Percutaneous ultrasound-guided versus open cut-down access to femoral vessels for the placement of a REBOA catheter.

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) may be useful in treating exsanguinating trauma patients. This study seeks to compare rates of success, complications and time required for vascular access between ultrasound-guidance and surgical cut-down for femoral sheath insertion as a prospective observational case control study. Participating clinicians from either trauma surgery or anesthesiology were allocated to surgical cut-down or percutaneous ultrasound-guided puncture on a 1:1 ratio. Time spans to vessel identification, successful puncture, and balloon inflation were recorded. 80 study participants were recruited and allocated to 40 open cut-down approaches and 40 percutaneous ultrasound-guided approaches. REBOA catheter placement was successful in 18/40 cases (45%) using a percutaneous ultrasound guided technique and 33/40 times (83%) using the open cut-down approach (p < 0.001). Median times [in seconds] compared between percutaneous ultrasound-guided puncture and surgical cut-down were 36 (18-73) versus 117(56-213) for vessel visualization (p < 0.001), 136 (97-175) versus 183 (156-219) for vessel puncture (p < 0.001), and 375 (240-600) versus 288 (244-379) for balloon inflation (p = 0.08) overall. Access to femoral vessels for REBOA catheter placement is safer when performed by cut-down and direct visualization but can be performed faster by an ultrasound-guided technique when vessels can be identified clearly and rapidly.

Using hemoglobin vesicles to treat operative hemorrhagic shock after pneu- monectomy in dog models: an experimental study.

Hemoglobin vesicles (HbVs), considered as red blood cell substitutes, are liposomes encapsulating purified hemoglobin, with a phospholipid bilayer membrane (diameter: 250 nm; P50, 28 Torr). In this study, we aimed to investigate HbV function during hemorrhagic shock in lung resection and analyze the details of oxygen delivery. Left pneumonectomy was performed in dogs under mechanical ventilation, followed by rapid exsanguination of approximately 30% of the total circulating blood volume, which led to shock, reducing the mean arterial pressure (MAP) by approximately 60% of baseline. Subsequently, either 5% human serum albumin (HSA) or HbVs suspended in 5% HSA were infused for resuscitation. The MAP only recovered to 75% of baseline after HSA administration, but fully recovered (100%) after HbV administration, with significant differences between the groups (P < 0.005). Oxygen delivery was restored in the HbV group and was significantly higher than that in the HSA group (P < 0.0001). The infusion of HbVs dispersed in a 5% HSA solution compensated for the rapid loss of approximately 30% of the total circulating blood volume in a dog pneumonectomy model, even with impaired lung function. Thus, HbVs can be used for resuscitation from hemorrhagic shock during thoracic surgery.

Management of Pelvic Trauma.

Pelvic fractures are common after blunt trauma with patients' presentation ranging from stable with insignificant fractures to life-threatening exsanguination from unstable fractures. Often, hemorrhagic shock from a pelvic fracture may go unrecognized and high clinical suspicion for a pelvic source lies with the clinician. A multidisciplinary coordinated effort is required for management of these complex patients. In the exsanguinating patient, hemorrhage control remains the top priority and may be achieved with external stabilization, resuscitative endovascular balloon occlusion of the aorta, preperitoneal pelvic packing, angiographic intervention, or a combination of therapies. These modalities have been shown to reduce mortality in this challenging population.

The Role of Resuscitative Endovascular Balloon Occlusion of the Aorta.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been utilized by trauma surgeons at the bedside for over a decade in both civilian and military settings. Both translational and clinical research suggest it is superior to resuscitative thoracotomy for specific patient populations. Technological advancements in recent years have significantly enhanced the safety profile of REBOA. Resuscitative balloon occlusion of the aorta has also swiftly found implementation in patients in shock from non-traumatic hemorrhage.

The degree of aortic occlusion in the setting of trauma alters the extent of acute kidney injury associated with mitochondrial preservation.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is used to control noncompressible hemorrhage not addressed with traditional tourniquets. However, REBOA is associated with acute kidney injury (AKI) and subsequent mortality in severely injured trauma patients. Here, we investigated how the degree of aortic occlusion altered the extent of AKI in a porcine model. Female Yorkshire-cross swine (n = 16, 68.1 ± 0.7 kg) were anesthetized and had carotid and bilateral femoral arteries accessed for REBOA insertion and distal and proximal blood pressure monitoring. Through a laparotomy, a 6-cm liver laceration was performed and balloon inflation was performed in zone 1 of the aorta for 90 min, during which animals were randomized to target distal mean arterial pressures of 25 or 45 mmHg via balloon volume adjustment. Blood draws were taken at baseline, end of occlusion, and time of death, at which point renal tissues were harvested 6 h after balloon deflation for histological and molecular analyses. Renal blood flow was lower in the 25-mmHg group (48.5 ± 18.3 mL/min) than in the 45-mmHg group (177.9 ± 27.2 mL/min) during the occlusion phase, which recovered and was not different after balloon deflation. AKI was more severe in the 25-mmHg group, as evidenced by circulating creatinine, blood urea nitrogen, and urinary neutrophil gelatinase-associated lipocalin. The 25-mmHg group had increased tubular necrosis, lower renal citrate synthase activity, increased tissue and circulating syndecan-1, and elevated systemic inflammatory cytokines. The extent of renal ischemia-induced AKI is associated with the magnitude of mitochondrial biomass and systemic inflammation, highlighting potential mechanistic targets to combine with partial REBOA strategies to prevent AKI.NEW & NOTEWORTHY Large animal models of ischemia-reperfusion acute kidney injury (IR-AKI) are lacking. This report establishes a titratable IR-AKI model in swine in which a balloon catheter can be used to alter distal pressures experienced by the kidney, thus controlling renal blood flow. Lower blood flow results in greater renal dysfunction and structural damage, as well as lower mitochondrial biomass, elevated systemic inflammation, and vascular dysfunction.

A NOVEL OLIGONUCLEOTIDE MRNA MIMIC ATTENUATES HEMORRHAGE-INDUCED ACUTE LUNG INJURY.

ABSTRACT: Hemorrhagic shock (HS) is accompanied by a pronounced activation of the inflammatory response in which acute lung injury (ALI) is one of the most frequent consequences. Among the pivotal orchestrators of this inflammatory cascade, extracellular cold-inducible RNA-binding protein (eCIRP) emerges as a noteworthy focal point, rendering it as a promising target for the management of inflammation and tissue injury. Recently, we have reported that oligonucleotide poly(A) mRNA mimic termed A 12 selectively binds to the RNA binding region of eCIRP and inhibits eCIRP binding to its receptor TLR4. Furthermore, in vivo administration of eCIRP induces lung injury in healthy mice and that mouse deficient in CIRP showed protection from inflammation-associated lung injury. We hypothesize that A 12 inhibits systemic inflammation and ALI in HS. To test the impacts of A 12 on systemic and lung inflammation, extent of inflammatory cellular infiltration and resultant lung damage were evaluated in a mouse model of HS. Male mice were subjected to controlled hemorrhage with a mean arterial pressure of 30 mm Hg for 90 min and then resuscitated with Ringer's lactate solution containing phosphate-buffered saline (vehicle) or A 12 at a dose of 4 nmol/g body weight (treatment). The infusion volume was twice that of the shed blood. At 4 h after resuscitation, mice were euthanized, and blood and lung tissues were harvested. Blood and tissue markers of inflammation and injury were evaluated. Serum markers of injury (lactate dehydrogenase, alanine transaminase, and blood urea nitrogen) and inflammation (TNF-α, IL-6) were increased after HS and A 12 treatment significantly decreased their levels. A 12 treatment also decreased lung levels of TNF-α, MIP-2, and KC mRNA expressions. Lung histological injury score, neutrophil infiltration (Ly6G staining and myeloperoxidase activity), and lung apoptosis were significantly attenuated after A 12 treatment. Our study suggests that the capacity of A 12 in attenuating HS-induced ALI and may provide novel perspectives in developing efficacious pharmaceutics for improving hemorrhage prognosis.

Is REBOA the Last Card to Control a Massive Gastrointestinal Bleeding?

INTRODUCTION: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a potential tool for the management of massive gastrointestinal bleeding (MGB). This study aims to describe the experience of the use of REBOA as adjunctive therapy in patients with MGB and to evaluate its effectiveness. METHODS: Serial cases of patients with hemorrhagic shock secondary to MGB in whom REBOA was placed were collected. Patient demographics, bleeding severity, etiology, management, and clinical outcomes were recorded. RESULTS: Between 2017 and 2020, five cases were analyzed. All patients had a severe gastrointestinal bleeding (Glasgow Blatchford Bleeding Score range 12-17; Clinical Rockal Score range 5-9). The etiologies of MGB were perforated gastric or duodenal ulcers, esophageal varices, and vascular lesions. Systolic blood pressure increased after REBOA placement and total occlusion time was 25-60 min. REBOA provided temporary hemorrhage control in all cases and allowed additional hemostatic maneuvers to be performed. Three patients survived more than 24 h. All patients died in index hospitalization. The main cause of death was related to hemorrhagic shock. CONCLUSIONS: Endovascular aortic occlusion can work as a bridge to further resuscitation and attempts at hemostasis in patients with MGB. REBOA provides hemodynamic support and may be used simultaneously with other hemostatic maneuvers, facilitating definitive hemorrhage control.

Near-infrared spectroscopy for kidney oxygen monitoring in a porcine model of hemorrhagic shock, hemodilution, and REBOA.

Acute kidney injury is a common complication of trauma and hemorrhagic shock. In a porcine model of hemorrhagic shock, resuscitative endovascular balloon aortic occlusion (REBOA) and hemodilution, we hypothesized that invasive kidney oxygen concentration measurements would correlate more strongly with noninvasive near infra-red spectroscopy (NIRS) oxygen saturation measurements when cutaneous sensors were placed over the kidney under ultrasound guidance compared to placement over the thigh muscle and subcutaneous tissue. Eight anesthetized swine underwent hemorrhagic shock 4 of which were resuscitated with intravenous fluids prior to the return of shed blood (Hemodilution protocol) and 4 of which underwent REBOA prior to resuscitation and return of shed blood (REBOA protocol). There was a moderate correlation between the NIRS and kidney tissue oxygen measurements (r = 0.61 p < 0.001; r = 0.67 p < 0.001; r = 0.66 p < 0.001for left kidney, right kidney, and thigh NIRS respectively). When the animals were separated by protocol, the Hemodilution group showed a weak or nonsignificant correlation between NIRS and kidney tissue oxygen measurements (r = 0.10 p < 0.001; r = 0.01 p = 0.1007; r = 0.28 p < 0.001 for left kidney, right kidney, and thigh NIRS respectively). This contrasts with the REBOA group, where left and right kidney as well as thigh NIRS were moderately correlated with kidney tissue oxygen (r = 0.71 p < 0.001; r = 0.74 p < 0.001; r = 0.70 p < 0.001; for left kidney, right kidney, and thigh NIRS respectively). There was a strong correlation between both kidney NIRS signals and thigh NIRS measurements (r = 0.85 p < 0.001; r = 0.88 p < 0.001;for left kidney vs thigh and right kidney vs thigh respectively). There was also a strong correlation between left and right kidney NIRS (r = 0.90 p < 0.001). These relationships were maintained regardless of the resuscitation protocol. These results suggest that kidney NIRS measurements were more closely related to thigh NIRS measurements than invasive kidney tissue oxygen concentration.

Computed tomography scanning is feasible in select patients with REBOA catheter deployment.

BACKGROUND: Rapidly localizing and controlling bleeding is central to treating hemorrhagic shock. While REBOA allows temporary control, identifying the source of bleeding remains challenging. CT imaging with REBOA in place may provide information to direct hemorrhage control. The purpose of this study is to provide a descriptive summary of data comparing patients who did and did not undergo CT scan following REBOA deployment. Our hypothesis was that performing CT scan after REBOA placement in select patients is safe and can guide management of hemorrhagic shock. METHODS: We queried the AAST AORTA registry for patients receiving REBOA at our level 1 trauma center from May 2017 to December 2021. Clinical data was obtained through the Trauma Registry of the American College of Surgeons (TRACS). Comparison groups were those who underwent CT scan after REBOA deployment versus those who did not undergo CT scan after REBOA deployment. The primary outcome was inhospital mortality, and secondary outcomes included hospital-, ICU-, and ventilator-free days. RESULTS: 61 patients underwent CT scan with REBOA in place; 25 patients proceeded directly to hemorrhage control. Patients with REBOA prior to CT were more likely to have blunt mechanism, higher ISS, pelvic bleeding, and zone 3 REBOA placement. Mortality was not significantly different (51 % vs. 64 %). Patients who underwent CT with REBOA were more likely to undergo hemorrhage control in interventional radiology (43 % vs. 0 %). There was no difference in hospital-, ICU-, and ventilator-free days. DISCUSSION: We demonstrate the feasibility of performing CT in select trauma patients who undergo REBOA. We describe a pathway to enable expeditious workup and management of these patients. Optimal hemorrhage control management is impacted by CT scans when it can be performed. It is important to note that this is a severely injured patient population, and mortality is high even when hemorrhage is controlled. LEVEL OF EVIDENCE: III.

Outcomes Associated With Aortic Balloon Occlusion Time in Patients With Zone 1 Resuscitative Endovascular Balloon Occlusion of the Aorta.

INTRODUCTION: Resuscitative endovascular balloon occlusion of the aorta (REBOA) has the potential to cause clinically relevant systemic ischemic burden with long durations of aortic occlusion (AO). We aimed to examine the association between balloon occlusion time and clinical complications and mortality outcomes in patients undergoing zone 1 REBOA. METHODS: A retrospective cohort analysis of American Association for the Surgery of Trauma Aortic Occlusion for Resuscitation in Trauma and Acuteregistry patients with Zone 1 REBOA between 2013 and 2022 was performed. Patients with cardiopulmonary resuscitation on arrival or who did not survive past the emergency department were excluded. Total AO times were categorized as follows: <15 min, 15-30 min, 31-60 min, and >60 min. Clinical and procedural variables and in-hospital outcomes were compared across groups using bivariate and multivariate regression analyses. RESULTS: There were 327 cases meeting inclusion criteria (n = 51 < 15 min, 83 15-30 min, 98 31-60 min, and 95 > 60 min, respectively). AO >60 min had higher admission lactate (8 ± 6; P = 0.004) compared to all other time groups, but injury severity score, heart rate, and systolic blood pressure were similar. Group average times from admission to definitive hemorrhage control ranged from 82 to 103 min and were similar across groups (85 min in AO >60 group). Longer AO times were associated with greater red blood cell, fresh frozen plasma transfusions (P < 0.001), and vasopressor use (P = 0.001). Mortality was greatest in the >60 min group (73%) versus the <15 min, 15-30 min, and 31-60 min groups (53%, 43%, and 45%, P < 0.001). With adjustment for injury severity score, systolic blood pressure, and lactate, AO >60 min had greater mortality (OR 3.7, 95% CI 1.6-9.4; P < 0.001) than other AO duration groups. Among 153 survivors, AO >60 min had a higher rate of multiple organ failure (15.4%) compared to the other AO durations (0%, 0%, and 4%, P = 0.02). There were no differences in amputation rates (0.7%) or spinal cord ischemia (1.4%). acute kidney injury was seen in 41% of >60 min versus 21%, 27%, and 33%, P = 0.42. CONCLUSIONS: Though greater preocclusion physiologic injury may have been present, REBOA-induced ischemic insult was correlated with poor patient outcomes, specifically, REBOA inflation time >60 min had higher rates of mortality and multiple organ failure. Minimizing AO duration should be prioritized, and AO should not delay achieving definitive hemostasis. Partial REBOA may be a solution to extend safe AO time and deserves further study.

Impact of Prehospital Exsanguinating Airway-Breathing-Circulation Resuscitation Sequence on Patients with Severe Hemorrhage.

BACKGROUND: At the 2023 ATLS symposium, the priority of circulation was emphasized through the "x-airway-breathing-circulation (ABC)" sequence, where "x" stands for exsanguinating hemorrhage control. With growing evidence from military and civilian studies supporting an x-ABC approach to trauma care, a prehospital advanced resuscitative care (ARC) bundle emphasizing early transfusion was developed in our emergency medical services (EMS) system. We hypothesized that prioritization of prehospital x-ABC through ARC would reduce in-hospital mortality. STUDY DESIGN: This was a single-year prospective analysis of patients with severe hemorrhage. These patients were combined with our institution's historic controls before prehospital blood implementation. Included were patients with systolic blood pressure (SBP) less than 90 mmHg. Excluded were patients with penetrating head trauma or prehospital cardiac arrest. Two-to-one propensity matching for x-ABC to ABC groups was conducted, and the primary outcome, in-hospital mortality, was compared between groups. RESULTS: A total of 93 patients (x-ABC = 62, ABC = 31) met the inclusion criteria. There was no difference in patient age, sex, initial SBP, initial Glasgow Coma Score, and initial shock index between groups. When compared with the ABC group, x-ABC patients had significant improvement in vitals at emergency department admission. Overall mortality was lower in the x-ABC group (13% vs 47%, p < 0.001). Multivariable regression revealed that prehospital circulation-first prioritization was independently associated with decreased in-hospital mortality (odds ratio 0.15, 95% CI 0.04 to 0.54, p = 0.004). CONCLUSIONS: This is the first analysis to demonstrate a prehospital survival benefit of x-ABC in this subset of patient with severe injury and hemorrhagic shock. Standardization of prehospital x-ABC management in this patient population warrants special consideration.

Hypoxically stored RBC resuscitation in a rat model of traumatic brain injury and severe hemorrhagic shock.

This study aims to investigate the effects of hypoxically stored Red Blood Cells (RBCs) in a rat model of traumatic brain injury followed by severe hemorrhagic shock (HS) and resuscitation. RBCs were made hypoxic using an O2 depletion system (Hemanext Inc. Lexington, MA) and stored for 3 weeks. Experimental animals underwent craniotomy and blunt brain injury followed by severe HS. Rats were resuscitated with either fresh RBCs (FRBCs), 3-week-old hypoxically stored RBCs (HRBCs), or 3-week-old conventionally stored RBCs (CRBCs). Resuscitation was provided via RBCs transfusion equivalent to 70 % of the shed blood and animals were followed for 2 h. The control group was comprised of healthy animals that were not instrumented or injured. Post-resuscitation hemodynamics and lactate levels were improved with FRBCs and HRBCs, and markers of organ injury in the liver (Aspartate aminotransferase [AST]), lung (chemokine ligand 1 [CXCL-1] and Leukocytes count), and heart (cardiac troponin, Interleukin- 6 [IL-6] and Tumor Necrosis Factor Alpha[TNF-α]) were lower with FRBCs and HRBCs resuscitation compared to CRBCs. Following reperfusion, biomarkers for oxidative stress, lipid peroxidation, and RNA/DNA injury were assessed. Superoxide dismutase [SOD] levels in the HRBCs group were similar to the FRBCs group and levels in both groups were significantly higher than CRBCs. Catalase levels were not different than control values in the FRBCs and HRBCs groups but significantly lower with CRBCs. Thiobarbituric acid reactive substances [Tbars] levels were higher for both CRBCs and HRBCs. Hypoxically stored RBCs show few differences from fresh RBCs in resuscitation from TBI + HS and decreased organ injury and oxidative stress compared to conventionally stored RBCs.

TiME OUT: Time-specific machine-learning evaluation to optimize ultramassive transfusion.

BACKGROUND: Ultramassive transfusion (UMT) is a resource-demanding intervention for trauma patients in hemorrhagic shock, and associated mortality rates remains high. Current research has been unable to identify a transfusion ceiling or point where UMT transitions from lifesaving to futility. Furthermore, little consideration has been given to how time-specific patient data points impact decisions with ongoing high-volume resuscitation. Therefore, this study sought to use time-specific machine learning modeling to predict mortality and identify parameters associated with survivability in trauma patients undergoing UMT. METHODS: A retrospective review was conducted at a Level I trauma (2018-2021) and included trauma patients meeting criteria for UMT, defined as ≥20 red blood cell products within 24 hours of admission. Cross-sectional data were obtained from the blood bank and trauma registries, and time-specific data were obtained from the electronic medical record. Time-specific decision-tree models predicating mortality were generated and evaluated using area under the curve. RESULTS: In the 180 patients included, mortality rate was 40.5% at 48 hours and 52.2% overall. The deceased received significantly more blood products with a median of 71.5 total units compared with 55.5 in the survivors ( p < 0.001) and significantly greater rates of packed red blood cells and fresh frozen plasma at each time interval. Time-specific decision-tree models predicted mortality with an accuracy as high as 81%. In the early time intervals, hemodynamic stability, undergoing an emergency department thoracotomy, and injury severity were most predictive of survival, while, in the later intervals, markers of adequate resuscitation such as arterial pH and lactate level became more prominent. CONCLUSION: This study supports that the decision of "when to stop" in UMT resuscitation is not based exclusively on the number of units transfused but rather the complex integration of patient and time-specific data. Machine learning is an effective tool to investigate this concept, and further research is needed to refine and validate these time-specific decision-tree models. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

EVIDENCE FOR BENEFICIAL USE OF THE COMPENSATORY RESERVE MEASUREMENT IN GUIDING INTRAOPERATIVE RESUSCITATION: A PROSPECTIVE COHORT STUDY OF ORTHOTOPIC LIVER TRANSPLANT RECIPIENTS.

ABSTRACT: Introduction: The compensatory reserve measurement (CRM) is a continuous noninvasive monitoring technology that provides an assessment of the integrated capacity of all physiological mechanisms associated with responses to a hypovolemic stressor such as hemorrhagic shock. No prior studies have analyzed its use for intraoperative resuscitation guidance. Methods: A prospective observational study was conducted of 23 patients undergoing orthotopic liver transplant. Chart review was performed to identify timing of various intraoperative events. Data were compared based on predefined thresholds for existence of hemorrhagic shock: CRM lower than 40%, systolic blood pressure (SBP) lower than 90 mm Hg (SBP90), and heart rate (HR) higher than 100 beats per minute (HR100). Regression analysis was performed for predicting resuscitation events, and nonlinear eXtreme Gradient Boosting (XGBoost) models were used to compare CRM with standard vital sign measures. Results: Events where CRM dropped lower than 40% were 2.25 times more likely to lead to an intervention, whereas HR100 and SBP90 were not associated with intraoperative interventions. XGBoost prediction models showed superior discriminatory capacity of CRM alone compared with the model with SBP and HR and no difference when all three were combined (CRM-HR-SBP). All XGBoost models outperformed equivalent linear regression models. Conclusion: These results demonstrate that CRM can provide an adjunctive clinical tool that can augment early and accurate of hemodynamic compromise and promote goal-directed resuscitation in the perioperative setting.

ASSESSMENT OF ABNORMAL SKELETAL MUSCLE PERFUSION BY CONTRAST-ENHANCED ULTRASOUND WITH PARAMETRIC IMAGING IN RATS AFTER SEVERE INJURY, HEMORRHAGIC SHOCK, AND WHOLE BLOOD RESUSCITATION.

ABSTRACT: Background: After severe injury, optical measures of microvascular blood flow (MBF) decrease and do not normalize with resuscitation to normal blood pressure. These changes are associated with organ dysfunction, coagulopathy, and death. However, the pathophysiology is not well understood. Several possible pathways could also contribute to the development of trauma-induced coagulopathy (TIC). A small-animal model of trauma-related MBF derangement that persists after resuscitation and includes TIC would facilitate further study. Parametric contrast-enhanced ultrasound (CEUS) is particularly advantageous in this setting, because it noninvasively assesses MBF in large, deep vascular beds. We sought to develop such a model, measuring MBF with CEUS. Methods: Sixteen male Sprague-Dawley rats were anesthetized, ventilated, and cannulated. Rats were subjected to either no injury (sham group) or a standardized polytrauma and pressure-targeted arterial catheter hemorrhage with subsequent whole blood resuscitation (trauma group). At prespecified time points, CEUS measurements of uninjured quadriceps muscle, viscoelastic blood clot strength, and complete blood counts were taken. Results: After resuscitation, blood pressure normalized, but MBF decreased and remained low for the rest of the protocol. This was primarily driven by a decrease in blood volume with a relative sparing of blood velocity. Viscoelastic blood clot strength and platelet count also decreased and remained low throughout the protocol. Conclusion: We present a rat model of MBF derangement in uninjured skeletal muscle and coagulopathy after polytrauma that persists after resuscitation with whole blood to normal macrohemodynamics. Parametric CEUS analysis shows that this change is primarily due to microvascular obstruction. This platform can be used to develop a deeper understanding of this important process.

Critical systolic blood pressure threshold for endovascular aortic occlusion-A multinational analysis to determine when to place a REBOA.

BACKGROUND: Systolic blood pressure (SBP) is a potential indicator that could guide when to use a resuscitative endovascular balloon occlusion of the aorta (REBOA) in trauma patients with life-threatening injuries. This study aims to determine the optimal SBP threshold for REBOA placement by analyzing the association between SBP pre-REBOA and 24-hour mortality in severely injured hemodynamically unstable trauma patients. METHODS: We performed a pooled analysis of the aortic balloon occlusion (ABO) trauma and AORTA registries. These databases record the details related to the use of REBOA and include data from 14 countries worldwide. We included patients who had suffered penetrating and/or blunt trauma. Patients who arrived at the hospital with a SBP pre-REBOA of 0 mm Hg and remained at 0 mm Hg after balloon inflation were excluded. We evaluated the impact that SBP pre-REBOA had on the probability of death in the first 24 hours. RESULTS: A total of 1,107 patients underwent endovascular aortic occlusion, of these, 848 met inclusion criteria. The median age was 44 years (interquartile range [IQR], 27-59 years) and 643 (76%) were male. The median injury severity score was 34 (IQR, 25-45). The median SBP pre-REBOA was 65 mm Hg (IQR, 49-88 mm Hg). Mortality at 24 hours was reported in 279 (32%) patients. Math modeling shows that predicted probabilities of the primary outcome increased steadily in SBP pre-REBOA below 100 mm Hg. Multivariable mixed-effects analysis shows that when SBP pre-REBOA was lower than 60 mm Hg, the risk of death was more than 50% (relative risk, 1.5; 95% confidence interval, 1.17-1.92; p = 0.001). DISCUSSION: In patients who do not respond to initial resuscitation, the use of REBOA in SBPs between 60 mm Hg and 80 mm Hg may be a useful tool in resuscitation efforts before further decompensation or complete cardiovascular collapse. The findings from our study are clinically important as a first step in identifying candidates for REBOA. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

Use of Low-Titer O-Positive Whole Blood in Female Trauma Patients: A Literature Review, Qualitative Multidisciplinary Analysis of Risk/Benefit, and Guidelines for Its Use as a Universal Product in Hemorrhagic Shock.

BACKGROUND: Whole blood transfusion is associated with benefits including improved survival, coagulopathy, and decreased transfusion requirements. The majority of whole blood transfusion is in the form of low-titer O-positive whole blood (LTOWB). Practice at many trauma centers withholds the use of LTOWB in women of childbearing potential due to concerns of alloimmunization. The purpose of this article is to review the evidence for LTOWB transfusion in female trauma patients and generate guidelines for its application. STUDY DESIGN: Literature and evidence for LTOWB transfusion in hemorrhagic shock are reviewed. The rates of alloimmunization and subsequent obstetrical outcomes are compared to the reported outcomes of LTOWB vs other resuscitation media. Literature regarding patient experiences and preferences in regards to the risk of alloimmunization is compared to current trauma practices. RESULTS: LTOWB has shown improved outcomes in both military and civilian settings. The overall risk of alloimmunization for Rhesus factor (Rh) - female patients in hemorrhagic shock exposed to Rh + blood is low (3% to 20%). Fetal outcomes in Rh-sensitized patients are excellent compared to historical standards, and treatment options continue to expand. The majority of female patients surveyed on the risk of alloimmunization favor receiving Rh + blood products to improve trauma outcomes. Obstetrical transfusion practices have incorporated LTOWB with excellent results. CONCLUSIONS: The use of whole blood resuscitation in trauma is associated with benefits in the resuscitation of severely injured patients. The rate at which severely injured, Rh-negative patients develop anti-D antibodies is low. Treatments for alloimmunized pregnancies have advanced, with excellent results. Fears of alloimmunization in female patients are likely overstated and may not warrant the withholding of whole blood resuscitation. The benefits of whole blood resuscitation likely outweigh the risks of alloimmunization.