Dismounted Complex Blast Injury Research Articles

Zone 1 REBOA in a combat DCBI swine model does not worsen brain injury

BackgroundZone 1 resuscitative endovascular balloon occlusion of the aorta has been recommended for refractory shock after a dismounted complex blast injury for the austere combat scenario. While resuscitative endovascular balloon occlusion of the aorta should enhance coronary perfusion, there is a potential risk of secondary brain injury due to loss of cerebral autoregulation. We developed a combat casualty relevant dismounted complex blast injury swine model to evaluate the effects of resuscitative endovascular balloon occlusion of the aorta zone I on intracranial pressure and cerebral edema. We hypothesized that zone 1 aortic occlusion with resuscitative endovascular balloon occlusion of the aorta would increase mean arterial pressure transmitted in excessive intracranial pressure, thereby worsening brain injury. Methods50 kg male Yorkshire swine were subjected to a combination dismounted complex blast injury model consisting of blast traumatic brain injury (50 psi, ARA Mobile Shock Laboratory), tissue injury (bilateral femur fractures), and hemorrhagic shock (controlled bleeding to a base deficit goal of 10 mEq/L). During the shock phase, pigs were randomized to no aortic occlusion (n = 8) or to 30 minutes of zone 1 resuscitative endovascular balloon occlusion of the aorta (zone 1 aortic occlusion group, n = 6). After shock, pigs in both groups received a modified Tactical Combat Casualty Care–based resuscitation and were monitored for an additional 240 minutes until euthanasia/death for a total of 6 hours. Intracranial pressure was monitored throughout, and brains were harvested for water content. Linear mixed models for repeated measures were used to compare mean arterial pressure and intracranial pressure between zone 1 aortic occlusion and no aortic occlusion groups. ResultsAfter dismounted complex blast injury, the zone 1 group had a significantly higher mean arterial pressure during hemorrhagic shock compared to the control group (41.2 mm Hg vs 16.7 mm Hg, P = .002). During balloon occlusion, intracranial pressure was not significantly elevated in the zone 1 aortic occlusion group vs control, but intracranial pressure was significantly lower in the zone 1 group at the end of the observation period. In addition, the zone 1 aortic occlusion group did not have increased brain water content (zone 1 aortic occlusion: 3.95 ± 0.1g vs no aortic occlusion: 3.95 ± 0.3 g, P = .87). Troponin levels significantly increased in the no aortic occlusion group but did not in the zone 1 aortic occlusion group. ConclusionZone 1 aortic occlusion using resuscitative endovascular balloon occlusion of the aorta in a large animal dismounted complex blast injury model improved proximal mean arterial pressure while not significantly increasing intracranial pressure during balloon inflation. Observation up to 240 minutes postresuscitation did not show clinical signs of worsening brain injury or cardiac injury. These data suggest that in a dismounted complex blast injury swine model, resuscitative endovascular balloon occlusion of the aorta in zone 1 may provide neuro- and cardioprotection in the setting of blast traumatic brain injury. However, longer monitoring periods may be needed to confirm that the neuroprotection is lasting.

A combat casualty relevant dismounted complex blast injury model in swine.

Improvised explosive devices have resulted in a unique polytrauma injury pattern termed dismounted complex blast injury (DCBI), which is frequent in the modern military theater. Dismounted complex blast injury is characterized by extremity amputations, junctional vascular injury, and blast traumatic brain injury (bTBI). We developed a combat casualty relevant DCBI swine model, which combines hemorrhagic shock (HS) and tissue injury (TI) with a bTBI, to study interventions in this unique and devastating military injury pattern. A 50-kg male Yorkshire swine were randomized to the DCBI or SHAM group (instrumentation only). Those in the DCBI group were subjected to HS, TI, and bTBI. The blast injury was applied using a 55-psi shock tube wave. Tissue injury was created with bilateral open femur fractures. Hemorrhagic shock was induced by bleeding from femoral arteries to target pressure. A resuscitation protocol modified from the Tactical Combat Casualty Care guidelines simulated battlefield resuscitation for 240 minutes. Eight swine underwent the DCBI model and five were allocated to the SHAM group. In the DCBI model the mean base excess achieved at the end of the HS shock was -8.57 ± 5.13 mmol·L -1 . A significant coagulopathy was detected in the DCBI model as measured by prothrombin time (15.8 seconds DCBI vs. 12.86 seconds SHAM; p = 0.02) and thromboelastography maximum amplitude (68.5 mm DCBI vs. 78.3 mm in SHAM; p = 0.0003). For the DCBI models, intracranial pressure (ICP) increased by a mean of 13 mm Hg, reaching a final ICP of 24 ± 7.7 mm Hg. We created a reproducible large animal model to study the combined effects of severe HS, TI, and bTBI on coagulation and ICP in the setting of DCBI, with significant translational applications for the care of military warfighters. Within the 4-hour observational period, the swine developed a consistent coagulopathy with a concurrent brain injury evidenced by increasing ICP.

Designed Antimicrobial Peptides Against Trauma-Related Cutaneous Invasive Fungal Wound Infections.

Cutaneous invasive fungal wound infections after life-threatening dismounted complex blast injury (DCBI) and natural disasters complicate clinical care. These wounds often require aggressive repeated surgical debridement, can result in amputations and hemipelvectomies and have a 38% mortality rate. Given the substantial morbidity associated with cutaneous fungal wound infections, patients at risk need immediate empiric treatment mandating the use of rapidly acting broad-spectrum antimicrobials, acting on both fungi and bacteria, that are also effective against biofilm and can be administered topically. Designed antimicrobial peptides (dAMPs) are engineered analogues of innate antimicrobial peptides which provide the first line of defense against invading pathogens. The antifungal and antibacterial effect and mammalian cytotoxicity of seven innovative dAMPs, created by iterative structural analog revisions and physicochemical and functional testing were investigated. The dAMPs possess broad-spectrum antifungal activity, in addition to being effective against Gram-negative and Gram-positive bacteria, which is crucial as many wounds are polymicrobial and require immediate empiric treatment. Three of the most potent dAMPs—RP504, RP556 and RP557—possess limited mammalian cytotoxicity following 8 h incubation. If these encouraging broad-spectrum antimicrobial and rapid acting results are translated clinically, these novel dAMPs may become a first line empiric topical treatment for traumatic wound injuries.

Military experience in the management of pelvic fractures from OIF/OEF

IntroductionPelvic fractures are a common occurrence in combat trauma. However, the fracture pattern and management within the most recent conflicts, i.e. Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF),...

A New Understanding of the Mechanism of Injury to the Pelvis and Lower Limbs in Blast.

Dismounted complex blast injury (DCBI) has been one of the most severe forms of trauma sustained in recent conflicts. This injury has been partially attributed to limb flail; however, the full causative mechanism has not yet been fully determined. Soil ejecta has been hypothesized as a significant contributor to the injury but remains untested. In this study, a small-animal model of gas-gun mediated high velocity sand blast was used to investigate this mechanism. The results demonstrated a correlation between increasing sand blast velocity and injury patterns of worsening severity across the trauma range. This study is the first to replicate high velocity sand blast and the first model to reproduce the pattern of injury seen in DCBI. These findings are consistent with clinical and battlefield data. They represent a significant change in the understanding of blast injury, producing a new mechanistic theory of traumatic amputation. This mechanism of traumatic amputation is shown to be high velocity sand blast causing the initial tissue disruption, with the following blast wind and resultant limb flail completing the amputation. These findings implicate high velocity sand blast, in addition to limb flail, as a critical mechanism of injury in the dismounted blast casualty.

Postdeployment Fertility Challenges and Treatment in the Modern Era.

Current war-fighting environments have shifted dramatically over the past decade, and with this change, new types of injuries are afflicting American soldiers. Operative Enduring Freedom and Operation Iraqi Freedom have noted an increased use of sophisticated improvised explosive devices by adversaries. Injuries not frequently seen in previous conflict are dismounted complex blast injuries, which involve multiple proximal amputations, pelvic fractures, and extensive perineal wounds. Thus, an unforeseen consequence of the decreased mortality rate after these complex blast injuries is a new wave of U.S. service members facing the challenges of recovering from the catastrophic amputations and genitourinary injuries. New applications of sperm retrieval methods may be used in these specific populations, as they recover and wish to purse family-building goals. Spinal cord injuries, traumatic brain injuries, and considerations unique to the female soldier are explored in this review of urologic care in wounded veterans.

Urinary Tract Infections after Combat-Related Genitourinary Trauma.

Background: We examined clinical outcomes among combat casualties with genitourinary injuries after blast trauma. Methods: Characteristics, clinical care, urologic complications, and infections for subjects enrolled in the Trauma Infectious Disease Outcomes Study (TIDOS) were collected from Department of Defense (DOD) and Department of Veterans Affairs (VA) sources. Logistic regression identified predictors for urinary tract infections (UTIs) after genitourinary trauma. Results: Among 530 TIDOS enrollees who entered VA care, 89 (17%) sustained genitourinary trauma. The majority of subjects (93%) were injured via a blast and 27% had a dismounted complex blast injury (DCBI). Sexual dysfunction was reported with 36% of subjects, whereas 14% had urinary retention/incontinence and 8% had urethral stricture. Urologic complications were comparable between patients with and without DCBIs. Nineteen (21%) subjects had one or more UTI with a total of 40 unique UTI events (25% during initial hospitalization and 75% during subsequent DOD or VA care). The UTI incidence rate was 0.89 per patient-year during initial hospitalization, 0.05 per patient-year during DOD follow-up, and 0.07 per patient-year during VA healthcare. Subjects with UTIs had a higher proportion of bladder injury (53% vs. 13%; p < 0.001), posterior urethral injury (26% vs. 1%; p = 0.001), pelvic fracture (47% vs. 4%; p < 0.001), soft-tissue infection of the pelvis/hip (37% vs. 4%; p = 0.001), urinary catheterization (47% vs. 11%; p < 0.001), urinary retention or incontinence (42% vs. 6%; p < 0.001), and stricture (26% vs. 3%; p = 0.004) compared with patients with genitourinary trauma and no UTI. Independent UTI risk factors were occurrence of a soft-tissue infection at the pelvis/hip, trauma to the urinary tract, and transtibial amputation. Conclusions: Among combat casualties with genitourinary trauma, UTIs are a common complication, particularly with severe blast injury and urologic sequelae. Episodes of UTIs typically occur early after the initial injury while in DOD care, however, recurrent infections may continue into long-term VA care.

High Bilateral Amputations and Dismounted Complex Blast Injury (DCBI).

High, combat-related bilateral lower extremity amputations rarely occur in isolation. Dismounted complex blast injury is a devastating and life-threatening constellation of multisystem injuries most commonly due to dismounted contact with improvised explosive devices. Rapid damage control resuscitation and surgery are essential to improve patient survival and minimize both early complications and late sequelae. A coordinated team approach is essential to provide simultaneous airway management, volume resuscitation (ideally with whole blood or ratio transfusion), and immediate control of life-threatening hemorrhage. Temporary aortic or iliac vessel clamping during concurrent exploratory or vascular control laparotomy is frequently required. Stabilization of unstable pelvic fractures is then performed, followed by debridement and irrigation of all wounds, which should be left open, and subsequent provisional stabilization of long bone fractures. The goal of the initial surgical resuscitative endeavor is rapid concurrent control of all sources of hemorrhage to avoid the lethal triad of acidosis, hypothermia and coagulopathy. To this end, multiple surgeons or surgical teams should be utilized whenever feasible. Patients then require ongoing resuscitation followed by early and frequent return to the operating suite throughout the evacuation chain. Utilizing this approach, a high survival rate with reasonable functional outcomes is achievable despite the extreme severity of the DCBI pattern.

Second Place: Dismounted complex blast injuries: patterns of remaining limb injuries in patients with single-limb lower extremity amputations

Background: The conflict tactic of the Afghanistan theater of operations utilizes blast weapons while most patrols are on foot, leading to a pattern of injuries associated with lower extremity amputation termed “dismounted complex blast injury” (DCBI). The purpose of this study was to better define and describe the injuries occurring to the nonamputated extremities in patients injured as the result of DCBI. Methods: A retrospective review was conducted of data from the United States and United Kingdom Joint Theater Trauma Registries of injuries resulting from a dismounted improvised explosive device (IED) blast. CT and radiographs were used to characterize injuries. Fisher’s exact test was used to compare categorical data, and binomial logistic regression was used to compare proportions of types of injuries by traumatic amputation level observed. Results: Of the 295 patients with lower extremity injuries, 201 had traumatic lower extremity amputations (140 with bilateral lower extremity and 61 with single-leg amputations). All were male, with a mean age 23.38+/-3.77. Below-knee amputation was most common (55.7%), followed by through-knee (25%), and least frequently through-ankle amputation. Hindfoot-level amputation was associated with an 8.1% increase in the odds of the presence of a skeletal foot injury in the nonamputated lower extremity. An association of above-knee amputation with bilateral distal upper extremity injury was found. There was a 10.9% increase in odds for the ipsilateral hand/wrist fracture given an AKA. Conclusions: Proximal lower extremity amputation levels are significantly associated with distal upper extremity skeletal injury. Hindfoot-level amputation is significantly associated with contralateral foot fractures. Amputation levels proximal to the ankle often presented with associated genitourinary injuries.

Dismounted complex blast injuries

Category: Trauma Introduction/Purpose: The United States Medical Corps has continued to evaluate and define the injury patterns of our service members in an effort to prevent injury and improve combat casualty care. The pattern of injury can be predicted by the mechanism of injury. One of the more recently described and studied mechanisms has been coined the ‘dismounted complex blast injury. This injury pattern involves traumatic amputation of at least one leg with a second injury involving another extremity in addition to an injury to either the pelvis, the abdomen, or the urogenital region. The purpose of this study was to better define and describe the injuries occurring to the non amputated extremity. Methods: This is a retrospectively review of data from the US and UK Joint Theater Trauma Registries (JTTR) of consecutive patients admitted to the UK Role 3 hospital at Camp Bastion, Afghanistan, from January 1, 2009, to February 29, 2012. Data was obtained from the US JTTR (Joint Theatre Trauma Registry). Each patient was assigned an Injury Severity Score (ISS) and an Abbreviated Injury Scale (AIS) score. Only those patients with an AIS of 3 or greater (a serious injury) were included. All xrays and CT scans were evaluated by two board certified orthopaedic surgeons and one board certified musculoskeletal radiologist. Fisher’s exact test was used to compare categorical data and binomial logistic regression was be used to compare proportions of types of injuries by traumatic amputation level observed. Results: There were 295 patients with lower extremity injuries identified. 201 had traumatic lower extremity amputations, 140 with bilateral lower extremity amputations, 61 with single leg amputations. The mean age was 23.38 +/-3.77 years. All were male. Below the knee amputation was the most frequent amputation type observed, representing 55.7% of the amputations (29/52), the next most frequent was the through knee amputation representing 25%. The least frequent was the through ankle amputation. The presence of a symes level amputation was associated with an 8.1% increase in the odds of the presence of a skeletal foot injury in the rear lower extremity. There was also an association found between AKA level amputation and skeletal injury in the contralateral upper extremity . Conclusion: This is among the first studies to correlate level of injury and associated musculoskeletal injury for the Afghanistan theater of operations. The results of this data set demonstrate that proximal lower extremity amputation levels are significantly associated with distal upper extremity skeletal injury. In addition, the Symes level of amputation is significantly associated with contralateral foot fractures. Amputation levels proximal to the ankle often present with associated Genitourinary injuries. Unique to this study is the demonstration of a significant association of upper extremity injury with a more proximal lower extremity amputation level .

Management of External Hemorrhage in Tactical Combat Casualty Care: The Adjunctive Use of XStat™ Compressed Hemostatic Sponges: TCCC Guidelines Change 15-03

Exsanguination from wounds in the so-called junctional regions of the body (i.e., the neck, the axilla, and the groin) was responsible for 19% of the combat fatalities who died from potentially survivable wounds sustained in Afghanistan or Iraq during 2001 to 2011. The development of improved techniques and technology to manage junctional hemorrhage has been identified in the past as a high-priority item by the Committee on Tactical Combat Casualty Care (CoTCCC) and the Army Surgeon General's Dismounted Complex Blast Injury (DCBI) Task Force. Additionally, prehospital care providers have had limited options with which to manage hemorrhage resulting from deep, narrow-track, penetrating trauma. XStat™ is a new product recently approved by the US Food and Drug Administration as a hemostatic adjunct to aid in the control of bleeding from junctional wounds in the groin or axilla. XStat has now been recommended by the CoTCCC as another tool for the combat medical provider to use in the management of junctional hemorrhage. The evidence that supports adding XStat to the TCCC Guidelines for the treatment of external hemorrhage is summarized in this paper.

Dismounted complex blast injury report of the army dismounted complex blast injury task force

Dismounted complex blast injury report of the army dismounted complex blast injury task force

Evolution of Orthopaedic Reconstructive Care

The patterns and severity of injury sustained by service members have continuously evolved over the past 10 years of combat in Iraq and Afghanistan. The 2010 surge of combat troops into Afghanistan, combined with a transition to counterinsurgency tactics with an emphasis on dismounted operations, resulted in increased exposure of US service members to improvised explosive devices and a new pattern of injury termed dismounted complex blast injury. This constellation of injuries typically includes multiple extremity injuries, high bilateral transfemoral amputations, amputated or mangled upper extremities, open pelvis fractures, and injury to the perineal and/or genital regions. These polytraumatized patients frequently present with head, abdominal, and genitourinary injuries, as well. Traditional methods of reconstruction must be optimized because tissue availability may be limited.