Doctor on board? What is the optimal skill-mix in military pre-hospital care?

Effect of special operational forces surgical resuscitation teams on combat casualty survival: A narrative review

IMPORTANCE

The most common cause of preventable death on the conventional battlefield or on special operations force (SOF) missions is hemorrhage. SOF missions may take place in remote and austere locations. Many preventable deaths in combat occur within 30 min of wounding. Therefore, SOF damage control resuscitation (DCR) and damage control surgery (DCS) teams may improve combat casualty survival in the SOF environment.

OBJECTIVE

To determine the effect of SOF DCR and DCS teams on combat casualty survival. Also, to describe commonalities in team structure, logistics, and blood product usage.

DESIGN

A narrative review of the English literature used a Medline and Embase search strategy. The authors were contacted for more details as required. The risk of bias was assessed using the Cochrane Collaboration's ROBINS-I tool. Pooling of data was not done to the heterogeneity of studies.

RESULTS

Weak evidence was identified showing a clinical benefit of SOF DCR and DCS teams. Conflicting evidence from less rigorous studies was also found. The overall risk of bias using ROBINS-I was serious to critical. Several commonalities in team structure, training, and logistics were found.

CONCLUSIONS AND RELEVANCE

There is conflicting evidence regarding the effect SOF DCR and DCS teams have on combat casualty survival. There is no strong evidence that SOF DCR and DCS teams cause harm. More robust data collection is recommended to evaluate these teams.

Extremity Tourniquet Training at High Seas

BACKGROUND

Future navy officers require unique training for emergency medical response in the isolated maritime environment. The authors issued a workshop on extremity bleeding control, using four different commercial extremity tourniquets onboard a training sail ship. The purposes were to assess participants' perceptions of this educational experience and evaluate self-application simplicity while navigating on high seas.

METHODS

A descriptive observational study was conducted as part of a workshop issued to volunteer training officers. A post-workshop survey collected their perceptions about the workshops' content usefulness and adequacy, tourniquet safety, self-application simplicity, and device preference. Tourniquet preference was measured by frequency count while the rest of the studied variables on a one-to-ten Likert scale. Frequencies and percentages were calculated for the studied variables, and application simplicity means compared using the ANOVA test (p < 0.05).

RESULTS

Fifty-one Spanish training naval officers, aged 20 or 21, perceived high sea workshop content's usefulness, adequacy, and safety level at 8.6/10, 8.7/10, and 7.5/10, respectively. As for application simplicity, CAT and SAM-XT were rated equally with a mean of 8.5, followed by SWAT (7.9) and RATS (6.9), this one statistically different from the rest (p < 0.01). Windlass types were preferred by 94%.

CONCLUSIONS

The training sail ship's extremity bleeding control workshop was perceived as useful and its content adequate by the participating midshipmen. Windlass types were regarded as easier to apply than elastic counterparts. They were also preferred by nine out of every ten participants.

Ultrasound-guided versus blind vascular access followed by REBOA on board of a medical helicopter in a hemorrhagic ovine model

BACKGROUND

The aim of this study is to evaluate the feasibility of en-route resuscitative endovascular balloon occlusion of the aorta (REBOA) on board of a helicopter.

METHODS

Six sedated male sheep (weighing 42-54 kg) underwent a controlled hemorrhage until the systolic blood pressure (BP) dropped to <90 mmHg, and were placed into a low capacity Eurocopter AS-350 (France). During the 30-minutes normal flight, every animal underwent blind (left side) and ultrasound-guided (US) (right side) vascular access (VA) to the femoral artery followed by REBOA: the first catheter (Rescue balloon, Japan) - into Zone I, the second one (MIT, Russia) - Zone III. In case of blind VA failure, an alternate US-puncture was attempted. Six experienced flight anesthetists were enrolled into the study. Vascular access and REBOA catheter placement (confirmed by X-Ray later) success rate and timing were recorded.

RESULTS

Among six blind punctures one was successful, 2/6 - were into the vein, 3/6 - completely failed and switched to US-punctures (making total number of US-punctures nine). Eight out of nine US-punctures were successful. However, correct wire insertion and sheath placement was performed in 1/6 animal in the 'blind' group and only in 6/9 animals in the 'US' group. It took a median of 65 seconds (range 5-260) for US-puncture and a median of 4 minutes to get the sheath in. Among the 9 VAs, there were 2 REBOA failures (1 ruptured balloon [MIT] and 1 mistaken vena cava placement primarily recognized by a sudden drop of BP and later confirmed by X-Ray). Five out of seven balloons were placed in a desired intra-aortic position: 4/5 in Zone I and 1/2 - in Zone III. A median time for a successful REBOA procedure was 5.0 (range 2.5-10.0) minutes (1 min after sheath placement).

CONCLUSION

Our study demonstrates the potential feasibility of the en-route REBOA which can be performed within 5 minutes. Ultrasound-guidance is critically important to achieve en-route VA.

Primary aeromedical retrieval crew composition: Do different teams impact clinical outcomes? A descriptive systematic review

OBJECTIVES

Military Forward Aeromedical Evacuation and civilian Helicopter Emergency Medical Services are widely used to conduct Primary Aeromedical Retrieval. Crew composition in Primary Aeromedical Retrieval missions varies considerably. The ideal composition is unknown. Thus, we conducted a descriptive systematic review on mortality and other outcomes for different Primary Aeromedical Retrieval crew compositions.

METHODS

Medline, Embase, and Cochrane Controlled Trials Register were searched up to January 2020. Results were reported per Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Studies of adult trauma air transported by different crews were included. Population, injury severity, crew composition, procedures, and outcomes, including mortality, were abstracted. Risk of bias was assessed using previously validated tools. A lack of reported effect measures precluded a quantitative analysis.

RESULTS

Sixteen studies met inclusion criteria (3 prospective studies, 1 case-control, and 12 retrospective). Overall, studies reported a mortality benefit associated with advanced health care providers. This was most apparent in patients with severe but survivable injuries. In this population, early rapid sequence induction, endotracheal intubation, mechanical ventilation, thoracostomies, blood products transfusion, and treatment of hemorrhagic shock are better performed by advanced providers and may improve outcomes. The quality of evidence reported a moderate risk of bias in the included studies.

CONCLUSIONS

Overall, findings were divergent but showed a trend to decreased mortality in patients treated by advanced providers with interventions beyond the basic paramedic level. This trend was most significant in patients with severe but survivable injuries. These results should be cautiously interpreted because most studies were observational, had small sample sizes, and had a high potential for confounding factors.

Five years of prolonged field care: prehospital challenges during recent French military operations

BACKGROUND

French military operations in the Sahel conducted since 2013 over more than 5 million square kilometers have challenged the French Military Health Service with specific problems in prolonged field care.

STUDY DESIGN AND METHODS

To describe these challenges, we retrospectively analyzed the prehospital data from the first 5 years of these operations within a delimited area.

RESULTS

One hundred eighty-three servicemen of different nationalities were evacuated, mainly as a result of explosions (73.2%) or gunshots (21.9%). Their mean number evacuation was 2.2 (minimum, 1; maximum, 8) per medical evacuation with a direct evacuation from the field to a Role 2 medical treatment facility (MTF) for 62% of them. For the highest-priority casualties (N = 46), the median time [interquartile range] from injury to a Role 2 MTF was 130 minutes [70 minutes to 252 minutes], exceeding 120 minutes in 57% of cases and 240 minutes in 26%. The most frequent out-of-hospital medical interventions were external hemostasis, airway and hemopneumothorax management, hypotensive resuscitation, analgesia, immobilization, and antibiotic administration. Prehospital transfusion (RBCs and/or lyophilized plasma) was started three times in the field, two times during helicopter medical evacuation, and five times in tactical fixed wing medical aircraft. Lyophilized plasma was confirmed to be particularly suitable in these settings. One of the specific issues involved in lengthy prehospital time was the importance to reassess and convert tourniquets prior to Role 2 MTF admission.

CONCLUSION

Main challenges identified include reducing evacuation times as much as possible, preserving ground deployment of sufficiently trained medics and medical teams, optimization of transfusion strategies, and strengthening specific prolonged field care equipment and training.

Prehospital Blood Product Resuscitation for Trauma: A Systematic Review

Introduction:

Administration of high ratios of plasma to packed red blood cells is a routine practice for in-hospital trauma resuscitation. Military and civilian emergency teams are increasingly carrying prehospital blood products (PHBP) for trauma resuscitation. This study systematically reviewed the clinical literature to determine the extent to which the available evidence supports this practice.

Methods:

Bibliographic databases and other sources were searched to July 2015 using keywords and index terms related to the intervention, setting, and condition. Standard systematic review methodology aimed at minimizing bias was used for study selection, data extraction, and quality assessment (protocol registration PROSPERO: CRD42014013794). Synthesis was mainly narrative with random effects model meta-analysis limited to mortality outcomes.

Results:

No prospective comparative or randomized studies were identified. Sixteen case series and 11 comparative studies were included in the review. Seven studies included mixed populations of trauma and non-trauma patients. Twenty-five of 27 studies provided only very low quality evidence. No association between PHBP and survival was found (OR for mortality: 1.29, 95% CI: 0.84–1.96, P = 0.24). A single study showed improved survival in the first 24 h. No consistent physiological or biochemical benefit was identified, nor was there evidence of reduced in-hospital transfusion requirements. Transfusion reactions were rare, suggesting the short-term safety of PHBP administration.

Conclusions:

While PHBP resuscitation appears logical, the clinical literature is limited, provides only poor quality evidence, and does not demonstrate improved outcomes. No conclusions as to efficacy can be drawn. The results of randomized controlled trials are awaited.

Deployed skills training for whole blood collection by a special operations expeditionary surgical team

BACKGROUND

Noncompressible hemorrhage is the leading cause of potentially preventable battlefield death. Combining casualty retrieval from the battlefield and damage control resuscitation (DCR) within the "golden hour" increases survival. However, transfusion requirements may exceed the current blood component stocks held by forward surgical teams. Warm fresh whole blood (WFWB) is an alternative. We report WFWB transfusion training developed by and delivered to a US Golden Hour Offset Surgical Treatment Team and the resulting improvement in confidence with WFWB transfusion.

METHODS

A bespoke instructional package was derived from existing operational clinical guidelines. All Golden Hour Offset Surgical Treatment Team personnel completed initial training, reinforced through ongoing casualty simulations. A record of blood types and donor eligibility was established to facilitate rapid identification of potential WFWB donors. Self-reported confidence in seven aspects of the WFWB transfusion process was assessed before and after training using a five-point Likert scale. Personnel were analyzed by groups consisting of those whose operational role includes WFWB transfusion ("transfusers"), clinical personnel without such responsibilities ("nontransfusers") and nonclinical personnel (other). Comparisons within and between groups were made using appropriate nonparametric tests.

RESULTS

Data were collected from 39 (89%) of 44 training participants: 24 (62%) transfusers, 12 (31%) nontransfusing clinicians, and 3 (8%) other personnel. Transfusers and nontransfusers reported increased comfort with all practical elements of WFWB transfusion. The confidence of other personnel also increased, but (likely due to small numbers) was not statistically significant.

CONCLUSION

WFWB transfusion is an integral part of modern deployed military remote DCR. Our in-theater training program rapidly and reproducibly enhanced the comfort in WFWB transfusion in providers from a range of backgrounds and skill-mixes. This model has the potential to improve both safety and effectiveness of WFWB remote DCR in the far-forward deployed setting.

LEVEL OF EVIDENCE

Therapeutic/care management study, level IV.

Defining the essential anatomical coverage provided by military body armour against high energy projectiles

INTRODUCTION

Body armour is a type of equipment worn by military personnel that aims to prevent or reduce the damage caused by ballistic projectiles to structures within the thorax and abdomen. Such injuries remain the leading cause of potentially survivable deaths on the modern battlefield. Recent developments in computer modelling in conjunction with a programme to procure the next generation of UK military body armour has provided the impetus to re-evaluate the optimal anatomical coverage provided by military body armour against high energy projectiles.

METHODS

A systematic review of the literature was undertaken to identify those anatomical structures within the thorax and abdomen that if damaged were highly likely to result in death or significant long-term morbidity. These structures were superimposed upon two designs of ceramic plate used within representative body armour systems using a computerised representation of human anatomy.

RESULTS AND CONCLUSIONS

Those structures requiring essential medical coverage by a plate were demonstrated to be the heart, great vessels, liver and spleen. For the 50th centile male anthropometric model used in this study, the front and rear plates from the Enhanced Combat Body Armour system only provide limited coverage, but do fulfil their original requirement. The plates from the current Mark 4a OSPREY system cover all of the structures identified in this study as requiring coverage except for the abdominal sections of the aorta and inferior vena cava. Further work on sizing of plates is recommended due to its potential to optimise essential medical coverage.

Trauma treatment in a role 1 medical facility in Afghanistan

BACKGROUND

Most of the emergency care delivered in Afghanistan is currently provided by the military sector and non-governmental organisations. Main Operating Base (MOB) Price in Helmand Province has a small medical centre and due to its location provides critical care to civilians and military casualties and this article describes the patterns in trauma patient care at the MOB Price medical centre regarding the types of patients and injuries.

MATERIALS AND METHODS

The study population consists of 64 consecutive critically injured patients treated in MOB Price during a 4-month period from September to December 2010. The outcomes were battle-related injuries, treatment received before arriving to MOB Price, types of injury and treatment.

RESULTS

There were 35 civilians (12 children and 23 adults), 28 Afghan National Security Forces and one International Security Assistance Force soldier; they were divided into three groups (civilian adults, civilian children and military). 22% of the patients suffered fragmentation injuries and civilians were more likely to incur fragment injury than military personnel (OR (95% CI) 7.04 (1.4 to 34.8)). Regarding intubation, there was a trend towards more civilians needing it than military personnel and significantly more children than adults underwent intubation (OR (95% Cl) 51 (5.2 to 498.5)). Gunshot wounds (GSW) occurred in 30% of the patients. Civilians patients had a lower OR for GSWs than military patients (OR (95% CI) 0.35 (0.1 to 1.1)). Other trends in injury types and treatment were apparent but did not reach significance due to the small number of patients.

CONCLUSIONS

Both civilians and military personnel benefitted from the in-theatre Role 1 medical facility treatment. The most frequent injuries were fragmentation damage and GSW.