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.

Scoping Evidence Review on Training and Skills Assessment for Open Emergency Surgery

OBJECTIVE

Scope evidence on technical performance metrics for open emergency surgery. Identify surgical performance metrics and procedures used in trauma training courses.

DESIGN

Structured literature searches of electronic databases were conducted from January 2010 to December 2019 to identify systematic reviews of tools to measure surgical skills employed in vascular or trauma surgery evaluation and training.

SETTING AND PARTICIPANTS

Faculty of Shock Trauma Anesthesiology Research Center, University of Maryland School of Medicine, Uniformed Services University of Health Sciences, Bethesda, Maryland and Implementation Science, King's College, London.

RESULTS

The evidence from 21 systematic reviews including over 54,000 subjects enrolled into over 840 eligible studies, identified that the Objective Structured Assessment of Technical Skill was used for elective surgery not for emergency trauma and vascular control surgery procedures. The Individual Procedure Score (IPS), used to evaluate emergency trauma procedures performed before and after training, distinguished performance of residents from experts and practicing surgeons. IPS predicted surgeons who make critical errors and need remediation interventions. No metrics showed Kirkpatrick's Level 4 evidence of technical skills training benefit to emergency surgery outcomes.

CONCLUSIONS

Expert benchmarks, errors, complication rates, task completion time, task-specific checklists, global rating scales, Objective Structured Assessment of Technical Skills, and IPS were found to identify surgeons, at all levels of seniority, who are in need of remediation of technical skills for open surgical hemorrhage control. Large-scale, multicenter studies are needed to evaluate any benefit of trauma technical skills training on patient outcomes.

Clinical risk factors and inflammatory biomarkers of post-traumatic acute kidney injury in combat patients

BACKGROUND

Post-traumatic acute kidney injury has occurred in every major military conflict since its initial description during World War II. To ensure the proper treatment of combat casualties, early detection is critical. This study therefore aimed to investigate combat-related post-traumatic acute kidney injury in recent military conflicts, used machine learning algorithms to identify clinical and biomarker variables associated with the development of post-traumatic acute kidney injury, and evaluated the effects of post-traumatic acute kidney injury on wound healing and nosocomial infection.

METHODS

We conducted a retrospective clinical cohort review of 73 critically injured US military service members who sustained major combat-related extremity wounds and had collected injury characteristics, assayed serum and tissue biopsy samples for the expression of protein and messenger ribonucleic acid biomarkers. Bivariate analyses and random forest recursive feature elimination classification algorithms were used to identify associated injury characteristics and biomarker variables.

RESULTS

The incidence of post-traumatic acute kidney injury was 20.5%. Of that, 86% recovered baseline renal function and only 2 (15%) of the acute kidney injury group required renal replacement therapy. Random forest recursive feature elimination algorithms were able to estimate post-traumatic acute kidney injury with the area under the curve of 0.93, sensitivity of 0.91, and specificity of 0.91. Post-traumatic acute kidney injury was associated with injury severity score, serum epidermal growth factor, and tissue activin A type receptor 1, matrix metallopeptidase 10, and X-C motif chemokine ligand 1 expression. Patients with post-traumatic acute kidney injury exhibited poor wound healing and increased incidence of nosocomial infections.

CONCLUSION

The occurrence of acute kidney injury in combat casualties may be estimated using injury characteristics and serum and tissue biomarkers. External validations of these models are necessary to generalize for all trauma patients.

Outcomes of tranexamic acid administration in military trauma patients with intracranial hemorrhage: a cohort study

Background

Tranexamic acid (TXA) may be a useful adjunct for military patients with severe traumatic brain injury (TBI). These patients are often treated in austere settings without immediate access to neurosurgical intervention. The purpose of this study was to evaluate any association between TXA use and progression of intracranial hemorrhage (ICH), neurologic outcomes, and venous thromboembolism (VTE) in TBI.

Methods

This was a retrospective cohort study of military casualties from October 2010 to December 2015 who were transferred to a military treatment facility (MTF) in the United States. Data collected included: demographics, types of injuries, initial and interval head computerized tomography (CT) scans, Glasgow Coma Scores (GCS), and six-month Glasgow Outcome Scores (GOS). Results were stratified based on TXA administration, progression of ICH, and VTE.

Results

Of the 687 active duty service members reviewed, 71 patients had ICH (10.3%). Most casualties were injured in a blast (80.3%), with 36 patients (50.7%) sustaining a penetrating TBI. Mean ISS was 28.2 ± 12.3. Nine patients (12.7%) received a massive transfusion within 24 h of injury, and TXA was administered to 14 (19.7%) casualties. Patients that received TXA had lower initial reported GCS (9.2 ± 4.4 vs. 12.5 ± 3.4, p = 0.003), similar discharge GCS (13.3 ± 4.0 vs. 13.8 ± 3.2, p = 0.58), and a larger improvement between initial and discharge GCS (3.7 ± 3.9 vs. 1.3 ± 3.1, p = 0.02). However, there was no difference in mortality (7.1% vs. 7.0%, p = 1.00), progression of ICH (45.5% vs. 14.7%, p = 0.09), frequency of cranial decompression (50.0% vs. 42.1%, p = 0.76), or mean GOS (3.5 ± 0.9 vs. 3.8 ± 1.0, p = 0.13). Patients administered TXA had a higher rate of VTE (35.7% vs. 7.0%, p = 0.01). On multivariate analysis, however, TXA was not independently associated with VTE.

Conclusions

Patients that received TXA were associated with an improvement in GCS but not in progression of ICH or GOS. TXA was not independently associated with VTE, although this may be related to a paucity of patients receiving TXA. Decisions about TXA administration in military casualties with ICH should be considered in the context of the availability of neurosurgical intervention as well as severity of extracranial injuries and need for massive transfusion.

Trauma Embolic Scoring System in military trauma: a sensitive predictor of venous thromboembolism

Introduction

Clinical decision support tools capable of predicting which patients are at highest risk for venous thromboembolism (VTE) can assist in guiding surveillance and prophylaxis decisions. The Trauma Embolic Scoring System (TESS) has been shown to model VTE risk in civilian trauma patients. No such support tools have yet been described in combat casualties, who have a high incidence of VTE. The purpose of this study was to evaluate the utility of TESS in predicting VTE in military trauma patients.

Methods

A retrospective cohort study of 549 combat casualties from October 2010 to November 2012 admitted to a military treatment facility in the USA was performed. TESS scores were calculated through data obtained from the Department of Defense Trauma Registry and chart reviews. Univariate analysis and multivariate logistic regression were performed to evaluate risk factors for VTE. Receiver operating characteristic (ROC) curve analysis of TESS in military trauma patients was also performed.

Results

The incidence of VTE was 21.7% (119/549). The median TESS for patients without VTE was 8 (IQR 4–9), and the median TESS for those with VTE was 10 (IQR 9–11). On multivariate analysis, Injury Severity Score (ISS) (OR 1.03, p=0.007), ventilator days (OR 1.05, p=0.02), and administration of tranexamic acid (TXA) (OR 1.89, p=0.03) were found to be independent risk factors for development of VTE. On ROC analysis, an optimal high-risk cut-off value for TESS was ≥7 with a sensitivity of 0.92 and a specificity of 0.53 (area under the curve 0.76, 95% CI 0.72 to 0.80, p<0.0001).

Conclusions

When used to predict VTE in military trauma, TESS shows moderate discrimination and is well calibrated. An optimal high-risk cut-off value of ≥7 demonstrates high sensitivity in predicting VTE. In addition to ISS and ventilator days, TXA administration is an independent risk factor for VTE development.

Level of evidence

Level III.

Evaluation of Military Use of Tranexamic Acid and Associated Thromboembolic Events

Importance

Since publication of the CRASH-2 and MATTERs studies, the US military has included tranexamic acid (TXA) in clinical practice guidelines. While TXA was shown to decrease mortality in trauma patients requiring massive transfusion, improper administration and increased risk of venous thromboembolism remain a concern.

Objective

To determine the appropriateness of TXA administration by US military medical personnel based on current Joint Trauma System clinical practice guidelines and to determine if TXA administration is associated with venous thromboembolism.

Design, Setting, and Participants

This cohort study of US military casualties in US military combat support hospitals in Afghanistan and a single US-based tertiary military treatment facility within the continental United States was conducted from 2011 to 2015, with follow-up through initial hospitalization and readmissions.

Exposures

Data collected for all patients included demographic information as well as Injury Severity Score; receipt of blood products, TXA, and/or a massive transfusion; and admission hemodynamics.

Main Outcomes and Measures

Variance from guidelines in TXA administration and venous thromboembolism. Tranexamic acid overuse was defined as a hemodynamically stable patient receiving TXA but not a massive transfusion, underuse was defined as a patient receiving a massive transfusion but not TXA, and TXA administration was considered delayed when given more than 3 hours after injury.

Results

Of the 455 identified patients, 443 (97.4%) were male, and the mean (SD) age was 25.3 (4.8) years. A total of 173 patients (38.0%) received a massive transfusion, and 139 (30.5%) received TXA in theater. Overuse occurred in 18 of 282 patients (6.4%) and underuse in 46 of 173 (26.6%) receiving massive transfusions, and delayed administration was found in 6 of 145 patients (4.3%) receiving TXA. Overuse increased at 3.3% per quarter (95% CI, 4.0-9.9; P < .001; R2 = 0.340) and underuse decreased at -4.4% per quarter (95% CI, -4.5 to -3.6; P < .001; R2 = 0.410). Tranexamic acid administration was an independent risk factor for venous thromboembolism (odds ratio, 2.58; 95% CI, 1.20-5.56; P = .02).

Conclusions and Relevance

Military medical personnel decreased missed opportunities to appropriately use TXA but also increased overuse. In addition, TXA administration was an independent risk factor for venous thromboembolism. A reevaluation of the use of TXA in combat casualties should be undertaken.

Damage- and pathogen-associated molecular patterns play differential roles in late mortality after critical illness

Multiple organ failure (MOF) is the leading cause of late mortality and morbidity in patients who are admitted to intensive care units (ICUs). However, there is an epidemiologic discrepancy in the mechanism of underlying immunologic derangement dependent on etiology between sepsis and trauma patients in MOF. We hypothesized that damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs), while both involved in the development of MOF, contribute differently to the systemic innate immune derangement and coagulopathic changes. We found that DAMPs not only produce weaker innate immune activation than counterpart PAMPs, but also induce less TLR signal desensitization, contribute to less innate immune cell death, and propagate more robust systemic coagulopathic effects than PAMPs. This differential contribution to MOF provides further insight into the contributing factors to late mortality in critically ill trauma and sepsis patients. These findings will help to better prognosticate patients at risk of MOF and may provide future therapeutic molecular targets in this disease process.

Critical errors in infrequently performed trauma procedures after training

BACKGROUND

Critical errors increase postoperative morbidity and mortality. A trauma readiness index was used to evaluate critical errors in 4 trauma procedures. In comparison to practicing and expert surgeon benchmarks, we hypothesized that pretraining trauma readiness index including both vascular and nonvascular trauma surgical procedures can identify residents who will make critical errors.

METHODS

In a prospective study, trained evaluators used a standardized script to evaluate performance of brachial, axillary, and femoral artery exposure and proximal control and lower-extremity fasciotomy on unpreserved cadavers. Forty residents were evaluated before and immediately after Advanced Surgical Skills for Exposure in Trauma training, and 38 were re-evaluated 14 months later. Residents were compared to 34 practicing surgeons evaluated once 30 months after training, and 10 experts.

RESULTS

Resident trauma readiness index increased with training (P < .001), remained unchanged 14 month later and was higher, with lower variance than practicing surgeons (P < .05). Expert trauma readiness index was higher than residents (P < .004) and practicing surgeons (P < .001). Resident training decreased critical errors when evaluated immediately and 14 months after Advanced Surgical Skills for Exposure in Trauma training. Practicing surgeons had more critical errors and performance variability than residents or experts. Experts had 5 to 7 times better error recovery than practicing surgeons or residents. Trauma readiness index area under the receiver operating curve with Youden Index <0.60 or <6 decile in their cohort, predicts a surgeon will make a critical error.

CONCLUSION

Low trauma readiness index was associated with critical errors occurring in all surgeon cohorts and can identify surgeons in need of remedial intervention.

Toll-like receptor activation as a biomarker in traumatically injured patients

BACKGROUND

Surgical insult and trauma have been shown to cause dysregulation of the immune and inflammatory responses. Interaction of damage-associated molecular patterns (DAMPs) with toll-like receptors (TLRs) initiates innate immune response and systemic inflammatory responses. Given that surgical patients produce high levels of circulating damage-associated molecular patterns, we hypothesized that plasma-activated TLR activity would be correlated to injury status and could be used to predict pathological conditions involving tissue injury.

METHODS

An observational study was performed using samples from a single-institution prospective tissue and data repository from a Level-1 trauma center. In vitro TLR 2, 3, 4, and 9 activation was determined in a TLR reporter assay after isolation of plasma from peripheral blood. We determined correlations between plasma-activated TLR activity and clinical course measures of severity.

RESULTS

Eighteen patients were enrolled (median Injury Severity Score 15 [interquartile range 10, 23.5]). Trauma resulted in significant elevation in circulation high mobility group box 1 as well as increase of plasma-activated TLR activation (2.8-5.4-fold) compared to healthy controls. There was no correlation between circulating high mobility group box 1 and trauma morbidity; however, the plasma-activated TLR activity was correlated with acute physiology and chronic health evaluation II scores (R square = 0.24-0.38, P < 0.05). Patients who received blood products demonstrated significant increases in the levels of plasma-activated TLRs 2, 3, 4, and 9 and had a trend toward developing systemic inflammatory response syndrome.

CONCLUSIONS

Further studies examining TLR modulation and signaling in surgical patients may assist in predictive risk modeling and reduction in morbidity and mortality.

Preclosure spectroscopic differences between healed and dehisced traumatic wounds

BACKGROUND

The complexity and severity of traumatic wounds in military and civilian trauma demands improved wound assessment, before, during, and after treatment. Here, we explore the potential of 3 charge-coupled device (3CCD) imaging values to distinguish between traumatic wounds that heal following closure and those that fail. Previous studies demonstrate that normalized 3CCD imaging values exhibit a high correlation with oxygen saturation and allow for comparison of values between diverse clinical settings, including utilizing different equipment and lighting.

METHODS

We screened 119 patients at Walter Reed National Military Medical Center and at Grady Memorial Hospital with at least one traumatic extremity wound of ≥ 75 cm2. We collected images of each wound during each débridement surgery for a total of 66 patients. An in-house written computer application selected a region of interest in the images, separated the pixel color values, calculated relative values, and normalized them. We followed patients until the enrolled wounds were surgically closed, quantifying the number of wounds that dehisced (defined as wound failure or infection requiring return to the operating room after closure) or healed.

RESULTS

Wound failure occurred in 20% (19 of 96) of traumatic wounds. Normalized intensity values for patients with wounds that healed successfully were, on average, significantly different from values for patients with wounds that failed (p ≤ 0.05). Simple thresholding models and partial least squares discriminant analysis models performed poorly. However, a hierarchical cluster analysis model created with 17 variables including 3CCD data, wound surface area, and time from injury predicts wound failure with 76.9% sensitivity, 76.5% specificity, 76.6% accuracy, and a diagnostic odds ratio of 10.8 (95% confidence interval: 2.6-45.9).

CONCLUSIONS

Imaging using 3CCD technology may provide a non-invasive and cost-effective method of aiding surgeons in deciding if wounds are ready for closure and could potentially decrease the number of required débridements and hospital days. The process may be automated to provide real-time feedback in the operating room and clinic. The low cost and small size of the cameras makes this technology attractive for austere and shipboard environments where space and weight are at a premium.

Management of Acute Upper Gastrointestinal Disease While at Sea

Management of complex acute surgical pathology in austere environments necessitates rapid evaluation and resource appropriate management to avoid time-associated morbidity and potentially mortality. Obstructive upper gastrointestinal (UGI) pathologies can be particularly challenging and associated with significant morbidity. Herein, we present six patients with UGI obstructions encountered over the course of an 8-mo deployment onboard a US Navy Aircraft Carrier. Each patient presented to our medical department with signs and symptoms of obstructive UGI pathology including one gastric volvulus requiring operative management at sea, one with a new diagnosis of achalasia requiring transportation and continental United States outpatient evaluation, and four patients with food impaction requiring urgent endoscopic management. Although UGI pathology is seldom encountered at sea, definitive surgical interventions, including prompt evaluation and management of these acute pathologies, can be performed in an austere environment. We wish to call attention to these potential encounters in order that underway deployed medical units and supporting resources ashore are prepared and equipped to intervene on acute UGI obstructive pathology.

Tube Thoracostomy Management in the Combat Wounded

The intent of this study was to characterize the management and subsequent complications of combat injury tube thoracostomies and to determine risk factors for the development of pneumonia (PNA) and retained hemothorax (RH). One hundred fifteen patients with 173 tube thoracostomies met the inclusion criteria and were analyzed. The mean injury severity score was 30.8 1 11.6, 23.5 per cent had traumatic amputations, 49.7 per cent had a hemothorax, and 50.3 per cent had a pneumothorax as indications for tube thoracostomy (TT) placement. Within 24 hours of injury, 89.6 per cent were intubated, the majority (54%) were injured by improvised explosive devices, 35.6 per cent sustained rib fractures, and 12.2 per cent had a diaphragm injury. A mean of 1.5 1 0.7(range 1–4) tube thoracostomies were placed, 18.3 per cent of patients had bilateral tube thoracostomies, and the average TT duration was 6.7 1 3.9 days. The incidence of PNA was 27 per cent (n = 31), RH was 9.6 per cent (n = 11), and empyema was 1.7 per cent (n = 2). Multivariable analysis identified the duration of ventilation [OR 1.2, 95% confidence interval (CI): 1.097–1.313, P < 0.001] as independently associated with the development of PNA. Bilateral TT placement (OR 3.848, 95% CI: 1.219–12.143, P = 0.0216) and injury severity score (OR 1.050, 95% CI: 1.001–1.102, P = 0.0443) were independently associated with PNA development when a patient was intubated for eight days or less. The number of tube thoracostomies placed (OR 3.08, 95% CI: 1.03–9.18, P = 0.0439) was independently associated with the development of RH. Further research is warranted to identify modifiable risk factors to reduce the incidence of PNA and RH in patients with TT placed for traumatic injuries.

Tube Thoracostomy Management in the Combat Wounded

The intent of this study was to characterize the management and subsequent complications of combat injury tube thoracostomies and to determine risk factors for the development of pneumonia (PNA) and retained hemothorax (RH). One hundred fifteen patients with 173 tube thoracostomies met the inclusion criteria and were analyzed. The mean injury severity score was 30.8 + 11.6, 23.5 per cent had traumatic amputations, 49.7 per cent had a hemothorax, and 50.3 per cent had a pneumothorax as indications for tube thoracostomy (TT) placement. Within 24 hours of injury, 89.6 per cent were intubated, the majority (54%) were injured by improvised explosive devices, 35.6 per cent sustained rib fractures, and 12.2 per cent had a diaphragm injury. A mean of 1.5 + 0.7(range 1-4) tube thoracostomies were placed, 18.3 per cent of patients had bilateral tube thoracostomies, and the average TT duration was 6.7 + 3.9 days. The incidence of PNA was 27 per cent (n = 31), RH was 9.6 per cent (n = 11), and empyema was 1.7 per cent (n = 2). Multivariable analysis identified the duration of ventilation [OR 1.2, 95% confidence interval (CI): 1.097-1.313, P < 0.001] as independently associated with the development of PNA. Bilateral TT placement (OR 3.848, 95% CI: 1.219-12.143, P = 0.0216) and injury severity score (OR 1.050, 95% CI: 1.001-1.102, P = 0.0443) were independently associated with PNA development when a patient was intubated for eight days or less. The number of tube thoracostomies placed (OR 3.08, 95% CI: 1.03-9.18, P = 0.0439) was independently associated with the development of RH. Further research is warranted to identify modifiable risk factors to reduce the incidence of PNA and RH in patients with TT placed for traumatic injuries.