Prehospital Plasma during Air Medical Transport in Trauma Patients at Risk for Hemorrhagic Shock.

BACKGROUND: After a person has been injured, prehospital administration of plasma in addition to the initiation of standard resuscitation procedures in the prehospital environment may reduce the risk of downstream complications from hemorrhage and shock. Data from large clinical trials are lacking to show either the efficacy or the risks associated with plasma transfusion in the prehospital setting. METHODS: To determine the efficacy and safety of prehospital administration of thawed plasma in injured patients who are at risk for hemorrhagic shock, we conducted a pragmatic, multicenter, cluster-randomized, phase 3 superiority trial that compared the administration of thawed plasma with standard-care resuscitation during air medical transport. The primary outcome was mortality at 30 days. RESULTS: A total of 501 patients were evaluated: 230 patients received plasma (plasma group) and 271 received standard-care resuscitation (standard-care group). Mortality at 30 days was significantly lower in the plasma group than in the standard-care group (23.2% vs. 33.0%; difference, -9.8 percentage points; 95% confidence interval, -18.6 to -1.0%; P=0.03). A similar treatment effect was observed across nine prespecified subgroups (heterogeneity chi-square test, 12.21; P=0.79). Kaplan-Meier curves showed an early separation of the two treatment groups that began 3 hours after randomization and persisted until 30 days after randomization (log-rank chi-square test, 5.70; P=0.02). The median prothrombin-time ratio was lower in the plasma group than in the standard-care group (1.2 [interquartile range, 1.1 to 1.4] vs. 1.3 [interquartile range, 1.1 to 1.6], P<0.001) after the patients' arrival at the trauma center. No significant differences between the two groups were noted with respect to multiorgan failure, acute lung injury-acute respiratory distress syndrome, nosocomial infections, or allergic or transfusion-related reactions. CONCLUSIONS: In injured patients at risk for hemorrhagic shock, the prehospital administration of thawed plasma was safe and resulted in lower 30-day mortality and a lower median prothrombin-time ratio than standard-care resuscitation. (Funded by the U.S. Army Medical Research and Materiel Command; PAMPer ClinicalTrials.gov number, NCT01818427 .).

Hemolytic markers following the transfusion of uncrossmatched, cold-stored, low-titer, group O+ whole blood in civilian trauma patients.

BACKGROUND: Low-titer group O whole blood (LTOWB) is increasingly being used in the civilian trauma setting, although there is a risk of hemolysis. This study evaluated the impact on hemolytic markers following the transfusion of 4 or more units of uncrossmatched LTOWB. METHODS: Civilian adult trauma patients who received four or more units of leukoreduced group O+, low-titer (<50 anti-A and anti-B), platelet-replete uncrossmatched whole blood during their initial resuscitation and who survived for more than 24 hours after the transfusion were included in this retrospective study. Lactate dehydrogenase (LDH), total bilirubin, haptoglobin, potassium, and creatinine were evaluated on the day of LTOWB transfusion (Day 0) and the next 3 days. Blood product administration over the first 24 hours of admission was recorded. RESULTS: There were 54 non-group O and 23 group O recipients of four or more LTOWB units. The median (interquartile range [IQR]) number of transfused LTOWB units was 4 (4-5) and 4 (4-4), respectively, the maximum number in both groups was eight. The non-group O patients received a median (IQR) volume of 1470 mL (1368-2052) of ABO-incompatible plasma. Comparing the non-group O to the group O recipients, there were no significant differences in the haptoglobin, LDH, total bilirubin, potassium, or creatinine concentrations at any of the time points. There were no reported transfusion reactions. CONCLUSION: Receiving at least four LTOWB units was not associated with biochemical or clinical evidence of hemolysis.

Opioid use patterns and risk characteristics among injured patients.

Background: Injured patients are at risk for prolonged opioid use after discharge from care. Limited evidence exists regarding how continued opioid use may be related to opioid medication misuse and opioid use disorder (OUD) following injury. This pilot study characterized opioid consumption patterns, health characteristics, and substance use among patients with active prescriptions for opioid medications following injury care. Methods: This study was a cross-sectional screening survey combined with medical record review from February 2017 to March 2018 conducted among outpatient trauma and orthopedic surgery clinic patients. Eligible patients were 18-64 years of age, admitted/discharged for an injury or trauma-related orthopedic surgery, returning for clinic follow-up ≤6 months post hospital discharge after the index injury, prescribed opioid pain medication at discharge, and currently taking an opioid medication (from discharge or a separate prescription post discharge). Data collected included demographic, substance use, mental health, and physical health information. Descriptive and univariate statistics were calculated to characterize the population and opioid-related risks. Results: Seventy-one participants completed the survey (92% response). Most individuals (≥75%) who screened positive for misuse or OUD reported no nonmedical/illicit opioid use in the year before the index injury. A positive depression screen was associated with a 3.88 times increased likelihood for misuse or OUD (95% confidence interval [CI] = 1.1-13.5). Nonopioid illicit drug use (odds ratio [OR] = 1.89, 95% CI = 1.1-3.4) and opioid craving (OR = 1.29, 95% CI = 1.1-1.5) were also associated with increased likelihood for misuse or OUD. Number of emergency department visits in the 3 years previous to the index injury was associated with a 22% likelihood of being misuse or OUD positive (95% CI = 1.0-1.5). Conclusions: Patients with behavioral health concerns and greater emergency department utilization may have heightened risk for experiencing adverse opioid-related outcomes. Future research must further establish these findings and possibly develop protocols to identify patients at risk prior to pain management planning.

Application of a recursive partitioning decision tree algorithm for the prediction of massive transfusion in civilian trauma: the MTPitt prediction tool.

BACKGROUND: A supervised machine learning algorithm was used to generate decision trees for the prediction of massive transfusion at a Level 1 trauma center. METHODS: Trauma patients who received at least one unit of RBCs and/or low-titer group O whole blood between January 1, 2015, and December 31, 2017, were included. Massive transfusion was defined as the transfusion of 10 or more units of RBCs and/or low-titer group O whole blood in the first 24 hours of admission. A recursive partitioning algorithm was used to generate two decision trees for prediction of massive transfusion using a training data set (n = 550): the first, MTPitt, was based on demographic and clinical parameters, and the second, MTPitt+Labs, also included laboratory data. Decision tree performance was compared with the Assessment of Blood Consumption score and the Trauma Associated Severe Hemorrhage score. RESULTS: The incidence of massive transfusion in the validation data set (n = 199) was 7.5%. The MTPitt decision tree had a higher balanced accuracy (81.4%) and sensitivity (86.7%) compared to an Assessment of Blood Consumption Score of 2 or higher (77.9% and 66.7%, respectively) and a Trauma Associated Severe Hemorrhage score of 9 or higher (75.0% and 73.3%, respectively), although the 95% confidence intervals overlapped. Addition of laboratory data to the MTPitt decision tree (MTPitt+Labs) resulted in a higher specificity and balanced accuracy compared to MTPitt without an increase in sensitivity. CONCLUSIONS: The MTPitt decisions trees are highly sensitive tools for identifying patients who received a massive transfusion and do not require computational resources to be implemented in the trauma setting.

How do I implement a whole blood program for massively bleeding patients?

Building on the successful military experience, interest has been rekindled in transfusing whole blood (WB) early in the resuscitation of traumatically injured civilians, often before their ABO group is known. WB efficiently provides treatment for shock and coagulopathy, as well as platelet hemostatic function, to patients losing large volumes of blood. Unlike group O uncrossmatched red blood cells (RBCs), group O WB contains a substantial amount of plasma, which is incompatible with the RBCs of all non-group O recipients. Thus, when implementing a WB program, it is important to decide how to mitigate the risk of immune-mediated hemolysis. Other questions that a hospital needs to answer before implementing a WB program include determining which patients will be eligible for this product, how many units eligible patients can receive, for how long it should be stored and under what conditions, and how to monitor for adverse events. The donor center needs to consider if the WB should be leukoreduced, how to comply with the AABB's transfusion-related acute lung injury risk mitigation standard, and into which storage solution it should be collected. This report describes the multidisciplinary approach taken to implementing a civilian WB program at a multihospital health care system in the United States.

Clinical outcomes among low-titer group O whole blood recipients compared to recipients of conventional components in civilian trauma resuscitation.

BACKGROUND: The serological safety of transfusing ≤4 units of low titer group O whole blood (LTOWB) in civilian trauma patients has been demonstrated. This study investigated clinical outcomes of LTOWB recipients compared to patients who received only conventional blood components during their resuscitation. STUDY DESIGN AND METHODS: A retrospective analysis of trauma patients' medical records who received LTOWB during the first 24 hours of their admission was performed. Using a 12-parameter propensity matching strategy, LTOWB recipients were matched to other patients who received at least one red blood cell (RBC) unit during their first 24 hours of admission but not LTOWB. The primary outcomes were mortality and blood use. RESULTS: A total of 135 patients who received LTOWB (median 2 units) were matched to 135 patients who received conventional components. There were no significant differences in the matching parameters between the groups. There were no significant differences in outcomes between the conventional component and LTOWB groups: median (interquartile range) in-hospital mortality, 24.4% vs. 18.5% (respectively, p = 0.24); 24-hour mortality, 12.6% vs. 8.9% (respectively, p = 0.33). The hospital and intensive care unit lengths of stay were not significantly different between groups. The median number of RBC units transfused, including the contribution from the LTOWB, was not significantly different between the groups. The time to normalization of elevated plasma lactate levels tended to be shorter among the LTOWB recipients compared to the conventional component recipients (median 8.1 [3.7-15.4] hr vs. 13.2 [4.4-26.8] hr, respectively, p = 0.05). CONCLUSION: The LTOWB recipients had similar clinical outcomes compared to recipients of conventional component therapy.

Safety profile of uncrossmatched, cold-stored, low-titer, group O+ whole blood in civilian trauma patients.

BACKGROUND: The use of cold-stored low-titer group O whole blood (LTOWB) for civilian trauma patients is gaining popularity. However, hemolysis might occur among non-group O recipients. This study evaluated the serologic safety of transfusing up to 4 units of LTOWB. STUDY DESIGN AND METHODS: Hypotensive male and at least 50-year-old female trauma patients who received leukoreduced, uncrossmatched, group O+, low-titer (<50 anti-A and anti-B), platelet-replete whole blood during initial resuscitation were included in this prospective, observational study. Biochemical markers of hemolysis were measured on the day of LTOWB receipt (Day 0) and over the next 2 days. Blood product administration in the first 24 hours of admission and reported transfusion-associated adverse events were also reviewed. RESULTS: There were 102 non-group O and 70 group O recipients of 1 to 4 LTOWB units analyzed. The non-group O recipients received a median volume of 600 mL (range, 300-4100 mL) of ABO-incompatible plasma, including the contribution from the LTOWB units. There were no significant differences in median haptoglobin, lactate dehydrogenase, total bilirubin, creatinine, or potassium levels at any time point between the non-group O and group O recipients. There were also no differences in these markers between the subset of 23 non-group O and 14 group O recipients who received 3 or 4 LTOWB units. No transfusion-associated adverse events were reported. CONCLUSIONS: Administration of up to 4 units of LTOWB in civilian trauma resuscitation was not associated with clinical or biochemical evidence of hemolysis. Six units per trauma patient are now permitted at these institutions.

Emergency Surgical Airways Following Activation of a Difficult Airway Management Team in Hospitalized Critically Ill Patients: A Case Series.

INTRODUCTION: An emergency surgical airway (ESA) is widely recommended for securing the airway in critically ill patients who cannot be intubated or ventilated. Little is known of the frequency, clinical circumstances, management methods, and outcomes of hospitalized critically ill patients in whom ESA is performed outside the emergency department or operating room environments. METHODS: We retrospectively reviewed all adult patients undergoing ESA in our intensive care units (ICUs) and other hospital units from 2008 to 2012 following activation of our difficult airway management team (DAMT). RESULTS: Of 207 DAMT activations for native airway events, 22 (10.6%) events culminated in an ESA, with 59% of these events occurring in ICUs with the remainder outside the ICU in the context of rapid response team activations. Of patients undergoing ESA, 77% were male, 63% were obese, and 41% had a history of a difficult airway (DA). Failed planned or unplanned extubations preceded 61% of all ESA events in the ICUs, while bleeding from the upper or lower respiratory tract led to ESA in 44% of events occurring outside the ICU. Emergency surgical airway was the primary method of airway control in 3 (14%) patients, with the remainder of ESAs performed following failed attempts to intubate. Complications occurred in 68% of all ESAs and included bleeding (50%), multiple cannulation attempts (36%), and cardiopulmonary arrest (27%). Overall hospital mortality for patients undergoing ESA was 59%, with 38% of deaths occurring at the time of the airway event. CONCLUSION: An ESA is required in approximately 10% of DA events in critically ill patients and is associated with high morbidity and mortality. Efforts directed at early identification of patients with a difficult or challenging airway combined with a multidisciplinary team approach to management may reduce the overall frequency of ESA and associated complications.

Blood component transfusion and wastage rates in the setting of massive transfusion in three regional trauma centers.

BACKGROUND: The purpose of massive transfusion protocols (MTPs) is to provide large quantities of blood products rapidly to exsanguinating patients. The expected rates of blood product transfusion and wastage in this setting have not been defined. This study was undertaken to assess the transfusion and wastage rates for bleeding patients requiring emergency issue of blood components at three American Level I trauma centers. STUDY DESIGN AND METHODS: Three hospitals participated, all of which are Level I trauma centers that have MTPs in place where uncrossmatched red blood cells (RBCs) can be ordered with or without platelets (PLTs), plasma, and cryoprecipitate. Data on the transfusion, return to blood bank, and wastage rates were recorded on all products issued within 3 hours after MTP activation. RESULTS: The majority of products were issued to the emergency department and/or operating room at all three institutions (84%-95%). The percentage of RBCs, plasma, and PLTs transfused during MTPs were 39% to 65%, 43% to 66%, and 75% to 100%, respectively. Wastage rates were comparable for RBCs (0%-9%), plasma (0%-7%), and PLTs (0%-7%). Cryoprecipitate had the highest wastage rates at all three sites (7%-33%). CONCLUSION: A large portion of blood products issued during MTPs are not transfused. Some are wasted due to stringent storage requirements and/or limited shelf lives. The optimum ratio of transfused to returned products in these patients is likely to be determined more by clinical need than by transfusion service policy.

Delayed splenic vascular injury after nonoperative management of blunt splenic trauma.

BACKGROUND: Delayed splenic vascular injury (DSVI) is traditionally considered a rare, often clinically occult, harbinger of splenic rupture in patients with splenic trauma that are managed conservatively. The purpose of our study was to assess the incidence of DSVI and associated features in patients admitted with blunt splenic trauma and managed nonoperatively. MATERIALS AND METHODS: A retrospective analysis was conducted over a 4-y time. Patients admitted with blunt splenic trauma, managed no-operatively and with a follow-up contrast-enhanced computed tomography (CT) scan study during admission were included. The CT scans were reviewed for American Association for the Surgery of Trauma splenic injury score, amount of hemoperitoneum, and presence of DSVI. Logistic regression models were used to investigate the risk factors associated with DSVI. RESULTS: A total of 100 patients (60 men and 40 women) constituted the study group. Follow-up CT scan demonstrated a 23% incidence of DSVI. Splenic artery angiography validated DSVI in 15% of the total patient population. Most DSVIs were detected only on arterial phase CT scan imaging. The American Association for the Surgery of Trauma splenic injury score (odds ratio = 1.73; P = 0.045) and the amount of hemoperitoneum (odds ratio = 1.90; P = 0.023) on admission CT scan were associated with the development of DSVI on follow-up CT scan. CONCLUSIONS: DSVI on follow-up CT scan imaging of patients managed nonoperatively after splenic injury is common and associated with splenic injury score assessed on admission CT scan.

Contemporary outcomes of civilian lower extremity arterial trauma.

OBJECTIVE: Lower extremity arterial injury may result in limb loss after blunt or penetrating trauma. This study examined outcomes of civilian lower extremity arterial trauma and predictors of delayed amputation. METHODS: The records of patients presenting to a major level I trauma center from 2004 to 2014 with infrainguinal arterial injury were identified from a prospective institutional trauma registry, and outcomes were reviewed. Standard statistical methods were used for data analysis. RESULTS: We identified 149 patients (86% male; mean age, 33 ± 14 years,). Of these, 46% presented with blunt trauma: 19 (13%) had common femoral artery, 26 (17%) superficial femoral artery, 50 (33%) popliteal, and 54 (36%) tibial injury. Seven patients underwent primary amputation; of the remainder, 21 (15%) underwent ligation, 85 (59%) revascularization (80% bypass grafting, 20% primary repair), and the rest were observed. Delayed amputation was eventually required in 24 patients (17%): 20 (83%) were due to irreversible ischemia or extensive musculoskeletal damage, despite having adequate perfusion. Delayed amputation rates were 26% for popliteal, 20% for tibial, and 4.4% for common/superficial femoral artery injury. The delayed amputation group had significantly more (P < .05) blunt trauma (79% vs 30%), popliteal injury (46% vs 27%), compound fracture/dislocation (75% vs 33%), bypass graft (63% vs 43%), and fasciotomy (75% vs 43%), and a higher mangled extremity severity score (6.1 ± 1.8 vs 4.3 ± 1.6). Predictors of delayed amputation included younger age, higher injury severity score, popliteal or multiple tibial injury, blunt trauma, and pulseless examination on presentation. CONCLUSIONS: Individualized decision making based on age, mechanism, pulseless presentation, extent of musculoskeletal trauma, and location of injury should guide the intensity of revascularization strategies after extremity arterial trauma. Although patients presenting with vascular trauma in the setting of multiple negative prognostic factors should not be denied revascularization, expectations for limb salvage in the short-term and long-term periods should be carefully outlined.

Very low rate of patient-related adverse events associated with the use of intraoperative cell salvage.

BACKGROUND: The rate of patient-related clinical adverse events (AEs) associated with the use of intraoperative cell salvage (ICS) was analyzed. STUDY DESIGN AND METHODS: The perfusion service and electronic risk management databases in a nine-hospital regional health care system were reviewed over an approximately 11-year period. The number of ICS cases performed during this period and basic patient demographics were also extracted. RESULTS: There were 43,198 patients for whom ICS was utilized during the study period. Recovered blood was returned to 33,351 (77.2%) patients. Electronic comments on the ICS procedure were found in 2348 of 33,351 (7.0%) cases. The vast majority of comments (2203/2348, 93.8%) described minor events that did not lead to patient-related AEs such as the surgeon requested higher than normal suction pressure or that no RBCs were returned. Only 144 of 2348 (6.1%) of the comments described procedural or equipment-related events or potential AEs. From these comments two potential AEs were identified: the first was a post-Cesarean section patient who became acutely tachycardic, hypertensive, and dyspneic with rigors. The second was a patient with postpartum hemorrhage who experienced acute dyspnea and hypotension. Both patients were rapidly stabilized and discharged from the hospital shortly thereafter without further complications. It is unclear if these events were caused by ICS reinfusion. No air emboli were reported. The overall rate of patient-related AEs associated with ICS reinfusion was between 0 and 2 per 33,351 (0%-0.006%). CONCLUSIONS: The use of ICS is safe with a very low rate of patient-related AEs.

The effect of stationary versus rocked storage of whole blood on red blood cell damage and platelet function.

BACKGROUND: Increasingly, cold-stored whole blood (WB) is being considered for the resuscitation of civilian trauma patients. It is unclear whether the WB should be agitated to enhance the function of the platelets (PLTs) or whether agitation will cause RBC damage. STUDY DESIGN AND METHODS: WB units were collected by standard procedures using a PLT-sparing inline leukoreduction filter and stored between 1 and 6°C. On Storage Day 3 each unit was divided into 4 subunits that were stored under one of the following conditions for 21 days: unrocked, manually rocked once daily, continuously rocked end over end, or continuously rocked horizontally. From Day 3 to Day 10, hemolysis and the mechanical fragility index (MFI) for RBC injury were measured daily and again on Days 15 and 21 (n = 9-16 units tested each time). On Days 4 and 10, rapid thromboelastogram (rTEG) measurements were performed (n = 8-10 units tested each time). RESULTS: Hemolysis and MFI increased significantly between Day 3 and Day 21 (p < 0.0001) for all RBC rocking conditions, as well as the unrocked units. Only the manually and horizontally rocked units demonstrated higher hemolysis (on Day 21) and MFI (starting on Day 10) compared to the unrocked units. Only the α-angle and maximum amplitude in the end-over-end rocked units increased significantly between Day 4 and Day 10. There were no significant differences between the rocked and unrocked units on Day 10 for any rTEG variable. CONCLUSIONS: Rocking does not appear to enhance in vitro PLT activity in cold-stored WB and can lead to increased hemolysis.

The confusion continues: results from an American Association for the Surgery of Trauma survey on massive transfusion practices among United States trauma centers.

BACKGROUND: Massive transfusion practices have undergone several recent developments. We sought to examine institutional practices guiding hemostatic resuscitation in the setting of massive hemorrhage. STUDY DESIGN AND METHODS: A 37-question online survey was sent to American Association for the Surgery of Trauma members. RESULTS: A total of 191 surgeons from 125 institutions completed the survey. Level I and II centers composed 70 and 18% of responding sites, respectively. A total of 123 institutions have a massive transfusion protocol (MTP); 54% report having an MTP for less than 5 years. The number of coolers and units of red blood cells, plasma, and platelets are highly variable. Tranexamic acid is part of the MTP at 64% of centers; 26% continue to use recombinant activated Factor VII. MTP activation occurs more than five times per month at 32% of centers. MTPs are utilized for nontrauma patients in 82% of institutions. Point-of-care prothrombin time, international normalized ratio, and partial thromboplastin time testing is utilized in 37% of institutions. Only 9% routinely utilize thromboelastography or rotational thromboelastometry (TEG/ROTEM) within their MTP. Just 7% use a validated scoring system to guide MTP activation. The incorporation of TEG/ROTEM into the MTP is associated with the use of a scoring system in regression analysis (p = 0.024). CONCLUSION: Most institutions regularly activate recently implemented MTPs for trauma and nontrauma indications; however, few use validated scoring systems for MTP activation. MTP content is highly variable. Few institutions use TEG, while most have incorporated tranexamic acid into their protocol. The lack of consistent practices underscores the need for outcome-based studies to guide transfusion practices.

The association between air ambulance distribution and trauma mortality.

OBJECTIVE: To determine whether increasing distance between helicopter ambulance airbase and either home residence or referring facility is associated with an increased risk of injury-related mortality. BACKGROUND: A dramatic increase in the absolute number and utilization of Helicopter Emergency Medical Services transports has occurred in the management of the critically injured patients. HEMS are resource intensive, and the most efficient geographic distribution of airbases necessary to improve patient outcomes is unknown. METHODS: We performed a retrospective analysis of 244,293 adult trauma patients who were treated at a designated trauma center (TC) in Pennsylvania during the period 1997 to 2007, using the Pennsylvania Trauma Outcomes Study data set. We performed a multivariate analysis, adjusting for differences in case mix, to determine whether airbase proximity to either residence or referring facility is associated with injury-related mortality. RESULTS: For patients residing distant (>20 miles) from a TC, increasing distance from an airbase is associated with an increased risk of death; for each mile, the risk of mortality increases by approximately 1% (adjusted odds ratio, 1.011; 95% confidence interval, 1.002-1.018; P = 0.02). There is no additional benefit to living close (<25 miles) to more than 1 airbase. However, most airbases are positioned near TC and other airbases. Despite the proliferation of helicopter ambulances, 18.1% of patients who did not live near a TC also did not live near airbase. CONCLUSIONS: For individuals residing distant from a TC, proximity to 1 airbase is associated with reduced risk of death. No additional benefit is observed when airbases are positioned close to a TC or other airbases.

The anchor point algorithm: A morphometric analysis of anatomic landmarks to guide placement of temporary aortic Rescue stent grafts for noncompressible torso hemorrhage.

BACKGROUND: Noncompressible hemorrhage remains a high-mortality injury, which requires rapid damage control within minutes to avoid exsanguination. Retrievable stent grafts offer perfusion preserving hemorrhage damage control, and yet algorithms for device selection and positioning are lacking for an anatomically diverse human population. We hypothesized that easily acquired external measurements could be used to rapidly triage patients to receive one of several presized stents and that these metrics may further predict a single target on the aorta by which to optimize both mesenteric perfusion and aortic hemorrhage control. METHODS: Metrics were acquired from computed tomography imaging of 203 male and female patients aged 18 to 50 years. Algorithms for metric based triage and stent sizing were examined against the cohort for effectiveness. Linear regression was used to predict a single target on the aorta for alignment of a multitiered stent. Next, the relationship of the anchor point to the palpable xiphoid was determined. RESULTS: Clavicle to pubis measurements correlated with aortic length and was used to triage patients to one of three stent grafts. Stents for each triage group were sized to achieve >75% coverage of aortic Zones 1 and 3 in most patients while preserving carotid and visceral perfusion. A metric/sex-based equation that predicts the location of the superior mesenteric artery relative to the palpable xiphoid was derived. By alignment of a single point on the stent with this target, known as the anchor point, the remainder of the stent can be rapidly deployed while minimizing coverage of critical branches. When applied back to the cohort, only 10.4% had potential serious branch coverage events predicted. CONCLUSION: Simple anatomic metrics offer rapid triage in this study population to one of three presized stent grafts and predict the location of key vascular branches. Confirmatory human trials will be essential to demonstrate safety and effectiveness of this approach. LEVEL OF EVIDENCE: Prognostic/Epidemiological; Level IV.

Prehospital low titer group O whole blood is feasible and safe: Results of a prospective randomized pilot trial.

INTRODUCTION: Low titer group O whole blood (LTOWB) resuscitation is increasingly common in both military and civilian settings. Data regarding the safety and efficacy of prehospital LTOWB remain limited. METHODS: We performed a single-center, prospective, cluster randomized, prehospital through in-hospital whole blood pilot trial for injured air medical patients. We compared standard prehospital air medical care including red cell transfusion and crystalloids followed by in-hospital component transfusion to prehospital and in-hospital LTOWB resuscitation. Prehospital vital signs were used as inclusion criteria (systolic blood pressure ≤90 mm Hg and heart rate ≥108 beats per minute or systolic blood pressure ≤70 mm Hg for patients at risk of hemorrhage). Primary outcome was feasibility. Secondary outcomes included 28-day and 24-hour mortality, multiple organ failure, nosocomial infection, 24-hour transfusion requirements, and arrival coagulation parameters. RESULTS: Between November 2018 and October 2020, 86 injured patients were cluster randomized by helicopter base. The trial has halted early at 77% enrollment. Overall, 28-day mortality for the cohort was 26%. Injured patients randomized to prehospital LTOWB (n = 40) relative to standard care (n = 46) were similar in demographics and injury characteristics. Intent-to-treat Kaplan-Meier survival analysis demonstrated no statistical mortality benefit at 28 days (25.0% vs. 26.1%, p = 0.85). Patients randomized to prehospital LTOWB relative to standard care had lower red cell transfusion requirements at 24 hours (p < 0.01) and a lower incidence of abnormal thromboelastographic measurements. No transfusion reactions during the prehospital or in-hospital phase of care were documented. CONCLUSION: Prehospital through in-hospital LTOWB resuscitation is safe and may be associated with hemostatic benefits. A large-scale clinical trial is feasible with protocol adjustment and would allow the effects of prehospital LTOWB on survival and other pertinent clinical outcomes to be appropriately characterized. LEVEL OF EVIDENCE: Therapeutic/Care Management, Level II.

Over reliance on computed tomography imaging in patients with severe abdominal injury: is the delay worth the risk?

BACKGROUND: Computed tomography (CT) has a high sensitivity and specificity for detecting abdominal injuries. Expeditious abdominal imaging in "quasi-stable" patients may prevent negative laparotomy. However, the significance of potential delay to laparotomy secondary to abdominal imaging remains unknown. We sought to analyze whether the use of abdominal CT (ABD CT) in patients with abdominal injury requiring laparotomy results in a significant delay and a higher risk of poor outcome. METHODS: A retrospective analysis of data from the National Trauma Data Bank (version 7.1) was performed. Inclusion criteria were adult patients (age>14 years), a scene admission (nontransfer), hypotension on arrival (emergency department systolic blood pressure<90 mm Hg), an abdominal Abbreviated Injury Scale (AIS) score>3, and undergoing a laparotomy within 90 minutes of arrival. Patients with severe brain injury (head AIS score>3) were excluded. The independent mortality risk associated with a preoperative ABD CT was determined using logistic regression after controlling important confounders. RESULTS: This cohort of patients (n=3,218) was significantly injured with a median Injury Severity Score of 25 ([interquartile range, 16-34]). Patients who underwent ABD CT had similar Glasgow Coma Scale scores, a lower head AIS, longer time delays to the operating room, and a higher crude mortality (45% vs. 30%; p=0.001). Logistic regression revealed that ABD CT was independently associated with more than a 70% higher risk of mortality (odds ratios, 1.71; 95% CI, 1.2-2.2; p<0.001). When stratified by injury mechanism, intubation status and whether or not a head CT was performed, the mortality risk remained significantly increased for each subgroup. When the laparotomy was able to occur within 30 minutes of arrival, an ABD CT was independently associated with more than a sevenfold higher risk of mortality (odds ratios, 7.6; p=0.038). CONCLUSION: Delay secondary to abdominal imaging in patients who require operative intervention results in an independent higher risk of mortality. ABD CT imaging is an important and useful tool after injury; however, these results suggest that delay caused by overreliance on ABD CT may result in poor outcome in specific patients. Clinicians who take care of critically injured patients should be aware of and understand these potential risks.

Delay to therapeutic interventional radiology postinjury: time is of the essence.

OBJECTIVE: Hemorrhage remains a leading cause of early death in injured patients, and definitive control of bleeding remains a fundamental principle of trauma management. Therapeutic interventional radiology (IR) procedures have increasingly become essential in the acute management of traumatic injury. The importance of time to control of hemorrhage for therapeutic IR procedures has not been adequately characterized. METHODS: A retrospective analysis was performed by using data derived from the National Trauma Data Bank, version 7.1. Inclusion criteria included the following: adult, hypotensive patients, scene admission, patients who underwent early therapeutic IR vascular occlusive procedures within in 3 hours of admission at a level I or II designated trauma center (n = 1,748). Exclusion criteria included intracranial or venous occlusion procedures, patients who underwent any abdominal, thoracic, vascular, or intracranial operative procedures throughout their entire hospital stay. Logistic regression analysis was used to analyze the independent mortality risk associated with DELAY to IR procedures after controlling for important confounders. RESULTS: The majority of patients who died did so within the first 48 hours from injury (80%). Regression analysis revealed that DELAY to IR was independently associated with more than a twofold higher risk of mortality (odds ratio 2.7, 95% confidence interval 1.6-4.9, p < 0.001). For every hour delay, the risk of mortality increased by 47%. These findings were independent of injury mechanism and most pertinent to level I trauma centers. CONCLUSION: In hemodynamically unstable trauma patients undergoing therapeutic catheter-based IR procedures, delay to IR was independently associated with more than a twofold higher risk of mortality. These results suggest that therapeutic IR procedures should be performed as expeditiously as possible and held to the same dogma as applied to definitive operative control of hemorrhage.

Tranexamic Acid During Prehospital Transport in Patients at Risk for Hemorrhage After Injury: A Double-blind, Placebo-Controlled, Randomized Clinical Trial.

IMPORTANCE: In-hospital administration of tranexamic acid after injury improves outcomes in patients at risk for hemorrhage. Data demonstrating the benefit and safety of the pragmatic use of tranexamic acid in the prehospital phase of care are lacking for these patients. OBJECTIVE: To assess the effectiveness and safety of tranexamic acid administered before hospitalization compared with placebo in injured patients at risk for hemorrhage. DESIGN, SETTING, AND PARTICIPANTS: This pragmatic, phase 3, multicenter, double-blind, placebo-controlled, superiority randomized clinical trial included injured patients with prehospital hypotension (systolic blood pressure ≤90 mm Hg) or tachycardia (heart rate ≥110/min) before arrival at 1 of 4 US level 1 trauma centers, within an estimated 2 hours of injury, from May 1, 2015, through October 31, 2019. INTERVENTIONS: Patients received 1 g of tranexamic acid before hospitalization (447 patients) or placebo (456 patients) infused for 10 minutes in 100 mL of saline. The randomization scheme used prehospital and in-hospital phase assignments, and patients administered tranexamic acid were allocated to abbreviated, standard, and repeat bolus dosing regimens on trauma center arrival. MAIN OUTCOMES AND MEASURES: The primary outcome was 30-day all-cause mortality. RESULTS: In all, 927 patients (mean [SD] age, 42 [18] years; 686 [74.0%] male) were eligible for prehospital enrollment (460 randomized to tranexamic acid intervention; 467 to placebo intervention). After exclusions, the intention-to-treat study cohort comprised 903 patients: 447 in the tranexamic acid arm and 456 in the placebo arm. Mortality at 30 days was 8.1% in patients receiving tranexamic acid compared with 9.9% in patients receiving placebo (difference, -1.8%; 95% CI, -5.6% to 1.9%; P = .17). Results of Cox proportional hazards regression analysis, accounting for site, verified that randomization to tranexamic acid was not associated with a significant reduction in 30-day mortality (hazard ratio, 0.81; 95% CI, 0.59-1.11, P = .18). Prespecified dosing regimens and post-hoc subgroup analyses found that prehospital tranexamic acid were associated with significantly lower 30-day mortality. When comparing tranexamic acid effect stratified by time to treatment and qualifying shock severity in a post hoc comparison, 30-day mortality was lower when tranexamic acid was administered within 1 hour of injury (4.6% vs 7.6%; difference, -3.0%; 95% CI, -5.7% to -0.3%; P < .002). Patients with severe shock (systolic blood pressure ≤70 mm Hg) who received tranexamic acid demonstrated lower 30-day mortality compared with placebo (18.5% vs 35.5%; difference, -17%; 95% CI, -25.8% to -8.1%; P < .003). CONCLUSIONS AND RELEVANCE: In injured patients at risk for hemorrhage, tranexamic acid administered before hospitalization did not result in significantly lower 30-day mortality. The prehospital administration of tranexamic acid after injury did not result in a higher incidence of thrombotic complications or adverse events. Tranexamic acid given to injured patients at risk for hemorrhage in the prehospital setting is safe and associated with survival benefit in specific subgroups of patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02086500.