conducted 30 tests each. RESULTS: Percentages for effectiveness (hemorrhage control, yes/no) and distal pulse cessation did not differ significantly by model. When compared with the RATS, the C-A-T performed better (ρ < .001) for time to hemorrhage control and fluid loss. The C-A-T and TMT had comparable responses for most measures, but the C-A-T applied more pressure (ρ = .04) than did the TMT for hemorrhage control. CONCLUSION: All three tactical tourniquets showed substantial capacity for hemorrhage control. However, the two new tourniquet models (RATS and TMT) did not offer any improvement over the C-A-T, which is currently issued to military services. Indeed, one of the new models, the RATS, was inferior to the C-A-T in terms of speed of application and simulated loss of blood. Opportunities were detected for refinements in design of the two new tourniquets that may offer future improvements in their performance.

Dose-Response Relationships for Meningioma Radiosurgery.

OBJECTIVE: Dose-response relationships for meningioma radiosurgery are poorly characterized. We evaluated determinants of local recurrence for meningiomas treated with Gamma Knife radiosurgery (GKRS), to guide future treatment approaches to optimize tumor control. MATERIALS AND METHODS: A total of 101 consecutive patients (108 tumors) who underwent GKRS for benign, atypical, or malignant meningiomas between 1998 and 2011 were studied. Local recurrence was assessed. Cox proportional hazards and logistic regression analyses were used to determine the association of patient-related, tumor-related, and treatment-related characteristics with local recurrence. Acute and late toxicity was evaluated. RESULTS: World Health Organization (2007 classification) tumor grade was I (82%), II (11%), or III (7%). Median dose was 14 Gy (range, 10 to 18 Gy) for grade I tumors and 16 Gy (range, 12 to 20 Gy) for grade II and III tumors. Median follow-up was 25 months (maximum, 17 y). Two- /5-year actuarial local control rates were 100%/98% for grade I tumors and 76%/56% for grade II/III tumors. Higher tumor grade and lower GKRS dose were associated with local failure. In this cohort, there was a 42% relative reduction in local recurrence for each 1 Gy of dose escalation. CONCLUSIONS: Treatment was well tolerated with no moderate or severe toxicity. Tumor control was excellent in benign tumors and suboptimal in higher grade tumors. Because the main determinant of local recurrence was GKRS dose, we recommend dose escalation for atypical or malignant tumors to doses between 16 and 20 Gy where critical structures allow.

Cinnarizine for Sea Sickness During a Remote Pacific Ocean Rescue Mission.

Motion sickness can be a limiting factor for sea and air missions. We report the experience of a Pararescue (PJ) team on a Pacific Ocean rescue mission in which motion sickness was prevalent. Cinnarizine, an antagonist of H1-histamine receptors, was used to treat affected PJs. We also report findings of a survey of PJs regarding motion sickness. A family of four on a disabled sailboat 900 miles off the coast of Mexico sent out a distress call because their 1-year-old daughter became severely ill with fever and diarrhea. Four PJs were deployed on a C-130, performed a free-fall parachute insertion into the ocean, and boarded the sailboat. All four PJs experienced onset of motion sickness at some point during the early part of the mission and symptoms persisted through the first 24 hours. Three PJs experienced ongoing nausea, vomiting, dizziness, and sensory imbalances. The captain of the sailboat offered the three sick PJs approximately 18mg of cinnarizine two or three times a day with relief of symptoms and improvement on operational effectiveness. A new, anonymous, voluntary survey of Air National Guard PJs and combat rescue officers revealed that 78.4% of Operators have experienced motion sickness at sea. We discuss the current theories on motion sickness, the effect of motion sickness on operational effectiveness, and research on treatment of motion sickness, including the medication cinnarizine.