Deployed military surgeons caring for combat casualties commonly face traumatic lower extremity injuries. Early amputation can be lifesaving, and limb salvage can require significant resources and expertise not always available in a resource constrained environment. The Mangled Extremity Severity Score (MESS) is the most commonly applied scoring system to predict the need for amputation, and it is generally agreed that a score of 7 or 8 is predictive of the need for amputation. However, the MESS is a civilian scoring system, and does not incorporate the common combat injury patterns of blast polytrauma, field tourniquet use, advanced blood-based resuscitation, and sophisticated patient transport. This work applies the MESS to combat casualties in order to better predict which patients will benefit from amputation or attempts at limb salvage.
This is a retrospective cohort study, utilizing the Fasciotomy and Vascular Injury Outcomes database (FaVIO). This is a subset of the larger DoD trauma registry, focusing on combat casualties with femoral, popliteal or tibial vascular injury who underwent a vascular salvage procedure- shunting, ligation, bypass, etc.- between 2004 and 2012. Importantly for this analysis primary surgical and traumatic amputations were excluded, as were casualties who died after the initial limb salvage maneuver. Statistical analysis applied the MESS at different cutoff values in an attempt to predict the need for amputation.
439 casualties were analyzed, nearly 100% were male with a median age of 24. Explosion with blast extremity trauma was the most common mechanism of injury. The median MESS of the cohort was 5 with an amputation rate overall of 22%. Statistically, the application of a MESS score of 8 to the data set had worse receiver operator characteristic curves (worse sensitivity and specificity) than a MESS of 7. Overall, a MESS of 7 predicted an amputation rate of only 43%, and a score 7 or less predicted an amputation rate of 12%. Injury severity was higher in the higher MESS groups, and higher ISS was associated with amputation. Tourniquet use and Tourniquet times were not associated with amputation. In univariate analysis mechanism of injury, presence of a fracture, high ISS, polytrauma and massive transfusion were associated with amputation, but critically the presence of all of these predictors (83 patients) only led to an amputation rate of 46%.
This review is the largest of its kind applied to combat injuries. Early traumatic and primary amputation are excluded, likely excluding the sickest patients in which either completion amputation or early surgical amputation is performed as a lifesaving maneuver. Encouragingly prehospital tourniquet use in the setting of rapid evacuation and transport are not predictive of amputation. Overall, MESS is a poor predictor of limb salvage in this population and thus should not be strictly applied as a military amputation prediction model.
The Military Heath System serves a dual mission- a peacetime mission of CONUS medical care to over 11 million servicemembers and beneficiaries as well as a readiness mission to support global operations. It is recognized that the younger, healthier population found in the military demographic generally require less complex and advanced medical care outside of combat wounded. In peacetime, or with the transition from war to peace, this can lead to a loss of skills specific to combat casualty care, colloquially known as the ‘Walker Dip.’ Case in point, Army general surgeons currently perform an average of 131 cases per year (one standard deviation below their civilian counterparts and often low acuity/complexity cases) and average only one operative procedure per month while deployed. In attempt to avoid this phenomenon, with the support of the 2017 National Defense Authorization Act and the centralization of military healthcare administration to the Defense Health Agency (DHA), the Clinical Readiness Program using KSA (Knowledge Skills and Abilities) metrics was developed and implemented. This paper represents the initial analysis of the implementation of the Clinical Readiness Program over 6 military treatment facilities.
The Clinical Readiness Program is comprised of a military relevant periodic knowledge assessment, pre-deployment critical wartime skills assessment, analysis of surgical practice via KSA metrics, and retraining as needed. The KSA metric analyzes the combat relevance of routine practice and assigns values to expeditionary relevant procedures. This metric was developed with a robust process described in detail in the manuscript, incorporating leadership and subject matter expertise. In brief, scores incorporate not only volume but case complexity and relevance, with low acuity cases limited to below 50% of the total case counts. The KSA score serves to benchmark the ability of the military Heath System to generate readiness.
Key results of this analysis and the current state of the system reveal that the Program is able to reliably measure and quantify individual surgeon and facility readiness. Many general surgeons currently do not meet the minimal threshold for readiness, though high case volume is clearly associated with higher KSA value. The top cases performed were lap chole, upper GI bariatric/hernia/and reflux procedures.
Currently, direct care at the MTFs is unable to meet the readiness demand given the limited acuity, case volumes, and high number of surgeons per facility. Purchased care, or the healthcare market, offer a greater volume of cases and breadth of pathology that could maintain KSAs. Using Lap Chole as a test case, MTFs over 12 months could offer 318 procedures (36K KSA points) vs 528 cases (60k KSA points) on the civilian market. Low volume high complexity cases like pancreatectomy (8 cases in 12 months at MTF vs 17 network) offer the additional opportunity to generate high readiness for an entire hospital system.
In summary, the Clinical Readiness Program and KSA metrics serve as a benchmarking tool to measure, assess, validate, and optimize surgical readiness. Continuing to use General Surgeons for the combat mission is paramount, and readiness can be maintained with creative solutions, either recapturing or expanding access to beneficiaries, or strategically shifting to a model of Military Civilian Partnerships.
This is a retrospective, Department of Defense Trauma Registry (DODTR) case series of 15 patients in U.S. military special operations teams who received at least one unit of low titer group O whole blood (LTOWB) at the point of injury (POI). The ability to transport and store LTOWB provides a significant advantage to a combat team over needing to identify and draw fresh whole blood from volunteers at the point of injury, particularly in a combat environment. The purpose of the report is to describe clinically relevant patient and injury information, injury mechanisms, indication for transfusion, time to transfusion, and outcomes. The report also provides the background for the 75thRanger Regiment’s whole blood program, or Ranger O Low Titer (ROLO) and the Armed Services Blood Program (ASBP) collaboration to provide safe, feasible whole blood transfusion.
A total of 15 patients received POI LOTWB between 1 January 2016 to 31 January 2019. The DODTR and Theater Medical Data Store were reviewed, as well as medic after action reports and medical records. The mean age of patients was 24 years, 86% were male, 50% were US military, and all patients sustained gunshot wounds (67%) or combat related blast injury (33%). Twelve patients survived to discharge, one died of wounds and two died pre-hospital (killed in action). Thirteen of the patients received 1u LTOWB, and 2 received 2u. The mean ISS was 20.47 (SD 19.28; IQR 14-35). Ten patients received additional blood products during evacuation to role 2 and/or role 3 medical treatment facilities. The mean pre-hospital systolic blood pressure was 80.50 mm Hg (SD 13.83 mm Hg), and mean heart rate 105 beats per minute (SD 21.28 beats per minute). Time to transfusion was available for only 6 of 15 patients, and ranged from < 5 – 90 minutes. The indications for transfusion included penetrating wound mechanisms and hypotension, and/or penetrating torso, pelvic, or extremity hemorrhage.
This case series begins to demonstrate the feasibility of a whole blood transfusion program implemented by a combat unit. The ASBP collaborated with the combat units to provide cold stored LTOWB for use at the POI with the support of the US Central Command. There were significant logistical hurdles that needed innovative solutions, including low volume, low weight cold storage devices. The discussion is robust and describes the ASBP efforts in the investigation of capabilities and the DOD Joint Trauma Systems ongoing work to improve battlefield survivability. This discussion also highlights the importance of continued and improved pre-hospital clinical data collection in order to support these efforts.
This open access article published in BMC Emergency Medicine seeks to evaluate the association of tranexamic acid (TXA) administration and outcomes in a population of military casualties with intra-cranial hemorrhage. This study is the first to describe outcomes in this trauma patient population using a retrospective analysis of patients surviving to evacuation to a role V medical treatment facility in the United States with a diagnosis of a military combat related intracranial hemorrhage (ICH) between October 1, 2010 to December 31, 2015.
The study included a total of 71 patients with ICH. All patients were male, and 80.3% were injured in a blast. A total of 50.7% sustained a penetrating head injury. Of those with penetrating injury, 69.4% were from a blast mechanism and 30.6% were from gunshot wounds. The ICH patterns were commonly combined in most patients and included intra-parenchymal (80.3%), subarachnoid (60.6%), subdural (46.5%), intraventricular (25.3%), and epidural hemorrhage (11.3%). Seven patients (9.9%) had diffuse axonal injury. The mean ISS was 28.2 (SD 12.3) and TXA was administered to 19.7% (14). The mean initial GCS was lower in patients receiving TXA, and these patients also had a larger improvement between initial and discharge GCS (3.7 ± 3.9 vs 1.3 ± 3.1, p = 0.02). Patients receiving TXA had a higher mean ISS (36.6 ± 12.5 vs 26.2 ± 11.4, p = 0.003). However, there was no difference in mortality, mean 6-month Glasgow Outcomes Scale (GOS), or need for cranial decompression. Forty-five patients had interval CT scans available for analysis, and 24.4% (11) demonstrated progression of their ICH with no difference in those that received TXA vs those that did not. Of note, in this series, TXA was not independently associated with VTE.
This study showed an improvement in GCS in patients with TXA administration, with no difference in ICH progression, need for cranial decompression, 6-month GOS, or mortality. There was no reported data on coagulation parameters or degree of fibrinolysis. Unlike the recently published CRASH 3 trial, no mortality benefit was seen in patients that received TXA. However, there are a number of differences in combat related traumatic brain injury to include a high proportion of penetrating injury mechanism and multiple concomitant injuries (penetrating torso, extremity amputation, etc.). The conclusions from this retrospective study should be taken with caution, as there was a limited number of participants, and only patients that survived evacuation to a role V MTF were included. As of this review, the Joint Trauma Systems Clinical Practice Guidelines have not provided recommendations regarding TXA in severe head injury (CPG ID:30, CPG ID:68). However, this study demonstrates that in a combat environment, evacuation time and proximity to neurosurgical capabilities should be considered when making the decision to give TXA.