Aeromedical Evacuation, the Expeditionary Medicine Learning Curve, and the Peacetime Effect

INTRODUCTION

Organizational proficiency increases with experience, which is known as a learning curve. A theoretical peacetime effect occurs when knowledge and skills degrade during peacetime. In this study, the intertheater evacuation system was examined for evidence of a military learning curve and peacetime effect.

MATERIALS AND METHODS

Data on medical evacuations from U.S. Central Command occurring between January 1, 2003, and December 31, 2022, were acquired from the TRANSCOM Regulating and Command & Control Evacuation System. Priority mission evacuation time corresponding to peak periods of activity in Iraq and Afghanistan and minimal activity in Afghanistan was analyzed. Any reduction or increase in the delivery time of casualties would be considered a change in proficiency.

RESULTS

There was a marginal monthly decline of 0.019 days (27.4 min) to perform a priority evacuation from Iraq (95% confidence interval [CI], 0.009 to 0.028 days, P < .001) and a decline of 0.010 days (14.4 min) from Afghanistan (95% CI, 0.003 to 0.016 days, P = .004) over 40 months from peak monthly average times. There was a monthly marginal increase in priority evacuation average time from Afghanistan of 0.008 days (11.5 min) (95% CI, 0.005 to 0.011, P < .001) between January 2013 and December 2020. The number of monthly evacuations estimated to maintain or improve monthly average evacuation time is approximately 50.

CONCLUSIONS

An intertheater aeromedical evacuation system increased in proficiency during periods of conflict and declined during relative peacetime. There is evidence of a peacetime effect on intertheater aeromedical evacuation.

Trauma and Critical Care Military-Civilian Publications Increased After the COVID-19 Pandemic: A Literature Review

INTRODUCTION

There continues to be a growing demand for military-civilian partnerships (MCPs) in research collaborations developing medical trauma care in domestic and international affairs. The objective of this comprehensive review is to investigate the difference in the quantity of MCP trauma and critical care publications before and after the COVID-19 pandemic.

METHODS

A systematic literature review was performed for the calendar years 2018 and 2021 utilizing MEDLINE, Cochrane, and EMBASE databases. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we performed a three-tiered review of 603 English language articles to identify trauma-related military and/or civilian partners and describe the changes in geographical relationships.

RESULTS

A total of 96 (2018) and 119 (2021) articles met screening criteria for trauma and critical care studies and were used for final data extraction. Ultimately, 59 (2018) and 71 (2021) papers met the inclusion criteria of identifying trauma/critical care MCPs and identified both military and civilian partners. There was also an increase from 10 (2018) to 17 (2021) publications that mentioned advocacy for MCP. Using the author affiliations, four regional MCP types were recorded: of 2018 articles, locoregional (3.4%), US-national (47.5%), single international country (42.4%), and between multiple countries (6.8%); of 2021 articles, locoregional (15.5%), US-national (38%), single international country (29.6%), and between multiple countries (16.9%). There has been an increase in the number of locoregional and multinational MCPs and an overall increase in the number of collaborative trauma publications and MCP advocacy papers. A national geographical heat map was developed to illustrate the changes from 2018 to 2021.

CONCLUSIONS

There has been an increase in the number of recorded trauma and critical care MCP publications post-pandemic. The growth in the number of manuscripts in more regions post-pandemic suggests an increase in the recognition of collaborations that contribute not only to conflict readiness but also advancements in trauma and surgical care.

Declining Military Surgical Cases and the Impact on Military Surgical Graduate Medical Education

BACKGROUND

Several studies have indicated a decline in the number, types, and complexity of surgical procedures within military treatment facilities (MTFs). This study aims to determine what effect, if any, these downward trends have had on the relationship between the military health system (MHS) and surgical graduate medical education.

METHODS

Graduating chief resident final ACGME case logs from 4 of thirteen military general surgery programs were evaluated from 2015 to 2020. The proportion of total cases performed by residents at military institutions were compared on a year over year basis.

RESULTS

The proportion of cases performed within the military hospitals declined 3.27% each year between 2015 and 2020 (P < .0001) in 4 MTFs. All individual hospitals had significant declines in case volume except one (William Beaumont Army Medical Center) which increased 6.05% with each year, but also increased the number of MTF partnerships within its program (P < .0001).

CONCLUSIONS

There has been a statistically significant decline over time in the proportion of cases logged by residents within the studied military treatment facilities. Investment into military hospitals to increase case numbers, case diversity, and complexity and/or acceptance of this gradual decline with greater shifting of educational workload onto civilian hospitals is required.

Perception of Treatment Success and Impact on Function with Antibiotics or Appendectomy for Appendicitis: A Randomized Clinical Trial with an Observational Cohort

OBJECTIVE

To compare secondary patient reported outcomes of perceptions of treatment success and function for patients treated for appendicitis with appendectomy vs. antibiotics at 30 days.

SUMMARY BACKGROUND DATA

The Comparison of Outcomes of antibiotic Drugs and Appendectomy trial found antibiotics noninferior to appendectomy based on 30-day health status. To address questions about outcomes among participants with lower socioeconomic status, we explored the relationship of sociodemographic and clinical factors and outcomes.

METHODS

We focused on 4 patient reported outcomes at 30 days: high decisional regret, dissatisfaction with treatment, problems performing usual activities, and missing >10 days of work. The randomized (RCT) and observational cohorts were pooled for exploration of baseline factors. The RCT cohort alone was used for comparison of treatments. Logistic regression was used to assess associations.

RESULTS

The pooled cohort contained 2062 participants; 1552 from the RCT. Overall, regret and dissatisfaction were low whereas problems with usual activities and prolonged missed work occurred more frequently. In the RCT, those assigned to antibiotics had more regret (Odd ratios (OR) 2.97, 95% Confidence intervals (CI) 2.05-4.31) and dissatisfaction (OR 1.98, 95%CI 1.25-3.12), and reported less missed work (OR 0.39, 95%CI 0.27-0.56). Factors associated with function outcomes included sociodemographic and clinical variables for both treatment arms. Fewer factors were associated with dissatisfaction and regret.

CONCLUSIONS

Overall, participants reported high satisfaction, low regret, and were frequently able to resume usual activities and return to work. When comparing treatments for appendicitis, no single measure defines success or failure for all people. The reported data may inform discussions regarding the most appropriate treatment for individuals.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT02800785.

Optimizing combat readiness for military surgeons without trauma fellowship training: engaging the 'voluntary faculty' model

BACKGROUND

Appropriate operative volume remains a critical component in mitigating surgical atrophy and maintaining clinical competency. The initiation of military-civilian surgical partnerships (MCP) has been proposed for addressing knowledge, skills, and abilities (KSA) metrics in order to address concerns over operational readiness and the low acuity experienced by military surgeons. This study investigates the first partnership for Navy surgical staff at a non-academic Military Treatment Facility (MTF) with a regional academic Army MTF and a civilian, non-academic level II trauma center devised to improve operational readiness for attending surgeons. We hypothesize that a skill sustainment MCP will allow military surgeons to meet combat readiness standards as measured by the KSA metric.

METHODS

A Memorandum of Understanding (MOU) was initiated between the Navy MTF (NMTF), the Army MTF (AMTF), and the civilian level II trauma center (CTC). The single military surgeon in this study was classified as 'voluntary faculty' at the CTC. Total case volume and acuity were recorded over an 11-month period. KSA metrics were calculated utilizing the standard national provider number (NPI) and the novel case-log based method.

RESULTS

156 cases were completed by a single surgeon over the study period, averaging 52 cases per institution. Significantly more KSAs were obtained at the CTC compared to NMTF (5954 v 2707; p < 0.001). Significantly more emergent cases were observed at the CTC compared to the MTFs (X2 = 7.1, n = 96, p < 0.05. At a single site, AMTF, a significant difference in the calculated KSA score was observed between the NPI and case-log methods (5278 v 3297; p = 0.04).

CONCLUSION

The skill sustainment MCP between NMTF and CTC increased surgical readiness and exposed surgeons to increased operative acuity. The 'voluntary faculty' model reduces direct litigation exposure and encourages clinical competency for military surgeons, while remaining a deployable asset to the global military effort.

LEVEL OF EVIDENCE

IV, Therapeutic/Care Management.

Evaluating Thera-101 as a Low-Volume Resuscitation Fluid in a Model of Polytrauma

Traumatic brain injury (TBI) and hemorrhage remain challenging to treat in austere conditions. Developing a therapeutic to mitigate the associated pathophysiology is critical to meet this treatment gap, especially as these injuries and associated high mortality are possibly preventable. Here, Thera-101 (T-101) was evaluated as low-volume resuscitative fluid in a rat model of TBI and hemorrhage. The therapeutic, T-101, is uniquely situated as a TBI and hemorrhage intervention. It contains a cocktail of proteins and microvesicles from the secretome of adipose-derived mesenchymal stromal cells that can act on repair and regenerative mechanisms associated with poly-trauma. T-101 efficacy was determined at 4, 24, 48, and 72 h post-injury by evaluating blood chemistry, inflammatory chemo/cytokines, histology, and diffusion tensor imaging. Blood chemistry indicated that T-101 reduced the markers of liver damage to Sham levels while the levels remained elevated with the control (saline) resuscitative fluid. Histology supports the potential protective effects of T-101 on the kidneys. Diffusion tensor imaging showed that the injury caused the most damage to the corpus callosum and the fimbria. Immunohistochemistry suggests that T-101 may mitigate astrocyte activation at 72 h. Together, these data suggest that T-101 may serve as a potential field deployable low-volume resuscitation therapeutic.

PEGylated Polyester Nanoparticles Trigger Adverse Events in a Large Animal Model of Trauma and in Naı̈ve Animals: Understanding Cytokine and Cellular Correlations with These Events

Intravenously infusible nanoparticles to control bleeding have shown promise in rodents, but translation into preclinical models has been challenging as many of these nanoparticle approaches have resulted in infusion responses and adverse outcomes in large animal trauma models. We developed a hemostatic nanoparticle technology that was screened to avoid one component of the infusion response: complement activation. We administered these hemostatic nanoparticles, control nanoparticles, or saline volume controls in a porcine polytrauma model. While the hemostatic nanoparticles promoted clotting as marked by a decrease in prothrombin time and both the hemostatic nanoparticles and controls did not active complement, in a subset of the animals, hard thrombi were found in uninjured tissues in both the hemostatic and control nanoparticle groups. Using data science methods that allow one to work across heterogeneous data sets, we found that the presence of these thrombi correlated with changes in IL-6, INF-alpha, lymphocytes, and neutrophils. While these findings might suggest that this formulation would not be a safe one for translation for trauma, they provide guidance for developing screening tools to make nanoparticle formulations in the complex milieux of trauma as well as for therapeutic interventions more broadly. This is important as we look to translate intravenously administered nanoparticle formulations for therapies, particularly considering the vascular changes seen in a subset of patients following COVID-19. We need to understand adverse events like thrombi more completely and screen for these events early to make nanomaterials as safe and effective as possible.

Analysis of Outcomes Associated With Outpatient Management of Nonoperatively Treated Patients With Appendicitis

IMPORTANCE

In the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial, which found antibiotics to be noninferior, approximately half of participants randomized to receive antibiotics had outpatient management with hospital discharge within 24 hours. If outpatient management is safe, it could increase convenience and decrease health care use and costs.

OBJECTIVE

To assess the use and safety of outpatient management of acute appendicitis.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study, which is a secondary analysis of the CODA trial, included 776 adults with imaging-confirmed appendicitis who received antibiotics at 25 US hospitals from May 1, 2016, to February 28, 2020.

EXPOSURES

Participants randomized to antibiotics (intravenous then oral) could be discharged from the emergency department based on clinician judgment and prespecified criteria (hemodynamically stable, afebrile, oral intake tolerated, pain controlled, and follow-up confirmed). Outpatient management and hospitalization were defined as discharge within or after 24 hours, respectively.

MAIN OUTCOMES AND MEASURES

Outcomes compared among patients receiving outpatient vs inpatient care included serious adverse events (SAEs), appendectomies, health care encounters, satisfaction, missed workdays at 7 days, and EuroQol 5-dimension (EQ-5D) score at 30 days. In addition, appendectomy incidence among outpatients and inpatients, unadjusted and adjusted for illness severity, was compared.

RESULTS

Among 776 antibiotic-randomized participants, 42 (5.4%) underwent appendectomy within 24 hours and 8 (1.0%) did not receive their first antibiotic dose within 24 hours, leaving 726 (93.6%) comprising the study population (median age, 36 years; range, 18-86 years; 462 [63.6%] male; 437 [60.2%] White). Of these participants, 335 (46.1%; site range, 0-89.2%) were discharged within 24 hours, and 391 (53.9%) were discharged after 24 hours. Over 7 days, SAEs occurred in 0.9 (95% CI, 0.2-2.6) per 100 outpatients and 1.3 (95% CI, 0.4-2.9) per 100 inpatients; in the appendicolith subgroup, SAEs occurred in 2.3 (95% CI, 0.3-8.2) per 100 outpatients vs 2.8 (95% CI, 0.6-7.9) per 100 inpatients. During this period, appendectomy occurred in 9.9% (95% CI, 6.9%-13.7%) of outpatients and 14.1% (95% CI, 10.8%-18.0%) of inpatients; adjusted analysis demonstrated a similar difference in incidence (-4.0 percentage points; 95% CI, -8.7 to 0.6). At 30 days, appendectomies occurred in 12.6% (95% CI, 9.1%-16.7%) of outpatients and 19.0% (95% CI, 15.1%-23.4%) of inpatients. Outpatients missed fewer workdays (2.6 days; 95% CI, 2.3-2.9 days) than did inpatients (3.8 days; 95% CI, 3.4-4.3 days) and had similar frequency of return health care visits and high satisfaction and EQ-5D scores.

CONCLUSIONS AND RELEVANCE

These findings support that outpatient antibiotic management is safe for selected adults with acute appendicitis, with no greater risk of complications or appendectomy than hospital care, and should be included in shared decision-making discussions of patient preferences for outcomes associated with nonoperative and operative care.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02800785.

Military deployment's impact on the surgeon's practice

BACKGROUND

As the United States withdraws from overseas conflicts, general surgeons remain deployed in support of global operations. Surgeons and surgical teams are foundational to combat casualty care; however, currently, there are few casualty producing events. Low surgical volume and acuity can have detrimental effects on surgical readiness for those frequently deployed. The surgical team cycle of deployment involves predeployment training, drawdown of clinical practice, deployment, postdeployment reintegration, and rebuilding of a patient panel. This study aims to assess these effects on typical general surgeon practices. Quantifying the overall impact of deployment may help refine and implement measures to mitigate the effects on skill retention and patient care.

METHODS

Surgeon case logs of eligible surgeons deploying between January 1, 2017, and January 1, 2020, were included from participating military treatment facilities. Eligible surgeons were surgeons whose case logs were primarily at a single military treatment facility 26 weeks before and after deployment and whose deployment duration, location, and number of deployed cases were obtainable.

RESULTS

Starting 26 weeks prior to deployment, analyzing in 1-week intervals toward deployment time, case count decreased by 4.8% (p < 0.0001). With each 1-week interval, postdeployment up to the 26-week mark, case count increased by 6% (p < 0.0001). Cases volumes most prominently drop 3 weeks prior to deployment and do not reach normal levels until approximately 7 weeks postdeployment. Case volumes were similar across service branches.

CONCLUSION

There is a significant decrease in the number of cases performed before deployment and increase after return regardless of military branch. The perideployment surgical volume decline should be understood and mitigated appropriately; predeployment training, surgical skill retention, and measures to safely reintegrate surgeons back into their practice should be further developed and implemented.

LEVEL OF EVIDENCE

Economic/Decision, Level III.

Cost and benefit of military quarantine policies

The initial response to COVID-19 included quarantine policies. This study aims to determine the infection containment proportions and cost of two variations of quarantine policies based on geographic travel and close contact with infected individuals within deployed US military populations. Special Operations Command Africa (SOCAF) records of individuals quarantined between March 1, 2020 and June 1, 2020 were examined. The infection containment proportion and cost in containment hours were compared between types of quarantine and between geographic areas. Geographic quarantine contained 2 cases out of 63 quarantined individuals in West Africa (3.2%) compared to 0 out of 221 in East Africa (p = 0.0486). Close contact quarantine contained 3 cases out of 31 quarantined individuals in West Africa compared to 4 out of 55 in East Africa (7.3%, p = 0.6989). Total confinement was 42,048 h for each contained infection using geographic quarantine compared to 4076 h using close contact quarantine. In the US military population deployed to Africa for COVID-19, quarantining based on geographic movement is an order of magnitude more costly in terms of time for each contained infection then quarantining based on close contact with infected individuals. There is not a statistical difference between East and West Africa. The associated costs of quarantine must be carefully weighed against the risk of disease spread.

An Endovascular Surgery Experience in Far-Forward Military Healthcare-A Case Series

SUMMARY

INTRODUCTION

The advancement of interventional neuroradiology has drastically altered the treatment of stroke and trauma patients. These advancements in first-world hospitals, however, have rarely reached far forward military hospitals due to limitations in expertise and equipment. In an established role III military hospital though, these life-saving procedures can become an important tool in trauma care.

MATERIALS AND METHODS

We report a retrospective series of far-forward endovascular cases performed by 2 deployed dual-trained neurosurgeons at the role III hospital in Kandahar, Afghanistan during 2013 and 2017 as part of Operations Resolute Support and Enduring Freedom.

RESULTS

A total of 15 patients were identified with ages ranging from 5 to 42 years old. Cases included 13 diagnostic cerebral angiograms, 2 extremity angiograms and interventions, 1 aortogram and pelvic angiogram, 1 bilateral embolization of internal iliac arteries, 1 lingual artery embolization, 1 administration of intra-arterial thrombolytic, and 2 mechanical thrombectomies for acute ischemic stroke. There were no complications from the procedures. Both embolizations resulted in hemorrhage control, and 1 of 2 stroke interventions resulted in the improvement of the NIH stroke scale.

CONCLUSIONS

Interventional neuroradiology can fill an important role in military far forward care as these providers can treat both traumatic and atraumatic cerebral and extracranial vascular injuries. In addition, knowledge and skill with vascular access and general interventional radiology principles can be used to aid in other lifesaving interventions. As interventional equipment becomes more available and portable, this relatively young specialty can alter the treatment for servicemen and women who are injured downrange.

Supercomputer-Based Ensemble Docking Drug Discovery Pipeline with Application to Covid-19

We present a supercomputer-driven pipeline for in silico drug discovery using enhanced sampling molecular dynamics (MD) and ensemble docking. Ensemble docking makes use of MD results by docking compound databases into representative protein binding-site conformations, thus taking into account the dynamic properties of the binding sites. We also describe preliminary results obtained for 24 systems involving eight proteins of the proteome of SARS-CoV-2. The MD involves temperature replica exchange enhanced sampling, making use of massively parallel supercomputing to quickly sample the configurational space of protein drug targets. Using the Summit supercomputer at the Oak Ridge National Laboratory, more than 1 ms of enhanced sampling MD can be generated per day. We have ensemble docked repurposing databases to 10 configurations of each of the 24 SARS-CoV-2 systems using AutoDock Vina. Comparison to experiment demonstrates remarkably high hit rates for the top scoring tranches of compounds identified by our ensemble approach. We also demonstrate that, using Autodock-GPU on Summit, it is possible to perform exhaustive docking of one billion compounds in under 24 h. Finally, we discuss preliminary results and planned improvements to the pipeline, including the use of quantum mechanical (QM), machine learning, and artificial intelligence (AI) methods to cluster MD trajectories and rescore docking poses.

Supercomputer-Based Ensemble Docking Drug Discovery Pipeline with Application to Covid-19

We present a supercomputer-driven pipeline for in-silico drug discovery using enhanced sampling molecular dynamics (MD) and ensemble docking. We also describe preliminary results obtained for 23 systems involving eight protein targets of the proteome of SARS CoV-2. THe MD performed is temperature replica-exchange enhanced sampling, making use of the massively parallel supercomputing on the SUMMIT supercomputer at Oak Ridge National Laboratory, with which more than 1ms of enhanced sampling MD can be generated per day. We have ensemble docked repurposing databases to ten configurations of each of the 23 SARS CoV-2 systems using AutoDock Vina. We also demonstrate that using Autodock-GPU on SUMMIT, it is possible to perform exhaustive docking of one billion compounds in under 24 hours. Finally, we discuss preliminary results and planned improvements to the pipeline, including the use of quantum mechanical (QM), machine learning, and AI methods to cluster MD trajectories and rescore docking poses.

Maintaining vascular trauma proficiency for military non-vascular surgeons

Background

Vascular injuries in combat casualty patients are common and remain an ongoing concern. In civilian trauma centers, vascular surgeons are frequently available to treat vascular injuries. Within the military, vascular surgeons are not available at all locations where specialty expertise may be optimal. This study aims to determine if a visiting surgeon model, where a general surgeon can visit a civilian trauma center, would be practical in maintaining proficiency in vascular surgery.

Methods

All vascular trauma relevant cases done by any surgical service were identified during a 2-year period at Saint Louis University Hospital between October 1, 2016 and September 30, 2018. These included cases performed by trauma/general, thoracic, vascular, and orthopedic surgery. Predictions on the number of call days to experience an operative case were then calculated.

Results

A total of 316 vascular cases were performed during the time period. A surgeon on call for five 24-hour shifts would experience 2.1 urgent vascular cases with 95% certainty. To achieve five cases with 95% certainty, a surgeon would have to be on call for 34 24-hour shifts.

Discussion

A visiting surgeon model would be very difficult to maintain to acquire or maintain proficiency in vascular surgery. High-volume trauma centers, or centers with significant open vascular cases in addition to trauma, may have more reasonable time requirements, but would have to be evaluated using these methods.

Level of evidence

Economic and value-based evaluations, level II.

Heterogeneity in Military Trauma Casualty Care

INTRODUCTION

Military combat casualty care is at the forefront of military medical readiness, but there is little data on current proficiency of deployed personnel. A previous study identified a potential performance gap in military trauma teams. This study aims to evaluate a subsequent team to determine if heterogeneity of teams exists and to determine if this level of efficiency persists or can be improved.

MATERIALS AND METHODS

Military trauma teams at the Role 3 hospital in Bagram, Afghanistan, were evaluated over the course of a single deployment between April and October 2018. Trauma teams were directly observed and performance of the ATLS primary trauma survey timed. These results were compared to previously published times from Kandahar and Bagram Role 3 sites from Oct 2016 to Apr 2017.

RESULTS

Time to completion of the primary survey in 2018 was statistically faster than the times reported from the Role 3 sites from Oct 2016 to Apr 2017 (344.75 s vs. 482.8 s, p < 0.05). The greatest improvements of efficiency were in the time periods between assessing the airway and breathing, evaluating the patient's circulation, and completing of the primary survey.

CONCLUSIONS

Trauma teams can vary significantly in their efficiency in evaluating trauma patients. Whether this is clinically significant is currently debatable, but it highlights a possible readiness gap for deploying military personnel and the heterogeneity of military combat casualty care.

Validation of a predictive model for operative trauma experience to facilitate selection of trauma sustainment military-civilian partnerships

Background

Trauma readiness is a Department of Defense requirement for military healthcare providers. Surgeons must maintain readiness to optimize surgical care on the battlefield and minimize preventable death. The objective of this study was to validate a predictive model for trauma operative exposure by applying the model prospectively.

Methods

The predictive model for operative trauma exposure was prospectively applied to predict the number of emergent operative cases that would be experienced over predetermined time periods at four separate trauma sustainment military-civilian partnerships (TS-MCP). Notional courses were designed to be 2 or 4 weeks long and consisting of 5 and 12 overnight call periods, respectively. A total of 51 separate 2-week courses and 49 4-week courses were evaluated using the model. The outcome measure was the number of urgent (occurring within a day of arrival) operative trauma cases.

Results

Trauma/general surgery case volumes during call periods of notional courses were within the predicted range at least 98% of the time. Orthopedic volumes were more variable with a range of 82%-98% meeting expectation depending on the course length and institution.

Conclusion

The previously defined model accurately predicted the number of urgent trauma/general surgery cases course participants would likely experience when applied prospectively to TS-MCP; however, the model was less accurate in predicting acute orthopedic trauma exposure. While it remains unknown how many cases need to be performed meet a trauma sustainment requirement, having a model with a predictive capability for case volume will facilitate metric development. This model may be useful when planning for future TS-MCP.

Level of evidence

Economic and Value Based Evaluations Level II.

CAVH in the Combat Environment: A Case Report and Lessons Learned in Southern Afghanistan

Background

Acute kidney injury is a common complication of both civilian and military trauma. The lack of dedicated resources restrict dialysis in the forward setting. We report a case of a combat polytrauma and renal failure, using continuous arteriovenous hemofiltration to clear uremia and remove volume, allowing for ventilator liberation and safe disposition.

Materials and Methods

The patient presented with traumatic lower extremity injuries and abdominal wounds and developed acute post-traumatic renal failure. Using available supplies, the patient was cannulated for continuous arteriovenous hemofiltration. Aggressive fluid and electrolyte management accomplished specific goals of ventilator liberation and clearance of uremia.

Results

Over 48 h, blood urea nitrogen was reduced from 101 mg/dL to 63 mg/dL. Creatinine was reduced from 8.2 mg/dL to 4.7 mg/dL. Acute respiratory distress syndrome was improved reducing P:F (PaO2:FiO2) ratio from 142 to 210. The patient was extubated and transferred safely.

Conclusions

The ability to perform acute dialysis can be lifesaving. Although resource constrained, we created a dialysis system in the forward environment with a filter and universally available equipment. This represents the first described use of continuous arteriovenous hemofiltration at the NATO Role 3 hospital in Afghanistan. This technique represents another potential tool for deployed trauma teams to improve care.

Objective model to facilitate designation of military-civilian partnership hospitals for sustainment of military trauma readiness

Background

A major dilemma of the military surgeon is the requirement for battlefield trauma expertise without regular exposure to a traumatically injured patient. To solve this problem, the military is partnering with civilian trauma centers to obtain the required trauma exposure. The main objective of this article is to quantify institutional differences and develop a predictive model for estimating the number of 24-hour trauma shifts a surgeon must be on call at civilian centers to experience urgent trauma cases.

Methods

Trauma databases from multiple institutions were queried to obtain all urgent trauma cases occurring during a 2-year period. A predictive model was used to estimate the number of urgent surgical cases in multiple specialties surgeons would experience over various numbers of 24-hour shifts and the number of 24-hour shifts required to experience a defined number of cases.

Results

Institution 1 had the lowest number of required 24-hour shifts to experience 10 urgent operative cases for general/trauma surgery (10 calls) and orthopedic surgery (6 calls) and the highest number of predicted cases over 12 days, 18.3 (95% CI 11 to 27), with 95% confidence. The expected trauma cases and 24-hour shifts at Institution 1 were statistically significant (p<0.0001). There were seasonal effects at all institutions except for Institution 3.

Discussion

There are significant variabilities in trauma center volume and therefore, the expected number of shifts and cases during a specific period of time is significantly different between trauma centers. This predictive model is objective and can therefore be used as an extrapolative tool to help and inform the military regarding placement of personnel in optimal centers for trauma currency rotations.

Level of evidence

Economic and value-based evaluations, level II.

Graduating Surgical Residents Lack Competence in Critical Care Ultrasound

OBJECTIVE

Ultrasound provides accessible imaging for bedside diagnostics and procedural guidance, but may lead to misdiagnosis in untrained users. The main objective of this study was to determine observed and self-perceived competence with critical care ultrasound in graduated general surgery residents.

DESIGN

The design of this study was a retrospective review. Ultrasound training program records were reviewed for number of prior ultrasound examinations performed, self-perceived competence, observed competence on faculty examinations, and intended future use of individual critical care ultrasound examinations.

SETTING

This study was undertaken at the R Adams Cowley Shock Trauma Center, which is a tertiary care center in Baltimore, MD.

PARTICIPANTS

Graduated general surgery residents were identified at the beginning of their surgical critical care fellowship at our institution, and were included if they participated in our critical care ultrasound education program. Fifteen graduated general surgery residents were included.

RESULTS

Prior ultrasound experience ranged from 100% for focused assessment of sonography for trauma (FAST) to 13.3% for advanced cardiac assessment. Self-perceived competence ranged from 46.7% with FAST to 0% for advanced cardiac assessment. Observed competence ranged from 20.0% for FAST examinations to 0% for basic cardiac assessment, advanced cardiac assessment, and inferior vena cava (IVC) assessment. All participants intended to use ultrasound in the future for FAST, pneumothorax detection and basic cardiac assessment, and 86.7% for IVC assessment and advanced cardiac assessment. Of participants with self-perceived competence, 28.6% had observed competence with FAST, 0% with IVC assessment, and 100% with pneumothorax detection.

CONCLUSIONS

Graduated general surgery residents are not competent in multiple critical care ultrasound examinations despite universally planning to use critical care ultrasound in future practice. Current exposure to ultrasound in residency may give a false sense of competency with ultrasound use. A standardized ultrasound curriculum is an urgent need for general surgery training.

Resuscitative Endovascular Balloon Occlusion of the Aorta: Pushing Care Forward

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA), used to temporize noncompressible and junctional hemorrhage, may be deployable to the forward environment. Our hypothesis was that nonsurgeon physicians and high-level military medical technicians would be able to learn the theory and insertion of REBOA.

METHODS

US Army Special Operations Command medical personnel without prior endovascular experience were included. All participants received didactic instruction of the Basic Endovascular Skills for Trauma Course™ together, with individual evaluation of technical skills. A pretest and a posttest were administered to assess comprehension.

RESULTS

Four members of US Army Special Operations Command-two nonsurgeon physicians, one physician assistant, and one Special Operations Combat Medic-were included. REBOA procedural times moving from trial 1 to trial 6 decreased significantly from 186 ± 18.7 seconds to 83 ± 10.3 seconds (ρ < .0001). All participants demonstrated safe REBOA insertion and verbalized the indications for REBOA insertion and removal through all trials. All five procedural tasks were performed correctly by each participant. Comprehension and knowledge between the pretest and posttest improved significantly from 67.6 ± 7.3% to 81.3 ± 8.1% (ρ = .039).

CONCLUSION

This study demonstrates that nonsurgeon and nonphysician providers can learn the steps required for REBOA after arterial access is established. Although insertion is relatively straightforward, the inability to gain arterial access percutaneously is prohibitive in providers without a surgical skillset and should be the focus of further training.

Through the looking glass: early non-invasive imaging in TBI predicts the need for interventions

Background

Early diagnosis and treatment of traumatic brain injury (TBI) lead to better outcomes. It is difficult to predict which patients benefit from specialised centres, leading to over triage or delay in definitive care. We propose that a non-invasive test comprising optic nerve sheath ultrasound, transcranial Doppler and quantitative papillary reactivity is feasible, correlates with CT findings and may allow for accurate early identification of TBI.

Methods

A 1-year, prospective observation study evaluated a low-risk, non-invasive method of assessing brain injury. Patients underwent a non-invasive neurological examination for trauma, including the above assessments. Data from the three examinations were collected within 6 hours of injury and at 24 hours, and were analysed. Demographics, haemodynamic data, imaging results and short-term outcomes/interventions were recorded.

Results

Trauma patients over the age of 18 years, with a Glascow coma scale (GCS) of <12 or CT evidence of TBI, and intubated were included (N=100). These were divided into +CT (n=49) and −CT groups (n=51) according to the Marshall CT classification of TBI. The +CT group was older, with worse GCS and higher lactate (p=0.008, p=0.001 and p=0.01) but were otherwise well matched. The +CT group included all TBI types, with 96% of the patients having more than one type of TBI. Pulsatility index and neurologic pupillary index were predictive of a +CT (p=0.04, p=0.02). Area under the receiver-operating curve for the logistic regression model for the prediction of positive radiographic findings was r=0.718. Finally, we suggest a preliminary scoring heuristic for predicting a positive radiological finding in a patient with TBI.

Conclusions

The proposed examination is a feasible, non-invasive tool that may have clinical utility in the early prediction of TBI. If validated, it may improve trauma triage for the brain-injured patient. Further studies are warranted to validate this model.

Leukocyte Intracellular Cytokine and Chemokine Response Kinetics to Poly-Trauma and Resuscitation in Non-Human Primates

Background

Traumatic injury induces a significant inflammatory response. Post-injury responses of leukocyte subtypes, to include activation kinetics remain to be fully characterized to effectively direct therapeutic immunomodulation. We sought to determine leukocyte response kinetics to poly-trauma and resuscitation in non-human primates (NHPs).

Methods

Rhesus macaques (n=32) were randomized into four groups: 30min hemorrhagic shock (30HS), 60min HS (60HS), 60HS + laparotomy, and 60HS + laparotomy + femur fracture/repair followed by resuscitation and 24 hours monitoring. Blood was collected at baseline (BSLN), end of shock (EOS), end of resuscitation (EOR), t=360min and t=1440min and stained with a pan-leukocyte panel for flow cytometric analysis. Samples were stained for intracellular markers to differentiate leukocyte subsets such as cytotoxic lymphocytes (CTL), T helper (Th), Macrophage and B-cells. Results reported as mean±SEM, statistical analysis: two-way ANOVA with p&lt;0.05 significance.

Results

Levels of IL-10 in CTL, Th, B, NK-cells, and neutrophils increased over the experiment from BSLN. Hemorrhage induces a significant elevation of regulatory T-cells at 24hours, however, the addition of injuries abrogates this expansion. No other marker was found significantly different between groups/time points.

Conclusion

We have demonstrated that comprehensive flow analysis is effective for determining leukocyte subset kinetics in a poly-trauma model. Increases in T-cell IL-10 during resuscitation indicate nominal regulatory T-cell bursts. This was not observed in animals with additional injuries, suggesting animals with severe trauma may suffer from unfettered inflammatory complications downstream.

Evaluation of the Inflammatory Response in Non-human Primate (NHP) Models of Poly-trauma

Background

Trauma is a leading cause of mortality, with those surviving their initial injuries remaining at risk for death due to deleterious inflammation. Preclinical investigations of immunomodulatory therapeutics are hindered by the limitations of available animal models. We sought to develop a translatable poly-trauma model in NHPs to facilitate future translational immunotherapeutic evaluation.

Methods

NHPs (n=24) were randomly assigned to: 60min hemorrhage shock alone(n=8) or in combination with laparotomy (n=8) ± femur fracture (n=8), resuscitation and 24hr survival. Blood was collected at baseline (BLSN), end of shock (EOS), end of resuscitation (EOR), T=360min and T=24hr; lung tissue was collected at T=24hr. Blood and tissue cytokines were quantified by a 23 plex multiplex. Results reported as mean±SEM, Statistics: Two-tailed T-Test, with p&lt;0.05 significant.

Results

Circulating IL-6, IL-10, IL-15, MCP-1, TGFa and VEGF were significantly elevated in all models as early as EOS; IL-1RA, IL-15, TNFa, IL-6, IL-10, MCP-1, TGFa and IL-5 were significantly increased as early as EOS and directly correlated with injury severity. Lung tissue G-CSF, IL-1b, IL-RA, IL-6, IL-10, IL-15, IL-17A, IL-18, MCP-1, sCD40L, TGFa and VEGF were significantly elevated and directly correlated with injury severity.

Conclusion

Increases in cytokines identified in all models are consistent with those reported in human trauma studies. Cytokines strongly associated with injury severity score (ISS) in humans directly correlated with model severity (IL-6 and IL-10). These models have uncovered cytokine responses not characterized in poly-trauma (IL-15), demonstrating their utility in identifying novel targets for human investigation.

Immunophenotypic Characterization of Hemorrhagic Shock and Poly-trauma in Non-Human Primates

Background

Severe hemorrhage and trauma initiates an inflammatory cascade that promotes innate and adaptive immune-dysregulation. The kinetics of immune-cell subtype expansion, recruitment and retention, remain to be elucidated. We sought to immunophenotypically characterize the innate and adaptive cell response to hemorrhage and poly-trauma in non-human primates (NHPs).

Methods

Rhesus macaques (n=32) were randomized into four injury groups: 30min hemorrhagic shock (30HS), 60 min HS (60HS), 60HS + laparotomy, and 60HS + laparotomy + femur fracture and repair. After injury, animals were resuscitated and monitored for24 hours prior to euthanasia. Whole blood was collected at baseline (BSLN), end of shock (EOS), end of resuscitation (EOR), t=360 min and t=1440 min. Flow cytometric analysis was performed to identify T-cells, B-cells, Natural Killer (NK) cells and monocytes/macrophages/granulocytes. Results reported as mean±SEM, statistical analysis: two-way ANOVA, with p&lt;0.05 significant.

Results

Ineach injury model, the proportion of lymphocytes decreased (p&lt;0.05), and myeloid population frequency increased (p&lt;0.05) from BSLN over the course of the experiment. Frequencies of lymphocytes decreased (p&lt;0.05); where as, frequencies of myeloid cells increased (p&lt;0.05). No significant differences were found between models.

Conclusion

The data demonstrates a shift in lymphoid to myeloid predominance following hemorrhage and injury, consistent with that reported in humans. Interestingly, severity of injury did not alter the magnitude of this response, implying an early trigger. Further investigations into post-traumatic immunomodulation should target myeloid cells.

Intervention to reduce heat stress and improve efficiency among sugarcane workers in El Salvador: Phase 1

BACKGROUND

Chronic heat stress and dehydration from strenuous work in hot environments is considered an essential component of the epidemic of chronic kidney disease in Central America.

OBJECTIVE

(1) To assess feasibility of providing an intervention modelled on OSHA's Water.Rest.Shade programme (WRS) during sugarcane cutting and (2) to prevent heat stress and dehydration without decreasing productivity.

METHODS

Midway through the 6-month harvest, the intervention introduced WRS practices. A 60-person cutting group was provided water supplied in individual backpacks, mobile shaded rest areas and scheduled rest periods. Ergonomically improved machetes and efficiency strategies were also implemented. Health data (anthropometric, blood, urine, questionnaires) were collected preharvest, preintervention, mid-intervention and at the end of harvest. A subsample participated in focus group discussions. Daily wet bulb globe temperatures (WBGT) were recorded. The employer provided individual production records.

RESULTS

Over the harvest WBGT was >26°C from 9:00 onwards reaching average maximum of 29.3±1.7°C, around 13:00. Postintervention self-reported water consumption increased 25%. Symptoms associated with heat stress and with dehydration decreased. Individual daily production increased from 5.1 to a high of 7.3 tons/person/day postintervention. This increase was greater than in other cutting groups at the company. Focus groups reported a positive perception of components of the WRS, and the new machete and cutting programmes.

CONCLUSIONS

A WRS intervention is feasible in sugarcane fields, and appears to markedly reduce the impact of the heat stress conditions for the workforce. With proper attention to work practices, production can be maintained with less impact on worker health.

Focus on PAINS: false friends in the quest for selective anti-protozoal lead structures from Nature?

Pan-assay interference compounds (PAINS) are molecules showing promising but deceptive activities in various biochemical screenings mainly due to unselective interactions with the target.

How to prepare neuroanatomical image data

As image data from a single neuroanatomical study can easily exceed tens of gigabytes, managing, analyzing, and presenting it is not trivial. Careful planning along multiple axes is required and includes the following: (1) Organizational methods developed for images should allow for easy and efficient access, selection, and potential reorganization of images. (2) Experimental information and other metadata should be readily available and accompany image data. (3) Even if a study's entire body of image data is made available, highlighting key results and preparing figures requires selecting image regions and resolutions, creating annotations, and adhering to publishing and community guidelines for image adjustments. Further, it may be necessary to assess Internet accessibility and infrastructure issues and to consider image formats appropriate for Web publishing. Finally, a strategy for robust, long-term, and efficient storage of image data should be developed. This unit provides a guide for preparing neuroanatomical image data.

PPARγ activation inhibits cerebral arteriogenesis in the hypoperfused rat brain

AIMS

PPARγ stimulation improves cardiovascular (CV) risk factors, but without improving overall clinical outcomes. PPARγ agonists interfere with endothelial cell (EC), monocyte and smooth muscle cell (SMC) activation, function and proliferation, physiological processes critical for arterial collateral growth (arteriogenesis). We therefore assessed the effect of PPARγ stimulation on cerebral adaptive and therapeutic collateral growth.

METHODS

In a rat model of adaptive cerebral arteriogenesis (3-VO), collateral growth and function were assessed (i) in controls, (ii) after PPARγ stimulation (pioglitazone 2.8 mg kg(-1); 10 mg kg(-1) compared with metformin 62.2 mg kg(-1) or sitagliptin 6.34 mg kg(-1)) for 21 days or (iii) after adding pioglitazone to G-CSF (40 μg kg(-1) every other day) to induce therapeutic arteriogenesis for 1 week. Pioglitazone effects on endothelial and SMC morphology and proliferation, monocyte activation and migration were studied.

RESULTS

PPARγ stimulation decreased cerebrovascular collateral growth and recovery of hemodynamic reserve capacity (CVRC controls: 12 ± 7%; pio low: -2 ± 9%; pio high: 1 ± 7%; metformin: 9 ± 13%; sitagliptin: 11 ± 12%), counteracted G-CSF-induced therapeutic arteriogenesis and interfered with EC activation, SMC proliferation, monocyte activation and migration.

CONCLUSION

Pharmacologic PPARγ stimulation inhibits pro-arteriogenic EC activation, monocyte function, SMC proliferation and thus adaptive as well as G-CSF-induced cerebral arteriogenesis. Further studies should evaluate whether this effect may underlie the CV risk associated with thiazolidinedione use in patients.

[Gastrointestinal bleeding in the elderly]

Peptic ulcer disease is a common cause of gastrointestinal bleeding, independent of the patient's age. With advancing age, an increase of lower gastrointestinal bleeding (diverticula, angiodysplasia) has been observed. The administration of non-steroidal anti-inflammatory drugs and aspirin is an important risk factor for upper and lower gastrointestinal bleeding, thus in patients aged 65 years and more a concomitant therapy with proton pump inhibitors is recommended in order to prevent ulcer bleeding. Even in very old individuals endoscopy should be used for the diagnosis of gastrointestinal bleeding, providing the opportunity for definite endoscopic bleeding therapy. In elderly patients with comorbidities and recurrent bleeding after endoscopic therapy or continuous blood loss, surgery or transarterial embolisation should be considered in good time.

Continuing promise 2009--assessment of a recent pediatric surgical humanitarian mission

PURPOSE

Surgical organizations have begun to focus their efforts on providing humanitarian assistance in international communities. Most surgeons do not have previous international experience and lack an understanding of what is expected and what care they can provide. The unknown factors include case types, patient volume, postoperative care, and equipment. This abstract presents humanitarian assistance mission and highlights the importance of preparation, host nation involvement, and understanding the local politics of each country.

METHODS

In April to July 2009, the USNS (United States Naval Ship) Comfort deployed to provide humanitarian assistance to 7 countries through Central and South America. Data collected included numbers and types of procedures, rate of rejection of patients for operation, patient age, American Society of Anesthesiology (ASA) score, and length of procedure.

RESULTS

These data represent the total mission of Continuing Promise 2009 including a total of 1137 surgical procedures of which 340 were pediatric (<18 years old). The average number of pediatric cases for each country in 7 days was 48.3 ± 21.4, with a range of 24 to 84. The average age was 7.5 years (range, 1 month to 18 years). In partnership with host physicians, preoperative screening occurred over 2 to 3 days for every 7 operative days. We maintained a low threshold for rejection (rate of 43%; range, 21%-62%) and average ASA score of 1.3. Including all pediatric subspecialties, the most frequent procedures were inguinal (23%) and umbilical (14%) hernias. Although these were the most frequent procedure, the range and variety of cases varied widely. We had a very low early complication rate (1.2%), including 3 wound infections and 1 early hernia recurrence.

CONCLUSIONS

Our data represent the largest collection to date on the pediatric surgical care of children in a humanitarian effort. Our experience can be used to identify the most likely types of cases in South and Central America and as a model for the safe and efficient treatment of children in a developing country.

Laparoscopic repair of a large interstitially incarcerated inguinal hernia

A 68 year old female presented for elective repair of an abdominal wall hernia. Preoperative CT imaging revealed a right inguinal hernia defect with hernia contents coursing cephalad between the external and internal abdominal oblique muscles. This was consistent with an interstitial inguinal hernia, a rare entity outside of post- traumatic hernias. At operation the hernia contents were reduced laparoscopically. The hernia was then repaired by transitioning to the totally extraperitoneal (TEP) approach using a 15cm X 15cm piece of polyester mesh. The patient had an uneventful recovery. Interstitial hernias are rare, difficult to diagnose and potentially dangerous if left untreated. There is no consensus on the ideal repair of these unique hernias. This represents a minimally invasive repair of an unusual hernia, with a novel approach to diagnose and manage the hernia and its redundant sac.

Tube width fluctuations in F-actin solutions

We determine the statistics of the local tube width in F-actin solutions, beyond the usually reported mean value. Our experimental observations are explained by a segment fluid theory based on the binary collision approximation. In this systematic generalization of the standard mean-field approach, effective polymer segments interact via a potential representing the topological constraints. The analytically predicted universal tube width distribution with a stretched tail is in good agreement with the data.

Dynamic structure factor of a stiff polymer in a glassy solution

We provide a comprehensive overview of the current theoretical understanding of the dynamic structure factor of stiff polymers in semidilute solution based on the wormlike chain (WLC) model. We extend previous work by computing exact numerical coefficients and an expression for the dynamic mean square displacement (MSD) of a free polymer and compare various common approximations for the hydrodynamic interactions, which need to be treated accurately if one wants to extract quantitative estimates for model parameters from experimental data. A recent controversy about the initial slope of the dynamic structure factor is thereby resolved. To account for the interactions of the polymer with a surrounding (sticky) polymer solution, we analyze an extension of the WLC model, the glassy wormlike chain (GWLC), which predicts near power law and logarithmic long-time tails in the dynamic structure factor.