Trauma System Development in a Theater of War: Experiences From Operation Iraqi Freedom and Operation Enduring Freedom

Non-therapeutic laparotomies in military trauma (2009-2014)

BACKGROUND

Combat casualties are frequently injured in austere settings where modern imaging modalities are unavailable. Exploratory laparotomies are often performed in these settings when there is suspicion for intra-abdominal injury. Prior studies of combat casualties reported non-therapeutic laparotomy (NTL) rates as high as 32%. Given improvements in combat casualty care over time, we evaluated NTLs performed during later years of the wars in Iraq and Afghanistan.

METHODS

Military personnel with combat-related injuries (6/1/2009-12/31/2014) who underwent exploratory laparotomy based on concern for abdominal injury (i.e. not performed for proximal vascular control or fecal diversion) and were evacuated to Landstuhl Regional Medical Center (Germany) before being transferred to participating U.S. military hospitals were assessed. An NTL was defined as a negative laparotomy without substantial intra-abdominal injuries requiring repair. Characteristics, indications for laparotomy, operative findings, and outcomes were examined.

RESULTS

Among 244 patients who underwent laparotomies, 41 (16.8%) had NTLs and 203 (83.2%) had therapeutic laparotomies (i.e. positive findings). Patients with NTLs had more computed tomography scans concerning for injury (48.8% vs 27.1%; p = 0.006), less penetrating injury mechanisms (43.9% vs 71.9%; p < 0.001), and lower Injury Severity Scores (26 vs 33; p = 0.003) compared to patients with therapeutic laparotomies. Patients with NTLs were also less likely to be admitted to the intensive care unit (70.7 vs 89.2% for patients with therapeutic laparotomies; p = 0.007). No patients with NTLs developed abdominal surgical site infections (SSI) compared to 16.7% of patients with therapeutic laparotomies (p = 0.002). There was no significant difference in mortality between the groups (p = 0.198).

CONCLUSIONS

Our proportion of NTLs was lower than reported from earlier years during the wars in Iraq and Afghanistan. No infectious complications from NTLs (i.e. abdominal SSIs) were identified. Nevertheless, surgeons should continue to have a low threshold for exploratory laparotomy in military patients in austere settings with concern for intra-abdominal injury.

A Seminested PCR Method for the Diagnosis of Invasive Fungal Infections in Combat Injured

Background

Among combat injured, invasive fungal infections (IFIs) result in significant morbidity. Cultures and histopathology are the primary diagnostic methods for IFIs, but they have limitations. We previously evaluated a panfungal polymerase chain reaction assay, which was 83% sensitive and 99% specific for angioinvasive IFIs. Here, we evaluated 3 less resource-intensive seminested assays targeting clinically relevant fungi in the order Mucorales and genera Aspergillus and Fusarium.

Methods

Formalin-fixed paraffin-embedded tissue specimens from a multicenter trauma IFI cohort (2009-2014) were used. Cases were US military personnel injured in Afghanistan with histopathologic IFI evidence. Controls were patients with similar injury patterns and no laboratory IFI evidence (negative culture and histopathology). Seminested assays specific to Mucorales (V4/V5 regions of 18S rDNA), Aspergillus (mitochondrial tRNA), and Fusarium (internal transcribed spacer [ITS]/28A regions of DNA) were compared with a panfungal assay amplifying the internal transcribed spacer 2 region of rDNA and to histopathology.

Results

Specimens from 92 injury sites (62 subjects) were compared with control specimens from 117 injuries (101 subjects). We observed substantial agreement between the seminested and panfungal assays overall, especially for the order Mucorales. Moderate agreement was observed at the genus level for Aspergillus and Fusarium. When compared with histopathology, sensitivity and specificity of seminested assays were 67.4% and 96.6%, respectively (sensitivity increased to 91.7% when restricted to sites with angioinvasion).

Conclusions

Prior studies of seminested molecular diagnostics have focused on culture-negative samples from immunocompromised patients. Our findings underscore the utility of the seminested approach in diagnosing soft-tissue IFIs using formalin-fixed paraffin-embedded tissue samples, especially with angioinvasion.

Analysis of the U.S. Military Trauma System in Accordance With Doctrinal Levels of Warfare

INTRODUCTION

In recent conflicts, the Joint Theater Trauma System (JTTS) led the systematic approach to improve battlefield trauma care, substantially contributing to the unprecedented survival of combat casualties. The Joint Trauma System (JTS) was codified in 2016 to preserve the lessons learned and functions of the JTTS, including the Department of Defense Trauma Registry. Concurrently, Combatant Commands (CCMD) were directed to establish CCMD Trauma Systems (CTS) "modeled after the JTTS" and to maintain a baseline of core functions intended to rapidly scale as needed. The complex nature of both CCMDs and the military trauma system has challenged the full implementation of the CTS. Analyzing the historical experiences of the JTTS, JTS, and CTS within a military doctrinal framework might enable the further success of the military trauma system.

METHODS

The strategic, operational, and tactical levels of warfare, in accordance with Joint Publication 1-0, Doctrine of the Armed Forces of the United States, and Joint Publication 3-0, Joint Operations, established the analytic framework for this study. The literature regarding the JTTS, CTS, and JTS was reviewed for relevant information concerning organizational structure and functions of trauma system performance improvement (PI) capabilities. A comprehensive analysis was performed using a thematic approach to evaluating descriptive data contained within the collected data set. Deployed trauma system PI tasks, functions, and responsibilities were identified, defined, and correlated according to the respective levels of warfare.

RESULTS

The comprehensive analysis revealed both discrete and overlapping tasks, functions, and responsibilities of the trauma system PI capabilities at each of the three levels of warfare. Strategic-level actions were categorized according to 12 distinct themes: reduce mortality; strategic reporting; centralized trauma registry; strategic communications; centralized organization; direct support to CCMDs; Department of Defense policy and doctrine; strategic-level PI; clinical practice guidelines; training and readiness standards; force structure, standardization, and interoperability; and research and development. Operational-level actions were categorized according to seven distinct themes: theater trauma system policies and requirements; theater trauma system leadership; stakeholder coordination; theater communication; theater standards for readiness and skill sustainment; trauma system planning; and medical logistics support. Tactical-level actions were categorized according to seven distinct themes: trauma system personnel; PI; documentation enforcement and patient care data collection; tactical planning recommendations for employing medical assets; research support; communication and reporting; and training and skills sustainment.

CONCLUSION

The deployed U.S. military trauma system requires a robust PI capability to optimize combat casualty care. Policy updates, a joint military trauma system doctrine, and force design updates are necessary for deployed military trauma system PI capabilities to function optimally across all levels of warfare.

Mental and Physical Health-Related Quality of Life Following Military Polytrauma

INTRODUCTION

The long-term impact of deployment-related trauma on mental and physical health-related quality of life (HRQoL) among military personnel is not well understood. We describe the mental and physical HRQoL among military personnel following deployment-related polytrauma after their discharge from the hospital and examine factors associated with HRQoL and longitudinal trends.

MATERIALS AND METHODS

The U.S. military personnel with battlefield-related trauma enrolled in the Trauma Infectious Diseases Outcomes Study were surveyed using SF-8 Health Surveys at 1 month post-discharge (baseline) and at follow-up intervals over 2 years. Inclusion in the longitudinal analysis required baseline SF-8 plus responses during early (3 and/or 6 months) and later follow-up periods (12, 18, and/or 24 months). Associations of demographics, injury characteristics, and hospitalization with baseline SF-8 scores and longitudinal changes in SF-8 scores during follow-up were examined. Survey responses were used to calculate the Mental Component Summary score (MCS) and the Physical Component Summary score (PCS). The MCS focuses on vitality, mental health, social functioning, and daily activity limitations, whereas PCS is related to general health, bodily pain, physical functioning, and physical activity limitations. Longitudinal trends in SF-8 scores were assessed using chi-square tests by comparing the median score at each timepoint to the median 1-month (baseline) score, as well as comparing follow-up scores to the immediately prior timepoint (e.g., 6 months vs. 3 months). Associations with the 1-month baseline SF-8 scores were assessed using generalized linear regression modeling and associations with longitudinal changes in SF-8 were examined using generalized linear regression modeling with repeated measures.

RESULTS

Among 781 enrollees, lower baseline SF-8 total scores and PCS were associated with spinal and lower extremity injuries (P < .001) in the multivariate analyses, whereas lower baseline MCS was associated with head/face/neck injuries (P < .001). Higher baseline SF-8 total was associated with having an amputation (P = .009), and lower baseline SF-8 total was also associated with sustaining a traumatic brain injury (TBI; P = .042). Among 524 enrollees with longitudinal follow-up, SF-8 scores increased, driven by increased PCS and offset by small MCS decreases. Upward SF-8 total score and PCS trends were associated with time post-hospital discharge and limb amputation (any) in the multivariate analyses (P < .05), whereas downward trends were independently associated with spinal injury and developing any post-discharge infection (P ≤ .001). Patients with lower extremity injuries had lower-magnitude improvements in PCS over time compared to those without lower extremity injuries (P < .001). Upward MCS trend was associated with higher injury severity (P = .003) in the multivariate analyses, whereas downward trends were independently associated with having a TBI (P < .001), time post-hospital discharge (P < .001), and occurrence of post-discharge infections (P = .002).

CONCLUSIONS

Overall, HRQoL increased during the 2-year follow-up period, driven by PCS improvement. Increasing HRQoL was associated with time since hospital discharge and limb amputation, whereas a downward trend in HRQoL was associated with spinal injury and post-discharge infection. The longitudinal decline in MCS, driven by TBI occurrence, time since hospital discharge, and developing post-discharge infections, emphasizes the importance of longitudinal mental health care in this population.

Seasonality of Microbiology of Combat-Related Wounds and Wound Infections in Afghanistan

INTRODUCTION

Battlefield-related wound infections are a significant source of morbidity among combat casualties. Seasonality of these infections was demonstrated in previous conflicts (e.g., Korea) but has not been described with trauma-related health care-associated infections from the war in Afghanistan.

METHODS

The study population included military personnel wounded in Afghanistan (2009-2014) medevac'd to Landstuhl Regional Medical Center and transitioned to participating military hospitals in the United States with clinical suspicion of wound infections and wound cultures collected ≤7 days post-injury. Analysis was limited to the first wound culture from individuals. Infecting isolates were collected from skin and soft-tissue infections, osteomyelitis, and burn soft-tissue infections. Data were analyzed by season (winter [ December 1-February 28/29], spring [March 1-May 31], summer [June 1-August 31], and fall [September 1-November 30]).

RESULTS

Among 316 patients, 297 (94.0%) sustained blast injuries with a median injury severity score and days from injury to initial culture of 33 and 3.5, respectively. Although all patients had a clinical suspicion of a wound infection, a diagnosis was confirmed in 198 (63%) patients. Gram-negative bacilli (59.5% of 316) were more commonly isolated from wound cultures in summer (68.1%) and fall (67.1%) versus winter (43.9%) and spring (45.1%; P < .001). Multidrug-resistant (MDR) Gram-negative bacilli (21.8%) were more common in summer (21.8%) and fall (30.6%) versus winter (7.3%) and spring (19.7%; P = .028). Findings were similar for infecting Gram-negative bacilli (72.7% of 198)-summer (79.5%) and fall (83.6%; P = .001)-and infecting MDR Gram-negative bacilli (27.3% of 198)-summer (25.6%) and fall (41.8%; P = .015). Infecting anaerobes were more common in winter (40%) compared to fall (11%; P = .036). Gram-positive organisms were not significantly different by season.

CONCLUSION

Gram-negative bacilli, including infecting MDR Gram-negative bacilli, were more commonly recovered in summer/fall months from service members injured in Afghanistan. This may have implications for empiric antibiotic coverage during these months.

Epidemiology of cranial infections in battlefield-related penetrating and open cranial injuries

BACKGROUND

Penetrating brain injuries are a potentially lethal injury associated with substantial morbidity and mortality. We examined characteristics and outcomes among military personnel who sustained battlefield-related open and penetrating cranial injuries during military conflicts in Iraq and Afghanistan.

METHODS

Military personnel wounded during deployment (2009-2014) were included if they sustained an open or penetrating cranial injury and were admitted to participating hospitals in the United States. Injury characteristics, treatment course, neurosurgical interventions, antibiotic use, and infection profiles were examined.

RESULTS

The study population included 106 wounded personnel, of whom 12 (11.3%) had an intracranial infection. Posttrauma prophylactic antibiotics were prescribed in more than 98% of patients. Patients who developed central nervous system (CNS) infections were more likely to have undergone a ventriculostomy ( p = 0.003), had a ventriculostomy in place for a longer period (17 vs. 11 days; p = 0.007), had more neurosurgical procedures ( p < 0.001), and have lower presenting Glasgow Coma Scale ( p = 0.01) and higher Sequential Organ Failure Assessment scores ( p = 0.018). Time to diagnosis of CNS infection was a median of 12 days postinjury (interquartile range, 7-22 days) with differences in timing by injury severity (critical head injury had median of 6 days, while maximal [currently untreatable] head injury had a median of 13.5 days), presence of other injury profiles in addition to head/face/neck (median, 22 days), and the presence of other infections in addition to CNS infections (median, 13.5 days). The overall length of hospitalization was a median of 50 days, and two patients died.

CONCLUSION

Approximately 11% of wounded military personnel with open and penetrating cranial injuries developed CNS infections. These patients were more critically injured (e.g., lower Glasgow Coma Scale and higher Sequential Organ Failure Assessment scores) and required more invasive neurosurgical procedures.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level IV.

Trends in Traumatic Brain Injury Among U.S. Service Members Deployed in Iraq and Afghanistan, 2002-2016

INTRODUCTION

Traumatic brain injury (TBI) is a major health issue for service members deployed and is more common in recent conflicts; however, a thorough understanding of risk factors and trends is not well described. This study aims to characterize the epidemiology of TBI in U.S. service members and the potential impacts of changes in policy, care, equipment, and tactics over the 15 years studied.

METHODS

Retrospective analysis of U.S. Department of Defense Trauma Registry data (2002-2016) was performed on service members treated for TBI at Role 3 medical treatment facilities in Iraq and Afghanistan. Risk factors and trends in TBI were examined in 2021 using Joinpoint regression and logistic regression.

RESULTS

Nearly one third of 29,735 injured service members (32.4%) reaching Role 3 medical treatment facilities had TBI. The majority sustained mild (75.8%), followed by moderate (11.6%) and severe (10.6%) TBI. TBI proportion was higher in males than in females (32.6% vs 25.3%; p<0.001), in Afghanistan than in Iraq (43.8% vs 25.5%; p<0.001), and in battle than in nonbattle (38.6% vs 21.9%; p<0.001). Patients with moderate or severe TBI were more likely to have polytrauma (p<0.001). TBI proportion increased over time, primarily in mild TBI (p=0.02), slightly in moderate TBI (p=0.04), and most rapidly between 2005 and 2011, with a 2.48% annual increase.

CONCLUSIONS

One third of injured service members at Role 3 medical treatment facilities experienced TBI. Findings suggest that additional preventive measures may decrease TBI frequency and severity. Clinical guidelines for field management of mild TBI may reduce the burden on evacuation and hospital systems. Additional capabilities may be needed for military field hospitals.

Advanced bleeding control in combat casualty care: An international, expert-based Delphi consensus

BACKGROUND

Hemorrhage from truncal and junctional injuries is responsible for the vast majority of potentially survivable deaths in combat casualties, causing most of its fatalities in the prehospital arena. Optimizing the deployment of the advanced bleeding control modalities required for the management of these injuries is essential to improve the survival of severely injured casualties. This study aimed to establish consensus on the optimal use and implementation of advanced bleeding control modalities in combat casualty care.

METHODS

A Delphi method consisting of three rounds was used. An international expert panel of military physicians was selected by the researchers to complete the Delphi surveys. Consensus was reached if 70% or greater of respondents agreed and if 70% or greater responded.

RESULTS

Thirty-two experts from 10 different nations commenced the process and reached consensus on which bleeding control modalities should be part of the standard equipment, that these modalities should be available at all levels of care, that only trained physicians should be allowed to apply invasive bleeding control modalities, but all medical and nonmedical personnel should be allowed to apply noninvasive bleeding control modalities, and on the training requirements for providers. Consensus was also reached on the necessity of international registries and guidelines, and on certain indications and contraindications for resuscitative endovascular balloon occlusion of the aorta (REBOA) in military environments. No consensus was reached on the role of a wound clamp in military settings and the indications for REBOA in patients with chest trauma, penetrating axillary injury or penetrating neck injury in combination with thoracoabdominal injuries.

CONCLUSION

Consensus was reached on the contents of a standard bleeding control toolbox, where it should be available, providers and training requirements, international registries and guidelines, and potential indications for REBOA in military environments.

Department of Defense Trauma Registry Infectious Disease Module Impact on Clinical Practice

BACKGROUND

The Joint Trauma System (JTS) is a DoD Center of Excellence for Military Health System trauma care delivery and the DoD's reference body for trauma care in accordance with National Defense Authorization Act for Fiscal Year 2017. Through the JTS, evidence-based clinical practice guidelines (CPGs) have been developed and subsequently refined to standardize and improve combat casualty care. Data are amassed through a single, centralized DoD Trauma Registry to support process improvement measures with specialty modules established as the registry evolved. Herein, we review the implementation of the JTS DoD Trauma Registry specialty Infectious Disease Module and the development of infection-related CPGs and summarize published findings on the subsequent impact of the Infectious Disease Module on combat casualty care clinical practice and guidelines.

METHODS

The DoD Trauma Registry Infectious Disease Module was developed in collaboration with the Infectious Disease Clinical Research Program (IDCRP) Trauma Infectious Disease Outcomes Study (TIDOS). Infection-related information (e.g., syndromes, antibiotic management, and microbiology) were collected from military personnel wounded during deployment June 1, 2009 through December 31, 2014 and medevac'd to Landstuhl Regional Medical Center in Germany before transitioning to participating military hospitals in the USA.

RESULTS

To support process improvements and reduce variation in practice patterns, data collected through the Infectious Disease Module have been utilized in TIDOS analyses focused on assessing compliance with post-trauma antibiotic prophylaxis recommendations detailed in JTS CPGs. Analyses examined compliance over three time periods: 6 months, one-year, and 5 years. The five-year analysis demonstrated significantly improved adherence to recommendations following the dissemination of the 2011 JTS CPG, particularly with open fractures (34% compliance compared to 73% in 2013-2014). Due to conflicting recommendations regarding use of expanded Gram-negative coverage with open fractures, infectious outcomes among patients with open fractures who received cefazolin or expanded Gram-negative coverage (cefazolin plus fluoroquinolones and/or aminoglycosides) were also examined in a TIDOS analysis. The lack of a difference in the proportion of osteomyelitis (8% in both groups) and the significantly greater recovery of Gram-negative organisms resistant to aminoglycosides or fluoroquinolones among patients who received expanded Gram-negative coverage supported JTS recommendations regarding the use of cefazolin with open fractures. Following recognition of the outbreak of invasive fungal wound infections (IFIs) among blast casualties injured in Afghanistan, the ID Module was refined to capture data (e.g., fungal culture and histopathology findings, wound necrosis, and antifungal management) needed for the TIDOS team to lead the DoD outbreak investigation. These data captured through the Infectious Disease Module provided support for the development of a JTS CPG for the prevention and management of IFIs, which was later refined based on subsequent TIDOS IFI analyses.

CONCLUSIONS

To improve combat casualty care outcomes and mitigate high-consequence infections in future conflicts, particularly in the event of prolonged field care, expansion, refinement, and a mechanism for sustainability of the DoD Trauma Registry Infectious Disease Module is needed to include real-time surveillance of infectious disease trends and outcomes.

Anastomotic Outcomes in Military Exploratory Laparotomies in the Modern Combat Era

Background

Intestinal anastomoses in military settings are performed in severely injured patients who often undergo damage control laparotomy in austere environments. We describe anastomotic outcomes of patients from recent wars.

Methods

Military personnel with combat-related intra-abdominal injuries (June 2009-December 2014) requiring laparotomy with resection and anastomosis were analyzed. Patients were evacuated from Iraq or Afghanistan to Landstuhl Regional Medical Center (Germany) before being transferred to participating U.S. military hospitals.

Results

Among 341 patients who underwent 1053 laparotomies, 87 (25.5%) required ≥1 anastomosis. Stapled anastomosis only was performed in 57.5% of patients, while hand-sewn only was performed in 14.9%, and 9.2% had both stapled and hand-sewn techniques (type unknown for 18.4%). Anastomotic failure occurred in 15% of patients. Those with anastomotic failure required more anastomoses (median 2 anastomoses, interquartile range [IQR] 1-3 vs. 1 anastomosis, IQR 1-2, P = .03) and more total laparotomies (median 5 laparotomies, IQR 3-12 vs. 3, IQR 2-4, P = .01). There were no leaks in patients that had only hand-sewn anastomoses, though a significant difference was not seen with those who had stapled anastomoses. While there was an increasing trend regarding surgical site infections (SSIs) with anastomotic failure after excluding superficial SSIs, it was not significant. There was no difference in mortality.

Discussion

Military trauma patients have a similar anastomotic failure rate to civilian trauma patients. Patients with anastomotic failure were more likely to have had more anastomoses and more total laparotomies. No definitive conclusions can be drawn about anastomotic outcome differences between hand-sewn and stapled techniques.

Resistance patterns and clinical outcomes of Klebsiella pneumoniae and invasive Klebsiella variicola in trauma patients

Recent reclassification of the Klebsiella genus to include Klebsiella variicola, and its association with bacteremia and mortality, has raised concerns. We examined Klebsiella spp. infections among battlefield trauma patients, including occurrence of invasive K. variicola disease. Klebsiella isolates collected from 51 wounded military personnel (2009-2014) through the Trauma Infectious Disease Outcomes Study were examined using polymerase chain reaction (PCR) and pulsed-field gel electrophoresis. K. variicola isolates were evaluated for hypermucoviscosity phenotype by the string test. Patients were severely injured, largely from blast injuries, and all received antibiotics prior to Klebsiella isolation. Multidrug-resistant Klebsiella isolates were identified in 23 (45%) patients; however, there were no significant differences when patients with and without multidrug-resistant Klebsiella were compared. A total of 237 isolates initially identified as K. pneumoniae were analyzed, with 141 clinical isolates associated with infections (remaining were colonizing isolates collected through surveillance groin swabs). Using PCR sequencing, 221 (93%) isolates were confirmed as K. pneumoniae, 10 (4%) were K. variicola, and 6 (3%) were K. quasipneumoniae. Five K. variicola isolates were associated with infections. Compared to K. pneumoniae, infecting K. variicola isolates were more likely to be from blood (4/5 versus 24/134, p = 0.04), and less likely to be multidrug-resistant (0/5 versus 99/134, p<0.01). No K. variicola isolates demonstrated the hypermucoviscosity phenotype. Although K. variicola isolates were frequently isolated from bloodstream infections, they were less likely to be multidrug-resistant. Further work is needed to facilitate diagnosis of K. variicola and clarify its clinical significance in larger prospective studies.

Risk factors for abdominal surgical site infection after exploratory laparotomy among combat casualties

BACKGROUND

Surgical site infections (SSIs) are well-recognized complications after exploratory laparotomy for abdominal trauma; however, little is known about SSI development after exploration for battlefield abdominal trauma. We examined SSI risk factors after exploratory laparotomy among combat casualties.

METHODS

Military personnel with combat injuries sustained in Iraq and Afghanistan (June 2009 to May 2014) who underwent laparotomy and were evacuated to participating US military hospitals were included. Log-binominal regression was used to identify SSI risk factors.

RESULTS

Of 4,304 combat casualties, 341 patients underwent a total of 1,053 laparotomies. Abdominal SSIs were diagnosed in 49 patients (14.4%): 8% with organ space SSI, 4% with deep incisional SSI, and 4% with superficial SSIs (4 patients had multiple SSIs). Patients with SSIs had more colorectal (p < 0.001), small bowel (p = 0.010), duodenum (p = 0.006), pancreas (p = 0.032), and abdominal vascular injuries (p = 0.040), as well as prolonged open abdomen (p = 0.004) and more infections diagnosed before the SSI (or final exploratory laparotomy) versus non-SSI patients (p < 0.001). Sustaining colorectal injuries (risk ratio [RR], 3.20; 95% confidence interval [CI], 1.58-6.45), duodenum injuries (RR, 6.71; 95% CI, 1.73-25.58), and being diagnosed with prior infections (RR, 10.34; 95% CI, 5.05-21.10) were independently associated with any SSI development. For either organ space or deep incisional SSIs, non-intra-abdominal infections, fecal diversion, and duodenum injuries were independently associated, while being injured via an improvised explosive device was associated with reduced likelihood compared with penetrating nonblast (e.g., gunshot wounds) injuries. Non-intra-abdominal infections and hypotension were independently associated with organ space SSIs development alone, while sustaining blast injuries were associated with reduced likelihood.

CONCLUSION

Despite severity of injuries and the battlefield environment, the combat casualty laparotomy SSI rate is relatively low at 14%, with similar risk factors and rates reported following severe civilian trauma.

LEVEL OF EVIDENCE

Epidemiological, level III.

PV[O]H: Noninvasive Enabling Technology, New Physiological Monitoring, and Big Data

INTRODUCTION

Measures of normal and abnormal physiology are interrelated and vary continuously. Our ability to detect and predict changes in physiology in real time has been limited in part by the requirement for blood sampling and the lack of a continuous data stream of various "signals", i.e., measurements of vital signs. It is important to determine which signals are most revealing for detection and treatment of, e.g., internal bleeding, managing fluid balance for mission/combat readiness, and hydration. Although our current algorithm for PV[O]H reflects changes in hematocrit and blood and plasma volumes, additional algorithms utilizing the whole raw PV[O]H data stream, along with other variables, can be constructed. We present a working prototype demonstrating that acceptable size, power, and complexity footprints for military needs can be achieved. Results of previous studies involving humans have demonstrated that PV[O]H can provide simultaneous, noninvasive, in vivo continuous monitoring of hematocrit, vascular volume, hemoglobin oxygen saturation, pulse rate, and breathing rate using a single light source with a reporting frequency of every 3 seconds.

MATERIALS AND METHODS

We have engineered an instrument implementing the PV[O]H algorithm in which (1) single channel photodetectors replace multichannel detection; (2) optical filters replace gratings; (3) battery power is used; and (4) sufficient computation with input/output capability moderated by application specific graphical user interfaces, and compatible with all cloud, wireless environment, and local protocols is implemented.

RESULTS

We have engineered a complete version of a two-probe PV[O]H system meeting military needs and have fabricated a first version. Testing of subsystems, calibration, and optical characterization of the optical probes are underway.

CONCLUSIONS

Simultaneous noninvasive continuous monitoring of peripheral vessels using a previous PV[O]H system demonstrates large, physiology revealing data sets. The technologies enable the methodical search for relevant physiological signals allowing the use of discriminant analysis, Bayesian approaches, and artificial intelligence to create predictive algorithms enabling timely interventions in medical care and troop training.

Outcomes of Exploratory Laparotomy and Abdominal Infections Among Combat Casualties

BACKGROUND

Abdominal injuries historically account for 13% of battlefield surgical procedures. We examined the occurrence of exploratory laparotomies and subsequent abdominal surgical site infections (SSIs) among combat casualties.

METHODS

Military personnel injured during deployment (2009-2014) were included if they required a laparotomy for combat-related trauma and were evacuated to Landstuhl Regional Medical Center, Germany, before being transferred to participating US military hospitals.

RESULTS

Of 4304 combat casualties, 341 (7.9%) underwent laparotomy. Including re-explorations, 1053 laparotomies (median, 2; interquartile range, 1-3; range, 1-28) were performed with 58% occurring within the combat zone. Forty-nine (14.4%) patients had abdominal SSIs (four with multiple SSIs): 27 (7.9%) with deep space SSIs, 14 (4.1%) with a deep incisional SSI, and 12 (3.5%) a superficial incisional SSI. Patients with abdominal SSIs had larger volume of blood transfusions (median, 24 versus 14 units), more laparotomies (median, 4 versus 2), and more hollow viscus injuries (74% versus 45%) than patients without abdominal SSIs. Abdominal closure occurred after 10 d for 12% of the patients with SSI versus 2% of patients without SSI. Mesh adjuncts were used to achieve fascial closure in 20.4% and 2.1% of patients with and without SSI, respectively. Survival was 98% and 96% in patients with and without SSIs, respectively.

CONCLUSIONS

Less than 10% of combat casualties in the modern era required abdominal exploration and most were severely injured with hollow viscus injuries and required massive transfusions. Despite the extensive contamination from battlefield injuries, the SSI proportion is consistent with civilian rates and survival was high.

A Consensus Framework for the Humanitarian Surgical Response to Armed Conflict in 21st Century Warfare

Question

What are consensus components of a framework for humanitarian surgical response in modern conflict zones?

Findings

This survey study using responses from 35 participants in the Stanford Humanitarian Surgical Response in Conflict Working Group suggests that humanitarian responses include both care of traumatic injury and emergency surgical needs of the population. Lessons from civilian and military trauma systems as well as humanitarian settings were translated into a tiered continuum of response from patient presentation through rehabilitation.

Meaning

Evidence suggests that modern trauma systems save lives but providing this standard of care in insecure conflict settings places new burdens on humanitarian systems; the framework presented herein integrates advances in surgical care to these environments.

Importance

Armed conflict in the 21st century poses new challenges to a humanitarian surgical response, including changing security requirements, access to patients, and communities in need, limited deployable surgical assets, resource constraints, and the requirement to address both traumatic injuries as well as emergency surgical needs of the population. At the same time, recent improvements in trauma care and systems have reduced injury-related mortality. This combination of new challenges and medical capabilities warrants reconsideration of long-standing humanitarian surgery protocols.

Objective

To describe a consensus framework for surgical care designed to respond to this emerging need.

Design, Setting, and Participants

An international group of 35 representatives from humanitarian agencies, US military, and academic trauma programs was invited to the Stanford Humanitarian Surgical Response in Conflict Working Group to engage in a structured process to review extant trauma protocols and make recommendations for revision.

Main Outcomes and Measures

The working group’s method adapted core elements of a modified Delphi process combined with consensus development conference from August 3 to August 5, 2018.

Results

Lessons from civilian and military trauma systems as well as recent battlefield experiences in humanitarian settings were integrated into a tiered continuum of response from point of injury through rehabilitation. The framework addresses the security and medical requirements as well as ethical and legal principles that guide humanitarian action. The consensus framework includes trained, lay first responders; far-forward resuscitation/stabilization centers; rapid damage control surgical access; and definitive care facilities. The system also includes nontrauma surgical care, injury prevention, quality improvement, data collection, and predeployment training requirements.

Conclusions and Relevance

Evidence suggests that modern trauma systems save lives. However, the requirements of providing this standard of care in insecure conflict settings places new burdens on humanitarian systems that must provide both emergency and trauma surgical care. This consensus framework integrates advances in trauma care and surgical systems in response to a changing security environment. It is possible to reduce disparities and improve the standard of care in these settings.

Classification of Trauma-Associated Invasive Fungal Infections to Support Wound Treatment Decisions

The proposed classification, based on diagnostic certainty, provides a framework for determining initial empiric and subsequent targeted therapy.

To evaluate a classification system to support clinical decisions for treatment of contaminated deep wounds at risk for an invasive fungal infection (IFI), we studied 246 US service members (413 wounds) injured in Afghanistan (2009–2014) who had laboratory evidence of fungal infection. A total of 143 wounds with persistent necrosis and laboratory evidence were classified as IFI; 120 wounds not meeting IFI criteria were classified as high suspicion (patients had localized infection signs/symptoms and had received antifungal medication for >10 days), and 150 were classified as low suspicion (failed to meet these criteria). IFI patients received more blood than other patients and had more severe injuries than patients in the low-suspicion group. Fungi of the order Mucorales were more frequently isolated from IFI (39%) and high-suspicion (21%) wounds than from low-suspicion (9%) wounds. Wounds that did not require immediate antifungal therapy lacked necrosis and localized signs/symptoms of infection and contained fungi from orders other than Mucorales.

Antibiotic Practice Patterns for Extremity Wound Infections among Blast-Injured Subjects

INTRODUCTION

We examined antibiotic management of combat-related extremity wound infections (CEWI) among wounded U.S. military personnel (2009-2012).

METHODS

Patients were included if they sustained blast injuries, resulting in ≥1 open extremity wound, were admitted to participating U.S. hospitals, developed a CEWI (osteomyelitis or deep soft-tissue infections) within 30 days post-injury, and received ≥3 days of relevant antibiotic (s) for treatment.

RESULTS

Among 267 patients, 133 (50%) had only a CEWI, while 134 (50%) had a CEWI plus concomitant non-extremity infection. In the pre-diagnosis period (4-10 days prior to CEWI diagnosis), 95 (36%) patients started a new antibiotic with 28% of patients receiving ≥2 antibiotics. During CEWI diagnosis week (±3 days of diagnosis), 209 (78%) patients started a new antibiotic (71% with ≥2 antibiotics). In the week following diagnosis (4-10 days after CEWI diagnosis), 121 (45%) patients started a new antibiotic with 39% receiving ≥2 antibiotics. Restricting to ±7 days of CEWI diagnosis, patients commonly received two (35%) or three (27%) antibiotics with frequent combinations involving carbapenem, vancomycin, and fluoroquinolones.

CONCLUSIONS

Substantial variation in antibiotic prescribing patterns related to CEWIs warrants development of combat-related clinical practice guidelines beyond infection prevention, to include strategies to reduce the use of unnecessary antibiotics and improve stewardship.

Molecular Detection of Filamentous Fungi in Formalin-Fixed Paraffin-Embedded Specimens in Invasive Fungal Wound Infections Is Feasible with High Specificity

Trauma-related invasive fungal wound infections (IFIs) are associated with significant morbidity and mortality. Early identification and treatment are critical. Traditional identification methods (e.g., fungal cultures and histopathology) can be delayed and insensitive. We assessed a PCR-based sequencing assay for rapid identification of filamentous fungi in formalin-fixed paraffin-embedded (FFPE) specimens obtained from combat casualties injured in Afghanistan. Blinded FFPE specimens from cases (specimens positive on histopathology) and controls (specimens negative on histopathology) were submitted for evaluation with a panfungal PCR. The internal transcribed spacer 2 (ITS2) region of the fungal ribosomal repeat was amplified and sequenced. The PCR results were compared with findings from histopathology and/or culture. If injury sites contributed multiple specimens, findings for the site were collapsed to the site level. We included 64 case subjects (contributing 95 sites) and 102 controls (contributing 118 sites). Compared to histopathology, panfungal PCR was specific (99%), but not as sensitive (63%); however, sensitivity improved to 83% in specimens from sites with angioinvasion. Panfungal PCR identified fungi of the order Mucorales in 33 of 44 sites with angioinvasion (75%), whereas fungal culture was positive in 20 of 44 sites (45%). Saksenaea spp. were the dominant fungi identified by PCR in specimens from angioinvasion sites (57%). Panfungal PCR is specific, albeit with lower sensitivity, and performs better at identifying fungi of the order Mucorales than culture. DNA sequencing offers significant promise for the rapid identification of fungal infection in trauma-related injuries, leading to more timely and accurate diagnoses.

Stenotrophomonas maltophilia infections: Clinical characteristics in a military trauma population

Stenotrophomonas maltophilia is a pathogen with unique resistance patterns. We assessed 70 combat casualties with S. maltophilia clinical isolates to examine its role as a nosocomial pathogen in critically-ill trauma patients. Incidence density was 0.36 S. maltophilia infections per 100 patient-days (95% CI: 0.29-0.44). Patients predominantly had blast trauma (97%) and were critically injured (injury severity score [ISS] >25; 80%). Restricting to patients with ISS >15, 50 patients with S. maltophilia infections were compared to 441 patients with infections attributed to other gram-negative bacilli. Patients with S. maltophilia infections had significantly more operating room visits prior to isolation, traumatic or early surgical amputations, longer hospitalization (median 71 vs 47 days), and higher overall mortality (10% vs 2%; P = 0.01). Initial and serial (≥7 days between initial and subsequent isolation) S. maltophilia isolates had high susceptibility to trimethoprim-sulfamethoxazole and minocycline. Evaluation of newer agents awaiting CLSI breakpoints, including moxifloxacin, showed promising results.

Antimicrobial Prophylaxis with Combat-Related Open Soft-Tissue Injuries

INTRODUCTION

All Department of Defense (DoD) guidance documents recommend cefazolin or clindamycin as post-trauma antibiotic prophylaxis for open soft-tissue injuries. Although not advocated, some patients with open soft-tissue injuries also received expanded Gram-negative coverage (EGN) prophylaxis based on the judgment of front-line trauma providers. During the study period, revised guidelines in 2011/2012 re-emphasized recommendations for using cefazolin or clindamycin, and stewardship efforts in the DoD trauma community aimed to reduce the practice of adding EGN to guideline-recommended antibiotic prophylaxis. Our objective was to examine antibiotic utilization among wounded military personnel with open extremity soft-tissue injuries over a 5-yr period and assess the impact on infectious outcomes in patients who received EGN prophylaxis versus guideline-directed prophylaxis.

METHODS

The study population included military personnel with open extremity soft-tissue injuries sustained in Iraq and Afghanistan (2009-2014) who transferred to participating hospitals in the USA following medical evacuation. The analysis was restricted to patients who were hospitalized for at least seven days at a U.S. facility and excluded those who sustained open fractures. Post-trauma antibiotic prophylactic regimens were defined as narrow if they followed recommended guidance (e.g., IV cefazolin or clindamycin) or EGN coverage when the narrow regimen also included fluoroquinolones and/or aminoglycosides. Intravenous amoxicillin-clavulanate, which is commonly used at non-U.S. coalition theater hospitals, was also classified as narrow because it conformed to coalition antibiotic prophylaxis guidelines. This study was approved by the Infectious Disease Institutional Review Board of the Uniformed Services University of the Health Sciences.

RESULTS

A total of 287 wounded personnel with open soft-tissue injuries were assessed, of which 212 (74%) received narrow prophylaxis and 75 (26%) received EGN coverage (p < 0.001). Among patients in the narrow prophylaxis group, 81% were given cefazolin and/or clindamycin, while 19% received amoxicillin-clavulanate. In the EGN group, 88% and 12% received a fluoroquinolone and aminoglycoside, respectively. Use of EGN coverage significantly declined during the study period from 39% in 2009-2010 to 11% in 2013-2014 (p < 0.001). Approximately 3% of patients who received a narrow regimen developed an extremity skin and soft-tissue infection, while there were no skin and soft-tissue infections among patients in the EGN coverage group. Nonetheless, this was not a significant difference (p = 0.345). In addition, the proportion of non-extremity infections was not significantly different between narrow and EGN regimen groups (11% and 15%, respectively). There were also no significant differences between the narrow and EGN regimen groups related to duration of hospitalization (median of 19 versus 20 d).

CONCLUSION

Use of non-guideline directed EGN-based post-trauma antibiotic prophylaxis does not improve infectious outcomes nor does it shorten hospital stay.

After the Battlefield: Infectious Complications among Wounded Warriors in the Trauma Infectious Disease Outcomes Study

INTRODUCTION

During recent wars in Iraq and Afghanistan, improved survivability in severe trauma corresponded with a rise in the proportion of trauma-related infections, including those associated with multidrug-resistant organisms (MDROs). Significant morbidity was reported in association with the infections. There is also concern regarding potential long-term impacts of the trauma-related infectious complications. Therefore, to meet the critical need of prospective collection of standardized infection-related data to understand the disease burden and improve outcomes of wounded personnel, the Trauma Infectious Disease Outcomes Study (TIDOS) was developed. Herein, we review accomplishments and key peer-reviewed findings of TIDOS.

METHODS

The TIDOS project is a multicenter observational study of short- and long-term infectious complications following deployment-related trauma. Wounded military personnel medevac'd to Landstuhl Regional Medical Center (LRMC; Germany) before transfer to a participating US military hospital between June 2009 and December 2014 were eligible for inclusion. An infectious disease module to supplement the Department of Defense Trauma Registry by collecting infection-related data from all trauma patients admitted to participating hospitals was developed. Specimens from trauma patients were also collected and retained in a microbiological isolate repository. During the initial hospitalization, patients were given the opportunity to enroll in a prospective follow-up cohort study. Patients who received Department of Veterans Affairs (VA) care were also given the opportunity to consent to ongoing VA follow-up.

RESULTS

A total of 2,699 patients transferred to participating military hospitals in the USA, of which 1,359 (50%) patients enrolled in the TIDOS follow-up cohort. In addition, 638 enrolled in the TIDOS-VA cohort (52% of TIDOS enrollees who entered VA healthcare). More than 8,000 isolates were collected from infection control surveillance and diagnostic evaluations and retained in the TIDOS Microbiological Repository. Approximately 34% of the 2,699 patients at US hospitals developed a trauma-related infection during their initial hospitalization with skin and soft-tissue infections being predominant. After discharge from the US hospitals, approximately one-third of TIDOS cohort enrollees developed a new trauma-related infection during follow-up and extremity wound infections (skin and soft-tissue infections and osteomyelitis) continued to be the majority. Among TIDOS cohort enrollees who received VA healthcare, 38% developed a new trauma-related infection with the incident infection being diagnosed a median of 88 days (interquartile range: 19-351 days) following hospital discharge. Data from TIDOS have been used to support the development of Joint Trauma System clinical practice guidelines for the prevention of combat-related infections, as well as the management of invasive fungal wound infections. Lastly, due to the increasing proportion of infections associated with MDROs, TIDOS investigators have collaborated with investigators across military laboratories as part of the Multidrug-Resistant and Virulent Organisms Trauma Infections Initiative with the objective of improving the understanding of the complex wound microbiology in order to develop novel infectious disease countermeasures.

CONCLUSIONS

The TIDOS project has focused research on four initiatives: (1) blast-related wound infection epidemiology and clinical management; (2) DoD-VA outcomes research; (3) Multidrug- Resistant and other Virulent Organisms Trauma Infections Initiative; and (4) Joint Trauma System clinical practice guidelines and antibiotic stewardship. There is a continuing need for longitudinal data platforms to support battlefield wound research and clinical practice guideline recommendation refinement, particularly to improve care for future conflicts. As such, maintaining a research platform, such as TIDOS, would negate the lengthy time needed to initiate data collection and analysis.

A 12-Year Analysis of Nonbattle Injury Among US Service Members Deployed to Iraq and Afghanistan

Importance

Nonbattle injury (NBI) among deployed US service members increases the burden on medical systems and results in high rates of attrition, affecting the available force. The possible causes and trends of NBI in the Iraq and Afghanistan wars have, to date, not been comprehensively described.

Objectives

To describe NBI among service members deployed to Iraq and Afghanistan, quantify absolute numbers of NBIs and proportion of NBIs within the Department of Defense Trauma Registry, and document the characteristics of this injury category.

Design, Setting, and Participants

In this retrospective cohort study, data from the Department of Defense Trauma Registry on 29 958 service members injured in Iraq and Afghanistan from January 1, 2003, through December 31, 2014, were obtained. Injury incidence, patterns, and severity were characterized by battle injury and NBI. Trends in NBI were modeled using time series analysis with autoregressive integrated moving average and the weighted moving average method. Statistical analysis was performed from January 1, 2003, to December 31, 2014.

Main Outcomes and Measures

Primary outcomes were proportion of NBIs and the changes in NBI over time.

Results

Among 29 958 casualties (battle injury and NBI) analyzed, 29 003 were in men and 955 were in women; the median age at injury was 24 years (interquartile range, 21-29 years). Nonbattle injury caused 34.1% of total casualties (n = 10 203) and 11.5% of all deaths (206 of 1788). Rates of NBI were higher among women than among men (63.2% [604 of 955] vs 33.1% [9599 of 29 003]; P < .001) and in Operation New Dawn (71.0% [298 of 420]) and Operation Iraqi Freedom (36.3% [6655 of 18 334]) compared with Operation Enduring Freedom (29.0% [3250 of 11 204]) (P < .001). A higher proportion of NBIs occurred in members of the Air Force (66.3% [539 of 810]) and Navy (48.3% [394 of 815]) than in members of the Army (34.7% [7680 of 22 154]) and Marine Corps (25.7% [1584 of 6169]) (P < .001). Leading mechanisms of NBI included falls (2178 [21.3%]), motor vehicle crashes (1921 [18.8%]), machinery or equipment accidents (1283 [12.6%]), blunt objects (1107 [10.8%]), gunshot wounds (728 [7.1%]), and sports (697 [6.8%]), causing predominantly blunt trauma (7080 [69.4%]). The trend in proportion of NBIs did not decrease over time, remaining at approximately 35% (by weighted moving average) after 2006 and approximately 39% by autoregressive integrated moving average. Assuming stable battlefield conditions, the autoregressive integrated moving average model estimated that the proportion of NBIs from 2015 to 2022 would be approximately 41.0% (95% CI, 37.8%-44.3%).

Conclusions and Relevance

In this study, approximately one-third of injuries during the Iraq and Afghanistan wars resulted from NBI, and the proportion of NBIs was steady for 12 years. Understanding the possible causes of NBI during military operations may be useful to target protective measures and safety interventions, thereby conserving fighting strength on the battlefield.

Combat-Related Extremity Wounds: Injury Factors Predicting Early Onset Infections

We examined risk factors for combat-related extremity wound infections (CEWI) among U.S. military patients injured in Iraq and Afghanistan (2009-2012). Patients with ≥1 combat-related, open extremity wound admitted to a participating U.S. hospital (≤7 days postinjury) were retrospectively assessed. The population was classified based upon most severe injury (amputation, open fracture without amputation, or open soft-tissue injury defined as non-fracture/non-amputation wounds). Among 1271 eligible patients, 395 (31%) patients had ≥1 amputation, 457 (36%) had open fractures, and 419 (33%) had open soft-tissue wounds as their most severe injury, respectively. Among patients with traumatic amputations, 100 (47%) developed a CEWI compared to 66 (14%) and 12 (3%) patients with open fractures and open soft-tissue wounds, respectively. In a Cox proportional hazard analysis restricted to CEWIs ≤30 days postinjury among the traumatic amputation and open fracture groups, sustaining an amputation (hazard ratio: 1.79; 95% confidence interval: 1.25-2.56), blood transfusion ≤24 hours postinjury, improvised explosive device blast, first documented shock index ≥0.80, and >4 injury sites were independently associated with CEWI risk. The presence of a non-extremity infection at least 4 days prior to a CEWI diagnosis was associated with lower CEWI risk, suggesting impact of recent exposure to directed antimicrobial therapy. Further assessment of early clinical management will help to elucidate risk factor contribution. The wound classification system provides a comprehensive approach in assessment of injury and clinical factors for the risk and outcomes of an extremity wound infection.

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.

Missed injuries in combat casualties: Lessons from Iraq and Afghanistan

INTRODUCTION

Once injured in the battlefield in Iraq and Afghanistan, U.S. and NATO troops receive medical treatment through tiered echelons of care with varying resources, from austere to state-of-the-art. Similar to civilian trauma systems, the aim is to provide rapid and safe patient movement toward definitive management. A consequence of the rapid transfer of patients is the possibility of missed or delayed diagnosis of injuries. With the new injury patterns seen during these conflicts, we aimed to identify and characterize which injuries are missed and what consequences do they have on our troops' road to recovery.

PATIENTS AND METHODS

A retrospective review of a PI database (established 2007) for consecutively admitted combat casualties was performed between 2007-2013. Baseline patient characteristics, injury year, admitting service, injury type, and subsequent management decisions were categorized and analyzed.

RESULTS

There were 301 missed injuries (MI) identified in 248 patients. The annual missed injury rate was 25 per 1000 admissions. Missed injuries were associated with a penetrating mechanism (82.7% vs 58.5%, p < 0.001), ICU admission (58.5% vs 27.4%, p < 0.001), higher ISS (median 14 vs 8, p < 0.001), and a longer length of stay (median 3 versus 2 days, p < 0.001). 194 (64.5%) missed injuries led to a change in management, with 68 (22.6%) requiring a surgical procedure. 1.3% of missed injuries were life threatening, 28.2% major and 65.4% minor. The most common injuries were distal extremity fractures (23.9%), followed by spine fractures (13.3%) and traumatic tympanic membrane rupture (12.6%), There were no deaths attributed to a missed injury.

DISCUSSION

Missed injuries during combat operations occur on a low but consistent basis. Most injuries are orthopedic in nature and typically occur in critically ill patients admitted to the ICU. It is rare that a missed injury results in a life-threatening condition.

CONCLUSION

As healthcare practitioners prepare for future deployments, this analysis may serve as a resource to focus on frequently missed injuries and possibly improve their detection.

Osteomyelitis Risk Factors Related to Combat Trauma Open Femur Fractures: A Case-Control Analysis

OBJECTIVES

To identify the risk factors for osteomyelitis development in US military personnel with combat-related, open femur fractures?

DESIGN

Retrospective observational case-control study.

SETTING

US military regional hospital in Germany and tertiary care hospitals in United States (2003-2009).

PATIENTS/PARTICIPANTS

One hundred three patients with open femur fractures who met diagnostic osteomyelitis criteria (medical record review verification) were classified as cases. Sixty-four patients with open femur fractures who did not meet osteomyelitis diagnostic criteria were included as controls.

MAIN OUTCOME MEASUREMENTS

The main outcome measurements were multivariable odds ratios (ORs) and 95% confidence interval (CI).

RESULTS

Among patients with surgical implants, osteomyelitis cases had significantly longer time to definitive orthopaedic surgery compared with controls (median: 21 vs. 13 days). Independent predictors for osteomyelitis risk were Gustilo-Anderson classification (transfemoral amputation OR: 19.3; CI: 3.0-123.0) and Orthopaedic Trauma Association Open Fracture Classification for muscle loss (OR: 5.7; CI: 1.3-25.1) and dead muscle (OR: 32.9; CI: 5.4-199.1). Being injured between 2003 and 2006, antibiotic bead use, and foreign body plus implant(s) at fracture site were also risk factors.

CONCLUSIONS

Patients with open femur fractures resulting in significant muscle damage have the highest osteomyelitis risk. Foreign body contamination was only significant when an implant was present. Increased risk with antibiotic bead use is likely a surrogate for clinical suspicion of contamination with complex wounds. The timeframe association is likely due to changing trauma system patterns around 2006-2007 (eg, increased negative pressure wound therapy, reduced high-pressure irrigation, decreased crystalloid use, and delayed definitive internal fixations).

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Is Bone Loss or Devascularization Associated With Recurrence of Osteomyelitis in Wartime Open Tibia Fractures?

BACKGROUND

During recent wars, 26% of combat casualties experienced open fractures and these injuries frequently are complicated by infections, including osteomyelitis. Risk factors for the development of osteomyelitis with combat-related open tibia fractures have been examined, but less information is known about recurrence of this infection, which may result in additional hospitalizations and surgical procedures.

QUESTIONS/PURPOSES

(1) What is the risk of osteomyelitis recurrence after wartime open tibia fractures and how does the microbiology compare with initial infections? (2) What factors are associated with osteomyelitis recurrence among patients with open tibia fractures? (3) What clinical characteristics and management approaches are associated with definite/probable osteomyelitis as opposed to possible osteomyelitis and what was the microbiology of these infections?

METHODS

A survey of US military personnel injured during deployment between March 2003 and December 2009 identified 215 patients with open tibia fractures, of whom 130 patients developed osteomyelitis and were examined in a retrospective analysis. No patients with bilateral osteomyelitis were included. Twenty-five patients meeting osteomyelitis diagnostic criteria were classified as definite/probable (positive bone culture, direct evidence of infection, or symptoms with culture and/or radiographic evidence) and 105 were classified as possible (bone contamination, organism growth in deep wound tissue, and evidence of local/systemic inflammation). Patients diagnosed with osteomyelitis were treated with débridement and irrigation as well as intravenous antibiotics. Fixation hardware was retained until fracture union, when possible. Osteomyelitis recurrence was defined as a subsequent osteomyelitis diagnosis at the original site ≥ 30 days after completion of initial treatment. This followup period was chosen based on the definition of recurrence so as to include as many patients as possible for analysis. Factors associated with osteomyelitis recurrence were assessed using univariate analysis in a subset of the population with ≥ 30 days of followup. Patients who had an amputation at or proximal to the knee after the initial osteomyelitis were not included in the recurrence assessment.

RESULTS

Of 112 patients meeting the criteria for assessment of recurrence, 31 (28%) developed an osteomyelitis recurrence, of whom seven of 25 (28%) had definite/probable and 24 of 87 (28%) had possible classifications for their initial osteomyelitis diagnosis. Risk of osteomyelitis recurrence was associated with missing or devascularized bone (recurrence, 14 of 31 [47%]; nonrecurrence, 22 of 81 [28%]; hazard ratio [HR], 3.94; 1.12-13.81; p = 0.032) and receipt of antibiotics for 22-56 days (recurrence, 20 of 31 [65%]; nonrecurrence: 37 of 81 [46%]; HR, 2.81; 1.05-7.49; p = 0.039). Compared with possible osteomyelitis, definite/probable osteomyelitis was associated with localized swelling at the bone site (13 of 25 [52%] versus 28 of 105 [27%]; risk ratio [RR], 1.95 [1.19-3.19]; p = 0.008) and less extensive skin and soft tissue injury at the time of trauma (9 of 22 [41%; three definite/probably patients missing data] versus 13 of 104 [13%; one possible patient missing data]; RR, 3.27 [1.60-6.69]; p = 0.001). Most osteomyelitis infections were polymicrobial (14 of 23 [61%; two patients with missing data] for definite/probable patients and 62 of 105 [59%] for possible patients; RR, 1.03 [0.72-1.48]; p = 0.870). More of the definite/probable patients received vancomycin (64%) compared with the possible patients (41%; p = 0.046), and the duration of polymyxin use was longer (median, 38 days versus 16 days, p = 0.018). Time to definitive fracture fixation was not different between the groups.

CONCLUSIONS

Recurrent osteomyelitis after open tibia fractures is common. In a univariate model, patients with an intermediate amount of bone loss and those treated with antibiotics for 22 to 56 days were more likely to experience osteomyelitis recurrence. Because only univariate analysis was possible, these findings should be considered preliminary. Osteomyelitis recurrence rates were similar, regardless of initial osteomyelitis classification, indicating that diagnoses of possible osteomyelitis should be treated aggressively.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Traumatic brain injury may worsen clinical outcomes after prolonged partial resuscitative endovascular balloon occlusion of the aorta in severe hemorrhagic shock model

BACKGROUND

The use of partial resuscitative endovascular balloon occlusion of the aorta (pREBOA) in combined hemorrhagic shock (HS) and traumatic brain injury (TBI) has not been well studied. We hypothesized that the use of pREBOA in the setting of TBI would be associated with worse clinical outcomes.

METHODS

Female Yorkshire swine were randomized to the following groups: HS-TBI, HS-TBI-pREBOA, and HS-pREBOA (n = 5/cohort). Animals in the HS-TBI group were left in shock for a total of 2 hours, whereas animals assigned to pREBOA groups were treated with supraceliac pREBOA deployment (60 minutes) 1 hour into the shock period. All animals were then resuscitated, and physiologic parameters were monitored for 6 hours. Further fluid resuscitation and vasopressors were administered as needed. At the end of the observation period, brain hemispheric swelling (%) and lesion size (mm) were assessed.

RESULTS

Mortality was highest in the HS-TBI-pREBOA group (40% [2/5] vs. 0% [0/5] in the other groups, p = 0.1). Severity of shock was greatest in the HS-TBI-pREBOA group, as defined by peak lactate levels and pH nadir (p < 0.05). Fluid resuscitation and norepinephrine requirements were significantly higher in the HS-TBI-pREBOA group (p < 0.05). No significant differences were noted in brain hemispheric swelling and lesion size between the groups.

CONCLUSION

Prolonged application of pREBOA in the setting of TBI does not contribute to early worsening of brain lesion size and edema. However, the addition of TBI to HS-pREBOA may worsen the severity of shock. Providers should be aware of the potential physiologic sequelae induced by TBI.

Microbiology of combat-related extremity wounds: Trauma Infectious Disease Outcomes Study

We present extremity wound microbiology data from 250 combat casualties (2009-2012). Confirmed extremity wound infections (EWIs) were based on clinical and laboratory findings. Suspected EWIs had isolation of organisms from wound cultures with associated signs/symptoms not meeting clinical diagnostic criteria. Colonized wounds had organisms isolated without any infection suspicion. A total of 335 confirmed EWIs (131 monomicrobial and 204 polymicrobial) were assessed. Gram-negative bacteria were predominant (57% and 86% of monomicrobial and polymicrobial infections, respectively). In polymicrobial infections, 61% grew only bacteria, while 30% isolated bacteria and mold. Multidrug resistance was observed in 32% of isolates from first monomicrobial EWIs ±3 days of diagnosis, while it was 44% of isolates from polymicrobial EWIs. Approximately 96% and 52% of the suspected and colonized wounds, respectively, shared ≥1 organism in common with the confirmed EWI on the same patient. Understanding of combat-related EWIs can lead to improvements in combat casualty care.

Infectious Complications After Deployment Trauma: Following Wounded US Military Personnel Into Veterans Affairs Care

Background

Infectious complications related to deployment trauma significantly contribute to the morbidity and mortality of wounded service members. The Trauma Infectious Disease Outcomes Study (TIDOS) collects data on US military personnel injured in Iraq and Afghanistan in an observational cohort study of infectious complications. Patients enrolled in TIDOS may also consent to follow-up through the Department of Veterans Affairs (VA). We present data from the first 337 TIDOS enrollees to receive VA healthcare.

Methods

Data were collected from the Department of Defense (DoD) Trauma Registry, TIDOS infectious disease module, DoD and VA electronic medical records, and telephone interview. Cox proportional hazard analysis was performed to identify predictors of post-discharge infections related to deployment trauma.

Results

Among the first 337 TIDOS enrollees who entered VA healthcare, 111 (33%) had 244 trauma-related infections during their initial trauma hospitalization (2.1 infections per 100 person-days). Following initial discharge, 127 (38%) enrollees had 239 trauma-related infections (170 during DoD follow-up and 69 during VA time). Skin and soft-tissue infections and osteomyelitis were predominant during and after the initial trauma hospitalization. In a multivariate model, a shorter time to development of a new infection following discharge was independently associated with injury severity score ≥10 and occurrence of ≥1 inpatient infection during initial trauma hospitalization.

Conclusions

Incident infections related to deployment trauma continue well after initial hospital discharge and into VA healthcare. Overall, 38% of enrolled patients developed a new trauma-related infection after their initial hospital discharge, with 29% occurring after the patient left military service.

Mobile forward-looking infrared technology allows rapid assessment of resuscitative endovascular balloon occlusion of the aorta in hemorrhage and blackout conditions

INTRODUCTION

Objective assessment of final resuscitative endovascular balloon occlusion of the aorta (REBOA) position and adequate distal aortic occlusion is critical in patients with hemorrhagic shock, especially as feasibility is being increasingly investigated in the prehospital setting. We propose that mobile forward-looking infrared (FLIR) thermal imaging is a fast, reliable, and noninvasive method to assess REBOA position and efficacy in scenarios applicable to battlefield and prehospital care.

METHODS

Ten swine were randomized to a 40% hemorrhage group (H, n = 5) or nonhemorrhage group (NH, n = 5). Three experiments were completed after Zone I placement of a REBOA catheter. Resuscitative endovascular balloon occlusion of the aorta was deployed for 30 minutes in all animals followed by randomized continued deployment versus sham in both light and blackout conditions. Forward-looking infrared images and hemodynamic data were obtained. Images were presented to 62 blinded observers for assessment of REBOA inflation status.

RESULTS

There was no difference in hemodynamic or laboratory values at baseline. The H group was significantly more hypotensive (mean arterial pressure 44 vs. 60 mm Hg, p < 0.01), vasodilated (systemic vascular resistance 634 vs. 938dyn·s/cm, p = 0.02), and anemic (hematocrit 12 vs. 23.2%, p < 0.01). Hemorrhage group animals remained more hypotensive, anemic, and acidotic throughout all three experiments. There was a significant difference in the temperature change (ΔTemp) measured by FLIR between animals with REBOA inflated versus not inflated (5.7°C vs. 0.7°C, p < 0.01). The H and NH animals exhibited equal magnitudes of ΔTemp in both inflated and deflated states. Blinded observer analysis of FLIR images correctly identified adequate REBOA inflation and aortic occlusion 95.4% at 5 minutes and 98.8% at 10 minutes (positive predictive value at 5 minutes = 99% and positive predictive value at 10 minutes = 100%).

CONCLUSIONS

Mobile thermal imaging is an easy, rapid, and reliable method for assessing distal perfusion after occlusion by REBOA. Smartphone-based FLIR technology allows for confirmation of adequate REBOA placement at the point of care, and performance was not degraded in the setting of major hemorrhage or blackout conditions.

Epidemiology of Trauma-Related Infections among a Combat Casualty Cohort after Initial Hospitalization: The Trauma Infectious Disease Outcomes Study

BACKGROUND

The Trauma Infectious Disease Outcomes Study (TIDOS) cohort follows military personnel with deployment-related injuries in order to evaluate short- and long-term infectious complications. High rates of infectious complications have been observed in more than 30% of injured patients during initial hospitalization. We present data on infectious complications related to combat trauma after the initial period of hospitalization.

PATIENTS AND METHODS

Data related to patient care for military personnel injured during combat operations between June 2009 and May 2012 were collected. Follow-up data were captured from interviews with enrolled participants and review of electronic medical records.

RESULTS

Among 1,006 patients enrolled in the TIDOS cohort with follow-up data, 357 (35%) were diagnosed with one or more infection during their initial hospitalization, of whom 160 (45%) developed a trauma-related infection during follow-up (4.2 infections per 10,000 person-days). Patients with three or more infections during the initial hospitalization had a significantly higher rate of infections during the follow-up period compared with those with only one inpatient infection (incidence rate: 6.6 versus 3.1 per 10,000 days; p < 0.0001). There were 657 enrollees who did not have an infection during initial hospitalization, of whom 158 (24%) developed one during follow-up (incidence rate: 1.6 per 10,000 days). Overall, 318 (32%) enrolled patients developed an infection after hospital discharge (562 unique infections) with skin and soft-tissue infections being predominant (66%) followed by osteomyelitis (16%). Sustaining an amputation or open fracture, having an inpatient infection, and use of anti-pseudomonal penicillin (≥7 d) were independently associated with risk of an extremity wound infection during follow-up, whereas shorter hospitalization (15-30 d) was associated with a reduced risk.

CONCLUSIONS

Combat-injured patients have a high burden of infectious complications that continue long after the initial period of hospitalization with soft-tissue and osteomyelitis being predominant. Further research on the long-term impact and outcomes of combat-associated infection is needed.

Variation in Postinjury Antibiotic Prophylaxis Patterns Over Five Years in a Combat Zone

In 2008, a clinical practice guideline (CPG) was developed for the prevention of infections among combat casualties and was later revised in 2011. We evaluated utilization of antimicrobials within 48 hours following injury in the combat zone over a 5-year period (June 2009 through May 2014) with regard to number of regimens, type of antimicrobial, and adherence to the 2011 CPG. The study population consisted of 5,196 wounded military personnel. Open fractures and skin and soft-tissue injuries were the most frequent injuries. Closed injuries had the highest overall compliance (83%), whereas open fractures and maxillofacial injuries had significant improvement in compliance from 2009-2010 (34 and 50%, respectively) to 2013-2014 (73 and 76%, respectively; p < 0.05). Part of the improvement with open fractures was a significant reduction of expanded Gram-negative coverage (61% received it in 2009-2010 compared to 7% in 2013-2014; p < 0.001). Use of Gram-negative coverage with maxillofacial injuries also significantly declined (37-12%; p = 0.001). Being injured during 2011-2014 compared to 2009-2010 was associated with CPG compliance (p < 0.001), while high injury severity scores (≥10) and admission to the intensive care unit in Germany were associated with noncompliance (p < 0.001). Our analysis demonstrates an increasing trend toward CPG compliance with significant reduction of expanded Gram-negative coverage.

Early Infections Complicating the Care of Combat Casualties from Iraq and Afghanistan

BACKGROUND

During the conflicts in Iraq and Afghanistan, more than 52,000 U.S. military members were wounded in action. The battlefield mortality rate was lower than in past conflicts, however, those surviving often had complex soft tissue and bone injuries requiring multiple surgeries. This report describes the rates, types, and risks of infections complicating the care of combat casualties.

PATIENTS AND METHODS

Infection and microbiology data obtained from the Trauma Infectious Disease Outcomes Study (TIDOS), a prospective observational study of infections complicating deployment-related injuries, were used to determine the proportion of infection, types, and associated organisms. Injury and surgical information were collected from the Department of Defense Trauma Registry. Multivariable Cox proportional hazards and logistic regression models were used to evaluate potential factors associated with infection.

RESULTS

From 2009-2012, 1,807 combat casualties were evacuated to U.S. TIDOS-participating hospitals. Among the 1,807 patients, the proportion of overall infections from time of injury through initial U.S. hospitalization was 34% with half being skin, soft tissue, or bone infections. Infected wounds most commonly grew Enterococcus faecium, Pseudomonas aeruginosa, Acinetobacter spp. or Escherichia coli. In the multivariable model, amputation, blood transfusions, intensive care unit admission, injury severity scores, mechanical ventilation, and mechanism of injury were associated with risk of infection.

CONCLUSIONS

One-third of combat casualties from Iraq and Afghanistan develop infections during their initial hospitalization. Amputations, blood transfusions, and overall injury severity are associated with risk of infection, whereas more easily modifiable factors such as early operative intervention or antibiotic administration are not.

Association of Enterococcus spp. with Severe Combat Extremity Injury, Intensive Care, and Polymicrobial Wound Infection

BACKGROUND

Combat-related extremity wound infections can complicate the recovery of injured military personnel. The Enterococcus genus contains both commensal and pathogenic bacteria found in many combat wounds. We describe the patient population susceptible to Enterococcus infection, the characteristics of Enterococcus spp. isolated from combat-related wounds, and the microbiological profile of Enterococcus-positive wounds.

METHODS

Patient and culture data were obtained from the Trauma Infectious Disease Outcomes Study. Subjects were divided into a case group with enterococcal extremity wound infections and a comparator group with wound infections caused by other micro-organisms.

RESULTS

Case and comparator subjects had similar patterns of injury and infection. Case subjects had higher Injury Severity Scores (33 vs. 30; p < 0.001), longer hospitalization at U.S. facilities (55 vs. 40 days; p = 0.004), and required more large-volume blood transfusions (>20 units) within 24 h post-injury (53% vs. 30%; p < 0.001). Approximately 60% of case subjects had three or more infections, and 91% had one or more polymicrobial infections, compared with 43% and 50%, respectively, in the comparator group. The thigh was the most common site of Enterococcus spp. isolation, contributing 50% of isolates. Enterococcus faecium was the predominant species isolated from case-group infections overall (66%), as well as in polymicrobial infections (74%). Frequent co-colonizing microbes in polymicrobial wound infections with Enterococcus were other ESKAPE pathogens (64%) (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae [and Escherichia coli], Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) and fungi (35%).

CONCLUSIONS

The specific pathogenicity of Enterococcus relative to other pathogens in polymicrobial wounds is unknown. Identifying strain-specific outcomes and investigating the interactions of Enterococcus strains with other wound pathogens could provide additional tools and strategies for infection mitigation in combat-related wounds.

Early infectious outcomes after addition of fluoroquinolone or aminoglycoside to posttrauma antibiotic prophylaxis in combat-related open fracture injuries

BACKGROUND

We examined combat-related open extremity fracture infections as a function of whether posttrauma antimicrobial prophylaxis included expanded Gram-negative (EGN) coverage.

METHODS

Military personnel with open extremity fractures sustained in Iraq and Afghanistan (2009-2014) who transferred to participating hospitals in the United States were assessed. The analysis was restricted to patients with a U.S. hospitalization period of ≥7 days. Prophylaxis was classified as narrow (e.g., IV cefazolin, clindamycin, and/or amoxicillin-clavulanate) or EGN, if the prophylactic regimen included fluoroquinolones and/or aminoglycosides.

RESULTS

The study population included 1,044 patients, of which 585 (56%) and 459 (44%) received narrow and EGN coverage, respectively (p < 0.001). Skin and soft-tissue infections (SSTIs) were more common among patients who received narrow prophylaxis compared to EGN coverage (28% vs. 22%; p = 0.029), whereas osteomyelitis rates were comparable between regimens (8%). Similar findings were noted when endpoints were measured at 2 and 4 weeks postinjury. There was no significant difference related to length of hospitalization between narrow and EGN regimens (median: 34 and 32 days, respectively) or operating room visits (median: 5 and 4). A higher proportion of EGN coverage patients had Gram-negative organisms isolated that were not susceptible to fluoroquinolones and/or aminoglycosides (49% vs. 40%; p < 0.001). In a Cox proportional model, narrow prophylaxis was independently associated with an increased risk of extremity SSTIs (hazard ratio: 1.41; 95% confidence interval: 1.09-1.83).

DISCUSSION

Despite seeing a small benefit with EGN coverage related to a reduction of SSTIs, it does not decrease the risk of osteomyelitis, and there seems to be a cost of increased antibiotic resistance associated with use. Overall, our findings support the current post-combat trauma antibiotic prophylaxis guidelines, which recommend the use of cefazolin or clindamycin with open fractures.

LEVEL OF EVIDENCE

Prognostic/Epidemiological, Level II; Therapy, level IV.

Impact of Operational Theater on Combat and Noncombat Trauma-Related Infections

The Trauma Infectious Disease Outcomes Study began in June 2009 as combat operations were decreasing in Iraq and increasing in Afghanistan. Our analysis examines the rate of infections of wounded U.S. military personnel from operational theaters in Iraq and Afghanistan admitted to Landstuhl Regional Medical Center between June 2009 and December 2013 and transferred to a participating U.S. hospital. Infection risk factors were examined in a multivariate logistic regression analysis (expressed as odds ratios [OR]; 95% confidence intervals [CI]). The study population includes 524 wounded military personnel from Iraq and 4,766 from Afghanistan. The proportion of patients with at least one infection was 28% and 34% from the Iraq and Afghanistan theaters, respectively. The incidence density rate was 2.0 (per 100 person-days) for Iraq and 2.7 infections for Afghanistan. Independent risk factors included large-volume blood product transfusions (OR: 10.68; CI: 6.73-16.95), high Injury Severity Score (OR: 2.48; CI: 1.81-3.41), and improvised explosive device injury mechanism (OR: 1.84; CI: 1.35-2.49). Operational theater (OR: 1.32; CI: 0.87-1.99) was not a risk factor. The difference in infection rates between operational theaters is primarily a result of increased injury severity in Afghanistan from a higher proportion of blast-related trauma during the study period.

Major scientific lessons learned in the trauma field over the last two decades

John B Holcomb summarizes recent conceptual and practical advances in trauma care, in both military and civilian settings, and presents directions for future research.

[A new concept of organization and scope of neurosurgical care in the US army during armed conflicts in the early 2000s]

Military operations in various parts of the world in the early 2000s are becoming more regionalized; new warfare tactics emerge, which makes it necessary to review and modify the neurosurgical care system. The article reviews the results of original studies on this issue and summarizes the experience of the US Army medical service in Afghanistan and Iraq. The article discusses the structure of sanitary losses, organization and scope of medical and evacuation neurosurgical measures, types and techniques of surgical interventions, and the rate of complications. We describe five levels of neurosurgical care echelons and an implemented "injury control - neurosurgery" concept; particular attention is paid to the peculiarities of research and specialist training. We demonstrate that implementation of the new concept for organization and scope of neurosurgical care has improved treatment outcomes and reduced the mortality rate in the mentioned military conflicts of recent years compared to those in the Vietnam War. We may conclude that the described experience of the US Army can be used to improve the efficacy of neurosurgical care to the wounded and victims of armed conflicts.

Incidence, risk factors, and mortality associated with acute respiratory distress syndrome in combat casualty care

BACKGROUND

The overall incidence and mortality of acute respiratory distress syndrome (ARDS) in civilian trauma settings have decreased over the past four decades; however, the epidemiology and impact of ARDS on modern combat casualty care are unknown. We sought to determine the incidence, risk factors, resource utilization, and mortality associated with ARDS in current combat casualty care.

METHODS

This was a retrospective review of mechanically ventilated US combat casualties within the Department of Defense Trauma Registry (formerly the Joint Theater Trauma Registry) during Operation Iraqi Freedom/Enduring Freedom (October 2001 to August 2008) for ARDS development, resource utilization, and mortality.

RESULTS

Of 18,329 US Department of Defense Trauma Registry encounters, 4,679 (25.5%) required mechanical ventilation; ARDS was identified in 156 encounters (3.3%). On multivariate logistic regression, ARDS was independently associated with female sex (odds ratio [OR], 2.62; 95% confidence interval [CI], 1.21-5.71; p = 0.02), higher military-specific Injury Severity Score (Mil ISS) (OR, 4.18; 95% CI, 2.61-6.71; p < 0.001 for Mil ISS ≥25 vs. <15), hypotension (admission systolic blood pressure <90 vs. ≥90 mm Hg; OR, 1.76; 95% CI, 1.07-2.88; p = 0.03), and tachycardia (admission heart rate ≥90 vs. <90 beats per minute; OR, 1.53; 95% CI, 1.06-2.22; p = 0.02). Explosion injury was not associated with increased risk of ARDS. Critical care resource utilization was significantly higher in ARDS patients as was all-cause hospital mortality (ARDS vs. no ARDS, 12.8% vs. 5.9%; p = 0.002). After adjustment for age, sex, injury severity, injury mechanism, Mil ISS, hypotension, tachycardia, and admission Glasgow Coma Scale score, ARDS remained an independent risk factor for death (OR, 1.99; 95% CI, 1.12-3.52; p = 0.02).

CONCLUSIONS

In this large cohort of modern combat casualties, ARDS risk factors included female sex, higher injury severity, hypotension, and tachycardia, but not explosion injury. Patients with ARDS also required more medical resources and were at greater risk of death compared with patients without ARDS. Thus, ARDS remains a significant complication in current combat casualty care.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level III.

The Military Orthopedic Trauma Registry: The potential of a specialty specific process improvement tool

BACKGROUND

The Military Orthopaedic Trauma Registry (MOTR) was designed to replicate the Department of Defense Trauma Registry's (DoDTR's) role as pillar for data-driven management of extremity war wounds. The MOTR continuously undergoes quality assurance checks to optimize the registry data for future quality improvement efforts. We conducted a quality assurance survey of MOTR entrants to determine if a simple MOTR data pull could provide robust orthopedic-specific information toward the question of causes for late amputation.

METHODS

Forty-five entrants into the DoDTR with late transtibial amputation were sequentially abstracted into MOTR by MOTR data abstractors. The MOTR record was then examined by an independent reviewer for three data fields pertaining to the events leading up to the late amputation: injury before limb amputation, complications before and after amputation, and complication or other factor directly contributing to the decision for amputation.

RESULTS

Thirty-nine subjects had at least one fracture of the tibial diaphysis, tibial pilon, calcaneus, or multiple foot fractures. Twenty-nine fractures were described as open injuries for which 27 included a Gustilo and Anderson classification in the available data fields. Complications could be identified along the treatment course for 43 of the 45 entrants specific to the amputated limb. A directly contributing factor to late amputation was identified in 36 (80%) of the subjects. Infection, either alone or associated with fracture nonunion, was a contributing factor in 46% of late amputations. Wound infection was the most common complication both before and after the amputation.

CONCLUSION

The MOTR, using a simple data extraction from a few registry fields, can provide a robust amount of information that can direct process and care improvement for severely injured limbs by providing the level of detail pertinent to an orthopedic surgeon.

LEVEL OF EVIDENCE

Prognostic/epidemiological study, level IV.

Multi-Drug-Resistant Gram-Negative Infections in Deployment-Related Trauma Patients

BACKGROUND

The contribution of multi-drug-resistant gram-negative bacilli infections (MDRGN-I) in patients with trauma is not well described. We present characteristics of MDRGN-Is among military personnel with deployment-related trauma (2009-2014).

PATIENTS AND METHODS

Data from the Trauma Infectious Disease Outcomes Study were assessed for infectious outcomes and microbial recovery. Infections were classified using standardized definitions. Gram-negative bacilli were defined as multi-drug-resistant if they showed resistance to ≥3 antibiotic classes or were producers of extended-spectrum β-lactamase or carbapenemases.

RESULTS

Among 2,699 patients admitted to participating U.S. hospitals, 913 (33.8%) experienced ≥1 infection event, of which 245 (26.8%) had a MDRGN-I. There were 543 MDRGN-I events (24.6% of unique 2,210 infections) with Escherichia coli (48.3%), Acinetobacter spp. (38.6%), and Klebsiella pneumoniae (8.4%) as the most common MDRGN isolates. Incidence of MDRGN-I was 9.1% (95% confidence interval [CI]: 8.0-10.2). Median time to MDRGN-I event was seven days with 75% occurring within 13 days post-trauma. Patients with MDRGN-Is had a greater proportion of blast injuries (84.1% vs. 62.5%; p < 0.0001), traumatic amputations (57.5% vs. 16.3%; p < 0.0001), and higher injury severity (82.0% had injury severity score ≥25 vs. 33.7%; p < 0.0001) compared with patients with either no infections or non-MDRGN-Is. Furthermore, MDRGN-I patients were more frequently admitted to the intensive care unit (90.5% vs. 48.5%; p < 0.0001), colonized with a MDRGN before infection (58.0% vs. 14.7%; p < 0.0001), and required mechanical ventilation (78.0% vs. 28.8% p < 0.0001). Antibiotic exposure before the MDRGN-I event was significantly higher across antibiotic classes except first generation cephalosporins and tetracyclines, which were very commonly used with all patients. Regarding outcomes, patients with MDRGN-Is had a longer length of hospitalization than the comparator group (53 vs. 18 days; p < 0.0001).

CONCLUSIONS

We found a high rate of MDRGN-I in our population characterized by longer hospitalization and greater injury severity. These findings inform treatment and infection control decisions in the trauma patient population.