Infectious complications of combat-related mangled extremity injuries in the British military

Systematic review of the microbiology of osteomyelitis associated with war injuries in the Middle East and North Africa

Osteomyelitis is a serious complication associated with war-related limb injuries requiring complicated treatment regimens and management. Few reports have been published from the Middle-East and North-Africa regions about the microbial aetiology of osteomyelitis caused by war injuries. The aim of this review is to collect published data about the microbiology of osteomyelitis in war-related injuries in the region and to derive targeted treatment regimens to manage these serious and limb-threatening infections. A thorough literature search was done using six search engines for pertinent articles. Articles with a minimum of five cases of osteomyelitis from war wounds, citation of microbial aetiology and mention of the timing of cultures obtained in relation to injury were included. Nine studies that met the eligibility criteria were included, involving 1644 patients and a total of 2332 cultures. Gram-negative bacteria were isolated from 1184 cultures, and Gram-positive bacteria were identified from 1148 cultures. Antibiotic coverage should be tailored for Gram-negative organisms in the early stages and Gram-positives in the chronic phase, respectively, with broader coverage reserved for critically ill patients. There is a dire need for further and larger studies about osteomyelitis from war injuries for targeted treatment.

Preclinical evaluation of a commercially available biofilm disrupting wound lavage for musculoskeletal trauma

BACKGROUND

Treatment of open fractures remains a significant challenge in trauma care as these fractures are accompanied by extensive soft tissue damage, exposing the wound site to contaminants and increasing infection risk. Formation of biofilm, a capsule-like environment that acts as a barrier to treatment, is a primary mode by which infecting pathogens persist at the wound site. Therefore, a pressing need exists to identify irrigation methods that can disrupt biofilm and expose pathogens to treatment. This study aims to evaluate the antibiofilm wound lavage, Bactisure™, in comparison with saline for care of severe musculoskeletal wounds and elucidate potential effects on antibiotic treatment success.

METHODS

UAMS-1 Staphylococcus aureus biofilms were formed in vitro and treated with Bactisure™ wound lavage or sterile normal saline, alone, or in combination with sub-biofilm inhibitory levels of vancomycin. Characterization methods included quantification of biofilm biomass, quantification of viable biofilm bacteria, and biofilm matrix imaging. For in vivo assessment, a delayed treatment model of contaminated open fracture was used wherein a critical-sized defect was created in a rat femur and wound site inoculated with UAMS-1. Following a 6 h delay, wounds were debrided, irrigated with lavage of interest, and antibiotic treatments administered. Bacterial enumeration was performed on bone and hardware samples after two weeks.

RESULTS

An immediate reduction in biofilm biomass was observed in vitro following antibiofilm lavage treatment, with a subsequent 2- to 3- log reduction in viable bacteria achieved after 24 h. Furthermore, biofilms treated with antibiofilm lavage in combination with vancomycin exhibited a minor, but statistically significant, decrease in viable bacteria compared to irrigation alone. In vivo, a minor, not statistically significant, decrease in median bioburden was observed for the antibiofilm lavage compared to saline when used in combination with antibiotics. However, the percentage of bone and hardware samples with detectable bacteria was reduced from 50 to 38%.

CONCLUSIONS

These results suggest that the antibiofilm wound lavage, Bactisure™, may hold promise in mitigating infection in contaminated musculoskeletal wounds and warrants further investigation. Here, we proposed multiple mechanisms in vitro by which this antibiofilm lavage may help mitigate infection, and demonstrate this treatment slightly outperforms saline in controlling bioburden in vivo.

Rapid, label-free pathogen identification system for multidrug-resistant bacterial wound infection detection on military members in the battlefield

US military service members experiencing combat-related wounds have higher risk of infection by multidrug-resistant bacteria. The gold standard culture-based antimicrobial susceptibility testing (AST) is not feasible in the battlefield environment. Thus, a rapid deployable system for bacteria identification and AST directly from wound sample is urgently needed. We report the potential of a Rapid, Label-free Pathogen Identification (RAPID) diagnostic system based on ATR-FTIR method to detect and distinguish multi-drug resistant strains for six different species in the ESKAPEE group. Our RAPID system combines sample processing on-broad to isolate and enrich bacteria cells from wound sample, ATR-FTIR measurement to detect antimicrobial-induced bacterial cell spectral changes, and machine learning model for automated, objective, and quantitative spectral analysis and unknown sample classification. Based on experimental results, our RAPID system is a promising technology for label-free, sensitive (104 cfu/mL from mixture), species-specific (> 95% accuracy), rapid (< 10 min for identification, ~ 4 hours for AST) bacteria detection directly from wound samples.

Prehospital Tourniquets in Civilians: A Systematic Review

OBJECTIVES

Terrorist attacks and civilian mass-casualty events are frequent, and some countries have implemented tourniquet use for uncontrollable extremity bleeding in civilian settings. The aim of this study was to summarize current knowledge on the use of prehospital tourniquets to assess whether their use increases the survival rate in civilian patients with life-threatening hemorrhages from the extremities.

DESIGN

Systematic literature review in Medline (Ovid), Embase (Ovid), Cochrane Library, and Epistemonikos was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guidelines. The search was performed in January 2019.

SETTING

All types of studies that examined use of tourniquets in a prehospital setting published after January 1, 2000 were included.

PRIMARY/SECONDARY OUTCOMES

The primary outcome was mortality with and without tourniquet, while adverse effects of tourniquet use were secondary outcomes.

RESULTS

Among 3,460 screened records, 55 studies were identified as relevant. The studies were highly heterogeneous with low quality of evidence. Most studies reported increased survival in the tourniquet group, but few had relevant comparators, and the survival benefit was difficult to estimate. Most studies reported a reduced need for blood transfusion, with few and mainly transient adverse effects from tourniquet use.

CONCLUSION

Despite relatively low evidence, the studies consistently suggested that the use of commercial tourniquets in a civilian setting to control life-threatening extremity hemorrhage seemed to be associated with improved survival, reduced need for blood transfusion, and few and transient adverse effects.

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.

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

OBJECTIVE

To determine risk factors for osteomyelitis in US military personnel with combat-related, extremity long bone (humerus, radius, and ulna) open fractures.

DESIGN

Retrospective observational case-control study.

SETTING

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

PATIENTS/PARTICIPANTS

Sixty-four patients with open upper extremity fractures who met diagnostic osteomyelitis criteria (medical record review verification) were classified as cases. Ninety-six patients with open upper extremity fractures who did not meet osteomyelitis diagnostic criteria were included as controls.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASUREMENTS

Multivariable odds ratios (ORs; 95% confidence interval [CI]).

RESULTS

Among patients with surgical implants, osteomyelitis cases had longer time to definitive orthopaedic surgery compared with controls (median: 26 vs. 11 days; P < 0.001); however, there was no significant difference with timing of radiographic union. Being injured between 2003 and 2006, use of antibiotic beads, Gustilo-Anderson [GA] fracture classification (highest with GA-IIIb: [OR: 22.20; CI: 3.60-136.95]), and Orthopaedic Trauma Association Open Fracture Classification skin variable (highest with extensive degloving [OR: 15.61; CI: 3.25-74.86]) were independently associated with osteomyelitis risk. Initial stabilization occurring outside of the combat zone was associated with reduced risk of osteomyelitis.

CONCLUSIONS

Open upper extremity fractures with severe soft-tissue damage have the highest risk of developing osteomyelitis. The associations with injuries sustained 2003-2006 and location of initial stabilization are likely from evolving trauma system recommendations and practice patterns during the timeframe.

LEVEL OF EVIDENCE

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

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.

The Israeli Defense Forces Point of Injury Antimicrobial Treatment Protocol - A New Protocol and Review of the Literature

INTRODUCTION

Combat wound infection is a common and serious complication, leading to significant morbidity and mortality. In 2005, a point of injury antimicrobial protocol was published by the Israel Defense Forces, in which Moxifloxacin was chosen. During 2016-2017, a revision of this protocol was performed and concluded with the publication of an updated protocol. The purpose of this report is to present this process and the revised protocol, together with a review of the literature.

METHODS

We searched "Medline" and "Google Scholar" for studies dealing with antimicrobial prophylaxis in trauma, for militaries' point of injury antimicrobial protocol protocols and for established surgical antimicrobial prophylaxis protocols.

RESULTS

Point of injury antimicrobial protocol is aimed at preventing early infection and its complications. The choice of Moxifloxacin for this purpose may not be optimal since Moxifloxacin spectrum might be overly broad, there is scant evidence supporting it for this indication, and the available preparation does not meet distinctive technical requirements. Contrarily, Ceftriaxone seemed to have suitable microbiological, pharmacological and technical features.

CONCLUSION

Point of injury antimicrobial protocol should be used especially when evacuation and definitive surgical treatment are delayed. According to present scientific data and operational needs, Ceftriaxone was chosen for most penetrating injuries, with Metronidazole addition for penetrating abdominal and cranial trauma.

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.

Value of antigranulocyte scintigraphy with Tc-99m-sulesomab in diagnosing combat-related infections of the musculoskeletal system

AIM

Combat-related extremity injuries are regularly associated with long-term complications such as chronic infection, especially osteomyelitis. Clinical examination and laboratory parameters do not usually allow reliable diagnosis. In contrast, imaging techniques enable constructive assertions to be made about the location and extent of an infection of the peripheral musculoskeletal system. The aim of this study was therefore to determine the diagnostic reliability of three-phase bone scanning and antigranulocyte scintigraphy using Tc-99m-sulesomab (Leukoscan) in the diagnostic clarification of infections associated with combat-related extremity injuries.

METHODS

Twenty-seven male patients (mean age 33.9 years) with suspected combat-associated infections of the extremities were included in this retrospective analysis. All patients underwent three-phase bone scanning using Tc-99m-HDP followed by antigranulocyte scintigraphy with Tc-99m-sulesomab. In 26 of the 27 patients, a CT scan of affected limb was obtained, where the secondary fusion with single photon emission CT data set was possible. The diagnostic reliability of imaging techniques was validated against microbiological samples obtained during surgery and used as gold standard.

RESULTS

Three-phase bone scanning yielded a positive result in all patients, with 18 scans classified as true positive (TP) and nine scans as false positive (FP). This produced a sensitivity of 100%, a specificity of 0% and a positive predictive value (PPV) of 67%. Antigranulocyte scintigraphy recognised 13 patients as TP, 1 patient as FP, 8 patients as true negative (TN) and 5 patients as false negative (FN), which gave a sensitivity of 72%, a specificity of 88%, a PPV of 93%, a negative predictive value (NPV) of 62% and an accuracy of 78%. CT recognised in 7 cases a TP result, in 3 cases an FP, in 5 cases a TN and in 11 cases an FN result. This produced a sensitivity of 39%, a specificity of 63%, a PPV of 70%, an NPV of 31% and an accuracy of 46%.

CONCLUSIONS

Three-phase bone scanning did not deliver any diagnostic benefit, since no result was able to differentiate unequivocally between infection-related and reactive changes. Antigranulocyte scintigraphy using Tc-99m-sulesomab represented a highly suitable technique for diagnostically clarifying combat-related infections of the extremities. It is superior to CT in sensitivity, specificity, PPV, NPV and accuracy.

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.

For debate: on-the-person battlefield antibiotics

Wound infection has always been an important contributor to mortality and morbidity on the battlefield. On-the-person antibiotics have long been suggested as one way to help combat this, which have already been implemented by some North Atlantic Treaty Organization partners. This paper is an up-to-date review of the evidence of the efficacy of on-the-person antibiotics and whether the British military should look to use them in the near future.

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

OBJECTIVES

We assessed osteomyelitis risk factors in US military personnel with combat-related open tibia fractures (2003-2009).

METHODS

Patients with open tibia fractures who met the diagnostic criteria of osteomyelitis were identified as cases using Military Health System data and verified through medical record review. Controls were patients with open tibia fractures who did not meet osteomyelitis criteria. The Gustilo-Andersen fracture classification scheme was modified to include transtibial amputations (TTAs) as the most severe level. Logistic regression multivariable odds ratios [ORs; 95% confidence intervals (CI)] were assessed.

RESULTS

A total of 130 tibia osteomyelitis cases and 85 controls were identified. Excluding patients with TTAs, osteomyelitis cases had significantly longer time to radiographic union compared with controls (median: 210 vs. 165 days). Blast injuries, antibiotic bead utilization, ≥ Gustilo-Andersen-IIIb fractures [highest risk with TTA (OR: 15.10; CI: 3.22-71.07)], and foreign body at the fracture site were significantly associated with developing osteomyelitis. In a separate model, the Orthopaedic Trauma Association Open Fracture Classification muscle variable was significant with increasing risk from muscle loss (OR: 5.62; CI: 2.21-14.25) to dead muscle (OR: 8.46; CI: 3.31-21.64). When TTAs were excluded, significant risk factors were similar and included sustaining an injury between 2003 and 2006.

CONCLUSIONS

Patients with severe blast trauma resulting in significant muscle damage are at the highest risk for osteomyelitis. The period association coincides with a time frame when several trauma system practice changes were initiated (eg, increased negative pressure wound therapy, decreased high-pressure irrigation, and reduced crystalloid use).

LEVEL OF EVIDENCE

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

Microbiology of French military casualties repatriated from overseas for an open traumatic injury

BACKGROUND

This study aimed to describe the microbiological epidemiology of repatriated French soldiers with an open traumatic injury, and to measure the proportion of multidrug-resistant bacteria (MDRB).

METHODS

Retrospective study including all French soldiers repatriated in 2011 and 2012 in Parisian military hospitals for open traumatic injury. Results of clinical samples and MDRB screening were collected. The antibiotic susceptibility was assessed using the agar disk diffusion method. Characterization of resistance mechanisms was performed using PCR. Genotyping of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) isolates was performed using rep-PCR.

RESULTS

A total of 139 patients were included; 70% of them were repatriated from Afghanistan. At admission, 24/88 were positive for MDRB (28%), mainly ESBL-E but no carbapenemase-producing Enterobacteriaceae and vancomycin-resistant Enterococcus faecium were identified. Forty-five patients had lesion sample collection, and 28/45 had a positive culture. The most frequently isolated pathogens were Enterobacter cloacae, Pseudomonas aeruginosa, and Escherichia coli. For eight patients, a MDRB was isolated from the wound, mainly ESBL-E (7/8) but also one methicillin-resistant Staphylococcus aureus and one imipenem-resistant Acinetobacter baumannii. Among ESBL-E, the PCR evidenced the high prevalence of CTX-M15 enzymes. Rep-PCR performed on the 23 ESBL-producing E. coli isolates highlighted numerous profiles.

CONCLUSIONS

Controlling the spread of ESBL-E is currently challenging for French Armed Forces. Despite any evidence of an epidemic clone, a high-level compliance with hygiene precautions is required throughout the chain of care to avoid cross contamination.

Bleeding Control With Limb Tourniquet Use in the Wilderness Setting: Review of Science

The purpose of this review is to summarize tourniquet science for possible translation to wilderness settings. Much combat casualty data has been studied since 2005, and use of tourniquets in the military has changed from a last resort to first aid. The US Government has made use of tourniquets a health policy aimed to improve public access to bleeding control items. International authorities believe that education in first aid should be universal, as all can and should learn first aid. The safety record of tourniquet use is mixed, but users are reliably safe if trained well. Well-designed tourniquets can reliably attain bleeding control, may mitigate risk of shock progression, and may improve survival rates, but conclusive proof of a survival benefit remains unclear in civilian settings. Even a war setting has a bias toward survivorship by sampling mostly survivors in hospitals. Improvised tourniquets are less reliable than well-designed tourniquets but may be better than none. The tourniquet model used most often in 2016 by the US military is the Combat Application Tourniquet (C-A-T), and civilians use an array of various models, including C-A-T. Evidence on tourniquet use to date indicates that most uses are safe and effective in civilian settings. Future directions for study relevant to the wilderness setting include consideration of research priorities, study of the burdens of injury or capability gaps in caregiving for various wilderness settings, determination of the skill needs of outdoor enthusiasts and wilderness caregivers, and survey of wilderness medicine stewards regarding bleeding control.

Field Wound Care: Prophylactic Antibiotics

Adequate management of wounds requires numerous interventions, one of which is the appropriate use of antimicrobials to attempt to minimize the risk of excess morbidity or mortality without increasing toxicity or multidrug resistant bacterial acquisition. There are numerous recommendations and opinions for not only the use of systemic prophylactic antimicrobials, but also the agent, dose, route, and duration. To best address the implementation of systemic antimicrobials in a field scenario, one must weigh the factors that go into that decision and then determine the best agents possible. The epidemiologic triangle (ie, the host, the agent, and the environment) forms the basis for selecting the correct prophylactic antibiotic for field wound care. Extreme conditions can be encountered in both military and nonmilitary systems, requiring a unique selection process to make the right antibiotic choice. A modifiable weighted matrix, recommended previously for point of injury combat casualty care, assists in selecting the best oral and intravenous/intramuscular agent based on the epidemiologic risk determination.

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.

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.

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.

Molecular Epidemiology of Carbapenem-Resistant Acinetobacter Baumannii Complex Isolates from Patients that were Injured During the Eastern Ukrainian Conflict

This study addressed carbapenem-resistant Acinetobacter baumannii complex (ABC) isolates from patients that were injured during the military conflict in the Eastern Ukraine and treated at German Armed Forces Hospitals in 2014 and 2015. Clonal diversity of the strains and potential ways of transmission were analyzed.

Patients with one or several isolation events of carbapenem-resistant ABC were included. Isolates were characterized by VITEK II-based identification and resistance testing, molecular screening for frequent carbapenemase genes, and DiversiLab rep-PCR-based typing. Available clinical information of the patients was assessed.

From 21 young male Ukrainian patients with battle injuries, 32 carbapenem- and fluoroquinolone-resistant ABC strains were isolated. Four major clonal clusters were detected. From four patients (19%), ABC isolates from more than one clonal cluster were isolated. The composition of the clusters suggested transmission events prior to the admission to the German hospitals.

The infection and colonization pressure in the conflict regions of the Eastern Ukraine with ABC of low clonal diversity is considerable. Respective infection risks have to be considered in case of battle-related injuries in these regions. The low number of local clones makes any molecular exclusion of transmission events difficult.

An In Vitro Comparison of PMMA and Calcium Sulfate as Carriers for the Local Delivery of Gallium(III) Nitrate to Staphylococcal Infected Surgical Sites

Antibiotic-loaded bone cements, including poly(methyl methacrylate) (PMMA) and calcium sulfate (CaSO₄), are often used for treatment of orthopaedic infections involving Staphylococcus spp., although the effectiveness of this treatment modality may be limited due to the emergence of antimicrobial resistance and/or the development of biofilms within surgical sites. Gallium(III) is an iron analog capable of inhibiting essential iron-dependent pathways, exerting broad antimicrobial activity against multiple microorganisms, including Staphylococcus spp. Herein, we evaluated PMMA and CaSO₄ as carriers for delivery of gallium(III) nitrate (Ga(NO₃)₃) to infected surgical sites by assessing the release kinetics subsequent to incorporation and antimicrobial activity against S. aureus and S. epidermidis. PMMA and to a lesser extent CaSO₄ were observed to be compatible as carriers for Ga(NO₃)₃, eluting concentrations with antimicrobial activity against planktonic bacteria, inhibiting bacterial growth, and preventing bacterial colonization of beads, and effective against established bacterial biofilms of S. aureus and S. epidermidis. Collectively, our in vitro results indicate that PMMA is a more suitable carrier compared to CaSO₄ for delivery of Ga(NO₃)₃; moreover they provide evidence for the potential use of Ga(NO₃)₃ with PMMA as a strategy for the prevention and/or treatment for orthopaedic infections.

Rifamycin Derivatives Are Effective Against Staphylococcal Biofilms In Vitro and Elutable From PMMA

BACKGROUND

Local antimicrobial delivery through polymethylmethacrylate beads (PMMA), commonly vancomycin, is used for the treatment of contaminated open fractures but has limited activity against Staphylococcus aureus biofilms, which occur commonly in such fractures. Rifamycins have activity against biofilms and are an effective treatment for osteoarticular infections involving staphylococcal biofilms, but there are limited studies evaluating the activity of rifamycin derivatives, other than rifampin, against biofilms of S. aureus and evaluating incorporation of these drugs into PMMA for treatment of contaminated open fractures.

QUESTIONS/PURPOSES

(1) Are rifamycin derivatives effective against established biofilms of clinical isolates of S. aureus? (2) Can PMMA be used as a carrier for rifamycin derivatives?

METHODS

Biofilms were developed and evaluated for susceptibility to a panel of antimicrobials in vitro using the minimum biofilm eradication concentration high-throughput model. Susceptibility was assessed by measuring bacterial recovery at 6 and 24 hours after antimicrobial treatment. Activity of rifamycin derivatives against intracellular bacteria was also evaluated using a gentamicin protection assay. Evaluation of PMMA as a carrier for rifampin and rifamycin derivatives was determined by assessing the curing time subsequent to loading of rifamycins and characterizing the release kinetics of rifamycins at daily intervals for 14 days from PMMA by performing bioassays.

RESULTS

Rifamycin derivatives between 1 and 8 µg/mL reduced bacteria within biofilms 5- to 9-logs and prevented bacterial recovery up to 24 hours post-treatment, indicating near to complete eradication of biofilms. Rifamycin derivatives at 32 µg/mL had activity against intracellular staphylococci, significantly reducing the number of internalized bacteria with limited effects on osteoblast viability. Rifampin was the only rifamycin observed to have a suitable release profile from PMMA, releasing 49% of the total antibiotic and maintaining a sustained released profile up to 14 days at a mean 28 ± 6 μg/mL.

CONCLUSIONS

Rifampin can be incorporated into PMMA and eluted at concentrations effective against biofilms and intracellular staphylococci.

CLINICAL RELEVANCE

Our in vitro findings suggest that local delivery of rifampin may be an effective strategy for the prevention and/or treatment of open fractures where S. aureus biofilms might develop. Clinical studies are needed to characterize what role this approach might have in the prevention and treatment of infections involving biofilms.

Late amputation may not reduce complications or improve mental health in combat-related, lower extremity limb salvage patients

INTRODUCTION

Following severe lower extremity trauma, patients who undergo limb reconstruction and amputations both endure frequent complications and mental health sequelae. The purpose of this study is to assess the extent to which late amputation following a period of limb salvage impacts the evolution of the clinical variables that can affect the patient's perception of his or her limb: ongoing limb associated complications and mental health conditions.

PATIENTS AND METHODS

A case series of US service members who sustained a late major extremity amputation from September 2001 through July 2011 were analysed. Pre- and post-amputation complications, mental health conditions, and reason(s) for desiring amputation were recorded.

RESULTS

Forty-four amputees with detailed demographic, injury and treatment data were identified. The most common reasons for desiring a late amputation were pain and being dissatisfied with the function of the salvage limb. An average of 3.2 (range 1-10) complications were reported per amputee prior to undergoing late amputation and an average of 1.8 (range 0-5) complications reported afterwards. The most common complication prior to and after late amputation was soft tissue infection (24 (17%) and 9 (22%), respectively). Twenty-nine (64%) late amputees were diagnosed with a mental health condition prior to undergoing their amputation and 27 (61%) late amputees were diagnosed with mental conditions after late amputation. Only three of the 15 patients who did not have a mental health condition documented prior to their late amputation remained free of a documented mental health condition after the amputation.

DISCUSSION

Ongoing complications and mental health conditions can affect how a patient perceives and copes with his or her limb following severe trauma. Patient dissatisfaction following limb reconstruction can influence the decision to undergo a late amputation. Patients with a severe, combat related lower extremity injury that are undergoing limb salvage may not have a reduction in their overall complication rate, a resolution of specific complications or an improvement of their mental health after undergoing late amputation.

CONCLUSION

Surgeons caring for limb salvage patients should counsel appropriately when managing expectations for a patient who desires a late amputation.

Impact of high prevalence of pseudomonas and polymicrobial gram-negative infections in major sub-/total traumatic amputations on empiric antimicrobial therapy: a retrospective study

Introduction

Emergency treatment of major sub-/total traumatic amputations continue to represent a clinical challenge due to high infection rates and serious handicaps. Effective treatment is based on two columns: surgery and antimicrobial therapy. Detailed identification of pathogen spectrum and epidemiology associated with these injuries is of tremendous importance as it guides the initial empiric antibiotic regimen and prevents adverse septic effents.

Methods

In this retrospective study 51 patients with major traumatic amputations (n = 16) and subtotal amputations (n = 35) treated from 2001 to 2010 in our trauma center were investigated. All patients received emergency surgery, debridement with microbiological testing within 6 h after admission and empircic antimicrobial therapy. Additionally to baseline patient characteristics, the incidence of positive standardized microbiologic testing combined with clinical signs of infection, pathogen spectrum, administered antimicrobial agents and clinical complications were analyzed.

Results

70.6% of the patients (n = 36) acquired wound infection. In 39% wounds were contaminated on day 1, whereas the mean length of duration until first pathogen detection was 9.1 ± 13.4 days after injury. In 37% polymicrobial colonization and 28% Pseudomonas were responsible for wound infections during hospitalization. In 45% the empirc antimicrobial therapy focussed on Gram positive strains did not cover the detected bacteria, according antimicrobial resistogram. It was significantly more often found in infections associated with Pseudomonas (p 0.02) or polymicrobial wound infections.

Conclusions

This epidemiologic study reveals a pathogen shift from Gram-positive to Gram-negative strains with high incidence of Pseudomonas and polymicrobial infections in sub-/total major traumatic amputations. Therefore, empiric antimicrobial treatment historically focussing on Gram-positive strains must be adjusted. We recommend the use of Piperacillin/Tazobactam for these injuries. As soon as possible antimicrobial treatment should be changed from empiric to goal directed therapy according to the microbiological tests and resistogram results.

Combat-Related Invasive Fungal Wound Infections

Combat-related invasive fungal (mold) wound infections (IFIs) have emerged as an important and morbid complication following explosive blast injuries among military personnel. Similar to trauma-associated IFI cases among civilian populations, as in agricultural accidents and natural disasters, these infections occur in the setting of penetrating wounds contaminated by environmental debris. Specific risk factors for combat-related IFI include dismounted (patrolling on foot) blast injuries occurring mostly in southern Afghanistan, resulting in above knee amputations requiring resuscitation with large-volume blood transfusions. Diagnosis of IFI is based upon early identification of a recurrently necrotic wound following serial debridement and tissue-based histopathology examination with special stains to detect invasive disease. Fungal culture of affected tissue also provides supportive information. Aggressive surgical debridement of affected tissue is the primary therapy. Empiric antifungal therapy should be considered when there is a strong suspicion for IFI. Both liposomal amphotericin B and voriconazole should be considered initially for treatment since many of the cases involve not only Mucorales species but also Aspergillus or Fusarium spp., with narrowing of regimen based upon clinical mycology findings.

A pre-clinical evaluation of silver, iodine and Manuka honey based dressings in a model of traumatic extremity wounds contaminated with Staphylococcus aureus

Prevention of extremity war wound infection remains a clinical challenge. Staphylococcus aureus is the most common pathogen in delayed infection. We hypothesised that choice of wound dressings may affect bacterial burden over 7 days reflecting the current practice of delayed primary closure of wounds within this timeframe. A randomised controlled trial of 3 commercially available dressings (Inadine(®) (Johnson & Johnson, NJ, USA), Acticoat(®) (Smith & Nephew, Hull, UK), Activon Tulle (Advancis Medical, Nottingham, UK)) was conducted in a rabbit model of contaminated forelimb muscle injury. A positive control group treated with antibiotics was included. Groups were compared to a saline soaked gauze control. The primary outcome was a statistically significant reduction (p < 0.05) in tissue S. aureus at 7 days post-injury. Secondary outcome measurements included bacteraemias, observational data, whole blood determination, ELISA for plasma biomarkers, PCR array analysis of wound healing gene expression and muscle/lymph node histopathology. Antibiotic, Inadine and Acticoat groups had statistically significant lower bacterial counts (mean 7.13 [95% CI 0.00-96.31]×10(2); 1.66 [0.94-2.58]×10(5); 8.86 [0.00-53.35]×10(4)cfu/g, respectively) and Activon Tulle group had significantly higher counts (2.82 [0.98-5.61]×10(6)cfu/g) than saline soaked gauze control (7.58 [1.65-17.83]×10(5)cfu/g). There were no bacteraemias or significant differences in observational data or whole blood determination. There were no significant differences in muscle/loss or pathology and lymph node cross-sectional area or morphology. There were some significant differences between treatment groups in the plasma cytokines IL-4, TNFα and MCP-1 in comparison to the control. PCR array data demonstrated more general changes in gene expression in the muscle tissue from the Activon Tulle group than the Inadine or Acticoat dressings with a limited number of genes showing significantly altered expression compared to control. This study has demonstrated that both Acticoat(®) and Inadine(®) dressings can reduce the bacteria burden in a heavily contaminated soft tissue wound and so they may offer utility in the clinical setting particularly where surgical treatment is delayed.

Prevention of combat-related infections: antimicrobial therapy in battlefield and barrier measures in French military medical treatment facilities

Infection is a major complication associated with combat-related injuries. Beside immobilization, wound irrigation, surgical debridement and delayed coverage, post-injury antimicrobials contribute to reduce combat-related infections, particularly those caused by bacteria of the early contamination flora. In modern warfare, bacteria involved in combat-related infections are mainly Gram-negative bacteria belonging to the late contamination flora. These bacteria are frequently resistant or multiresistant to antibiotics and spread through the deployed chain of care. This article exposes the principles of war wounds antimicrobial prophylaxis recommended in the French Armed Forces and highlights the need for high compliance to hygiene standard precautions, adapted contact precautions and judicious use of antibiotics in French deployed military medical treatment facilities (MTF).

The burden of infection in severely injured trauma patients and the relationship with admission shock severity

BACKGROUND

Infection following severe injury is common and has a major impact on patient outcomes. The relationship between patient, injury, and physiologic characteristics with subsequent infections is not clearly defined. The objective of this study was to characterize the drivers and burden of all-cause infection in critical care trauma patients.

METHODS

A prospective cohort study of severely injured adult patients admitted to critical care was conducted. Data were collected prospectively on patient and injury characteristics, baseline physiology, coagulation profiles, and blood product use. Patients were followed up daily for infectious episodes and other adverse outcomes while in the hospital.

RESULTS

Three hundred patients (Injury Severity Score [ISS] >15) were recruited. In 48 hours or less, 29 patients (10%) died, leaving a cohort of 271. One hundred forty-one patients (52%) developed at least one infection. Three hundred four infections were diagnosed overall. Infection and noninfection groups were matched for age, sex, mechanism, and ISS. Infection rates were greater with any degree of admission shock and threefold higher in the most severely shocked cohort (p < 0.01). In multivariate analysis, base deficit (odds ratio [OR], 1.78, 95% confidence interval [CI], 1.48-1.94; p < 0.001) and lactate (OR, 1.36; 95% CI, 1.10-1.69; p = 0.05) were independently associated with the development of infection. Outcomes were significantly worse for the patients with infection. In multivariate logistic regression, infection was the only factor independently associated with multiple-organ failure (p < 0.001; OR, 15.4; 95% CI, 8.2-28.9; r = 0.402), ventilator-free days (p < 0.001; β, -4.48; 95% CI, -6.7 to -2.1; r = 0.245), critical care length of stay (p < 0.001; β, 13.2; 95% CI, 10.0-16.4; r = 0.466), and hospital length of stay (p < 0.001; β, 31.1; 95% CI, 24.0-38.2; r = 0.492).

CONCLUSION

Infectious complications are a burden for severely injured patients and occur early in the critical care stay. Severity of admission shock was predictive of infection and represents an opportunity for interventions to improve infectious outcomes. The incidence of infection may also have utility as an end point for clinical trials in trauma hemorrhage given the relationship with patient-experienced outcomes.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level II.

Biofilms and persistent wound infections in United States military trauma patients: a case-control analysis

Background

Complex traumatic injuries sustained by military personnel, particularly when involving extremities, often result in infectious complications and substantial morbidity. One factor that may further impair patient recovery is the persistence of infections. Surface-attached microbial communities, known as biofilms, may play a role in hindering the management of infections; however, clinical data associating biofilm formation with persistent or chronic infections are lacking. Therefore, we evaluated the production of bacterial biofilms as a potential risk factor for persistent infections among wounded military personnel.

Methods

Bacterial isolates and clinical data from military personnel with deployment-related injuries were collected through the Trauma Infectious Disease Outcomes Study. The study population consisted of patients with diagnosed skin and soft-tissue infections. Cases (wounds with bacterial isolates of the same organism collected 14 days apart) were compared to controls (wounds with non-recurrent bacterial isolates), which were matched by organism and infectious disease syndrome. Potential risk factors for persistent infections, including biofilm formation, were examined in a univariate analysis. Data are expressed as odds ratios (OR; 95% confidence interval [CI]).

Results

On a per infected wound basis, 35 cases (representing 25 patients) and 69 controls (representing 60 patients) were identified. Eight patients with multiple wounds were utilized as both cases and controls. Overall, 235 bacterial isolates were tested for biofilm formation in the case–control analysis. Biofilm formation was significantly associated with infection persistence (OR: 29.49; CI: 6.24-infinity) in a univariate analysis. Multidrug resistance (OR: 5.62; CI: 1.02-56.92), packed red blood cell transfusion requirements within the first 24 hours (OR: 1.02; CI: 1.01-1.04), operating room visits prior to and on the date of infection diagnosis (OR: 2.05; CI: 1.09-4.28), anatomical location of infected wound (OR: 5.47; CI: 1.65-23.39), and occurrence of polymicrobial infections (OR: 69.71; CI: 15.39-infinity) were also significant risk factors for persistent infections.

Conclusions

We found that biofilm production by clinical strains is significantly associated with the persistence of wound infections. However, the statistical power of the analysis was limited due to the small sample size, precluding a multivariate analysis. Further data are needed to confirm biofilm formation as a risk factor for persistent wound infections.

Combat Casualty Care research programme

The Combat Casualty Care research programme is an integrated suite of projects designed to address Defence Medical Services' research needs for casualty care. The programme covers a broad spectrum of topics ranging from the pathophysiological and immunological impact of military relevant injuries to the effects of these disturbances on the response to early treatment. Dstl Porton Down has a long history of studying military injuries and has developed models, both in vivo and physical, to address the research needs. The work is conducted in close collaboration with clinical colleagues at the Royal Centre for Defence Medicine who have direct experience of the clinical issues faced by combat casualties and insights into the potential clinical implications of emerging strategies. This article reviews progress in research areas spanning forward resuscitation, with a particular focus on blast-related injuries, trauma coagulopathy, effects of drugs on the response to haemorrhage and deployed research. A significant 'value added' component has been the underpinning of higher degrees for seconded military clinicians at Dstl Porton Down who have made a valuable contribution to the overall programme.

Translational research to improve the treatment of severe extremity injuries

OBJECTIVES

Severe extremity injuries are the most significant injury sustained in combat wounds. Despite optimal clinical management, non-union and infection remain common complications. In a concerted effort to dovetail research efforts, there has been a collaboration between the UK and USA, with British military surgeons conducting translational studies under the auspices of the US Institute of Surgical Research. This paper describes 3 years of work.

METHODS

A variety of studies were conducted using, and developing, a previously validated rat femur critical-sized defect model. Timing of surgical debridement and irrigation, different types of irrigants and different means of delivery of antibiotic and growth factors for infection control and to promote bone healing were investigated.

RESULTS

Early debridement and irrigation were independently shown to reduce infection. Normal saline was the most optimal irrigant, superior to disinfectant solutions. A biodegradable gel demonstrated superior antibiotic delivery capabilities than standard polymethylmethacrylate beads. A polyurethane scaffold was shown to have the ability to deliver both antibiotics and growth factors.

DISCUSSION

The importance of early transit times to Role 3 capabilities for definitive surgical care has been underlined. Novel and superior methods of antibiotic and growth factor delivery, compared with current clinical standards of care, have been shown. There is the potential for translation to clinical studies to promote infection control and bone healing in these devastating injuries.

Staphylococcus aureus colonization of healthy military service members in the United States and Afghanistan

BACKGROUND

Staphylococcus aureus [methicillin-resistant and methicillin-susceptible (MRSA/MSSA)] is a leading cause of infections in military personnel, but there are limited data regarding baseline colonization of individuals while deployed. We conducted a pilot study to screen non-deployed and deployed healthy military service members for MRSA/MSSA colonization at various anatomic sites and assessed isolates for molecular differences.

METHODS

Colonization point-prevalence of 101 military personnel in the US and 100 in Afghanistan was determined by swabbing 7 anatomic sites. US-based individuals had received no antibiotics within 30 days, and Afghanistan-deployed personnel were taking doxycycline for malaria prophylaxis. Isolates underwent identification and testing for antimicrobial resistance, virulence factors, and pulsed-field type (PFT).

RESULTS

4 individuals in the US (4 isolates- 3 oropharynx, 1 perirectal) and 4 in Afghanistan (6 isolates- 2 oropharynx, 2 nare, 1 hand, 1 foot) were colonized with MRSA. Among US-based personnel, 3 had USA300 (1 PVL+) and 1 USA700. Among Afghanistan-based personnel, 1 had USA300 (PVL+), 1 USA800 and 2 USA1000. MSSA was present in 40 (71 isolates-25 oropharynx, 15 nare) of the US-based and 32 (65 isolates- 16 oropharynx, 24 nare) of the Afghanistan-based individuals. 56 (79%) US and 41(63%) Afghanistan-based individuals had MSSA isolates recovered from extra-nare sites. The most common MSSA PFTs were USA200 (9 isolates) in the US and USA800 (7 isolates) in Afghanistan. MRSA/MSSA isolates were susceptible to doxycycline in all but 3 personnel (1 US, 2 Afghanistan; all were MSSA isolates that carried tetM).

CONCLUSION

MRSA and MSSA colonization of military personnel was not associated with deployment status or doxycycline exposure. Higher S. aureus oropharynx colonization rates were observed and may warrant changes in decolonization practices.

The Human Cathelicidin Antimicrobial Peptide LL-37 as a Potential Treatment for Polymicrobial Infected Wounds

Diabetic patients often have ulcers on their lower-limbs that are infected by multiple biofilm-forming genera of bacteria, and the elimination of the biofilm has proven highly successful in resolving such wounds in patients. To that end, antimicrobial peptides have shown potential as a new anti-biofilm approach. The single human cathelicidin peptide LL-37 has been shown to have antimicrobial and anti-biofilm activity against multiple Gram-positive and Gram-negative human pathogens, and have wound-healing effects on the host. The combination of the anti-biofilm effect and wound-healing properties of LL-37 may make it highly effective in resolving polymicrobially infected wounds when topically applied. Such a peptide or its derivatives could be a platform from which to develop new therapeutic strategies to treat biofilm-mediated infections of wounds. This review summarizes known mechanisms that regulate the endogenous levels of LL-37 and discusses the anti-biofilm, antibacterial, and immunological effects of deficient vs. excessive concentrations of LL-37 within the wound environment. Here, we review recent advances in understanding the therapeutic potential of this peptide and other clinically advanced peptides as a potential topical treatment for polymicrobial infected wounds.

The effects of explosion on the musculoskeletal system

Explosions remain the leading cause of death and injury to combatants in conflict. The current ‘Global War on Terror’ has resulted in a shift of explosive-related injuries from the battlefield into civilian centres. Despite musculoskeletal injuries being the most common injury witnessed in blast, there remains little research into the effects of blast on this system. In order to develop new treatment regimens and mitigation systems, there is a requirement to have a better understanding of skeletal trauma in this unique environment. The aim of this review article is to deconstruct the complex injury mechanisms witnessed in blast and relate them to its effects on the musculoskeletal system.

Evaluation of military trauma system practices related to complications after injury

BACKGROUND

The Joint Theater Trauma System (JTTS) was developed with the vision that every soldier, marine, sailor, and airman injured on the battlefield would have the optimal chance for survival and maximum potential for functional recovery. In this analysis, we hypothesized that injury and complication after injury surveillance information diffusion through the JTTS, via the dissemination of clinical practice guidelines and process improvements, would be associated with improved combat casualty clinical outcomes.

METHODS

The current analysis was designed to profile different aspects of trauma system performance improvement, including monitoring of frequent posttraumatic complications, the assessment of an emerging complication trend, and measurement of the impact of the system interventions to identify potential practices for future performance improvement. Data captured from the Joint Theater Trauma Registry on patients admitted to military medical treatment facilities as a result of wounds incurred in Iraq and Afghanistan from 2003 to 2010 were retrospectively analyzed to determine the potential impact of complication surveillance and process improvement initiatives on clinical practice.

RESULTS

Developed metrics demonstrated that the surveillance capacity and evidence-based quality improvement initiatives disseminated through the JTTS were associated with improved identification and mitigation of complications following battlefield injury.

CONCLUSION

The Joint Trauma System enables evidence-based practice across the continuum of military trauma care. Concurrent data collection and performance improvement activities at the local and system level facilitate timely clinical intervention on identified trauma complications and the subsequent measurement of the effectiveness of those interventions.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

Modern military surgery

The types of explosive devices used in warfare and the pattern of war wounds have changed in recent years. There has, for instance, been a considerable increase in high amputation of the lower limb and unsalvageable leg injuries combined with pelvic trauma.

The conflicts in Iraq and Afghanistan prompted the Department of Military Surgery and Trauma in the United Kingdom to establish working groups to promote the development of best practice and act as a focus for research.

In this review, we present lessons learnt in the initial care of military personnel sustaining major orthopaedic trauma in the Middle East.

Acinetobacter in modern warfare

Increasing appreciation of the role of Acinetobacter baumannii in the aetiology of severe nosocomial infections, together with its ability to employ several mechanisms to rapidly develop resistance to multiple classes of antimicrobial agents, has led to growing interest in this organism over recent years. Recognition and subsequent investigation of the significance of pathogenic Acinetobacter infections in military personnel sustaining injuries during the conflicts in Afghanistan and Iraq has provided an important contribution to the epidemiology of infections with Acinetobacter spp. The following review examines this recent military experience.