Massive Hemorrhage

#### MASSIVE HEMORRHAGE

J Trauma Acute Care Surg. 2019 Jan 18 Epub ahead of print

# From the Battlefield to Main Street: Tourniquet Acceptance, Use, and Translation from the Military to Civilian Settings.

Goodwin T, Moore K, Pasley J, Troncoso R Jr, Levy M, Goolsby C

Throughout history, battlefield medicine has led to advancements in civilian trauma care. In the most recent conflicts of OEF/OIF, one of the most important advances is increasing use of point-of-injury hemorrhage control with tourniquets. Tourniquets are gradually gaining acceptance in the civilian medical world-in both the prehospital setting and trauma centers. An analysis of EMS data shows an increase of prehospital tourniquet utilization from 0 to nearly 4,000 between 2008 and 2016. Additionally, bystander educational campaigns such as the

Stop the Bleed program is expanding, now with over 125,000 trained on tourniquet placement. As the medical community and the population at large has broader acceptance and training on the use of tourniquets, there is greater potential for saving lives from preventable hemorrhagic deaths.

J Trauma Acute Care Surg. 2019 Jan;86(1):43-51

# Prehospital tourniquet use in penetrating extremity trauma: Decreased blood transfusions and limb complications.

Smith A, Ochoa J, Wong S, Beatty S, Elder J, Guidry C, McGrew P, McGinness C, Duchesne J, Schroll R.

BACKGROUND: Despite increasing popularity of prehospital tourniquet use in civilians, few studies have evaluated the efficacy and safety of tourniquet use. Furthermore, previous studies in civilian populations have focused on blunt trauma patients. The objective of this study was to determine if prehospital tourniquet use in patients with major penetrating trauma is associated with differences in outcomes compared to a matched control group.

METHODS: An 8-year retrospective analysis of adult patients with penetrating major extremity trauma amenable to tourniquet use (major vascular trauma, traumatic amputation and near-amputation) was performed at a Level I trauma center. Patients with prehospital tourniquet placement (TQ) were identified and compared to a matched group of patients without tourniquets (N-TQ). Univariate analysis was used to compare outcomes in the groups.

RESULTS: A total of 204 patients were matched with 127 (62.3%) in the prehospital TQ group. No differences in patient demographics or injury severity existed between the two groups. Average time from tourniquet application to arrival in the emergency department (ED) was 22.5 ± 1.3 minutes. Patients in the TQ group had higher average systolic blood pressure on arrival in the ED (120 ± 2 vs. 112 ± 2, p = 0.003). The TQ group required less total PRBCs (2.0 ± 0.1 vs. 9.3 ± 0.6, p < 0.001) and FFP (1.4 ± 0.08 vs. 6.2 ± 0.4, p < 0.001). Tourniquets were not associated with nerve palsy (p = 0.330) or secondary infection (p = 0.43). Fasciotomy was significantly higher in the N-TQ group (12.6% vs. 31.4%, p < 0.0001) as was limb amputation (0.8% vs. 9.1%, p = 0.005).

CONCLUSION: This study demonstrated that prehospital tourniquets could be safely used to control bleeding in major extremity penetrating trauma with no increased risk of major complications. Prehospital tourniquet use was also associated with increased systolic blood pressure on arrival to the ED, decreased blood product utilization and decreased incidence of limb related complications, which may lead to improved long-term outcomes and increased survival in trauma patients.

LEVEL OF EVIDENCE: Therapeutic, level IV.

J Spec Oper Med. Winter 2018;18(4):97-102.

# A Novel, Perfused-Cadaver Simulation Model for Tourniquet Training in Military Medics.

Grabo DJ Jr, Polk T, Strumwasser A, Inaba K, Foran C, Luther C, Minneti M, Kronstedt S, Wilson A, Demetriades D.

BACKGROUND: Exsanguinating limb injury is a significant cause of preventable death on the battlefield and can be controlled with tourniquets. US Navy corpsmen rotating at the Navy Trauma Training Center receive instruction on tourniquets. We evaluated the effectiveness of traditional tourniquet instruction compared with a novel, perfused-cadaver, simulation model for tourniquet training.

METHODS: Corpsmen volunteering to participate were randomly assigned to one of two tourniquet training arms. Traditional training (TT) consisted of lectures, videos, and practice sessions. Perfused-cadaver training (PCT) included TT plus training using a regionally perfused cadaver. Corpsmen were evaluated on their ability to achieve hemorrhage control with tourniquet(s) using the perfused cadaver. Outcomes included (1) time to control hemorrhage, (2) correct placement of tourniquet(s), and (3) volume of simulated blood loss. Participants were asked about confidence in understanding indications and skills for tourniquets.

RESULTS: The 53 corpsmen enrolled in the study were randomly assigned as follows: 26 to the TT arm and 27 to the PCT arm. Corpsmen in the PCT group controlled bleeding with the first tourniquet more frequently (96% versus 83%; p < .03), were quicker to hemorrhage control (39 versus 45 seconds; p < .01), and lost less simulated blood (256mL versus 355mL; p < .01). There was a trend toward increased confidence in tourniquet application among all corpsmen.

CONCLUSIONS: Using a perfused- cadaver training model, corpsmen placed tourniquets more rapidly and with less simulated-blood loss than their traditional training counterparts. They were more likely to control hemorrhage with first tourniquet placement and gain confidence in this procedure. Additional studies are indicated to identify components of effective simulation training for tourniquets.

Trauma Surg Acute Care Open. 2019 Jan 24;4(1):e000267. doi: 10.1136/tsaco-2018-000267. eCollection 2019.

# Effect of prehospital tourniquets on resuscitation in extremity arterial trauma.

McNickle A, Fraser D, Chestovich P, Kuhls D, Fildes J

Background: Timely tourniquet placement may limit ongoing hemorrhage and reduce the need for blood products. This study evaluates if prehospital tourniquet application altered the initial transfusion needs in arterial injuries when compared with a non-tourniquet control group.

Methods: Extremity arterial injuries were queried from our level I trauma center registry from 2013 to 2017. The characteristics of the cohort with prehospital tourniquet placement (TQ+) were described in terms of tourniquet use, duration, and frequency over time. These cases were matched 1:1 by the artery injured, demographics, Injury Severity Score, and mechanism of injury to patients arriving without a tourniquet (TQ-). The primary outcome was transfusion within the first 24 hours, with secondary outcomes of morbidity (rhabdomyolysis, renal failure, compartment syndrome), amputation (initial vs. delayed), and length of stay. Statistical tests included t-test and χ2 for continuous and categorical variables, respectively, with p<0.05 considered as significant.

Results: Extremity arterial injuries occurred in 192 patients, with 69 (36%) having prehospital tourniquet placement for an average of 78 minutes. Tourniquet use increased over time from 9% (2013) to 62% (2017). TQ+ patients were predominantly male (81%), with a mean age of 35.0 years. Forty-six (67%) received blood transfusion within the first 24 hours. In the matched comparison (n=69 pairs), TQ+ patients had higher initial heart rate (110 vs. 100, p=0.02), frequency of transfusion (67% vs. 48%, p<0.01), and initial amputations (23% vs. 6%, p<0.01). TQ+ patients had increased frequency of initial amputation regardless of upper (n=43 pairs) versus lower (n=26 pairs) extremity involvement; however, only upper extremity TQ+ patients had increased transfusion frequency and volume. No difference was observed in morbidity, length of stay, and mortality with tourniquet use.

Discussion: Tourniquet use has increased over time in patients with extremity arterial injuries. Patients having prehospital tourniquets required a higher frequency of transfusion and initial amputation, without an increase in complications.

Level of evidence: Therapeutic study, level IV.

Int J Exerc Sci. 2019 Jan 1;12(3):136-143

# The Effect of Cuff Width for Determining Limb Occlusion Pressure: A Comparison of Blood Flow Restriction Devices.

Weatherholt A, Vanwye W, Lohmann J, Owens J

The purpose of this study was to compare the standing lower extremity limb occlusion pressure (LOP) between two units. It was hypothesized that the Delfi unit, which utilizes a wider cuff (11.5 cm), would require significantly less LOP as compared to the KAASTU unit, which utilizes a narrow cuff (5 cm). Twenty-nine healthy participants (22 men, 7 women) mean age 24 years old (± 1.7 SD) volunteered. The procedure was identical for each cuff, completed with 5 minutes of rest in between. The cuff was placed on the proximal left thigh in the standing position. The initial pressure was set to 50 mmHg and then increased in 50 mmHg increments until complete arterial occlusion was achieved or the unit went to its maximum pressure. Arterial blood flow was determined by a mobile ultrasound measured at the left popliteal artery. Paired samples t-tests were used to determine differences in LOP (mmHg) between the Delfi and KAATSU unit cuffs. Significant differences were observed between the cuffs (wide: 239.4 mmHg vs. narrow: 500 mmHg; p < 0.001). We were able to achieve complete arterial occlusion with the wide cuff. The KAATSU unit reached maximum pressure with all participants, therefore we were unable to achieve complete arterial occlusion with the narrow cuff. Although achieving complete arterial occlusion is not indicated or safe for BFR training, relative pressures are used and determined as a percentage of LOP. Our study found that the relative pressure of the wide cuff is lower than the narrow cuff.

Pediatrics. 2019 Jun;e20183447.

# Adult Tourniquet for Use in School-Age Emergencies.

Harcke H, Lawrence L, Gripp E, Kecskemethy H, Kruse R, Murphy S

BACKGROUND: Gunshot injuries are a leading cause of morbidity and mortality in the pediatric population. The Pediatric Trauma Society supports the use of tourniquets for exsanguinating hemorrhage in severe extremity trauma. The Combat Application Tourniquet (CAT) used with success in adults has not been prospectively tested in children. Our objective with this study was to determine if the CAT is successful in arresting extremity arterial blood flow in school-aged children.

METHODS: Sixty school-aged volunteers (ages 6-16 years) recruited by age cohort had the CAT applied to an upper arm and thigh while peripheral pulse was monitored by Doppler. The number of windlass turns (maximum allowed: 3 [1080°]) required to arrest arterial pulse was recorded. Success was analyzed by BMI percentile for age and extremity circumference.

RESULTS: The CAT was successful in occluding arterial blood flow as detected by Doppler pulse in all 60 (100%) of the upper extremities tested. In the lower extremity, 56 (93%) had successful occlusion. The 3-turn maximum allowed by the protocol was not adequate in some obese, older subjects (BMI >30). In both the upper and lower extremity, the number of turns required to occlude blood flow gradually increased with an increase in arm and thigh circumference.

CONCLUSIONS: Prospective testing of a cohort of school-aged children 6 to 16 years revealed the CAT tourniquet to be suitable for use in both the upper and lower extremity.

J Spec Oper Med. Spring 2019;19(1):35-43.

# Limb Tourniquet Configuration: Preliminary Investigation of Problems and Principles.

Kragh JF Jr, Aden JK 3rd, Dubick MA.

BACKGROUND: A tourniquet's readiness during emergencies depends on how it is configured. We investigated configuration so ways of improving readiness can be developed.

METHODS: This study was conducted at the Institute of Surgical Research in 2018 as sequential investigations by one user of Combat Application Tourniquets (C-A-Ts) in a band-and-rod design.

RESULTS: Each tourniquet comes packaged with paper instructions for use, which include directions on how to configure it in preparation for caregiving. The paper and video instructions for use omit tensioning of the tourniquet in configuration, and the video misconfigured a time strap over the rod. In first-aid classrooms, we saw unwitting learners troubleshoot that misconfiguration. Problems with configuration were also seen in caregiving and with tourniquets stowed in kits. In deliberate practice, we self-applied a tourniquet to a thigh. In configuration after each of 100 uses, tourniquet elongation due to tensioning averaged 2.4 in was important for restoring the tourniquet to its full length. During configuration, if the C-A-T's stabilization plate slid along the band, out of position, the user slid the plate back into position. In various ways of testing other C-A-Ts, elongations averaged from 0.4 in to 0.9 in, depending on whether the tourniquet was self-applied or applied to a firm manikin. Elongation increments accrued as the tourniquet's band flattened. Configuration time averaged 22 seconds, and accrued experience improved the compactness of configuration.

CONCLUSION: People are too often unreliable at putting C-A-Ts into the optimal configuration for use. That ready-to-use configuration includes the tourniquet being at its full length, having the stabilization plate positioned correctly along the band, and having the strap fastened to its clip of origin. When used, tourniquets had normal, small elongations in part due to band flattening. This tourniquet study showed the importance of optimal configuration to first-aid readiness practices.

Prehosp Disaster Med. 2019 Apr;34(2):175-181

# External Soft-Tissue Hemostatic Clamp Compared to a Compression Tourniquet as Primary Hemorrhage Control Device in Pilot Flow Model Study.

Paquette R, Bierle R, Wampler D, Allen P, Cooley C, Ramos R, Michalek J, Gerhardt R

INTRODUCTION: Acute blood loss represents a leading cause of death in both civilian and battlefield trauma, despite the prioritization of massive hemorrhage control by well-adopted trauma guidelines. Current Tactical Combat Casualty Care (TCCC) and Tactical Emergency Casualty Care (TECC) guidelines recommend the application of a tourniquet to treat life-threatening extremity hemorrhages. While extremely effective at controlling blood loss, the proper application of a tourniquet is associated with severe pain and could lead to transient loss of limb function impeding the ability to self-extricate or effectively employ weapons systems. As a potential alternative, Innovative Trauma Care (San Antonio, Texas USA) has developed an external soft-tissue hemostatic clamp that could potentially provide effective hemorrhage control without the aforementioned complications and loss of limb function. Thus, this study sought to investigate the effectiveness of blood loss control by an external soft-tissue hemostatic clamp versus a compression tourniquet.

HYPOTHESIS: The external soft-tissue hemostatic clamp would be non-inferior at controlling intravascular fluid loss after damage to the femoral and popliteal arteries in a normotensive, coagulopathic, cadaveric lower-extremity flow model using an inert blood analogue, as compared to a compression tourniquet.

METHODS: Using a fresh cadaveric model with simulated vascular flow, this study sought to compare the effectiveness of the external soft-tissue hemostatic clamp versus the compression tourniquet to control fluid loss in simulated trauma resulting in femoral and posterior tibial artery lacerations using a coagulopathic, normotensive, cadaveric-extremity flow model. A sample of 16 fresh, un-embalmed, human cadaver lower extremities was used in this randomized, balanced two-treatment, two-period, two-sequence, crossover design. Statistical significance of the treatment comparisons was assessed with paired t-tests. Results were expressed as the mean and standard deviation (SD).

RESULTS: Mean intravascular fluid loss was increased from simulated arterial wounds with the external soft-tissue hemostatic clamp as compared to the compression tourniquet at the lower leg (119.8mL versus 15.9mL; P &lt;.001) and in the thigh (103.1mL versus 5.2mL; P &lt;.001).

CONCLUSION: In this hemorrhagic, coagulopathic, cadaveric-extremity experimental flow model, the use of the external soft-tissue hemostatic clamp as a hasty hemostatic adjunct was associated with statistically significant greater fluid loss than with the use of the compression tourniquet.Paquette R, Bierle R, Wampler D, Allen P, Cooley C, Ramos R, Michalek J, Gerhardt RT. External soft-tissue hemostatic clamp compared to a compression tourniquet as primary hemorrhage control device in pilot flow model study.

Medicine (Baltimore). 2018 Nov;97(46):e13134

# Radial artery occlusion with a kaolin-filled pad after transradial cardiac catheterization.

Chiang C, Chang W, Ho C, Hong C, Shih J, Wu W, Chen Z, Chou M

Radial artery occlusion (RAO) occurs in 2% to 18% of patients after transradial access (TRA) cardiac catheterization. Using a kaolin-filled pad (QuikClot) reduces compression time during TRA and might reduce RAO. We examined the RAO risk with the kaolin-filled pad after TRA cardiac catheterization. This was a prospective cross-sectional study of 260 patients who underwent TRA cardiac catheterization in a cardiac ward of a Medical Center from 2012 to 2016. Patients were randomly assigned to 1 of 2 groups: the case group (n = 130) was postoperatively treated with a kaolin-filled pad, and the control group (n = 130) was treated with conventional hemostasis. Color duplex ultrasound was used to evaluate the 24-hour and 1-month postoperative radial artery flow velocity, diameter, patency, and RAO risk. RAO risk was not significantly different between the case and control groups after 24 hours (4.6% vs 5.4%, P = .776) or after 1 month (5.4% vs 6.1%, P = .789), regardless of whether it was a first TRA cardiac catheterization (after 24 hours [P = .153] or after 1month [P = .617], respectively) or a repeated TRA cardiac catheterization (after 24 hours [P = .754] or after 1month [P = .753], respectively).Using a kaolin-filled pad after TRA cardiac catheterization did not significantly reduce RAO risk compared with conventional hemostasis.

BMC Surg. 2018 Nov 16;18(1):101

# Factors predicting the need for hemorrhage control intervention in patients with blunt pelvic trauma: a retrospective study.

Kim M, Lee J, Lee S

BACKGROUND: Blunt pelvic injuries are often associated with pelvic fractures and injuries to the rectum and genitourinary tract. Pelvic fractures can lead to life-threatening hemorrhage, which is a common cause of morbidity and mortality in trauma. Thus, early identification of patients with pelvic fractures at risk severe bleeding requiring urgent hemorrhage control is crucial. This study aimed to investigate early factors predicting the need for hemorrhage control in blunt pelvic trauma.

METHODS: The medical records of 1760 trauma patients were reviewed retrospectively between January 2013 and June 2018. We enrolled 187 patients with pelvic fracture due to blunt trauma who were older than 15 years. The pelvic fracture pattern was classified according to the Orthopedic Trauma Association/Arbeitsgemeinschaft fur Osteosynthesefragen (OTA/AO) classification. A multivariate logistic regression model was used to determine independent predictors of the need for pelvic hemorrhage control intervention.

RESULTS: The most common pelvic fracture pattern was type A (54.5%), followed by types B (36.9%) and C (8.6%). Of 187 patients, 48 (25.7%) required pelvic hemorrhage control intervention. Hemorrhage control interventions were most frequently performed in patients with type B fractures (54.2%). Multivariate logistic regression analysis revealed that type B (odds ratio [OR] = 4.024, 95% confidence interval [CI] = 1.666-9.720, p = 0.002) and C (OR = 7.077, 95% CI = 1.781-28.129, p = 0.005) fracture patterns, decreased body temperature (OR = 2.275, 95% CI = 0.134-0.567, p < 0.001), and elevated serum lactate level (OR = 1.234, 95% CI = 1.061-1.435, p = 0.006) were factors predicting the need for hemorrhage control intervention in patients with blunt pelvic trauma.

CONCLUSION: Patients with type B and C fracture patterns on the OTA/AO classification, hypothermia, or an elevated serum lactate level are at risk for bleeding and require pelvic hemorrhage control intervention.

J Spec Oper Med. Spring 2019;19(1):89-94.

# Impact of Marine Exposure on Hemostatic Gauzes Using Thromboelastography.

George T, Jordan M, Bianchi W, Boboc M, Zarow GJ, Natarajan R, Walchak AC, Roszko

PJD.

BACKGROUND: Military forces render emergency care in marine environments, where care for exsanguination is challenging. However, the effect of saltwater on the functionality of hemostatic agents is unknown. In this study, we used thromboelastography (TEG) to quantify the effect of saltwater on the efficacy of five gauze products.

METHODS: Blood from 24 healthy adult men was diluted by 30% with hetastarch to mimic hemodilution. Dry and saltwater-soaked Kerlix™, ChitoGauze®, Combat Gauze®, NuStat™, and WoundClot™ were contrasted in terms of the TEG parameters of speed of clot initiation (R), clot amplification (K), α angle (i.e., clot formation rate), and maximum amplitude of clot (MA), using repeated-measures analysis of variance at the p < .05 statistical significance threshold.

RESULTS: Compared with untreated dilute blood, R was significantly faster when any dry or wet gauze was added, with the fastest R values recorded for Combat Gauze. K and α angle findings were mixed. MA was greater than diluted blood for dry hemostatic gauze, but in the wet condition, only the MA for Combat Gauze was significantly greater than that of diluted blood.

CONCLUSION: Gauze products, wet or dry, improved clotting compared to diluted blood without gauze. Saltwater exposure did not significantly detract from this benefit. Our findings suggest that Combat Gauze may be the choice hemostatic gauze for maritime environments.

Int J Biol Macromol. 2019 Mar 1;124:138-147

# A review on recent advances in chitosan based composite for hemostatic dressings.

Khan M, Mujahid M

High mortality rate in potentially survivable casualties due to severe hemorrhage is a major challenge in today's battlefield because technological advancements have revolutionized the combat tactics and complicated the type and severity associated with wound grades. Quality of pre-hospital care prior to patient evacuation is crucial in determining the survival rate in injured patients. To deal with this challenge, considerable improvements in the hemostatic dressings have been introduced and pre-hospital care has been upgraded in many tactical combat casually care guidelines. Combat Gauze has been widely used bandage which is now been replaced by different chitosan based hemostatic dressings. It not only exhibits anti-bacterial activity but also induces hemostasis via direct interaction with erythrocytes and platelets. Its hemostasis mechanism is not dependent on host coagulation pathway which makes it an ideal dressing to stop bleeding in coagulopathic patients. Different generations of chitosan bandages have been developed to overcome the limitations of previous ones. This review provides performance analysis of chitosan bandage generations and discusses the progress made in its fabrication methods during the recent years.

Bull Emerg Trauma. 2019 Jan;7(1):41-48

# Stereological Comparison of Imbibed Fibrinogen Gauze versus Simple Gauze in External Packing of Grade IV Liver Injury in Rats.

Paydar S, Mahmoudi Nezhad G, Karami M, Abdolrahimzadeh H, Samadi M, Makarem A, Noorafshan A

Objective: To evaluate the effect of imbibed fibrinogen gauze on survival, bleeding and healing in liver trauma.

Methods: This animal experimental study was conducted on 20 adult male Sprague-Dawley rats; with a mean weight of 300±50 gram; divided into two groups. Grade IV injury was induced to the subjects' liver. Then, the bleeding site was packed with simple gauze in the control group, and imbibed fibrinogen gauze in the experimental group. All animals were re-evaluated for liver hemostasis 48 hours after the initial injury. Bleeding in the intra peritoneal cavity was measured using Tuberculosis Syringe in the first and second operations. Subjects were followed-up for 14 days. Eventually, the rats were sacrificed and their livers were sent to a lab for stereological assessment. Statistical comparisons were performed via Mann-Whitney U-test using SPSS. P-Values less than 0.05 were considered to be statistically significant.

Results: Half of the rats in the control group died, while all the rats in the imbibed fibrinogen gauze group survived after two weeks (p= 0.032). Bleeding in the imbibed fibrinogen gauze was significantly less than control group, 48 hours' post-surgery (p<0.001). According to the stereological results, granulation tissue in the imbibed fibrinogen gauze group were more than the control group (P= 0.032). Also, fibrosis in the imbibed fibrinogen gauze group were more than the control group (P= 0.014).

Conclusion: Our study indicated that imbibed fibrinogen gauze can potentially control liver bleeding and improve survival through increasing granulation tissue and fibrosis in injured liver.

J Trauma Acute Care Surg. 2019 Mar;86(3):424-430

# Initial evaluation of the efficacy and safety of in-hospital expandable hemostatic minisponge use in penetrating trauma.

Warriner Z, Lam L, Matsushima K, Benjamin E, Strumwasser A, Demetriades D, Inaba K.

BACKGROUND: Hemorrhage remains the leading cause of preventable death after trauma. The XSTAT expandable minisponge hemostatic device was developed for the control of severe, life-threatening bleeding from junctional wounds not amenable to tourniquet application. This is an initial report of the clinical use of this novel method of hemorrhage control for civilian penetrating injury.

METHODS: A review of trauma admissions at a high-volume Level I trauma center was performed from July 2016 to November 2017. All patients sustaining penetrating trauma with active hemorrhage were evaluated for XSTAT use. Ten device deployments occurred during this time. Each deployment was reviewed in detail, capturing patient and injury data, efficacy of hemorrhage control, and evaluation of any potential device or treatment related complications.

RESULTS: Six thousand three hundred sixty-three trauma admissions were reviewed with 22.1% sustaining a penetrating mechanism of injury. XSTAT was deployed in 10 (0.7%) penetrating trauma admissions with a mean age of 38.3 (range, 16-59) years, systolic blood pressure (SBP) of 126.7 (range, 74-194) mm Hg, Glasgow Coma Scale (GCS) score of 14.5 (range, 13-15), and New Injury Severity Score (NISS) of 9.5 (range, 1-27). Eight patients had an identifiable arterial injury; the remainder had vein or soft tissue bleeding. Overall, half were junctional injuries. XSTAT was able to stop bleeding in nine of ten patients on the first deployment, with the remaining patient requiring one repeat injection. Dwell times ranged from 1 hour to 40 hours (median, 15 hours). There were no technical device failures or embolic complications. Retained sponges were identified in two patients on initial postremoval x-rays following wound exploration for definitive hemorrhage control and sponge removal. No patient died during the study period.

CONCLUSION: XSTAT use appears safe. It is rapid, reliable, and provides a high degree of hemorrhage control on first deployment. Sponge removal should always be followed by radiographic clearance. For patients with hemorrhage from cavitary wounds not amenable to tourniquet placement, this device was effective. Further study is warranted as XSTAT use becomes more widespread.

LEVEL OF EVIDENCE: Therapeutic study, level V.

Biomaterials. 2019 Jun;205:23-37

# A highly efficient, in situ wet-adhesive dextran derivative sponge for rapid hemostasis.

Liu C, Liu X, Liu C, Wang N, Chen H, Yao W, Sun G, Song Q, Qiao W

Uncontrolled hemorrhage is closely related to the high risk of death. However, local hemostats still have various defects and side effects. Herein, an aldehyde dextran (PDA) sponge with proper absorption and adhesion properties is developed for hemorrhage control. PDA sponge with pore size of ∼30-50 μm fabricated by lyophilization not only absorbs blood quickly (47.7 g/g), but also possesses strong tissue adhesion (∼100 kPa). PDA sponge with low cytotoxicity and hemolysis achieves effective hemostasis and remarkable blood loss reduction in the ear vein, femoral artery and liver injuries of rabbit models. Furthermore, the exploration of hemostatic mechanisms related to tissue, blood, plasma, cells and coagulation system indicates that PDA sponge can significantly accelerate coagulation by rapid wound block, fast cells aggregation and initiation, and high coagulation factors concentration, instead of by the coagulation cascade activation. Importantly, this hemostat exhibits excellent biodegradability and nearly no skin irritation. Overall, the biodegradable and tissue adhesive PDA sponge will be a promising quick-hemostatic dressing for uncontrollable hemorrhage.

Prehosp Emerg Care. 2019 Mar 15:1-7. doi: 10.1080/10903127.2019.1593566

# Layperson Ability and Willingness to Use Hemostatic Dressings: A Randomized, Controlled Trial.

Goolsby C, Rojas L, Moore K, Kretz E, Singletary E, Klimczak V, Charlton N.

BACKGROUND: The Hartford Consensus and Stop the Bleed Campaign empower the public to stop bleeding. While evidence for civilian tourniquet use is mounting, there is limited evidence regarding the public's ability to use hemostatic dressings. This study seeks to determine if laypeople can apply hemostatic dressings, and which hemostatic dressing they can use most successfully.

METHODS: 360 layperson participants in Maryland and Virginia completed 4 arms of this randomized, prospective controlled trial: plain gauze (control), z-folded gauze, s-rolled gauze, and injectable sponge (experimental) arms. Participants watched a standardized video, practiced hands-on dressing application, and were assessed applying the dressing via checklists and feedback mechanisms for pressure, timing, and packing. Participants completed pre and post questionnaires regarding willingness to use hemostatic dressings.

RESULTS: Overall, 202 participants (56%) applied the dressings correctly, and 83 (92%) applied the injectable sponges correctly. This is a significant difference from the other arms (p < 0.001), and OR 17.2 (95% CI 6.8 - 48.1) compared to control. 38 participants (40%) correctly applied plain gauze, while 37 (43%) and 44 (48%) participants correctly applied z-folded and s-rolled gauzes. The primary reasons for failure were not holding pressure long enough (n = 103, 65%) and not applying adequate pressure (n = 64, 41%). Participants in all arms had significant improvements in willingness to use hemostatic dressings: 154 (43.6%) participants pre vs. 344 (97.5%) post study participation (p < 0.001).

CONCLUSIONS: More than half of laypeople can apply hemostatic dressings, and they are most successful applying injectable sponges. Brief education increases laypeople's reported willingness to use hemostatic dressings. Educators and planners should consider including injectable sponges in their Stop the Bleed programs and products.

LEVEL OF EVIDENCE: II (RCT with significant difference. One negative criterion for observer blinding).

Int J Biol Macromol. 2019 Mar 1;124:138-147

# A review on recent advances in chitosan based composite for hemostatic dressings.

Khan M, Mujahid M

High mortality rate in potentially survivable casualties due to severe hemorrhage is a major challenge in today's battlefield because technological advancements have revolutionized the combat tactics and complicated the type and severity associated with wound grades. Quality of pre-hospital care prior to patient evacuation is crucial in determining the survival rate in injured patients. To deal with this challenge, considerable improvements in the hemostatic dressings have been introduced and pre-hospital care has been upgraded in many tactical combat casually care guidelines. Combat Gauze has been widely used bandage which is now been replaced by different chitosan based hemostatic dressings. It not only exhibits anti-bacterial activity but also induces hemostasis via direct interaction with erythrocytes and platelets. Its hemostasis mechanism is not dependent on host coagulation pathway which makes it an ideal dressing to stop bleeding in coagulopathic patients. Different generations of chitosan bandages have been developed to overcome the limitations of previous ones. This review provides performance analysis of chitosan bandage generations and discusses the progress made in its fabrication methods during the recent years.

J Spec Oper Med. Winter 2018;18(4):106-110.

# Efficacy of the Abdominal Aortic Junctional Tourniquet-Torso Plate in a Lethal Model of Noncompressible Torso Hemorrhage.

Bonanno A, Hoops H, Graham T, Davis B, McCully B, Wilson L, Madtson B, Ross J

BACKGROUND: The Abdominal Aortic Junctional Tourniquet, when modified with an off-label, prototype, accessory pressure distribution plate (AAJT-TP), has the potential to control noncompressible torso hemorrhage in prolonged field care.

METHODS: Using a lethal, noncompressible torso hemorrhage model, 24 male Yorkshire swine (81kg-96kg) were randomly assigned into two groups (control or AAJT-TP). Anesthetized animals were instrumented and an 80% laparoscopic, left-side liver lobe transection was performed. At 10 minutes, the AAJT-TP was applied and inflated to an intraabdominal pressure of 40mmHg. At 20 minutes after application, the AAJT-TP was deflated, but the windlass was left tightened. Animals were observed for a prehospital time of 60 minutes. Animals then underwent damage control surgery at 180 minutes, followed by an intensive care unit-phase of care for an additional 240 minutes. Survival was the primary end point.

RESULTS: Compared with Hextend, survival was not significantly different in the AAJT-TP group (ρ = .564), nor was blood loss (3.3L ± 0.5L and 3.0L ± 0.5L, respectively; p = .285). There was also no difference in all physiologic parameters between groups at the end of the study or end of the prehospital phase. Three of 12 AAJT-TP animals had an inferior vena cava thrombus.

CONCLUSION: The AAJT-TP did not provide any survival benefit compared with Hextend alone in this model of noncompressible torso hemorrhage.

J Trauma Acute Care Surg. 2019 Mar;86(3):532-539

# The effectiveness of junctional tourniquets: A systematic review and meta-analysis.

Smith S, White J, Wanis K, Beckett A, McAlister V, Hilsden R.

BACKGROUND: Junctional tourniquets have been incorporated into tactical combat casualty care for junctional vascular trauma. They apply external compression to stop blood flow in the groin and axilla.

OBJECTIVES: The primary outcome was effectiveness in achieving arterial occlusion. Secondary outcomes included time to application and pain scores.

DATA SOURCES: Medline and EMBASE databases were searched.

STUDY APPRAISAL AND SYNTHESIS METHODS: A random-effects meta-analysis was conducted to estimate the average effectiveness and time to effective application for each device.

RESULTS: Eight studies reported the effectiveness of junctional tourniquets in healthy volunteers. The average effectiveness was 52% (95% confidence interval [CI], 15-87%) for the abdominal application of the abdominal aortic and junctional tourniquet (AAJT), 83% (95% CI, 73-89%; 26%) for the junctional Emergency Treatment Tool, 87% (95% CI, 79-92%; 15%) for the SAM junctional tourniquet (SJT), and 95% (95% CI, 90-98%) for the Combat Ready Clamp. The groin application of the AAJT was studied in two articles with 100% in both studies. The average time to application was 101 seconds for the SAM junctional tourniquet (95% CI, 50-152 seconds) and the Combat Ready Clamp (95% CI, 63-139 seconds), while it was 130 seconds (95% CI, 85-176 seconds) for the Junctional Emergency Treatment Tool. The abdominal application of AAJT had an average time to application of 92 and 171 seconds in two studies.

LIMITATIONS: All studies were conducted in healthy volunteers.

CONCLUSION AND IMPLICATIONS: Junctional tourniquets may meet a medical need in combat, and in the civilian environment, to control hemorrhage from these difficult injuries. All four Food and Drug Administration-approved devices demonstrate the ability to achieve vascular occlusion in healthy volunteers; however, effectiveness in patient transport has not been evaluated, and outcomes of their use in the field need to be captured and reported.

LEVEL OF EVIDENCE: Systematic review, level III.

Mil Med. 2019 Mar 1;184(Suppl 1):367-373

# Pilot Study of a Novel Swine Model for Controlling Junctional Hemorrhage Using the iTClamp in Conjunction With Hemostatic Agents.

Stuart S, Zarow G, Walchak A, McLean J, Roszko P

Exsanguinating hemorrhage is a primary cause of battlefield death. The iTClamp is a relatively new device (FDA approval in 2013) that takes a different approach to hemorrhage control by applying mechanism wound closure. However, no previous studies have explored the feasibility of utilizing the iTClamp in conjunction with hemostatic packing. To fill this important gap in the literature, a novel swine model was developed, and a total of 12 trials were performed using QuikClot Combat Gauze or XSTAT sponges in conjunction with the iTClamp to treat arterial injuries through 5 cm or 10 cm skin incisions in the groin, axilla, or neck. First-attempt application success rate, application time, and blood loss were recorded. Hemostasis was achieved on all wounds, though reapplication was required in one Combat Gauze and three XSTAT applications. Application averaged ~50% slower for Combat Gauze (M = 41 seconds, 95%CI: 22-32 seconds) than for XSTAT (M = 27 seconds, 95%CI: 35-47 seconds). XSTAT application was faster than Combat Gauze for each wound location and size. The 10 cm wounds took ~10 seconds (36%) longer to close (M = 27 seconds, 95%CI: 35-47 seconds) than the 5 cm wounds (M = 27 seconds, 95%CI: 35-47 seconds). Blood loss was similar for Combat Gauze (M = 51 mL, 95%CI: 25-76 mL) and XSTAT (M = 60 mL, 95%CI: 30-90 mL). Blood loss was roughly twice as great for 10 cm wounds (M = 73 mL, 95%CI: 47-100 mL) than for 5 cm wounds (M = 38 mL, 95%CI: 18-57 mL). This pilot study supports the feasibility of a novel model for testing the iTClamp in conjunction with hemostatic packing towards controlling junctional hemorrhage.

J Trauma Acute Care Surg. 2019 Jul;87(1S Suppl 1):S172-S177

# Predictors and timing of amputations in military lower extremity trauma with arterial injury.

Kauvar D, Thomas S, Schechtman D, Walters T

INTRODUCTION: Military lower extremity arterial injuries present threats to life and limb. These injuries are common and limb salvage is a trauma system priority. Understanding the timing and predictors of amputation through the phases of casualty evacuation can help inform future limb salvage efforts. This study characterizes limbs undergoing amputation at different operationally relevant time points.

METHODS: A retrospective cohort study of casualties with lower extremity arterial injuries undergoing initial vascular limb salvage in Iraq and Afghanistan was undertaken. Amputations were grouped as having been performed early (in theater at Role 2 or 3) or late (after evacuation to Role 4 or 5). Further distinction was made between late and delayed (after discharge from initial hospitalization) amputations.

RESULTS: 455 casualties met inclusion criteria with 103 (23%) amputations. 21 (20%) were performed in theater and 82 (80%) were performed following overseas evacuation. 21 (26% of late amputations) were delayed, a median of 359 days from injury (IQR 176-582). Most amputations were performed in the first 4 days following injury. Amputation incidence was highest in popliteal injuries (28%). Overall amputation was predicted by higher incidence of blast mechanism and fracture and greater limb and casualty injury severity. Early amputations had higher limb injury severity than late amputations. Delayed amputations had greater incidence of motor and sensory loss and contracture than early amputations.

CONCLUSION: Casualty and limb injury severity predict predictors and timing of amputation in military lower extremity arterial injury. Amputation following overseas evacuation was more common than in-theater amputation and functional loss is associated with delayed amputation. Future limb salvage efforts should focus on post-evacuation and rehabilitative care.

EVIDENCE LEVEL: Level III, epidemiologic.

J Surg Res. 2019 Apr;236:247-258

# Large Animal Models of Proximal Aortic Balloon Occlusion in Traumatic Hemorrhage: Review and Identification of Knowledge Gaps Relevant to Expanded Use.

Kauvar D, Dubick M, Martin M

BACKGROUND: The aim of this study was to review and summarize the large animal data on resuscitative endovascular balloon occlusion of the aorta (REBOA) for traumatic hemorrhage and identify knowledge gaps pertinent to the proposed broader use of the technique in prehospital situations.

METHODS: A review of published large animal models of traumatic hemorrhage incorporating REBOA with a primary outcome of the effect of aortic occlusion was performed. Data were collected on experimental protocols, hemodynamic effects, resuscitation requirements, mortality, metabolic and tissue consequences of induced ischemia-reperfusion, and effects on hemorrhage volume and other injuries.

RESULTS: A limited number of REBOA studies exist, and there is variability in the species and size of animals used. Various controlled and uncontrolled hemorrhage protocols have been studied, and a number of balloon devices used. Hemodynamic effects of occlusion were consistent as were basic systemic physiological effects. Minimal study of the effects of partial aortic occlusion and hemodynamic and metabolic physiology distal to the balloon has been performed, and partial or complete occlusion times >90 min have not been studied.

CONCLUSIONS: Significant knowledge gaps exist, which are potentially relevant to the expanded use of REBOA. Investigation into the physiology of partial occlusion and the metabolic effects and potential mitigation strategies for large-scale ischemia and reperfusion are particularly needed.

Trauma Case Rep. 2019 Jul 3;22:100217. doi: 10.1016/j.tcr.2019.100217. eCollection 2019 Aug.

# Tactical tourniquet: Surgical management must be within 3 hours.

Caubère A, de Landevoisin E, Schlienger G, Demoures T, Romanat P

Despite longstanding controversy, tourniquets are widely used in tactical combat casualty care, with undisputed benefits for recent conflicts in Iraq and Afghanistan. Increased time delays are a particular issue in large areas, such as the Sahel-Saharan band. Complications associated with tourniquet use are predominantly related to acute ischemia with risk of amputation and ischaemia-reperfusion injury, as shown in the first clinical case. Often stated but poorly described, misuse of tourniquet and subsequent failure to interrupt arterial blood flow is also a clinical scenario that should be recognized. In the case of misuse of the tourniquet, more significant blood loss may be expected because of venous compression (« venous tourniquet », second clinical case). Early medical re-evaluation of the tourniquet is an essential component in prolonged field care. This includes reassessment of the tourniquet's ability to achieve hemostasis, abolish the downstream pulse and the relevance of the tourniquet altogether. This combat tool requires training to be successful and complications are time dependent. Tourniquet use requires appropriate application, re-evaluation and triage of wounded personnel within 3 h towards more structured surgical management.

J Spec Oper Med. 2019 Summer;19(2):128-133.

# Improvised Inguinal Junctional Tourniquets: Recommendations From the Special Operations Combat Medical Skills Sustainment Course.

Kerr W, Hubbard B, Anderson B, Montgomery HR, Glassberg E, King DR, Hardin RD Jr, Knight RM, Cunningham CW.

Effectively and rapidly controlling significant junctional hemorrhage is an important effort of Tactical Combat Casualty Care (TCCC) and can potentially contribute to greater survival on the battlefield. Although the US Food and Drug Administration (FDA) has approved labeling of four devices for use as junctional tourniquets, many Special Operations Forces (SOF) medics do not carry commercially marketed junctional tourniquets. As part of ongoing educational improvement during Special Operations Combat Medical Skills Sustainment Courses (SOCMSSC), the authors surveyed medics to determine why they do not carry commercial tourniquets and present principles and methods of improvised junctional tourniquet (IJT) application. The authors describe the construction and application of IJTs, including the use of available pressure delivery devices and emphasizing that successful application requires sufficient and repetitive training.

J Spec Oper Med. 2019 Summer;19(2):69-72.

# The Use of the Abdominal Aortic and Junctional Tourniquet Versus Combat Gauze in a Porcine Hemicorporectomy Model.

Schwartz RB, Shiver SA, Reynolds BZ, Lowry J, Holsten SB, Akers TW, Lyon M.

BACKGROUND: Junctional hemorrhage is a potentially preventable cause of death. The Abdominal Aortic and Junctional Tourniquet (AAJT) compresses major vascular structures and arrests blood flow in exsanguinating hemorrhage. In a human model, the AAJT was effective in stopping blood flow in the femoral arteries via compression of the distal aorta. This study compares the ability of AAJT and Combat Gauze (CG) to stop hemorrhagic bleeding from a hemicorporectomy in a swine model.

METHOD: Six anesthetized swine were used. Carotid arterial catheters were placed for continuous mean arterial pressure (MAP) readings. A hemicorporectomy was accomplished with a blade lever device by cutting the animal through both femoral heads transecting the proximal iliac arteries and veins. Hemorrhage control was attempted with the AAJT and regular Kerlix gauze or CG packing and direct pressure followed by Kerlix gauze placed over the CG. The primary outcome measure was survival at 60 minutes.

RESULTS: The 60-minute survival was 100% for the AAJT and 0% for the CG group. During the 60-minute monitoring period, only one CG animal achieved hemostasis. For the AAJT group, the mean time to hemostasis was 30 seconds. Initial MAP was higher in the AAJT group (mean, 87mmHg) than the CG group (mean, 70mmHg). The mean 60-minute MAP was 73mmHg for the AAJT group. Mean blood loss at 5 minutes and mean total blood loss were greater in the CG group than in the AAJT group.

CONCLUSION: AAJT is superior to CG in controlling hemorrhage in a junctional wound in a swine model.

Eur J Trauma Emerg Surg. 2019 Aug 20; Epub ahead of print

The safety and efficacy of improvised tourniquets in life-threatening hemorrhage: a systematic review.

Cornelissen M, Brandwijk A, Schoonmade L, Giannakopoulos G, van Oostendorp S, Geeraedts L

OBJECTIVE: The increased incidence of mass casualty incident (MCI) with penetrating injuries in the civilian setting creates a call for implementing devices, such as a tourniquet (TQ), in civilian first aid. Bystanders could act as immediate responders after an MCI in order to prevent a victim from exsanguination using direct pressure or commercial tourniquets (C-TQ). Reports have shown that immediate access to C-TQs was not available and bystanders used objects available at the trauma scene to make an improvised tourniquet (I-TQ). The aim of this systematic review of literature was to summarize the existing literature on designs, efficacy and safety of I-TQs.

METHODS: A systematic review of the literature was performed. Bibliographic databases PubMed, EMBASE.com and Cochrane Library were searched. All types of original studies about I-TQ's were included. Review studies, exempts from textbooks or studies with TQs applied during elective surgeries were excluded.

RESULTS: Twenty studies were included. In both simulated experiments and real-life situations, I-TQs outperformed commercial TQs (C-TQ) regarding success rate. Of the I-TQs, the band and windlass design performed most consistently. Although lacking any statistical analysis, there was no reported difference in adverse events between I-TQs and C-TQs.

CONCLUSION: The use of- and training in I-TQ by civilian immediate responders is not recommended because of limited efficacy and safety concerns; direct pressure is a viable alternative. However, I-TQs may save lives when applied correctly with proper objects; therefore, future studies regarding the best design and training in application of effective and safe I-TQs should be encouraged.

J Trauma Acute Care Surg. 2019 Sep;87(3):740-741

# Safe duration of Abdominal Aortic and Junctional Tourniquet application.

Kheirabadi B, Dubick M

NO ABSTRACT AVAILABLE

J Spec Oper Med. 2019 Fall;19(3):45-50.

# Deliberate Practice in Combat Application Tourniquet Placement by Loop Passage.

Kragh JF Jr, Aden JK 3rd, Dubick MA.

BACKGROUND: We sought opportunities to develop learning practices of individual first aid providers. In this study, we simulated deliberate practice in placing limb tourniquets.

METHODS: This study comprised tourniquet uses by two experienced persons. Their practice sessions focused on developing a motor skill with periodic coaching. The Combat Application Tourniquet is 1.5-inches wide and was used in a technique of loop passage around the end of the limb to place it 2-3 inches above the wound. The simulated limb was a Z-Medica Hemorrhage Control Trainer. Both users applied the tourniquet six times over 5 days to accrue 30 uses individually (N = 60 tourniquet applications for the study).

RESULTS: When represented as summary parameters, differences were small. For example, average ease of use was the same for both users, but such parameters only took a snapshot of performance, yielding a general assessment. However, for a learning curve by use number, a surrogate of experience accrual, application time revealed spiral learning. The amount that users compressed a limb averaged -15% compared with its unsqueezed state. Placement accuracy was classified relative to gap widths between the tourniquet and the wound, and of 60 performances, 55 were satisfactory and five were unsatisfactory (i.e., placement was <2 inches from the wound). When a tourniquet only overlaid the 2-inch edge of the placement zone (i.e., tourniquet was 2-3.5 inches away from the wound), no error was made, but errors were made in crossing that 2-inch edge. These gauging errors led us to create a template for learners to see and to demonstrate what the meaning of 2-3 inches is.

CONCLUSION: Each metric had value in assessing first aid, but turning attention to gauging wound-tourniquet gaps revealed placement errors. Analysis of such errors uncovered what 2-3 inches meant in operation. Spiral learning may inform the development of best readiness practices such as coaching deliberate-practice sessions.

J Spec Oper Med. 2019 Fall;19(3):31-44.

# Management of Hemorrhage From Craniomaxillofacial Injuries and Penetrating Neck Injury in Tactical Combat Casualty Care: iTClamp Mechanical Wound Closure Device TCCC Guidelines Proposed Change 19-04 06 June 2019.

Onifer DJ, McKee JL, Faudree LK, Bennett BL, Miles EA, Jacobsen T, Morey JK, Butler FK Jr.

The 2012 study Death on the battlefield (2001-2011) by Eastridge et al.1 demonstrated that 7.5% of the prehospital deaths caused by potentially survivable injuries were due to external hemorrhage from the cervical region. The increasing use of Tactical Combat-Casualty Care (TCCC) and other medical interventions have dramatically reduced the overall rate of combat-related mortality in US forces; however, uncontrolled hemorrhage remains the number one cause of potentially survivable combat trauma. Additionally, the use of personal protective equipment and adaptations in the weapons used against US forces has caused changes in the wound distribution patterns seen in combat trauma. There has been a significant proportional increase in head and neck wounds, which may result in difficult to control hemorrhage. More than 50% of combat wounded personnel will receive a head or neck wound. The iTClamp (Innovative Trauma Care Inc., Edmonton, Alberta, Canada) is the first and only hemorrhage control device that uses the hydrostatic pressure of a hematoma to tamponade bleeding from an injured vessel within a wound. The iTClamp is US Food and Drug Administration (FDA) approved for use on multiple sites and works in all compressible areas, including on large and irregular lacerations. The iTClamp's unique design makes it ideal for controlling external hemorrhage in the head and neck region. The iTClamp has been demonstrated effective in over 245 field applications. The device is small and lightweight, easy to apply, can be used by any level of first responder with minimal training, and facilitates excellent skills retention. The iTClamp reapproximates wound edges with four pairs of opposing needles. This mechanism of action has demonstrated safe application for both the patient and the provider, causes minimal pain, and does not result in tissue necrosis, even if the device is left in place for extended periods. The Committee on TCCC recommends the use of the iTClamp as a primary treatment modality, along with a CoTCCC-recommended hemostatic dressing and direct manual pressure (DMP), for hemorrhage control in craniomaxillofacial injuries and penetrating neck injuries with external hemorrhage.

Anaesthesiol Intensive Ther. 2019;51(3):240-248

# Pre-hospital environment bleeding: from history to future prospects.

Pereira B, Dorigatti A, Calderon L, Negrão M, Meirelles G, Duchesne J

While the blood was related to life since antiquity, scientific investigations on anatomy and physio-logy of the circulation system had to wait until the arrival of the 16th century. In trauma patients, hemorrhagic shock is the main risk factor for multiple organ dysfunction and consequent increased mortality. On the pre-hospital setting intravenous administration of crystalloid solution became the more common intervention during resuscitation of trauma patient due to many reasons although currently new discussions have blossomed on regards type of fluids and resuscitation. The object of this manuscript is to review the history of pre-hospital care bleeding management and to gather new perspectives for the future. Herein authors discuss several issues on bleeding control: 1. Current status and future possibilities on stop the bleeding in the the pre-hospital setting - movements after the Hartford Consensus, use of topic homeostatic agents, tourniquets, REBOA and other radical interventions; 2. Damage control resuscitation in the pre-hospital environment - is massive transfusion protocol feasible at this setting? Tranexemic acid should be done? Possibilities that may improve survival and coagulopathy understanding; 3. Critical decision and decision making on stop the bleed; 4. Proposed flowchart on bleeding control. The implementation of measures to stop acute bleeding in the pre-hospital setting is a well-known and well-founded measure. However, the provision of current evidence demonstrates that these measures go far beyond compression and elevation of the limb as was known in the past. The deep understanding of the mechanism of coagulopathy and the new adjuvant arsenal to control bleeding are essential for a better quality of pre-hospital medical care as well as lower mortality rates.

Eur J Trauma Emerg Surg. 2019 Sep 5;Epub ahead of print

# International perspective of tourniquet use in extremity vascular trauma: a commentary from the Sri Lankan civil war experience.

Ratnayake A, Bala M, Worlton T

Civilian trauma care has always been influenced by lessons learned in war trauma. Currently this transfer of knowledge has been exemplified by The Hartford Consensus III: Implementation of Bleeding Control which examines and advocates for tourniquet use in civilian settings. The authors seek to share their unique experience with combat extremity vascular trauma for a global perspective on use of tourniquets in unconventional warfare.

A recent single-institution retrospective analysis by Smith et al. of pre hospital tourniquet application matched with a comparable group without tourniquets in a civilian level 1 trauma center concluded that tourniquet application was favorably associated with less shock at presentation to emergency department, decreased blood product utilization and decreased limb related complications. In this study, the average time from tourniquet placement to arrival in the Emergency Department was 23.9 min and the majority were placed by trained medical personnel.

J Spec Oper Med. 2019 Fall;19(3):123-127.

# Proficiency in Improvised Tourniquets for Extremities: A Review.

Rohrich C, Plackett T, Scholz B, Hetzler M

Tourniquets have become ubiquitous tools for controlling hemorrhage in the modern prehospital environment, and while commercial products are preferable, improvised tourniquets play an important role when commercial options are not available. A properly constructed improvised tourniquet can be highly effective provided the user adheres to certain principles. This review article identifies key skills in the construction and application of improvised tourniquets on an extremity. An improvised tourniquet design for an extremity should include three components: a strap, a rod, and a securing mechanism. The strap can be made from a variety of materials, but cravat- like fabric has been shown to work well. Optimal strap dimensions should be at least 2cm in width and a continuous segment long enough to extend around the extremity while still offering ends to accommodate and secure the rod. The rod should be constructed from a material that is hard, strong, and capable of withstanding the torque placed on it without bending or breaking. After torque is applied, the rod must be secured into position to maintain the constricting force and survive patient transport. Finally, the need for an improvised tourniquet is a contingency that all first responders should anticipate. Hands-on training should be conducted routinely in conjunction with other first responder tasks.

J Trauma Acute Care Surg. 2019 Oct 14;Epub ahead of print

# A Comprehensive Review of Topical Hemostatic Agents: The Good, The Bad, and the Novel.

Tompeck A, Gajdhar A, Dowling M, Johnson S, Barie P, Winchell R, King D, Scalea T, Britt L, Narayan M

Exsanguination remains the leading cause of preventable death for trauma patients, many of whom die in the pre-hospital setting. Without expedient intervention, trauma-associated hemorrhage induces a host of systemic responses, including the acute coagulopathy of trauma. For this reason, healthcare providers and pre-hospital personnel face the challenge of rapid, effective hemorrhage control. The utilization of adjuncts to facilitate hemostasis was first recorded in 1886. Commercial products have since expanded to include topical hemostats, surgical sealants, and adhesives. The ideal product balances efficacy, safety, practicality, and cost-effectiveness. This review of hemostatic agents provides a guide for successful implementation and simultaneously highlights future opportunities.

Trauma Surg Acute Care Open. 2019 Jul 12;4(1):e000335

# 'Step Up' approach to the application of REBOA technology in a rural trauma system.

Vernamonti J, Holcomb J, Mick N, Falank C, Ontengco J, Rappold J, Sheppard F

Our group has developed a 'Step Up' approach to the application of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in a rural trauma system. This incorporates viewing REBOA as a spectrum of technology. Examples of REBOA technology use to improve outcomes and provision of our system's clinical practice guideline for the Step-Up application of REBOA technology in the care of trauma patients are presented.

J Spec Oper Med. 2019 Fall;19(3):52-63.

# Review: Getting Tourniquets Right = Getting Tourniquets Tight.

Wall P, Buising C, Sahr S

Tourniquet application to stop limb bleeding is conceptually simple, but optimal application technique matters, generally requires training, and is more likely with objective measures of correct application technique. Evidence of problems with application techniques, knowledge, and training can be ascertained from January 2007 to August 2018 PubMed peer-reviewed papers and in Stop The Bleed-related videos. Available data indicates optimal technique when not under fire involves application directly on skin. For nonelastic tourniquets, optimal application technique includes pulling the strap tangential to the limb at the redirect buckle (parallel to the limb-encircling strap entering the redirect buckle). Before engaging the mechanical advantage tightening system, the secured strap should exert at least 150mmHg inward, and skin indentation should be visible. For Combat Application Tourniquets, optimal technique includes the slot in the windlass rod parallel to the stabilization plate during the single 180° turn that should be sufficient for achieving arterial occlusion, which involves visible skin indentation and pressures of 250mmHg to 428mmHg on normotensive adult thighs. Appropriate pressures on manikins and isolated-limb simulations depend on how the under-tourniquet pressure response of each compares to the under-tourniquet pressure response of human limbs for matching tourniquet force applications. Lack of such data is one of several concerns with manikin and isolated-limb simulation use. Regardless of model or human limb use, pictures and videos purporting to show proper tourniquet application techniques should show optimal tourniquet application techniques and properly applied, arterially occlusive limb tourniquets. Ideally, objective measures of correct tourniquet application technique would be included.

Sci Rep. 2019 Oct 10;9(1):14608

# Evaluation of Chitosan-based Dressings in a Swine Model of Artery-Injury-Related Shock.

Wang Y, Liu C, Cherng J, Fan G, Wang Y, Chang S, Hong Z, Lin Y, Hsu S

Uncontrolled haemorrhage shock is the highest treatment priority for military trauma surgeons. Injuries to the torso area remain the greatest treatment challenge, since external dressings and compression cannot be used here. Bleeding control strategies may thus offer more effective haemostatic management in these cases. Chitosan, a linear polysaccharide derived from chitin, has been considered as an ideal material for bleeding arrest. This study evaluated the potential of chitosan-based dressings relative to commercial gauze to minimise femoral artery haemorrhage in a swine model. Stable haemostasis was achieved in animals treated with chitosan fibre (CF) or chitosan sponge (CS), resulting in stabilisation of mean arterial pressure and a substantially higher survival rate (100% vs. 0% for gauze). Pigs receiving treatment with CF or CS dressings achieved haemostasis within 3.25 ± 1.26 or 2.67 ± 0.58 min, respectively, significantly more rapidly than with commercial gauze (>100 min). Moreover, the survival of animals treated with chitosan-based dressings was dramatically prolonged (>180 min) relative to controls (60.92 ± 0.69 min). In summary, chitosan-based dressings may be suitable first-line treatments for uncontrolled haemorrhage on the battlefield, and require further investigation into their use as alternatives to traditional dressings in prehospital emergency care.