Trauma hemostasis and oxygenation research position paper on remote damage control resuscitation: definitions, current practice, and knowledge gaps

The marriage of surgical simulation and telementoring for damage-control surgical training of operational first responders: A pilot study

BACKGROUND

Hemorrhage is the leading cause of preventable posttraumatic death. Many such deaths may be potentially salvageable with remote damage-control surgical interventions. As recent innovations in information technology enable remote specialist support to point-of-care providers, advanced interventions, such as remote damage-control surgery, may be possible in remote settings.

METHODS

An anatomically realistic perfused surgical training mannequin with intrinsic fluid loss measurements (the "Cut Suit") was used to study perihepatic packing with massive liver hemorrhage. The primary outcome was loss of simulated blood (water) during six stages, namely, incision, retraction, direction, identification, packing, and postpacking. Six fully credentialed surgeons performed the same task as 12 military medical technicians who were randomized to remotely telementored (RTM) (n = 7) or unmentored (UTM) (n=5) real-time guidance by a trauma surgeon.

RESULTS

There were no significant differences in fluid loss between the surgeons and the UTM group or between the UTM and RTM groups. However, when comparing the RTM group with the surgeons, there was significantly more total fluid loss (p = 0.001) and greater loss during the identification (p = 0.002), retraction (p = 0.035), direction (p = 0.014), and packing(p = 0.022) stages. There were no significant differences in fluid loss after packing between the groups despite differences in the number of sponges used; RTM group used more sponges than the surgeons and significantly more than the UTM group (p = 0.048). However, mentoring significantly increased self-assessed nonsurgeon procedural confidence (p = 0.004).

CONCLUSION

Perihepatic packing of an exsanguinating liver hemorrhage model was readily performed by military medical technicians after a focused briefing. While real-time telementoring did not improve fluid loss, it significantly increased nonsurgeon procedural confidence, which may augment the feasibility of the concept by allowing them to undertake psychologically daunting procedures.

Fresh frozen plasma and spray-dried plasma mitigate pulmonary vascular permeability and inflammation in hemorrhagic shock

BACKGROUND

In retrospective and prospective observational studies, fresh frozen plasma (FFP) has been associated with a survival benefit in massively transfused trauma patients. A dry plasma product, such as spray-dried plasma (SDP), offers logistical advantages over FFP. Recent studies on FFP have demonstrated that FFP modulates systemic vascular stability and inflammation. The effect of SDP on these measures has not been previously examined. This study compares SDP with FFP using in vitro assays of endothelial function and in vivo assays of lung injury using a mouse model of hemorrhagic shock (HS) and trauma.

METHODS

FFP, SDP, and lactated Ringer's (LR) solution were compared in vitro using assays of endothelial cell (EC) permeability, cytokine production and content, gene expression, as well as tight and adherens junction stability. All resuscitation products were also compared in a murine model of HS. Mean arterial pressures and physiologic measures were assessed. Pulmonary vascular permeability was measured using tagged dextran. Lung tissues were stained for CD68, VE-cadherin, and occludin.

RESULTS

Treatment of ECs with FFP and SDP, but not LR, preserved the integrity of EC monolayers in vitro and resulted in similar EC gene expression patterns and cytokine/growth factor production. FFP and SDP also reduced HS-induced pulmonary vascular permeability in vivo to the same extent. In mice with HS, mean arterial pressures and base excess were corrected by both FFP and SDP to levels observed in sham-treated mice. Treatment after HS with FFP and SDP but not LR solution reduce alveolar wall thickening, leukocyte infiltration, and the breakdown of EC junctions, as measured by staining for VE-cadherin, and occludin.

CONCLUSION

Both FFP and SDP similarly modulate pulmonary vascular integrity, permeability, and inflammation in vitro and in vivo in a murine model of HS and trauma.

Coagulation function of stored whole blood is preserved for 14 days in austere conditions: A ROTEM feasibility study during a Norwegian antipiracy mission and comparison to equal ratio reconstituted blood

BACKGROUND

Formulation of a medical preparedness plan for treating severely bleeding casualties during naval deployment is a significant challenge because of territory covered during most missions. The aim of this study was to evaluate the concept of "walking blood bank" as a supportable plan for supplying safe blood and blood products.

METHODS

In 2013, the Royal Norwegian Navy conducted antipiracy operations from a frigate, beginning in the Gulf of Aden and ending in the Indian Ocean. Crews were on 24-hour emergency alert in preparation for an enemy assault on the frigate. Under an approved command protocol, a "walking blood bank," using crew blood donations, was established for use on board and on missions conducted in rigid-hulled inflatable boats, during which freeze-dried plasma and leukoreduced, group O low anti-A/anti-B titer, cold-stored whole blood were stored in Golden Hour Boxes. Data demonstrating the ability to collect, store, and provide whole blood were collected to establish feasibility of implementing a whole blood-focused remote damage-control resuscitation program aboard a naval vessel. In addition, ROTEM data were collected to demonstrate feasibility of performing this analysis on a large naval vessel and to also measure hemostatic efficacy of cold-stored leukoreduced whole blood (CWB) stored during a period of 14 days. ROTEM data on CWB was compared with reconstituted whole blood.

RESULTS

Drills simulating massive transfusion activation were conducted, in which 2 U of warm fresh whole blood with platelet sparing leukoreduction were produced in 40 minutes, followed by collection of two additional units at 15-minute increments. The ROTEM machine performed well during ship-rolling, as shown by the overlapping calculated and measured mechanical piston movements measured by the ROTEM device. Error messages were recorded in 4 (1.5%) of 267 tests. CWB yielded reproducible ROTEM results demonstrating preserved fibrinogen function and platelet function for at least 3.5 weeks and 2 weeks, respectively. The frequency of ROTEM tests were as follows: EXTEM (n = 88), INTEM (n = 85), FIBTEM (n = 82), and APTEM (n = 12). CWB results were grouped. Compared with Days 0 to 2, EXTEM maximum clot firmness was significantly reduced, beginning on Days 10 to 14; however, results through that date remained within reference ranges and were comparable with the EXTEM maximum clot firmness for the reconstituted whole blood samples containing Day 5 room temperature-stored platelets.

CONCLUSION

A "walking blood bank" can provide a balanced transfusion product to support damage-control resuscitation/remote damage-control resuscitation aboard a frigate in the absence of conventional blood bank products. ROTEM analysis is feasible to monitor damage-control resuscitation and blood product quality. ROTEM analysis was possible in challenging operational conditions.

LEVEL OF EVIDENCE

Therapeutic study, level V.

All plasma products are not created equal: Characterizing differences between plasma products

BACKGROUND

Plasma can be manufactured by multiple methods. Few studies have compared quality parameters between plasma products that may affect efficacy and safety.

METHODS

Four different plasma products were analyzed to include fresh frozen plasma (FFP), liquid plasma (LP), solvent detergent plasma (SDP), and a spray-dried, solvent detergent-treated plasma (SD-SDP) at multiple time points of storage. Parameters measured included red blood cell, platelet, and white blood cell counts; microparticle phenotypes; thrombin generation; and thrombelastography. These parameters were compared in 10 samples of each product.

RESULTS

SDP and SD-SDP contained the smallest number of residual cells compared with FFP and LP. Platelets were the most common residual cell in all products and were highest in LP. FFP contained the greatest number of residual red blood cells. Total microparticle counts were elevated in LP and FFP compared with SDP and SD-SDP. Cell-derived microparticles in both LP and FFP were mostly platelet in origin. Microparticle counts in SDP and SD-SDP were negligible. Thrombelastography results demonstrated similar thrombin, fibrinogen, and platelet function on Day 28 LP compared with Day 5 thawed FFP. Thrombin generation assays revealed that the total, lag time to, and peak thrombin formation were higher in SDP and SD-SDP compared with FFP and LP. All parameters in FFP and LP products were characterized by a large degree of variability.

CONCLUSION

The differences in cellular, microparticle, and functional hemostatic parameters measured between plasma products have the potential to affect efficacy and safety. Further study is needed to elucidate the potential immune effects of the cellular and microparticle differences noted as well as the clinical implications of altered thrombin generation kinetics in SD products.

Blood far forward: Time to get moving!

In planning for future contingencies, current problems often crowd out historical perspective and planners often turn to technological solutions to bridge gaps between desired outcomes and the reality of recent experience. The US Military, North Atlantic Treaty Organization, and other allies are collectively taking stock of 10-plus years of medical discovery and rediscovery of combat casualty care after the wars in Iraq and Afghanistan. There has been undeniable progress in the treatment of combat wounded during the course of the conflicts in Southwest Asia, but continued efforts are required to improve hemorrhage control and provide effective prehospital resuscitation that treats both coagulopathy and shock. This article presents an appraisal of the recent evolution in medical practice in historical context and suggests how further gains in far forward resuscitation might be achieved using existing technology and methods based on whole-blood transfusion while research on new approaches continues.

An International Normalized Ratio-Based Definition of Acute Traumatic Coagulopathy Is Associated With Mortality, Venous Thromboembolism, and Multiple Organ Failure After Injury

OBJECTIVES

Acute traumatic coagulopathy is associated with adverse outcomes including death. Previous studies examining acute traumatic coagulopathy's relation with mortality are limited by inconsistent criteria for syndrome diagnosis, inadequate control of confounding, and single-center designs. In this study, we validated the admission international normalized ratio as an independent risk factor for death and other adverse outcomes after trauma and compared two common international normalized ratio-based definitions for acute traumatic coagulopathy.

DESIGN

Multicenter prospective observational study.

SETTING

Nine level I trauma centers in the United States.

PATIENTS

A total of 1,031 blunt trauma patients with hemorrhagic shock.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

International normalized ratio exhibited a positive adjusted association with all-cause in-hospital mortality, hemorrhagic shock-associated in-hospital mortality, venous thromboembolism, and multiple organ failure. Acute traumatic coagulopathy affected 50% of subjects if defined as an international normalized ratio greater than 1.2 and 21% of subjects if defined by international normalized ratio greater than 1.5. After adjustment for potential confounders, acute traumatic coagulopathy defined as an international normalized ratio greater than 1.5 was significantly associated with all-cause death (odds ratio [OR], 1.88; p < 0.001), hemorrhagic shock-associated death (OR, 2.44; p = 0.001), venous thromboembolism (OR, 1.73; p < 0.001), and multiple organ failure (OR, 1.38; p = 0.02). Acute traumatic coagulopathy defined as an international normalized ratio greater than 1.2 was not associated with an increased risk for the studied outcomes.

CONCLUSIONS

Elevated international normalized ratio on hospital admission is a risk factor for mortality and morbidity after severe trauma. Our results confirm this association in a prospectively assembled multicenter cohort of severely injured patients. Defining acute traumatic coagulopathy by using an international normalized ratio greater than 1.5 but not an international normalized ratio greater than 1.2 identified a clinically meaningful subset of trauma patients who, adjusting for confounding factors, experienced more adverse outcomes. Targeting future therapies for acute traumatic coagulopathy to patients with an international normalized ratio greater than 1.5 may yield greater returns than using a lower international normalized ratio threshold.

Early hemostatic responses to trauma identified with hierarchical clustering analysis

BACKGROUND

Trauma-induced coagulopathy is a complex multifactorial hemostatic response that is poorly understood.

OBJECTIVES

To identify distinct hemostatic responses to trauma and identify key components of the hemostatic system that vary between responses.

PATIENTS/METHODS

A cross-sectional observational study of adult trauma patients at an urban level I trauma center emergency department was performed. Hierarchical clustering analysis was used to identify distinct clusters of similar subjects according to vital signs, injury/shock severity, and comprehensive assessment of coagulation, clot formation, platelet function, and thrombin generation.

RESULTS

Among 84 total trauma patients included in the model, three distinct trauma clusters were identified. Cluster 1 (N = 57) showed platelet activation, preserved peak thrombin generation, plasma coagulation dysfunction, a moderately decreased fibrinogen concentration and normal clot formation relative to healthy controls. Cluster 2 (N = 18) showed platelet activation, preserved peak thrombin generation, and a preserved fibrinogen concentration with normal clot formation. Cluster 3 (N = 9) was the most severely injured and shocked, and showed a strong inflammatory and bleeding phenotype. Platelet dysfunction, thrombin inhibition, plasma coagulation dysfunction and a decreased fibrinogen concentration were present in this cluster. Fibrinolytic activation was present in all clusters, but was particularly increased in cluster 3. Trauma clusters were most noticeably different in their relative fibrinogen concentration, peak thrombin generation, and platelet-induced clot contraction.

CONCLUSIONS

Hierarchical clustering analysis identified three distinct hemostatic responses to trauma. Further insights into the underlying hemostatic mechanisms responsible for these responses are needed.

Freedom from frozen: the first British military use of lyophilised plasma in forward resuscitation

Prehospital use of blood products may improve survival. However, transfusion support with frozen blood components is logistically burdensome and constrains the configuration of prehospital medical support. Alternatives to frozen plasma, including lyophilised plasma, offer the potential for advanced resuscitation in the prehospital environment. We describe the successful use of lyophilised plasma by a UK patrol in the prehospital environment during operations in Afghanistan in 2012 and reflect on recent military experience and the need for further developments.

The ebb and flow of fluid (as in resuscitation)

Since the early 1960's "resuscitation" following major trauma involved use of replacement crystalloid fluid/estimated blood loss in volumes of 3/1, in the ambulance, emergency room, operating room and surgical intensive care unit. During the past 20 years, MAJOR paradigm shifts have occurred in this concept. As a result hypotensive resuscitation with a view towards restriction of crystalloid, and prevention of complications has occurred. Improved results in both civilian and military environments have been reported. As a result there is new focus on trauma surgical involvement in all aspects of trauma patient management, focus on early aggressive surgical approaches (which may or may not involve an operation), and movement from crystalloid to blood, plasma, and platelet replacement therapy.