Circulation - Hemorrhage Control

#### HEMORRHAGE CONTROL

J Trauma Acute Care Surg. 2019 Nov;87(5):1096-1103

# Missing expectations: Windlass tourniquet use without formal training yields poor results.

Dennis A, Bajani F, Schlanser V, Tatebe L, Impens A, Ivkovic K, Li A, Pickett T, Butler C, Kaminsky M, Messer T, Starr F, Mis J, Bokhari F.

BACKGROUND: Despite significant attempts to educate civilians in hemorrhage control, the majority remain untrained. We sought to determine if laypersons can successfully apply one of three commercially available tourniquets; including those endorsed by the United States Military and the American College of Surgeons.

METHODS: Preclinical graduate health science students were randomly assigned commercially available windless tourniquet: SAM XT, Combat Application Tourniquet (CAT), or Special Operation Forces Tactical Tourniquet (SOFT-T). Each was given up to 1 minute to read package instructions and asked to apply it to the HapMed Leg Tourniquet Trainer. Estimated blood loss was measured until successful hemostatic pressure was achieved or simulated death occurred from exsanguination. Simulation survival, time to read instructions and stop bleeding, tourniquet pressure, and blood loss were analyzed.

RESULTS: Of the 150 students recruited, 55, 46, and 49 were randomized to the SAM XT, CAT, SOFT-T, respectively. Mean overall simulation survival was less than 66% (65%, 72%, 61%; p = 0.55). Of survivors, all three tourniquets performed similarly in median pressure applied (319, 315, and 329 mm Hg; p = 0.54) and median time to stop bleeding (91, 70, 77 seconds; p = 0.28). There was a statistical difference in median blood loss volume favoring SOFT-T (SAM XT, 686 mL; CAT, 624 mL; SOFT-T, 433 mL; p = 0.03). All 16 participants with previous experience were able to successfully place the tourniquet compared with 81 (62%) of 131 first-time users (p = 0.008).

CONCLUSION: No one should die of extremity hemorrhage, and civilians are our first line of defense. We demonstrate that when an untrained layperson is handed a commonly accepted tourniquet, failure is unacceptably high. Current devices are not intuitive and require training beyond the enclosed instructions. Plans to further evaluate this cohort after formal "Stop the Bleed" training are underway.

J Inj Violence Res. 2019 Jan;11(1):29-34

# The iTClamp in the treatment of prehospital craniomaxillofacial injury: a case series study.

Mckee J, Mckee I, Ball C, Tan E, Moloff A, McBeth P, LaPorta A, Bennett B, Filips D, Teicher C, Kirkpatrick AW.

BACKGROUND: Craniomaxillofacial (CMF) injuries are very common in both civilian and military settings. Nearly half of all civilian trauma incidents include a scalp laceration and historical rates of CMF battle injuries increased from 16%-21% to 42.2%. The scalp is highly vascular tissue and uncontrolled bleeding can lead to hypotension, shock and death. Therefore, enabling on-scene providers, both military and civilian, to immediately manage scalp and face lacerations, in a manner that allows them to still function in a tactical way, offers operational advantages. This case series examines how effectively a wound-clamp (iTClamp) controlled bleeding from CMF injuries pre-hospital environment.

METHODS: The use of the iTClamp for CMF (scalp and face laceration) was extracted from iTrauma Care's post market surveillance database. Data was reviewed and a descriptive analysis was applied.

RESULTS: 216 civilian cases of iTClamp use were reported to iTrauma Care. Of the 216 cases, 37% (n=80) were for control of CMF hemorrhage (94% scalp and 6% face). Falls (n=24) and MVC (n=25) accounted for 61% of the mechanism of injury. Blunt accounted for 66% (n=53), penetrating 16% (n=13) and unknown 18% (n=14). Adequate hemorrhage control was reported in 87.5% (n=70) of cases, three respondents reported inadequate hemorrhage control and in seven cases hemorrhage control was not reported. Direct pressure and packing was bandoned in favor of the iTClamp in 27.5% (n=22) of cases.

CONCLUSIONS: CMF injuries are common in both civilian and military settings. Current options like direct manual pressure (DMP) often do not work well, are formidable to maintain on long transports and Raney clips are a historical suggestion. The iTClamp offers a new option for control of external hemorrhage from open wounds within compressible zones.

J Emerg Med. 2019 Jan 29. pii: S0736-4679(18)31197-1. doi:n10.1016/j.jemermed.2018.12.008. [Epub ahead of print]

# A Randomized Controlled Trial using iTClamp, Direct Pressure, and Balloon Catheter Tamponade to Control Neck Hemorrhage in a Perfused Human Cadaver Model.

Mckee J, Mckee I, Bouclin M, Filips D, Atkinson I, Ball C, McBeth P, Kirkpatrick M

BACKGROUND: Penetrating neck wounds are common in the civilian and military realms. Whether high or low velocity, they carry a substantial morbidity and mortality rate.

OBJECTIVES: We endeavored to ascertain whether the iTClamp is equivalent to direct manual pressure (DMP) and Foley catheter balloon tamponade (BCT).

METHODS: Using a perfused cadaver, a 4.5-cm wound was made in Zone 2 of the neck with a 1-cm carotid arteriotomy. Each of the hemorrhage control modalities was randomized and then applied to the wound separately. Time to apply the device and fluid loss with and without neck motion was recorded.

RESULTS: There was no significant difference between the fluid loss/no movement (p > 0.450) and fluid loss/movement (p > 0.215) between BCT and iTClamp. There was significantly more fluid lost with DMP than iTClamp with no movement (p > 0.000) and movement (p > 0.000). The iTClamp was also significantly faster to apply than the Foley (p > 0.000).

CONCLUSIONS: The iTClamp and BCT were associated with significantly less fluid loss than DMP in a perfused cadaver model. The iTClamp required significantly less time to apply than the BCT. Both the iTClamp and the BCT were more effective than simple DMP. The iTClamp offers an additional option for managing hard-to-control bleeding in the neck.

J Trauma Acute Care Surg. 2019 Apr;86(4):625-634

# Minimally invasive preperitoneal balloon tamponade and abdominal aortic junctional tourniquet versus open packing for pelvic fracture-associated hemorrhage: Not all extrinsic compression is equal.

Do W, Forte D, Sheldon R, Weiss J, Barron M, Sokol K, Black G, Hegge S, Eckert M, Martin M

BACKGROUND: Minimally invasive preperitoneal balloon tamponade (PPB) and abdominal aortic junctional tourniquets (AAJT) have been proposed as alternatives to open preperitoneal packing (OP) for the management of pelvic fracture-associated hemorrhage. We hypothesized that the PPB (SpaceMaker Pro) and AAJT would result in similar rates of survival and blood loss versus OP.

METHODS: Thirty-two swine underwent creation of a combined open-book pelvic fracture and major iliac vascular injuries. Animals were randomized to no intervention (n = 7), OP (n = 10), PPB (n = 9), or AAJT (n = 6) at a mean arterial pressure <40 mm Hg following initiation of uncontrolled hemorrhage. Survival (up to 60 minutes + 10 minutes after intervention reversal), hemodynamics, extraperitoneal pressures, blood loss, and associated complications were compared between groups.

RESULTS: Prior to injury, no difference was measured between groups for weight, hemodynamics, lactate, and hematocrit (all p > 0.05). The injury was uniformly lethal without intervention, with survival time (mean) of 5 minutes, peak preperitoneal pressure (PP) of 14 mm Hg, blood loss of 960 g, and peak lactate of 2.6 mmol/L. Survival time was 44 minutes with OP versus 60 minutes with PPB and AAJT (p < 0.01). Peak PP (mm Hg) was 19 with OP, 23 with PPB, and 23 with AAJT (p > 0.05). Blood loss (g) was 850 with OP, 930 with PPB, and 600 with AAJT (p > 0.05). Peak lactate (mmol/L) was 3.3 with OP, 4.3 with PPB, and 6.3 with AAJT (p < 0.01). Only 33% of AAJT animals survived intervention reversal versus 60% for OP and 67% for PPB (p < 0.01). Necropsy revealed bowel/bladder injury in 50% of AAJT subjects versus 0% in all other arms (p < 0.01).

CONCLUSION: Preperitoneal balloon tamponade is a safe and potentially effective alternative to OP for the management of lethal pelvic fracture-associated hemorrhage. Abdominal aortic junctional tourniquet offers a similar survival benefit to PPB but has concerning rates of ischemia-reperfusion and compressive abdominal organ injury.

#### PELVIC IMMOBILIZATION / HEMORRHAGE

J Trauma Acute Care Surg. 2019 Jan;86(1):155-159

# Endovascular control of pelvic hemorrhage: Concomitant use of resuscitative endovascular balloon occlusion of the aorta and endovascular intervention.

Adnan S, Wasicek P, Crawford A, Dubose J, Brenner M, Scalea T, Morrison J

CONCLUSIONS: We describe the technical considerations for endovascular interventions concurrent with REBOA use in patients with pelvic hemorrhage. Determining the access site for angiography and intervention is a major therapeutic consideration in pelvic hemorrhage, with options including upper and lower extremity arteries, each with practical considerations. Lower extremity access affords the use of shorter systems but can be more challenging in terms of vessel access and the maneuvering of wires and catheters. Upper extremity access can be a useful way of avoiding the groin region altogether but involves specialist equipment and limits some endovascular interventions such as large diameter-covered stent-graft deployment. The use of upper or lower extremity access should be made on the basis of patient factors and clinical capability. Further research is required in this area to optimize the timely care of this critical patient group.

J Med Case Rep. 2018 Sep 21;12(1):271

# False negative computed tomography scan due to pelvic binder in a patient with pelvic disruption: a case report and review of the literature.

Jamme S, Poletti A, Gamulin A, Rutschmann O, Andereggen E, Grosgurin O, Marti C

BACKGROUND: Pelvic binders are routinely used in the prehospital setting for stabilization of pelvic injuries in patients with trauma. Emergency department trauma management relies on primary and secondary survey assessment and imaging, most often computed tomography, in hemodynamically stable patients. Maintaining the pelvic binder in situ allows stabilization of pelvic injuries during imaging but may hinder the visualization of some pelvic lesions. We report a very rare case of severe pelvic disruption with an absolutely normal computed tomography scan due to the effective placement of a pelvic binder.

CASE PRESENTATION: We report the case of a 49-year-old Caucasian man referred to our Emergency Department after a high velocity motorcycle accident. Primary assessment revealed a left wrist deformation and pelvic pain, and a pelvic binder was applied by paramedics. A total body computed tomography scan was performed after arrival in our Emergency Department and did not reveal any pelvic injury. The pelvic binder was removed and because of persisting symphyseal pain, pelvic plain radiography was performed revealing a pelvic disruption with an opening of the pubic symphysis and of the left sacroiliac joint ("open book" type pelvic injury) requiring surgical stabilization.

CONCLUSIONS: Pelvic binders may mask pelvic disruption in patients with trauma. Pelvic plain radiography should be repeated after pelvic binder removal in patients with high velocity trauma and pelvic symptoms or neurological alterations limiting the reliability of clinical examination.

Bull Emerg Trauma. 2019 Apr;7(2):156-161

# Three Dimensional Quality Assessments of Applied Pelvic Binders.

Bakhshayesh P, Risling D, Enocson A

Objective: To assess the quality of applied pelvic binders using three dimensional computer tomography (3D CT).

Methods: A local trauma registry was used to identify patients with pelvic fractures after high-energy trauma during 2011-2015. A 3D CT reconstruction was made from the initial trauma computer tomography images to assess the level of application, symmetricity of the binder and achieved fracture reduction. An acceptable application of the pelvic binder was deemed if it was at the trochanteric level, symmetric and minimized residual displacement.

Results: We found 73 patients with a pelvic fracture and a pelvic binder on the initial trauma CT-scan. The mean (±SD) age of the patients was 46±17 years and 40% (n=29) were females. The median ISS score was 38 (IQR;29-50), the mean systolic blood pressure on arrival was 106±46 mmHg and the median GCS on arrival was 14 (IQR;7-15). We found that 59% (n=43) of the binders were correctly applied (symmetric at the trochanteric level, symmetrical and with acceptable residual displacement of the fracture). The 30-day mortality was higher in patients with non-correct application 17% (n=5/30) compared to patients with correct application of the pelvic binder 9.3% (n=4/43) however this was not statistically significant (p=0.562).

Conclusion: A substantial number of patients had non-correct application of pelvic binders. Future studies using 3D technique are encouraged to further investigate clinical impacts of non-appropriate application of pelvic binders.

Injury. 2019 Aug 10. pii: S0020-1383(19)30456-5

# Haemodynamics as a determinant of need for pre-hospital application of a pelvic circumferential compression device in adult trauma patients.

McCreary D, Cheng C, Lin Z, Nehme Z, Fitzgerald M, Mitra B

INTRODUCTION: Pelvic ring fractures are common following high-energy blunt trauma and can lead to substantial haemorrhage, morbidity and mortality. Pelvic circumferential compression devices (PCCDs) improve position and stability of open-book type pelvic fracture, and can improve haemodynamics in patients with hypovolaemic shock. However, PCCDs may cause adverse outcomes including worsening of lateral compression fracture patterns and routine use is associated with high costs. Controversy regarding indication of PCCDs exists with some centres recommending PCCD in the setting of hypovolaemic shock compared to placement for any suspected pelvic injury.

OBJECTIVE: To assess the need for PCCD application based on pre-hospital vital signs and mechanism of injury.

METHODS: A retrospective cohort study was conducted in a single adult major trauma centre examining a 2-year period. Patients were sub-grouped based on initial pre-hospital and emergency department observations as haemodynamically normal (heart rate <100 bpm, systolic blood pressure ≥100 mmHg and Glasgow Coma Scale ≥13) or abnormal. Diagnostic accuracy of pre-hospital haemodynamics as a predictor of pelvic fracture requiring intervention within 24 h was assessed.

RESULTS: There were 376 patients with PCCD in-situ on hospital arrival. Pelvic fractures were diagnosed in 137 patients (36.4%). Of these, 39 (28.5%) were haemodynamically normal and 98 (71.5%) were haemodynamically abnormal. The most common mechanisms of injury were motor vehicle collision (57.7%) and motorcycle collision (13.8%). Of those with fractures, 40 patients (29.2%) required pelvic intervention within 24 h of admission; of these, 8 (20%) were haemodynamically normal and 32 (80%) were haemodynamically abnormal. As a test for pelvic fracture requiring intervention within 24 h, abnormal pre-hospital haemodynamics had a sensitivity of 0.80 (95% CI 0.64-0.91), specificity of 0.32 (95% CI 0.27-0.38) and negative predictive value (NPV) of 0.93 (95% CI 0.88-0.96). Combined with absence of a major mechanism of injury, normal haemodynamics had a sensitivity 1.00, specificity 0.51 (95% CI 0.36-0.66) and NPV of 1.00 for pelvic intervention within 24 h.

CONCLUSION: Normal haemodynamic status, combined with absence of major mechanism of injury can rule out requirement for urgent pelvic intervention. Ongoing surveillance is recommended to monitor for any adverse effects of this change in practice.

J Trauma Acute Care Surg. 2019 Jul;87(1):117-124

# The effect of hemorrhage control adjuncts on outcome in severe pelvic fracture: A multi-institutional study.

Duc hesne J, Costantini T, Khan M, Taub E, Rhee P, Morse B, Namias N, Schwarz A, Graves J, Kim DY, Howell E, Sperry J, Anto V, Winfield RD, Schreiber M, Behrens B, Martinez B, Raza S, Seamon M, Tatum D.

BACKGROUND: Hemodynamically unstable patients with severe pelvic fracture are a significant challenge to trauma surgeons and have high mortality. Significant variability across institutions in hemorrhage control adjuncts used to quell pelvic bleeding has been demonstrated. However, the effect of these methods on time to definitive bleeding control, type of resuscitation given, and outcomes remains unknown. We sought to elucidate those effects.

METHODS: This was a multicenter retrospective review of severe pelvic fracture patients in shock between 2011 and 2016. Shock was defined as systolic blood pressure less than 90 mm Hg, heart rate greater than 120 beats per minute, or base deficit less than -5. Definitive bleeding control was defined as time to surgical control in the operating room or embolization by interventional radiology. Significance level was at p less than 0.05.

RESULTS: A total of 279 severe pelvic fracture patients with shock on admission from 12 trauma centers were included. The cohort was primarily male (62%) with median (interquartile range) age of 40 years (28-54 years), Injury Severity Score of 38 (29-50), and Glasgow Coma Scale score of 13 (3-15). Overall mortality was 32%. The most common adjunct used was pelvic binder (50%) followed by no adjunct (30.5%); least common was resuscitative balloon occlusion of the aorta (REBOA) (2.5%). Preperitoneal packing alone and REBOA alone/with other adjunct(s) resulted in the fastest times to operating room/interventional radiology but also had the highest blood utilization and mortality rates. Resuscitative balloon occlusion of the aorta was most often used along with pelvic binder (6 of 13; 46%).

CONCLUSION: Marked variation in management of severe pelvic fracture patients in shock indicates the need for a standardized approach to maximize outcomes and minimize transfusion requirements. The use of preperitoneal packing and/or REBOA yielded fastest times to definitive bleeding control. However, REBOA continues to be infrequently used. Future prospective analysis of this combination needs further validation in patients with severe pelvic hemorrhage.

LEVEL OF EVIDENCE: Therapeutic study, level IV.

Air Med J. 2019 Jul - Aug;38(4):294-297

# Clinical Examination of the Pelvic Ring in the Prehospital Phase.

van Leent EAP(1), van Wageningen B(2), Sir Ö(3), Hermans E(4), Biert J(2).

INTRODUCTION: Instable pelvic fractures are associated with significant hemorrhage and shock. Instability of the pelvic ring should be tested with the manual compression test (MCT) and instable pelvic ring fractures should prompt mechanical stabilization. However, the accuracy of the prehospital MCT in patients, that sustained a high energetic trauma, is still unknown.

SETTING: Radboudumc Nijmegen, level 1 trauma center, the Netherlands.

METHODS: This prospective blind observational study included all patients after a high impact blunt trauma treated by an experienced Helicopter Emergency Medical Service (HEMS) physician. Nominal arranged questionnaires were filled in by the HEMS physician prior to the radiological examination of the patient.

RESULTS: We included 56 patients of which 11 sustained a pelvic ring fracture. 13 patients were treated with pelvic compression devices, of which only five patients had a pelvic ring fracture. Prehospital performed clinical examination by the HEMS physicians had an overall sensitivity of 0.45 (95% CI 0.16-0.75) and a specificity of 0.93 (95% CI 0.29-0.96).

CONCLUSION: Pelvic ring instability cannot accurately be diagnosed in the prehospital setting, based on the MCT. The use of the pelvic binder should standard in high impact blunt trauma patients, independently of the MCT or trauma mechanism.

Eur J Trauma Emerg Surg. 2019 Oct 14;Epub ahead of print

# Is there any benefit in the pre-hospital application of pelvic binders in patients with suspected pelvic injuries?

Schweigkofler U, Wohlrath B, Trentzsch H, Horas K, Hoffmann R, Wincheringer D

BACKGROUND: Massive hemorrhage is a common cause of death in patients sustaining instable pelvic ring fractures. Pelvic binders have been propagated for rapid, non-invasive pelvic ring stabilization and control of severe pelvic hemorrhage. There is a recommendation to applicate a pelvic binder due to the trauma mechanism alone. However, there is little evidence to support this advice. The aim of this study was to evaluate effects of an early pelvic binder application on transfusion requirements and hospital mortality.

METHODS: This was a subgroup analysis of a study investigating clinical examination for pelvic stability. We included 64 patients who showed radiologically proven pelvic ring fracture (Tile type B or C). Study data were complemented by retrospective chart review to assess transfusion requirements. We used descriptive statistical analysis.

RESULTS: 37 patients had a pelvic binder applied during prehospital treatment (pb), 27 received no binder (npb). Both showed no statistically significant difference in terms of injury severity or probability of survival. We found a trend towards higher ISS (29.7 vs. 24.4) and a lower probability of survival (RISC-II Prognosis 81% vs. 89%) in the pb group. Risk for massive transfusion according to TASH-Scores (10% vs. 6%), and average number of RPBC transfused (10.5 vs. 7.5) was higher in the pb group, without statistically significance. 20 patients (54%) in the pb group and 15 patients (55%) in the npb group showed a need of RPBC within the first 72 h. There was no significant difference in hospital mortality (20% vs. 13.3%).

CONCLUSION: We were unable to identify blood-saving effects with application of a pelvic binder to patients with instable pelvic ring fractures in terms of RPBC requirements. Nevertheless, some salutary effect of prehospital pb application may be assumed. Better studies are needed to elucidate the value of this intervention.

#### ADVANCED HEMORRHAGE CONTROL

J Spec Oper Med. Winter 2018;18(4):70-74.

# Feasibility Study Vascular Access and REBOA Placement: From Zero to Hero.

Borger van der Burg B, Maayen R, van Dongen T Gerben C, Eric C, DuBose J, Horer T, Bowyer M, Hoencamp R.

BACKGROUND: Vascular access is a necessary prerequisite for REBOA placement in patients with severe hemorrhagic shock.

METHODS: During an EVTM workshop, 10 Special Forces (SOF) medics, five combat nurses, four military nonsurgeon physicians, and four military surgeons participated in our training program. The military surgeons functioned as the control group. A formalized curriculum was constructed including basic anatomy and training in access materials for resuscitative endovascular balloon occlusion of the aorta (REBOA) placement. Key skills were (1) preparation of endovascular toolkit, (2) achieving vascular access in the model, and (3) bleeding control with REBOA.

RESULTS: The baseline knowledge of anatomy for SOF medics was significantly less than that for nurses and physicians. Medics had a median time of 3:59 minutes to sheath insertion; nurses, 2:47; physicians, 2:34; and surgeons, 1:39. Military surgeons were significantly faster than medics and military nurses (ρ = .037 resp. 0.034). Medics had a median total time from start to REBOA inflation of 5:05 minutes; nurses, 4:06; military physicians, 3:36; and surgeons, 2:36.

CONCLUSION: This study showed that a comprehensive theoretical and practical training program using a task training model can be used for percutaneous femoral access and REBOA placement training of military medical personnel without prior ultrasound or endovascular experience. Higher levels of training reduce procedure times.

J Spec Oper Med. Winter 2018;18(4):37-55.

# Advanced Resuscitative Care in Tactical Combat Casualty Care: TCCC Guidelines Change 18-01:14 October 2018.

Butler FK Jr, Holcomb JB, Shackelford S, Barbabella S, Bailey JA, Baker JB, Cap

AP, Conklin CC, Cunningham CW, Davis M, DeLellis SM, Dorlac WC, DuBose JJ,

Eastridge B, Fisher AD, Glasser JJ, Gurney J, Jenkins DA, Johannigman J, King DR,

Kotwal RS, Littlejohn LF, Mabry RL, Martin MJ, Miles EA, Montgomery HR, Northern

DM, O'Connor KC, Rasmussen TE, Riesberg JC, Spinella PC, Stockinger Z, Strandenes

G, Via DK, Weber MA.

TCCC has previously recommended interventions that can effectively prevent 4 of the top 5 causes of prehospital preventable death in combat casualties-extremity hemorrhage, junctional hemorrhage, airway obstruction, and tension pneumothorax- and deaths from these causes have been markedly reduced in US combat casualties. Noncompressible torso hemorrhage (NCTH) is the last remaining major cause of

preventable death on the battlefield and often causes death within 30 minutes of wounding. Increased use of whole blood, including the capability for massive transfusion, if indicated, has the potential to increase survival in casualties with either thoracic and/or abdominopelvic hemorrhage. Additionally, Zone 1 Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) can provide temporary control of bleeding in the abdomen and pelvis and improve hemodynamics in casualties who may be approaching traumatic cardiac arrest as a result of hemorrhagic shock. Together, these two interventions are designated Advanced Resuscitative Care (ARC) and may enable casualties with severe NCTH to survive long enough to reach the care of a surgeon. Although Special Operations units are now using whole blood far-forward, this capability is not routinely present in other US combat units at this point in time. REBOA is not envisioned as care that could be accomplished by a unit medic working out of his or her aid bag. This intervention should be undertaken only by designated teams of advanced combat medical personnel with special training and equipment.

World J Emerg Surg. 2018 Nov 21;13:54

# Three cases of resuscitative endovascular balloon occlusion of the aorta (REBOA) in austere pre-hospital environment-technical and methodological aspects.

de Schoutheete J, Fourneau I, Waroquier F, De Cupere L, O'Connor M, Van Cleynenbreugel K, Ceccaldi J, Nijs S

Background: The present paper describes three cases where ER-REBOA® was used with partial aorta occlusion (AO), by performing a partial resuscitative endovascular balloon occlusion of the aorta or pREBOA, in an austere pre-hospital military environment.In addition, because no specific REBOA algorithm for pre-hospital environment exists yet, this paper seeks to fill this gap, proposing a new pragmatic REBOA algorithm.

Methods: Belgian Special Operations Surgical Team applied REBOA in three patients according to a decisional algorithm, based on the MIST acronym used for trauma patients. Only 3 ml, in the first instance, was inflated in the balloon to get AO. The balloon was then progressively deflated, and reperfusion was tracked through changes of end-tidal carbon dioxide (EtCO2).

Results: Systolic blood pressure (SBP) before ER-REBOA® placement was not higher than 60 mmHg. However, within the first 5 min after AO, SBP improved in all three cases. Due to the aortic compliance, a self-made pREBOA was progressively achieved while proximal SBP was raising with intravenous fluid infusion. Afterwards, during deflation, a steep inflection point was observed in SBP and EtCO2.

Conclusions: ER-REBOA® is suitable for use in an austere pre-hospital environment. The MIST acronym can be helpful to select the patients for which it could be beneficial. REBOA can also be performed with pREBOA in a dynamic approach, inflating only 3 mL in the balloon and using the aortic compliance. Furthermore, while proximal SBP can be convenient to follow the occlusion, EtCO2 can be seen as an easy and interesting marker to follow the reperfusion.

J Trauma Acute Care Surg. 2019 Jan;86(1):79-85

# Aortic branch vessel flow during resuscitative endovascular balloon occlusion of the aorta.

Hoehn M, Teeter W, Morrison J, Gamble W, Hu P, Stein D, Brenner M, Scalea T

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a torso hemorrhage control adjunct. Aortic branch vessel flow (BVF) during REBOA is poorly characterized and has implications for ischemia-reperfusion injury. The aim of this study is to quantify BVF in hypovolemic shock with and without REBOA.

METHODS: Female swine (79-90 kg) underwent anesthesia, 40% controlled hemorrhage and sonographic flow monitoring of the carotid, hepatic, superior mesenteric, renal, and femoral arteries. Animals were randomized to REBOA (n = 5) or no-REBOA (n = 5) for 4 hours, followed by full resuscitation and balloon deflation for 1 hour.

RESULTS: All animals were successfully induced into hemorrhagic shock with a mean decrease of flow in all vessels of 50% from baseline (p < 0.001). Deployment of REBOA resulted in a 200% to 400% increase in carotid flow, but near complete abolition of BVF distal to the balloon. The no-REBOA group saw recovery of BVF to 100% of baseline in all measured vessels, except the hepatic at 50% to 75%. two-way analysis of variance confirmed a significant difference between the groups throughout the protocol (p < 0.001). During resuscitation, the REBOA group saw BVF restore to between 25% and 50%, but never achieving baseline values. The lactate at 4 hours was significantly higher in the REBOA versus no-REBOA group (17.2 ± 0.1 vs. 4.9 ± 1.4; p < 0.001).

CONCLUSION: REBOA not only abolishing BVF during occlusion, but appears to have a post-REBOA effect, reducing visceral perfusion. This may be a source of REBOA associated ischemia-reperfusion injury and warrants further investigation in order to mitigate this effect.

JAMA Surg. 2019;Epub ahead of print]

# Nationwide Analysis of Resuscitative Endovascular Balloon Occlusion of the Aorta in Civilian Trauma.

Joseph B, Zeeshan M, Sakran J, Hamidi M, Kulvatunyou N, Khan M, O'Keeffe T, Rhee P

Importance: The need for improved methods of hemorrhage control and resuscitation has resulted in a reappraisal of resuscitative endovascular balloon occlusion of the aorta (REBOA). However, there is a paucity of data regarding the use of REBOA on a multi-institutional level in the United States.

Objective: To evaluate the outcomes in trauma patients after REBOA placement.

Design, Setting, and Participants: A case-control retrospective analysis was performed of the 2015-2016 American College of Surgeons Trauma Quality Improvement Program data set, a national multi-institutional database of trauma patients in the United States. A total of 593 818 adult trauma patients (aged ≥18 years) were analyzed and 420 patients were matched and included in the study; patients who were dead on arrival or were transferred from other facilities were excluded. Trauma patients who underwent REBOA placement in the ED were identified and matched with a similar cohort of patients (the no-REBOA group). Both groups were matched in a 1:2 ratio using propensity score matching for demographics, vital signs, mechanism of injury, injury severity score, head abbreviated injury scale score, each body region abbreviated injury scale score, pelvic fractures, lower extremity vascular injuries and fractures, and number and grades of intra-abdominal solid organ injuries.

Main Outcomes and Measures: Outcome measures were the rates of complications and mortality.

Results: Of 593 818 trauma patients, 420 patients (the REBOA group, 140 patients; 36 women and 104 men; mean [SD] age, 44 [20] years; the no-REBOA group, 280 patients; 77 women and 203 men; mean [SD] age, 43 [19] years) were matched and included in the analysis. Among the REBOA group, median injury severity score was 29 (interquartile range [IQR], 18-38) and 129 patients (92.1%) had a blunt mechanism of injury. There was no significant difference between groups in median 4-hour blood transfusion (REBOA: packed red blood cells, 6 U [IQR, 3-8 U]; platelets, 4 U [IQR, 3-9 U], and plasma, 3 U [IQR, 2-5 U]; and no-REBOA: packed red blood cells, 7 U [IQR, 3-9 U]; platelets, 4 U [IQR, 3-8 U], and plasma, 3 U [IQR, 2-6 U]) or 24-hour blood transfusion (REBOA: packed red blood cells, 9 U [IQR, 5-20 U]; platelets, 7 U [IQR, 3-13 U], and plasma, 9 U [IQR, 6-20 U]; and no-REBOA: packed red blood cells, 10 U [IQR, 4-21 U]; platelets, 8 U [IQR, 3-12 U], and plasma, 10 U [IQR, 7-20 U]), median hospital length of stay (REBOA, 8 days [IQR, 1-20 days]; and no-REBOA, 10 days [IQR, 5-22 days]), or median intensive care unit length of stay (REBOA, 5 days [IQR, 2-14 days]; and no-REBOA, 6 days [IQR, 3-15 days]). The mortality rate was higher in the REBOA group as compared with the no-REBOA group (50 [35.7%] vs 53 [18.9%]; P = .01). Patients who underwent REBOA placement were also more likely to develop acute kidney injury (15 [10.7%] vs 9 [3.2%]; P = .02) and more likely to undergo lower extremity amputation (5 [3.6%] vs 2 [0.7%]; P = .04).

Conclusions and Relevance: Placement of REBOA in severely injured trauma patients was associated with a higher mortality rate compared with a similar cohort of patients with no placement of REBOA. Patients in the REBOA group also had higher rates of acute kidney injury and lower leg amputations. There is a need for a concerted effort to clearly define when and in which patient population REBOA has benefit.

Curr Opin Anaesthesiol. 2019 Apr;32(2):213-226

# Resuscitative endovascular balloon occlusion of the aorta: an option for noncompressible torso hemorrhage?

Kulla M, Popp E, Knapp J

PURPOSE OF REVIEW: Hemorrhage is the major cause of early death in severely injured patients. In civilian emergency medical services, the majority of life-threatening bleedings are found in noncompressible body regions (e.g. abdomen and pelvis). Resuscitative endovascular balloon occlusion of the aorta (REBOA) has therefore been discussed in recent years as a possible lifesaving procedure and numerous studies, meta-analyses and guidelines have been published. In this review, the data situation of REBOA in the management of bleeding trauma patients is discussed and practical implementation is depicted.

RECENT FINDINGS: The typical indication for REBOA is a traumatic life-threatening hemorrhage below the diaphragm in patients unresponsive or only transiently responsive to the usual conservative therapeutic measures. REBOA appears to be a safe and effective procedure to reduce blood loss and stabilize the patient's hemodynamic status. However, surgical hemostasis has to be achieved within 30-60 min after occlusion of the aorta. Data on clear advantages of REBOA over resuscitative thoracostomy are inconclusive.

SUMMARY: REBOA could play an important role in the management of the severely bleeding patient in the future. Together with transfusion and therapy of coagulation disorders, REBOA may be an additional tool in the anesthetist's hands for trauma management in interprofessional care concepts.

Injury. 2019 Apr;50(4):855-858

# Zones matter: Hemodynamic effects of zone 1 vs zone 3 resuscitative endovascular balloon occlusion of the aorta placement in trauma patients.

Beyer C, Johnson M, Galante J, DuBose J

INTRODUCTION: Resuscitative endovascular balloon occlusion of the aorta (REBOA) has emerged as a therapy for hemorrhagic shock to limit ongoing bleeding and support proximal arterial pressures. Current REBOA algorithms recommend zone selection based on suspected anatomic location of injury rather than severity of shock. We examined the effects of Zone 1 versus Zone 3 REBOA in patients enrolled in the American Association for the Surgery of Trauma Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery (AORTA) Registry.

PATIENTS AND METHODS: The prospective observational AORTA Registry was queried from November 2013 to November 2017. Patients who received REBOA were included if their initial systolic blood pressure (SBP) was less than 90 mmHg upon arrival and they were not receiving cardiopulmonary resuscitation.

RESULTS: There were 762 patients recorded in the AORTA database during the study period. Of these, 245 underwent REBOA and 99 patients met inclusion criteria. The initial balloon position was Zone 1 in 55 patients, Zone 3 in 36 patients, and unknown or Zone 2 in 8 patients. The change in proximal SBP was greater after REBOA in the Zone 1 group compared to the Zone 3 group (58 ± 4 mmHg vs 41 ± 4 mmHg, P = 0.008). The zone of occlusion was significantly associated with the change in proximal SBP in a linear regression analysis which included initial SBP, Glasgow Coma Scale score, and Injury Severity Score (Coefficient 26.82, 95% Confidence Interval 8.11-45.54, P = 0.006).

CONCLUSIONS: In the hypotensive trauma patient, initial Zone 1 REBOA provides maximal hemodynamic support. Algorithms recommending initial Zone 3 placement for hypotensive trauma patients should be reconsidered.

J Trauma Acute Care Surg. 2019 Mar 1; Epub ahead of print

# CT Correlation of Skeletal Landmarks and Vascular Anatomy in Civilian Adult Trauma Patients: Implications for Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA).

Eliason J, Derstine B, Horbal S, Wang N, Holcombe S, Chiu C, Ross B, Bromwell B, Morrison J, Wang S

BACKGROUND: REBOA is a valuable resuscitative adjunct in a variety of clinical settings. In resource-limited or emergency environments, REBOA may be required with delayed or absent image-guidance or verification. Catheter insertion lengths may be informed by making CT correlations of skeletal landmarks with vascular lengths.

METHODS: 2247 trauma patients with CT imaging between 2000-2015 at a single civilian tertiary care center were identified, yielding 1789 patients with adequate contrast opacification of the arterial system in the chest, abdomen, and pelvis. Individual scans were analyzed using MATLAB software, with custom high-throughput image processing algorithms applied to correlate centerline vascular anatomy with musculoskeletal landmarks. Data were analyzed using R version 3.3.

RESULTS: The median centerline distance from the skin access to the aortic bifurcation was longer by 0.3 cm on the right than on the left side. Median Aortic Zone I length was 21.6 (IQR, 20.3-22.9) cm, while Zone III was 8.7 (7.8-9.5) cm. Torso extent (TE) correlation to Zone I was much higher than for Zone III (R2 0.58 vs 0.26 (right) and 0.58 vs. 0.27 (left), p<0.001). Assuming a 4 cm balloon length, optimal fixed insertion length would be 48 cm and 28 cm for Zones I and III (Error 0.4% vs 33.3%), respectively, although out of zone placements can be reduced if adjusted for TE (Error 0% vs 26.4%).

CONCLUSIONS: CT morphometry suggests a fixed REBOA catheter insertion length of 48 cm for Zone I and 28 cm for Zone III is optimal (on average, for average-height individuals), with improved accuracy by formulaic adjustments for torso extent. High residual error for Zone III placement may require redesign of existing catheter balloon lengths or consideration of the relative risk associated with placing the balloon catheter too low or too high.

J Trauma Acute Care Surg. 2019 Apr;86(4):658-663

# Impact of a simplified management algorithm on outcome following exsanguinating pelvic fractures: A 10-year experience.

Lewis R, Sharpe J, Berning B, Fabian T, Croce M, Magnotti L

BACKGROUND: Optimal management of exsanguinating pelvic fractures remains controversial. Our previous experience suggested that management decisions based on a defined algorithm were associated with a significant reduction in transfusion requirements and mortality. Based on these outcomes, a clinical pathway (PW) for the management of exsanguinating pelvic fractures was developed. The purpose of this study was to evaluate the impact of this PW on outcomes.

METHODS: Consecutive patients over 10 years with blunt pelvic fractures subsequent to the implementation of the clinical PW were identified. Patients with hemodynamically unstable pelvic fractures are managed initially with a pelvic orthotic device. For those with continued hemodynamic instability and no extrapelvic source of hemorrhage, pelvic angiography was performed followed by elective pelvic fixation. Patients managed according to the PW were compared with those patients whose management deviated (DEV) from the PW.

RESULTS: There were 3,467 patients identified. Three hundred twelve (9%) met entry criteria: 246 (79%) comprised the PW group and 66 (21%) the DEV group. injury severity, as measured by Injury Severity Score (35 vs. 36; p = 0.55), admission Glasgow Coma Scale (10 vs. 10; p = 0.58), admission BE (-7.4 vs. -6.4, p = 0.38), admission SBP (107 vs. 104, p = 0.53), and PRBC requirements during initial resuscitation (6.1 units vs. 6.6 units, p = 0.22) were similar between the groups. Pelvic orthotic device use was 48% in the DEV group (p < 0.001). Twenty-four percent of the PW group required angiography compared with 74% of the DEV group (p < 0.001). Forty-eight-hour transfusions (11 vs. 16, p = 0.01) and mortality (35% vs. 48%, p = 0.04) were reduced in the PW group compared with the DEV group. Pathway adherence was identified as an independent predictor of both decreased transfusions (β = -5.8, p = 0.002) via multiple linear regression and decreased mortality (hazard ratio, 0.74; 95% confidence interval, 0.42-0.98) via multivariable cox proportional hazards analysis.

CONCLUSION: Adherence to a defined clinical PW simplified the management of exsanguinating pelvic fractures and contributed to a reduction in both transfusion requirements and mortality.

LEVEL OF EVIDENCE: Prognostic, level III.

World J Surg. 2019 Jul;43(7):1700-1707

# Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) for Severe Torso Trauma in Japan: A Descriptive Study.

Matsumoto S, Hayashida K, Akashi T, Jung K, Sekine K, Funabiki T, Moriya T

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) has the potential to be an alternative to open aortic cross-clamping (ACC). However, its practical indication remains unknown. We examined the usage trend of REBOA and ACC in Japan for severe torso trauma and investigated whether these procedures were associated with the time of death distribution based on a large database from the Japan Trauma Data Bank (JTDB).

METHODS: The JTDB from 2004 to 2014 was reviewed. Eligible patients were restricted to those with severe torso trauma, which was defined as an abbreviated injury scale score of ≥4. Patients were classified into groups according to the aortic occlusion procedures. The primary outcomes were the rates of REBOA and ACC use according to the clinical situation. We also evaluated whether the time of death distribution for the first 8 h differed based on these procedures.

RESULTS: During the study period, a total of 21,533 patients met our inclusion criteria. Overall, REBOA was more commonly used than ACC for patients with severe torso trauma (2.8% vs 1.5%). However, ACC was more frequently used in cases of thoracic injury and cardiac arrest. Regarding the time of death distribution, the cumulative curve for death in REBOA cases was elevated much more slowly and mostly flat for the first 100 min.

CONCLUSIONS: REBOA is more commonly used compared to ACC for patients with severe torso trauma in Japan. Moreover, it appears that REBOA influences the time of death distribution in the hyperacute phase.

Can J Surg. 2019 Apr 1;62(2):142-144

# Deployment of second-generation resuscitative endovascular balloon occlusion of the aorta for unresponsive hypotension in a polytrauma patient

Paradis T, Bekdache O, Bracco D, Grushka J, Razek T, Lasry D, Beckett A

Summary: Noncompressible hemorrhagic control remains one of the most challenging areas in damage control medicine and continues to be a leading cause of preventable death. For decades, emergency thoracotomy or laparotomy and aortic cross clamping have remained the gold standard intervention. Recently, there has been a movement toward less invasive techniques for noncompressible hemorrhagic control, such as resuscitative endovascular balloon occlusion of the aorta (REBOA). The REBOA technique involves inflation of an endovascular balloon within the abdominal aorta proximal to the vascular injury to temporarily inhibit bleeding. Although the literature is robust on this new technique, skepticism remains about whether REBOA is superior to aortic cross clamping, as it has been associated with complications including organ and limb ischemia, limb amputation, femoral aneurysm, and thrombosis.

Trauma. 2019 Jan;21(1):45-54

# A one-year cost-utility analysis of REBOA versus RTACC for non-compressible torso haemorrhage.

Renna M, van Zeller C, Abu-Hijleh F, Tong C, Gambini J, Ma M

Introduction: Major trauma is a leading cause of death and disability in young adults, especially from massive non-compressible torso haemorrhage. The standard technique to control distal haemorrhage and maximise central perfusion is resuscitative thoracotomy with aortic cross-clamping (RTACC). More recently, the minimally invasive technique of resuscitative endovascular balloon occlusion of the aorta (REBOA) has been developed to similarly limit distal haemorrhage without the morbidity of thoracotomy; cost-utility studies on this intervention, however, are still lacking. The aim of this study was to perform a one-year cost-utility analysis of REBOA as an intervention for patients with major traumatic non-compressible abdominal haemorrhage, compared to RTACC within the U.K.'s National Health Service.

Methods: A retrospective analysis of the outcomes following REBOA and RTACC was conducted based on the published literature of survival and complication rates after intervention. Utility was obtained from studies that used the EQ-5D index and from self-conducted surveys. Costs were calculated using 2016/2017 National Health Service tariff data and supplemented from further literature. A cost-utility analysis was then conducted.

Results: A total of 12 studies for REBOA and 20 studies for RTACC were included. The mean injury severity scores for RTACC and REBOA were 34 and 39, and mean probability of death was 9.7 and 54%, respectively. The incremental cost-effectiveness ratio of REBOA when compared to RTACC was £44,617.44 per quality-adjusted life year. The incremental cost-effectiveness ratio, by exceeding the National Institute for Health and Clinical Effectiveness's willingness-to-pay threshold of £30,000/quality-adjusted life year, suggests that this intervention is not cost-effective in comparison to RTACC. However, REBOA yielded a 157% improvement in utility with a comparatively small cost increase of 31.5%.

Conclusion: Although REBOA has not been found to be cost-effective when compared to RTACC, ultimately, clinical experience and expertise should be the main factor in driving the decision over which intervention to prioritise in the emergency context.

Radiol Case Rep. 2019 Mar 15;14(5):623-626

# The utility of resuscitative endovascular balloon occlusion of the aorta for temporary hemostasis after extensive bilateral lower extremity injuries: A case report.

Shinjo T, Izawa Y, Watanabe N, Tominaga K, Yonekawa C, Lefor A, Mato T

A 75-year-old pedestrian was struck by a truck and in shock with both lower extremities significantly deformed, with injuries extending proximally to the inguinal region and degloving injuries. Resuscitative endovascular balloon occlusion of the aorta was performed to achieve temporary hemostasis and the patient became hemodynamically stable. Following stabilization, both lower extremities were amputated. Resuscitative endovascular balloon occlusion of the aorta may be effective to achieve temporary hemostasis in patients with extensive injuries of the lower extremities, especially with extension to the inguinal region which precludes use of a tourniquet.

Mil Med. 2019 Mar 1;184(3-4):e285-e289

# Radiofrequency Identification of the ER-REBOA: Confirmation of Placement Without Fluoroscopy.

Wessels L, Wallace J, Bowie J, Butler W, Spalding C, Krzyzaniak M

INTRODUCTION: Non-compressible torso hemorrhage accounts for 70% of battlefield deaths. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emerging technology used to mitigate massive truncal hemorrhage. Use of REBOA on the battlefield is limited by the need for radiographic guided balloon placement. Radiofrequency identification (RFID) is a simple, portable, real-time technology utilized to detect retained sponges during surgery. We investigated the feasibility of RFID to confirm the placement of ER-REBOA.

MATERIALS AND METHODS: This was a single-arm prospective proof-of-concept experimental study approved by the institutional review board at Naval Medical Center San Diego. The ER-REBOA (Prytime Medical Devices, Inc, Boerne, TX, USA) was modified by placement of a RFID tag. The tagged ER-REBOA was placed in zone I or zone III of the aorta in a previously perfused cadaver. Exact location was documented with X-ray. Five blinded individuals used the RF Assure Detection System (Medtronic, Minneapolis, MN, USA) handheld detection wand to predict catheter tip location from the xiphoid process (zone I) or pubic tubercle (zone III).

RESULTS: In zone I, actual distance (Da) of the catheter tip was 11 cm from the xiphoid process. Mean predicted distance (Dp) from Da was 1.52 cm (95% CI 1.19-1.85). In zone III, Da was 14 cm from the pubic tubercle. Mean Dp from Da was 4.11 cm (95% CI 3.68-4.54). Sensitivity of detection was 100% in both zones. Specificity (Defined as Dp within 2 cm of Da) was 86% in zone I and 16% in zone III.

CONCLUSIONS: Using RFID to confirm the placement of ER-REBOA is feasible with specificity highest in zone I. Future work should focus on refining this technology for the forward-deployed setting.

Patient Saf Surg. 2019 Jun 24;13:25

# Technical limitations of REBOA in a patient with exsanguinating pelvic crush trauma: a case report.

Özkurtul O, Staab H, Osterhoff G, Ondruschka B, Höch A, Josten C, Fakler J

Background: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an effective adjunct in hemodynamic unstable patients with uncontrolled and non-compressible torso hemorrhage promoting temporary stability during injury repair. The aim of our study was to analyze real life usability of REBOA based on a case report and to review the literature with respect to its possibilities and limitations.

Case presentation: We present the case of a 17-years old female patient who sustained a severe roll-over trauma and pelvic crush injury as a bicyclist by a truck. Upon arrival of the first responders, the patient was awake, alert, and following commands.Subsequent to lifting the truck, the patient became hypotensive and required cardiopulmonary resuscitation, application of a pelvic binder, and endotracheal intubation at the accident scene. She was then admitted by ambulance to our trauma center under ongoing resuscitative measures. After primary survey, it was decided to perform a REBOA with surgical approach to the left femoral artery. Initial insertion of the catheter was successful but could not be advanced beyond the inguinal region. Hence, the patient was transferred to the operating room (OR) but died despite maximum therapy. In the OR and later autopsy, we found a long-distance ruptured and dehiscent external iliac artery with massive bleeding into the pelvis in the context of a bilateral vertical shear fractured pelvic bone.

Conclusion: REBOA can be a useful adjunct but there is a major limitation with potential vascular injury after pelvic trauma. In these situations, cross-clamping the proximal aorta or pre-peritoneal pelvic packing as "traditional" approaches of hemorrhage control during resuscitation may be the most considerable methods for temporary stabilization in severely injured trauma patients. More clinical and cadaveric studies are needed to further understand indications and limitations of REBOA after severe pelvic trauma.

Eur J Trauma Emerg Surg. 2019 Oct 1;Epub ahead of print

# Resuscitative endovascular balloon occlusion of the aorta (REBOA) in a swine model of hemorrhagic shock and blunt thoracic injury.

Beyer C, Hoareau G, Kashtan H, Wishy A, Caples C, Spruce M, Grayson J, Neff L, Williams T, Johnson M

PURPOSE: While resuscitative endovascular balloon occlusion of the aorta (REBOA) is contraindicated in patients with aortic injuries, this technique may benefit poly-trauma patients with less extreme thoracic injuries. The purpose of this study was to characterize the effects of thoracic injury on hemodynamics during REBOA and the changes in pulmonary contusion over time in a swine model.

METHODS: Twelve swine were anesthetized, instrumented, and randomized to receive either a thoracic injury with 5 impacts to the chest or no injury. All animals underwent controlled hemorrhage of 25% blood volume followed by 45 min of Zone 1 REBOA. Animals were then resuscitated with shed blood, observed during a critical care period, and euthanized after 6 h of total experimental time.

RESULTS: There were no differences between the groups at baseline. The only difference after 6 h was a lower hemoglobin in the thoracic trauma group (8.4 ± 0.8 versus 9.4 ± 0.6 g/dL, P = 0.04). The average proximal mean arterial pressures were significantly lower in the thoracic trauma group during aortic occlusion [103 (98-108) versus 117 (115-124) mmHg, P = 0.04]. There were no differences between the pulmonary contusion before REBOA and at the end of the experiment in size (402 ± 263 versus 356 ± 291 mL, P = 0.782) or density (- 406 ± 127 versus - 299 ± 175 HFU, P = 0.256).

CONCLUSIONS: Thoracic trauma blunted the proximal arterial pressure augmentation during REBOA but had minimal impacts on resuscitative outcomes. This initial study indicates that REBOA does not seem to exacerbate pulmonary contusion in swine, but blunt thoracic injuries may attenuate the expected rises in proximal blood pressure during REBOA.

J Trauma Acute Care Surg. 2019 Sep;87(3):590-598

# Resuscitative endovascular balloon occlusion of the aorta induced myocardial injury is mitigated by endovascular variable aortic control.

Beyer C, Hoareau G, Tibbits E, Davidson A, DeSoucy E, Simon M, Grayson J, Neff L, Williams TK, Johnson MA.

BACKGROUND: The cardiac effects of resuscitative endovascular balloon occlusion of the aorta (REBOA) are largely unknown. We hypothesized that increased afterload from REBOA would lead to cardiac injury, and that partial flow using endovascular variable aortic control (EVAC) would mitigate this injury.

METHODS: Eighteen anesthetized swine underwent controlled 25% blood volume hemorrhage. Animals were randomized to either Zone 1 REBOA, Zone 1 EVAC, or no intervention (control) for 45 minutes. Animals were then resuscitated with shed blood, observed during critical care, and euthanized after a 6-hour total experimental time. Left ventricular function was measured with a pressure-volume catheter, and blood samples were drawn at routine intervals.

RESULTS: The average cardiac output during the intervention period was higher in the REBOA group (9.3 [8.6-15.4] L/min) compared with the EVAC group (7.2 [5.8-8.0] L/min, p = 0.01) and the control group (6.8 [5.8-7.7] L/min, p < 0.01). At the end of the intervention, the preload recruitable stroke work was significantly higher in both the REBOA and EVAC groups compared with the control group (111.2 [102.5-148.6] and 116.7 [116.6-141.4] vs. 67.1 [62.7-87.9], p = 0.02 and p < 0.01, respectively). The higher preload recruitable stroke work was maintained throughout the experiment in the EVAC group, but not in the REBOA group. Serum troponin concentrations after 6 hours were higher in the REBOA group compared with both the EVAC and control groups (6.26 ± 5.35 ng/mL vs 0.92 ± 0.61 ng/mL and 0.65 ± 0.38 ng/mL, p = 0.05 and p = 0.03, respectively). Cardiac intramural hemorrhage was higher in the REBOA group compared with the control group (1.67 ± 0.46 vs. 0.17 ± 0.18, p = 0.03), but not between the EVAC and control groups.

CONCLUSION: In a swine model of hemorrhagic shock, complete aortic occlusion resulted in cardiac injury, although there was no direct decrease in cardiac function. EVAC mitigated the cardiac injury and improved cardiac performance during resuscitation and critical care.

J Trauma Acute Care Surg. 2019 Oct;87(4):849-855

# Transition from abdominal aortic and junctional tourniquet to zone 3 resuscitative endovascular balloon occlusion of the aorta is feasible with hemodynamic support after porcine class IV hemorrhage.

Brännström A, Dahlquist A, Gustavsson J, Arborelius UP, Günther M.

BACKGROUND: Traumatic hemorrhage remains a major cause of death in rural civilian and combat environments. Potential interventions to control hemorrhage from the pelvis and lower junctional regions include the abdominal aortic and junctional tourniquet (AAJT) and resuscitative endovascular balloon occlusion of the aorta (REBOA). The AAJT requires low technical skills and may thus be used by nonmedical professionals, but is associated with time-dependent ischemic complications. In combination with delayed patient evacuation, it may therefore be deleterious. Transition to zone 3 REBOA in higher levels of care may be a possibility to maintain hemostasis, mitigate adverse effects and enable surgery in patients resuscitated with the AAJT. It is possible that a transition between the interventions could lead to hemodynamic penalties. Therefore, we investigated the feasibility of replacing the AAJT with zone 3 REBOA in a porcine model of uncontrolled femoral hemorrhage.

METHODS: Domestic pigs (n = 12) averaging 57 kg were exposed to a class IV uncontrolled hemorrhage from the common femoral artery. The animals were randomized to 60-minute AAJT (n = 6) or 30-minute AAJT with transition to 30-minute zone 3 REBOA. Hemodynamic and metabolic parameters and ultrasonographic measurements of the common femoral artery were collected.

RESULTS: Transition from AAJT to zone 3 REBOA caused a significant decrease in mean arterial pressure (25 mm Hg). Hemostasis was maintained. The common femoral artery diameter decreased by 1.8 mm (38%) after hemorrhage and further 0.7 mm (23%) after aortic occlusion.

CONCLUSION: Transition from AAJT to zone 3 REBOA after a class IV bleeding is feasible with hemodynamic support. Vascular access to the femoral artery for REBOA insertion poses a technical challenge after hemorrhage and AAJT application.

LEVEL OF EVIDENCE: Laboratory animal study, level IV.

Eur J Obstet Gynecol Reprod Biol. 2019 Sep;240:151-155

# Uterine packing with chitosan-covered gauze compared to balloon tamponade for managing postpartum hemorrhage.

Dueckelmann A, Hinkson L, Nonnenmacher A, Siedentopf J, Schoenborn I, Weizsaecker K, Kaufner L, Henrich W, Braun T

BACKGROUND: Postpartum hemorrhage (PPH) is a major cause of maternal death worldwide. Management of PPH includes the administration of uterotonics, and intrauterine packing techniques.

OBJECTIVE: In this study the effectiveness and safety of chitosan covered gauze versus a balloon tamponade for managing severe PPH should be assessed.

STUDY DESIGN: This retrospective cohort study was conducted at the Department of Obstetrics, Charité, university hospital Berlin, between October 2016 and June 2018. Women with PPH were treated according to management guidelines. When bleeding persisted, we applied additional uterine packing with either chitosan covered gauze or a balloon tamponade. The primary outcome was uterine bleeding termination without additional surgical interventions. Secondary outcomes included the amount of blood loss, the amount of blood transfusions and maternal complications.

RESULTS: Among the 78 patients included in this study, 47 (60.3%) received chitosan covered gauze tamponade and 31 (39.7%) received a balloon tamponade. The major reason for PPH was atonic bleeding, no statistically significant group differences were observed. With respect to the outcomes monitored, the groups were not significantly different in postpartum vital signs, hemoglobin levels, blood loss, admission to intensive care unit, or inflammation parameters. However, three patients in balloon tamponade group required a hysterectomy. No hysterectomy was required in gauze group.

CONCLUSION: Chitosan covered gauze is an excellent option for treating PPH, it appeared to be at least equivalent to the balloon tamponade, in our experience particularly suitable for atony or placenta bed bleeding after spontaneous delivery or during cesarean sections, in cases of lower uterine segment atony, placenta previa bed bleeding, and/or coagulopathy.

Anesth Analg. 2019 Nov;129(5):e146-e149

# Anesthetic Management of Patients After Traumatic Injury With Resuscitative Endovascular Balloon Occlusion of the Aorta.

Engdahl A, Parrino C, Wasicek P, Galvagno S, Brenner M, Anders M, Conti B, Rock P, McCunn M

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a temporizing maneuver for noncompressible torso hemorrhage. To our knowledge, this single-center brief report provides the most extensive anesthetic data published to date on patients who received REBOA. As anticipated, patients were critically ill, exhibiting lactic acidosis, hypotension, hyperglycemia, hypothermia, and coagulopathy. All patients received blood products during their index operations and received less inhaled anesthetic gas than normally required for healthy patients of the same age. This study serves as an important starting point for clinician education and research into anesthetic management of patients undergoing REBOA.

J Trauma Acute Care Surg. 2019 Nov;87(5):1015-1025

# Titrate to equilibrate and not exsanguinate! Characterization and validation of a novel partial resuscitative endovascular balloon occlusion of the aorta catheter in normal and hemorrhagic shock conditions.

Forte D, Do W, Weiss J, Sheldon R, Kuckelman J, Eckert M, Martin M

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a significant advancement in the control of noncompressible truncal hemorrhage. However, its ischemic burden and reperfusion injury following balloon deflation limits its utilization. Partial restoration of aortic flow during REBOA has the potential to balance hemorrhage control and ischemia. This study validates the mechanics, physiology, and optimal partial flow rates using a prototype partial REBOA (pREBOA) device.

METHODS: Twenty-five swine underwent placement of aortic flow probes and zone 1 pREBOA. Experiment 1 (N = 5) animals were not injured and assessed the tested the catheters ability to titrate and control flow. Experiment 2 (N = 10) added 20% hemorrhage and either solid organ, or abdominal vascular injury to compare flow rate and rebleeding from injuries. Experiment 3 (N = 10) swine were similarly prepared, hemorrhaged, and underwent pREBOA at set partial flow rates for 2 hours followed by complete deflation for 30 minutes.

RESULTS: Balloon volume at minimum flow (mean, 0.09 L/min) was 3.5 mL to 6.0 mL. Half maximal flow was achieved with 56.5% of maximum balloon inflation. Partial REBOA allowed very fine titration of flow rates. Rebleeding occurred at 0.45 L/min to 0.83 L/min. Distal flow of 0.7 L/min had 50% survival, 0.5 had 100% survival, and 0.3 L had 50% survival with mean end lactates of 9.6, 12.6, and 13.3, respectively. There was a trend toward hyperkalemia and hypocalcemia in nonsurvivors.

CONCLUSION: The pREBOA device demonstrated a high level of titratability for restoration of aortic flow. An optimal partial flow of 0.5 L/min was effective at hemorrhage control while limiting the burden of ischemic injury, and extending the tolerable duration of zone 1 occlusion. Aggressive calcium supplementation prior to and during partial occlusion and reperfusion may be warranted to prevent hyperkalemic arrest.

Injury. 2019 Nov;50(11):1908-1914

# Renal effects of three endoaortic occlusion strategies in a swine model of hemorrhagic shock.

Hoareau G, Tibbits E, Simon M, Davidson A, DeSoucy E, Faulconer E, Grayson J, Stewart I, Neff L, Williams T, Johnson M

INTRODUCTION: Trauma patients are predisposed to kidney injury. We hypothesized that in shock, zone 3 REBOA would increase renal blood flow (RBF) compared to control and that a period of zone 3 occlusion following zone 1 occlusion would improve renal function compared to zone 1 occlusion alone.

MATERIALS AND METHODS: Twenty-four anesthetized swine underwent hemorrhagic shock, 45 min of zone 1 REBOA (Z1, supraceliac), zone 3 REBOA (Z3, infrarenal), or no intervention (control) followed by resuscitation with shed blood and 5 h of critical care. In a fourth group (Z1Z3), animals underwent 55 min of zone 3 REBOA following zone 1 occlusion. Physiologic parameters were recorded, blood and urine were collected at specified intervals.

RESULTS: During critical care, there were no differences in RBF between the Z1 and Z3 groups. The average RBF during critical care in Z1Z3 was significantly lower than in Z3 alone (98.2 ± 23.9 and 191.9 ± 23.7 mL/min; p = 0.046) and not different than Z1. There was no difference in urinary neutrophil gelatinase-associated lipocalin-to-urinary creatinine ratio between Z1 and Z1Z3. Animals in the Z1Z3 group had a significant increase in the ratio at the end of the experiment compared to baseline [median (IQR)] [9.2 (8.2-13.2) versus 264.5 (73.6-1174.6)]. Following Z1 balloon deflation, RBF required 45 min to return to baseline.

CONCLUSION: Neither zone 3 REBOA alone nor zone 3 REBOA following zone 1 REBOA improved renal blood flow or function. Following zone 1 occlusion, RBF is restored to baseline levels after approximately 45 min.

J Trauma Acute Care Surg. 2019 Nov;87(5):1026-1034

# Effect of partial and complete aortic balloon occlusion on survival and shock in a swine model of uncontrolled splenic hemorrhage with delayed resuscitation.

Kauvar D, Schechtman D, Thomas S, Prince M, De Guzman R, Polykratis I, Kheirabadi B, Dubick M

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is accepted as a resuscitation adjunct and bridge to definitive hemostasis. The ischemic burden of REBOA may be mitigated by a partial REBOA (P-REBOA) strategy permitting longer occlusion times and military use for combat trauma. We evaluated REBOA and P-REBOA in a swine multiple trauma model with uncontrolled solid organ hemorrhage and delayed resuscitation and surgical hemostasis.

METHODS: Anesthetized swine (51.9 ± 2.2 kg) had 20 mL/kg hemorrhage and closed femur fracture. Splenic transection was performed and free bleeding permitted for 10 minutes. Controls (n = 5) were hemorrhaged but had no REBOA, REBOA (n = 8) had 60 minutes complete zone 1 occlusion, P-REBOA (n = 8) had 15 minutes complete occlusion and 45 minutes 50% occlusion. Splenectomy was performed and plasma (15 mL/kg) resuscitation initiated 5 minutes prior to deflation. Resuscitation goal was 80 mm Hg systolic with epinephrine as needed. Animals were monitored for 6 hours.

RESULTS: An initial study with 120-minute occlusion had universal fatality in three REBOA (upon deflation) and three P-REBOA animals (after 60 minutes inflation). With 60-minute occlusion, mortality was 100%, 62.5%, and 12.5% in the control, REBOA, and P-REBOA groups, respectively (p < 0.05). Survival time was shorter in controls (120 ± 89 minutes) than REBOA and P-REBOA groups (241 ± 139, 336 ± 69 minutes). Complete REBOA hemorrhaged less during inflation (1.1 ± 0.5 mL/kg) than Control (5.6 ± 1.5) and P-REBOA (4.3 ± 1.4), which were similar. Lactate was higher in the REBOA group compared with the P-REBOA group after balloon deflation, remaining elevated. Potassium increased in REBOA after deflation but returned to similar levels as P-REBOA by 120 minutes.

CONCLUSION: In a military relevant model of severe uncontrolled solid organ hemorrhage 1-hour P-REBOA improved survival and mitigated hemodynamic and metabolic shock. Two hours of partial aortic occlusion was not survivable using this protocol due to ongoing hemorrhage during inflation. There is potential role for P-REBOA as part of an integrated minimally invasive field-expedient hemorrhage control and resuscitation strategy.

Ann Emerg Med. 2019 Nov;74(5):706-710

# Point-of Care Ultrasonographically Guided Proximal External Aortic Compression in the Emergency Department.

Michel W, Lachance A, Turcotte A, Morris J

In cases of severe subdiaphragmatic vascular trauma, only in extremis interventions such as emergency thoracotomy with aortic cross clamping or resuscitative endovascular balloon occlusion of the aorta are available for temporization until definitive care. This case report proposes a noninvasive approach consisting of localizing the proximal aorta with ultrasonographic guidance and applying a compressive force to occlude the aorta and limit distal flow. Using point-of-care ultrasonography allows precise compression, continuous monitoring of its efficacy, and early detection of return of spontaneous circulation in arrest patients. We present the case of a patient who sustained a gunshot wound causing a left iliac artery injury and subsequent cardiac arrest while he was on route to the hospital. Point-of-care ultrasonographically guided proximal external aortic compression was attempted and return of spontaneous circulation was achieved and maintained, allowing transfer of the patient to the operating room. This single-case report suggests that point-of-care ultrasonographically guided proximal external aortic compression could be used as a bridge to definitive care or to more advanced techniques such as resuscitative endovascular balloon occlusion of the aorta and emergency department thoracotomy with aortic cross clamping.

Am J Surg. 2019 Dec;218(6):1162-1168

# Resuscitative endovascular balloon occlusion of the aorta (REBOA) is associated with improved survival in severely injured patients: A propensity score matching analysis.

Yamamoto R, Cestero R, Suzuki M, Funabiki T, Sasaki J

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a technique for temporary control of arterial hemorrhage. However, its effectiveness and clinical outcomes are unclear.

METHODS: Using a nationwide database (2004-2016) in Japan, trauma patients with survival data were identified. Patients were divided between REBOA and non-REBOA groups, and a propensity score was developed using multivariate logistic regression. Survival to discharge was compared between the groups after propensity score matching.

RESULTS: Among 82,371 patients included in this study, 385 were treated with REBOA. After propensity score matching, 117 pairs were selected. Survival to discharge was significantly higher among patients treated with REBOA than among those treated without REBOA (53 [45.3%] vs. 38 [32.5%]; odds ratio = 1.72; 95% CI = 1.01-2.93; p = 0.04).

CONCLUSIONS: REBOA use was associated with improved survival to discharge and should therefore be considered during the management of severely injured trauma patients.