Low-Dose Heparin Infusion as Venous Thromboembolism Chemoprophylaxis in Patients With Blunt Cerebrovascular Injury.

INTRODUCTION: Blunt cerebrovascular injury (BCVI) can result in devastating stroke. Because of operative inaccessibility, the most common treatment for BCVI is aspirin or a low-dose systemic heparin infusion. While it is assumed that low dose heparin infusion imparts venous thromboembolism (VTE) prophylaxis, this has not been evaluated in the BCVI population. The purpose of this study was to evaluate VTE rates in patients receiving low-dose heparin infusion as treatment for BCVI. METHODS: Patients diagnosed with BCVI between 2014 and 2018 were reviewed for initiation of low-dose systemic heparin treatment. VTE was defined as a deep vein thrombosis or pulmonary embolism. BCVI patients without systemic heparin treatment were compared to BCVI patients with heparin treatment for overall VTE rates. Comparisons were also made to injured patients without a BCVI in our Trauma Activation Protocol (TAP) database. RESULTS: During the 5-year study period, 265 patients were identified with a BCVI. The majority (61%) were men with a median injury severity score (ISS) 22 (interquartile range [IQR]:14-33). Of these patients, 146 (55.1%) received a heparin infusion to treat BCVI. VTE was identified in eight of these patients (5.5%). Compared to TAP patients (n = 1020) who received standard dosing of VTE chemoprophylaxis, there was no difference in VTE rates compared to BCVI patients who were started on a low dose heparin infusion (3% versus 5.5%, P = 0.16). Area under the receiver operating characteristics (AUROC) was used to evaluate the predictive power of time to initiation of heparin infusion (AUC = 0.64 95% CI 0.42-0.85, P = 0.2) and time to reaching PTT goal (AUC = 0.52 95% CI 0.27-0.77, P = 0.83) as a predictor VTE events. CONCLUSIONS: Low dose heparin infusion is frequently used as an initial treatment of BCVI. In injured patients with BCVI, a low dose heparin infusion is associated with a low rate of VTE, comparable to injured patients without BCVI that received standard VTE chemoprophylaxis.

Succinate Activation of SUCNR1 Predisposes Severely Injured Patients to Neutrophil-mediated ARDS.

OBJECTIVES: Identify the metabolites that are increased in the plasma of severely injured patients that developed ARDS versus severely injured patients that did not, and assay if these increased metabolites prime pulmonary sequestration of neutrophils (PMNs) and induce pulmonary sequestration in an animal model of ARDS. We hypothesize that metabolic derangement due to advanced shock in critically injured patients leads to the PMNs, which serves as the first event in the ARDS. Summary of Background Data: Intracellular metabolites accumulate in the plasma of severely injured patients. METHODS: Untargeted metabolomics profiling of 67 critically injured patients was completed to establish a metabolic signature associated with ARDS development. Metabolites that significantly increased were assayed for PMN priming activity in vitro. The metabolites that primed PMNs were tested in a 2-event animal model of ARDS to identify a molecular link between circulating metabolites and clinical risk for ARDS. RESULTS: After controlling for confounders, 4 metabolites significantly increased: creatine, dehydroascorbate, fumarate, and succinate in trauma patients who developed ARDS ( P < 0.05). Succinate alone primed the PMN oxidase in vitro at physiologically relevant levels. Intravenous succinate-induced PMN sequestration in the lung, a first event, and followed by intravenous lipopolysaccharide, a second event, resulted in ARDS in vivo requiring PMNs. SUCNR1 inhibition abrogated PMN priming, PMN sequestration, and ARDS. Conclusion: Significant increases in plasma succinate post-injury may serve as the first event in ARDS. Targeted inhibition of the SUCNR1 may decrease ARDS development from other disease states to prevent ARDS globally.

28-day thawed plasma maintains α2 -antiplasmin levels and inhibits tPA-induced fibrinolysis.

INTRODUCTION: Evidence supports the use of plasma-first resuscitation in the treatment of trauma-induced coagulopathy (TIC). While thawed plasma (TP) has logistical benefits, the ability of plasma proteins to attenuate fibrinolysis and correct TIC remain unknown. We hypothesize that TP retains the ability to inhibit tissue plasminogen activator(tPA)-induced fibrinolysis at 28-day storage. METHODS: Healthy volunteers underwent blood draws followed by 50% dilution of whole blood (WB) with TP at 28-, 21-, 14-, 7-, 5-, and, 0-day storage, normal saline (NS), and WB control. Samples underwent citrated tPA-challenge (75 ng/ml) thromboelastography (TEG). Plasminogen activator inhibitor-1 (PAI-1) and α2 -antiplasmin (α2 -AP) concentrations in thawed or stored plasma were determined. RESULTS: In the presence of tPA, 28-day TP inhibited tPA-induced coagulopathy as effectively as WB. 28-day TP had a similar R-time, MA, and fibrinolysis (P > 0·05 for all) compared to WB, while angle was enhanced (P = 0·02) compared to WB. Significant correlations were present between storage time and clot strength (P = 0·04) and storage time and fibrinolysis (P = 0·0029). Active PAI-1 levels in thawed plasma were 1·10 ± 0·54 ng/mL while total PAI-1 levels were 4·79 ± 1·41 ng/mL. There was no difference of α2 -AP levels in FFP (40·45 ± 3·5 µg/mL) compared to plasma thawed for 14 (36·78 ± 5·39 µg/mL, P = 0·65) or 28 days (45·16 ± 5·61 µg/mL, P = 0·51). DISCUSSION: Thawed plasma retained the ability to inhibit tPA-induced fibrinolysis over 28-day storage at 1-4°C. α2 -AP levels were maintained in plasma thawed for 28 days and FFP. These in vitro results suggest consideration should be made to increasing the storage life of TP.

Effects of Blood Components and Whole Blood in a Model of Severe Trauma-Induced Coagulopathy.

BACKGROUND: Plasma resuscitation ameliorates hyperfibrinolysis (HF) and trauma-induced coagulopathy (TIC). However, the use of other blood components to reduce HF has not been evaluated. Therefore, our aim was to determine the effect of individual blood components and whole blood (WB) on an in vitro model of severe HF/TIC. METHODS: A "TIC" solution was made with 1:1 dilution of WB with saline and exacerbated with tissue plasminogen activator (tPA). Components were added in proportions equivalent to the thromboelastography (TEG) based goal-directed resuscitation used at our institution. Whole blood was added at proportions equal to what has been transfused in injured patients. Samples (n = 9) underwent citrated native and tPA-challenge (75 ng/mL) TEG with analysis of R-time, angle, MA, and LY30. Statistical analyses were completed employing the nonparametric Kruskal-Wallis and Dunn's multiple comparisons tests. RESULTS: TIC solution, when compared to control, had a decrease in clot strength (MA 41 mm versus 51.5 mm, P < 0.01). The addition of tPA resulted in a severe coagulopathy (MA 24.5 mm versus 41 mm and LY30 52.8% versus 2.4%, P < 0.03 for all). The addition of 4U of WB improved clot strength compared to TIC + tPA (P = 0.03). No individual blood component resulted in improved fibrinolysis (P > 0.7). Cryoprecipitate improved R-time (7.5 versus 11.9 min, P < 0.01), angle (56.8 versus 30.2°) and MA (49 mm versus 36.25 mm), while platelets improved MA (44 mm versus 36.25 mm) compared to TIC + tPA (P < 0.03 for all). CONCLUSIONS: No single blood component or volume of whole blood led to attenuation of tPA-mediated fibrinolysis in an in vitro model of TIC. Cryoprecipitate was the most effective at improving coagulation function.

Rotational thromboelastometry thresholds for patients at risk for massive transfusion.

BACKGROUND: Goal-directed hemostatic resuscitation based on thrombelastography has a survival benefit compared to conventional coagulation assays. While thrombelastography transfusion thresholds for patients at risk for massive transfusion (MT) have been defined, similar cutoffs do not exist for the other commonly used viscoelastic assay, rotational thromboelastometry (ROTEM). The purpose of this study was to develop ROTEM blood product thresholds in patients at risk for MT. METHODS: ROTEM was assessed in trauma activation patients admitted from 2010 to 2016 (n = 222). Receiver operating characteristic curve analyses were performed to test the predictive performance of ROTEM measurements in patients requiring MT. The Youden Index defined optimal thresholds for ROTEM-based resuscitation. RESULTS: Patients who required MT (n = 37, 17%) were more severely injured. EXTEM clotting time (CT) was longer in patients with MT compared to non-MT (87 versus 64 s, P < 0.0001). EXTEM angle was shallower in MT patients compared to non-MT (54° versus 69°, P < 0.0001). Clot amplitude after 10 min (CA10) was less in MT compared to non-MT patients (30.5 versus 50 mm, P < 0.0001). Clot lysis index 60 min (CLI60) was lower in patients who had MT than non-MT (47 versus 94%, P = 0.0006). EXTEM CT yielded an area under the receiver operating characteristic curve (AUROC) = 0.7116 and a cut point of >78.5 s. EXTEM angle had an AUROC = 0.865 and a cut point of <64.5°. EXTEM CA10 had an AUROC = 0.858, with a cut point of <40.5 mm. CLI60 had an AUROC = 0.6788 with a cut point at <74%. CONCLUSIONS: We have identified ROTEM thresholds for transfusion of blood components in severely injured patients requiring an MT. Based on our analysis, we propose plasma transfusion for EXTEM CT > 78.5 s, fibrinogen for angle <64.5°, platelet transfusion for CA10 < 40.5 mm, and antifibrinolytics for CLI60 < 74%.

Microfluidics contrasted to thrombelastography: perplexities in defining hypercoagulability.

BACKGROUND: Elevated clot strength (maximum amplitude [MA]) measured by thrombelastography (TEG) is associated with thrombotic complications. However, it remains unclear how MA translates to thrombotic risks, as this measurement is independent of time, blood flow, and clot degradation. We hypothesize that under flow conditions, increased clot strength correlates to time-dependent measurements of coagulation and resistance to fibrinolysis. MATERIALS AND METHODS: Surgical patients at high risk of thrombotic complications were analyzed with TEG and total thrombus-formation analysis system (T-TAS). TEG hypercoagulability was defined as an r <10.2 min, angle >59, MA >66 or LY30 <0.2% (based off of healthy control data, n = 141). The T-TAS AR and PL chips were used to measure clotting at arterial shear rates. T-TAS measurements include occlusion start time, occlusion time (OT), occlusion speed (OSp), and total clot generation (area under the curve). These measurements were correlated to TEG indices (R time, angle, MA, and LY30). Both T-TAS and TEG assays were challenged with tissue plasminogen activator (t-PA) to assess clot resistance to fibrinolysis. RESULTS: Thirty subjects were analyzed, including five controls. TEG-defined hypercoagulability by MA was detected in 52% of the inflammatory bowel disease/cancer patients; 0% was detected in the controls. There were no TEG measurements that significantly correlated with T-TAS AR and PL chip. However, in the presence of t-PA, T-TAS AR determined OSp to have an inverse relationship with TEG angle (-0.477, P = 0.012) and LY30 (-0.449, P = 0.019), and a positive correlation with R time (0.441 P = 0.021). In hypercoagulability determined by TEG MA, T-TAS PL had a significantly reduced OT (4:07 versus 6:27 min, P = 0.043). In hypercoagulability defined by TEG LY30, T-TAS PL had discordant findings, with a significantly prolonged OT (6:36 versus 4:30 min, P = 0.044) and a slower OSp (10.5 versus 19.0 kPa/min, P = 0.030). CONCLUSIONS: Microfluidic coagulation assessment with T-TAS has an overall poor correlation with most TEG measurements in a predominantly hypercoagulable patient population, except in the presence of t-PA. The one anticipated finding was an elevated MA having a shorter time to platelet-mediated microfluidic occlusion, supporting the role of platelets and hypercoagulability. However, hypercoagulability defined by LY30 had opposing results in which a low LY30 was associated with a longer PL time to occlusion and slower OSp. These discordant findings warrant ongoing investigation into the relationship between clot strength and fibrinolysis under different flow conditions.

Trauma and hemorrhagic shock activate molecular association of 5-lipoxygenase and 5-lipoxygenase-Activating protein in lung tissue.

BACKGROUND: Post-traumatic lung injury following trauma and hemorrhagic shock (T/HS) is associated with significant morbidity. Leukotriene-induced inflammation has been implicated in the development of post-traumatic lung injury through a mechanism that is only partially understood. Postshock mesenteric lymph returning to the systemic circulation is rich in arachidonic acid, the substrate of 5-lipoxygenase (ALOX5). ALOX5 is the rate-limiting enzyme in leukotriene synthesis and, following T/HS, contributes to the development of lung dysfunction. ALOX5 colocalizes with its cofactor, 5-lipoxygenase-activating protein (ALOX5AP), which is thought to potentiate ALOX5 synthetic activity. We hypothesized that T/HS results in the molecular association and nuclear colocalization of ALOX5 and ALOX5AP, which ultimately increases leukotriene production and potentiates lung injury. MATERIALS AND METHODS: To examine these molecular interactions, a rat T/HS model was used. Post-T/HS tissue was evaluated for lung injury through both histologic analysis of lung sections and biochemical analysis of bronchoalveolar lavage fluid. Lung tissue was immunostained for ALOX5 and ALOX5AP with association and colocalization evaluated by fluorescence resonance energy transfer. In addition, rats undergoing T/HS were treated with MK-886, a known ALOX5AP inhibitor. RESULTS: ALOX5 levels increase and ALOX5/ALOX5AP association occurred after T/HS, as evidenced by increases in total tissue fluorescence and fluorescence resonance energy transfer signal intensity, respectively. These findings coincided with increased leukotriene production and with the histological changes characteristic of lung injury. ALOX5/ALOX5AP complex formation, leukotriene production, and lung injury were decreased after inhibition of ALOX5AP with MK-886. CONCLUSIONS: These results suggest that the association of ALOX5/ALOX5AP contributes to leukotriene-induced inflammation and predisposes the T/HS animal to lung injury.

Freeze-dried plasma enhances clot formation and inhibits fibrinolysis in the presence of tissue plasminogen activator similar to pooled liquid plasma.

BACKGROUND: Systemic hyperfibrinolysis is an integral part of trauma-induced coagulopathy associated with uncontrolled bleeding. Recent data suggest that plasma-first resuscitation attenuates hyperfibrinolysis; however, the availability, transport, storage, and administration of plasma in austere environments remain challenging and have limited its use. Freeze-dried plasma (FDP) is a potential alternative due to ease of storage, longer shelf life, and efficient reconstitution. FDP potentially enhances clot formation and resists breakdown better than normal saline (NS) and albumin and similar to liquid plasma. STUDY DESIGN AND METHODS: Healthy volunteers underwent citrated blood draw followed by 50% dilution with NS, albumin, pooled plasma (PP), or pooled freeze-dried plasma (pFDP). Citrated native and tissue plasminogen activator (t-PA)-challenge (75 ng/mL) thrombelastography were done. Proteins in PP, pFDP, and albumin were analyzed by mass spectroscopy. RESULTS: pFDP and PP had superior clot-formation rates (angle) and clot strength (maximum amplitude) compared with NS and albumin in t-PA-challenge thrombelastographies (angle: pFDP, 67.9 degrees; PP, 67.8 degrees; NS, 40.6 degrees; albumin, 35.8 degrees; maximum amplitude: pFDP, 62.4 mm; PP, 63.5 mm; NS, 44.8 mm; albumin, 41.1 mm). NS and albumin dilution increased susceptibility to t-PA-induced hyperfibrinolysis compared with pFDP and PP (NS, 62.4%; albumin, 62.6%; PP, 8.5%; pFDP, 6.7%). pFDP was similar to PP in the attenuation of t-PA-induced fibrinolysis. Most proteins (97%) were conserved during the freeze-dry process, with higher levels in 12% of pFDP proteins compared with PP. CONCLUSION: pFDP enhances clot formation and attenuates hyperfibrinolysis better than NS and albumin and is a potential alternative to plasma resuscitation in the treatment of hemorrhagic shock.

Tranexamic acid is associated with increased mortality in patients with physiological fibrinolysis.

BACKGROUND: Tranexamic acid (TXA) administration after trauma has not been proven to improve survival in the United States. Trauma patients were presented to the hospital with a spectrum of fibrinolytic activity, in which physiological levels of fibrinolysis are associated with the lowest mortality. We hypothesize that trauma patients who present to the hospital with physiological levels of fibrinolysis will have increased mortality if they receive TXA. MATERIALS AND METHODS: Severely injured trauma patients, followed prospectively from 2014 to 2016, were included in the analysis. The patient's first thrombelastography was used to stratify patients into fibrinolysis phenotypes which included fibrinolysis shutdown, physiological fibrinolysis, and systemic hyperfibrinolysis. The primary outcome was in-hospital mortality. RESULTS: A total of 232 patients were analyzed (11% received TXA) with an overall mortality rate of 20%. TXA administration was associated with a higher new injury severity score (49 versus 28; P = 0.001), massive transfusion rate (69% versus 12%; P < 0.001), and mortality (52% versus 17%; P < 0.001). Hyperfibrinolysis and shutdown had higher mortality rates than physiological group (24% versus 30% versus 14%; P = 0.050). The effect of TXA within phenotypes was not significant for shutdown (28% versus 38%; P = 0.604) but was significant in the physiological group (11% versus 63%; P < 0.001) and systemic hyperfibrinolysis (19% versus 55%; P = 0.023). After adjusting for new injury severity score, TXA remained a significant predictor of mortality for patients with physiological fibrinolysis (P = 0.018). CONCLUSIONS: There was no clear benefit of receiving TXA in this study, and patients who present to the hospital with physiologic levels of fibrinolysis, who received TXA, had the highest mortality. The role of TXA in mature trauma systems remains unclear, and emerging data supports it may have adverse effects.

Thrombelastography indicates limitations of animal models of trauma-induced coagulopathy.

BACKGROUND: Thrombelastography (TEG) has been used to characterize the coagulation changes associated with injury and shock. Animal models developed to investigate trauma-induced coagulopathy (TIC) have failed to produce excessive bleeding. We hypothesize that a native TEG will demonstrate marked differences in humans compared with these experimental models, which explains the difficulties in reproducing a clinically relevant coagulopathy in animal models. METHODS: Whole blood was collected from 138 healthy human volunteers, 25 swine and 66 Sprague-Dawley rats before experimentation. Citrated native TEGs were conducted on each whole blood sample within 2 h of collection. The clot initiation (R-time, minutes), angle (degrees), maximum amplitude (MA; millimeter), and lysis 30 min after MA (LY30; percentage) were analyzed and contrasted between species with data represented as the median and 25th to 75th quartile range. Difference between species was conducted with a Kruskal-Wallis test with alpha adjusted with a Bonferroni correction for multiple comparisons (alpha = 0.016). RESULTS: Median R-time (clot initiation) was 14.65 min (IQR: 13.2-16.3 min) for humans, 5.7 min (4.9-8.8) for pigs, and 5.2 min (4.4-6) for rodents. Humans had longer R-times than both pigs (P < 0.0001) and rats (P < 0.0001); pigs were not different from rats (P = 0.4439). Angle (fibrin cross-linking) was 42.3° (interquartile range [IQR]: 37.5-50.2) for humans, 71.7° (64.3-75.6) for pigs, and 61.8° (56.8-66.7) for rats. Humans had reduced angle compared with both pigs (P < 0.0001) and rats (P < 0.0001); pigs were not different from rats (P = 0.6052). MA (clot strength) was 55.5 mm (IQR: 52.0-59.5) for humans, 72.5 mm (70.4-75.5) for pigs, and 66.5 mm (56.5-68.6) for rats. Humans had reduced MA compared with both pigs (P < 0.0001) and rats (P < 0.0001); pigs were not different from rats (P = 0.0161). LY30 (fibrinolysis) was 1.5% (IQR: 0.975-2.5) for humans, 3.3% (1.9-4.3) for pigs, and 0.5% (0.1-1.2) for rats. Humans had a lesser LY30 than pigs (P = 0.0062) and a greater LY30 than rats (P < 0.0001), and pigs had a greater LY30 than rats (P < 0.0001). CONCLUSIONS: Humans, swine, and rodents have distinctly different coagulation systems, when evaluated by citrated native TEG. Animals are hypercoagulable with rapid clotting times and clots strengths nearly 50% stronger than humans. These coagulation differences indicate the limitations of previous models of trauma-induced coagulopathy in producing coagulation abnormalities associated with increased bleeding. The inherent hypercoagulable baseline tendencies of these animals may result in subclinical biochemical changes that are not detected by conventional TEG and should be taken into consideration when extrapolated to clinical medicine.

14-Day thawed plasma retains clot enhancing properties and inhibits tPA-induced fibrinolysis.

BACKGROUND: Plasma-first resuscitation attenuates trauma-induced coagulopathy (TIC); however, the logistics of plasma-first resuscitation require thawed plasma (TP) be readily available due to the obligatory thawing time of fresh frozen plasma (FFP). The current standard is storage of TP for up to 5 days at 4°C, based on factor levels at outdate, for use in patients at risk for TIC, but there remains a 2.2% outdated wastage rate. However, the multitude of plasma proteins in attenuating TIC remains unknown. We hypothesize that TP retains the ability to enhance clotting and reduce tPA-induced fibrinolysis at 14-day storage. METHODS: FFP was thawed and stored at 4°C at the following intervals: 14, 10, 7, 5, 3, and 1-day prior to the experiment. Healthy volunteers underwent blood draws followed by 50% dilution with TP stored at previously mentioned intervals as well as FFP, normal saline (NS), albumin, and whole blood (WB) control. Samples underwent tPA-modified (75 ng/mL) thrombelastography (TEG) with analysis of R-time, angle, maximum amplitude (MA), and LY30. RESULTS: TEG properties did not change significantly over the thawed storage. 14-day TP retained the ability to inhibit tPA-induced hyperfibrinolysis (median LY30% 9.6%) similar to FFP (5.6%), WB (14.6%), and superior to albumin (59.3%) and NS (58.1%). 14-day TP also retained faster clot formation (median angle, 66.2°) and superior clot strength (MA, 61.5 mm) to albumin (34.8°, 21.6 mm) and NS (41.6°, 32.2 mm). CONCLUSIONS: TP plasma stored for 14 days retains clot-enhancing ability and resistance to clot degradation similar to FFP. A clinical trial is needed to validate these in vitro results.

Preoperative thrombelastography maximum amplitude predicts massive transfusion in liver transplantation.

BACKGROUND: Massive transfusion (MT) is frequently required during liver transplantation. Risk stratification of transplant patients at risk for MT is an appealing concept but remains poorly developed. Thrombelastography (TEG) has recently been shown to reduce mortality when used for trauma resuscitation. We hypothesize that preoperative TEG can be used to risk stratify patients for MT. MATERIAL AND METHODS: Liver transplant patients had blood drawn before surgical incision and assayed via TEG. Preoperative TEG measurements were collected in addition to standard laboratory coagulation tests. TEG variables including R-time (reaction time), angle, maximum amplitude (MA), and LY30 (clot lysis 30 min after MA) were correlated to red blood cell units, plasma (fresh frozen plasma), cryoprecipitate, and platelets during the first 24 h after surgery and tested for their performance using a receiver-operating characteristic curve. RESULTS: Twenty-eight patients were included in the analysis with a median Model for End-Stage Liver Disease score of 17; 36% received a MT. The TEG variables associated with MT (defined as ≥10 red blood cell units/24 h) were a low MA (P < 0.001) and low angle (P = 0.014). A high international normalized ratio of prothrombin time (P = 0.003) and low platelet count (P = 0.007) were also associated with MT. MA had the highest area under the curve (0.861) followed by international normalized ratio of prothrombin time (0.803). An MA of less than 47 mm has a sensitivity of 90% and specificity of 72% to predict a MT. MA was the only coagulation variable that correlated strongly to all blood products transfused. CONCLUSIONS: TEG MA has a high predictability of MT during liver transplantation. The use of TEG preoperatively may help guide more cost effective blood bank preparation for this procedure as only a third of patients required a MT.

Cecal volvulus secondary to mesodiverticular band.

Meckel's diverticula are one of the most common gastrointestinal anomalies, yet mesodiverticular bands are rare. The treatment of these bands commonly requires surgery. A healthy patient in his 20s presented to the emergency department with a 1 day history of acute onset abdominal pain. Computed tomography imaging was consistent with volvulus of the large intestine. In the operating room, the patient was noted to have a band between the ileal mesentery and tip of a Meckel's diverticulum, consistent with a mesodivertiular band, through which cecum had volvulized. The patient underwent resection. The patient recovered without major complications. Mesodiverticular bands are rare, but may present as hemoperitoneum, small bowel obstruction, or volvulus. Pre-operative diagnosis of a mesodiverticular band is often difficult and they are most commonly diagnosed intraoperatively. Treatment should include surgery and may include simple lysis of the band, bowel resection, or more extensive resection if other pathology is present.

Are Data Driving Our Ambulances? Liberal Use of Tranexamic Acid in the Prehospital Setting.

BACKGROUND: Current data on tranexamic acid (TXA) supports early administration for severe hemorrhagic shock. Administration by EMS has been facilitated by developing protocols and standing orders informed by these data. In this study, patterns of TXA use by EMS agencies serving a large level 1 trauma center were examined. We hypothesized that current widespread TXA use often includes administration outside of data-driven indications. METHODS: The trauma registry at a level 1 trauma center was queried for patients who received TXA. To determine the practice patterns and appropriateness of administration of TXA, patients' physiologic state in the prehospital environment based on EMS records, physiologic state on arrival to hospital, and interventions performed in both settings were examined. Over 20 separately managed EMS systems that administer TXA transport patients to this trauma center, allowing for a broad survey of practices. RESULTS: From 2016 to 2021 1089 patients received TXA, 406 (37.3%) having treatment initiated by EMS services. Of these, the average prehospital systolic blood pressure (SBP) was 108.2 mmHg and initial ED SBP was 107.8 mmHg. Only 58.4% of these patients received blood transfusion after arrival to this trauma center. Compliance with standard indications was low with only 14.6% of administrations meeting any data-driven SBP indication. Similar levels of compliance were seen across high volume EMS services. DISCUSSION: Tranexamic acid use has become common in trauma and has been adopted by many EMS systems. These results indicate TXA in the prehospital setting is over-used as administration is not being limited to indications that have shown benefit in prior data.

Pre-Injury Statin Exposure is Associated With Improved Outcomes in Injured Patients That Receive Whole Blood.

Introduction: Whole blood (WB) is associated with improved mortality while lowering blood product utilization. Furthermore, statin medications are associated with favorable outcomes in traumatic brain injury and risk reduction of venous thromboembolism. However, the use of statin medications has not been evaluated in those receiving WB. The objective of this study is to determine the effects of pre-injury statin exposure on patients receiving WB.Methods: Patients that underwent WB first resuscitation and received pre-injury statins were compared to those that did not receive pre-injury statins. Demographics as well as complication rates, blood product transfusion volumes, and mortality were evaluated. Univariate and multivariable analyses were used to determine independent predictors of mortality.Results: In the study period, 785 patients received WB as part of their resuscitation. One hundred and thirty five patients (17.3%) took statin medications prior to injury. Patients that were exposed to a pre-injury statin had a lower mortality rate than those that were not exposed (21.5% vs 32.5%, P = .01). After adjusting for imbalances, age, ISS, Glasgow Coma Scale, admission systolic blood pressures, and pre-injury statin use were independent predictors of mortality following multiple logistic regression. When evaluating outcomes based on statin intensity, the use of high-intensity statins was associated with lower mortality (OR: .37, 95% CI: .13-.93), whereas moderate and low-intensity statins were not.Conclusion: In patients resuscitated with WB, pre-injury statins use was associated with improved outcomes. Specifically, patients that received high-intensity pre-injury statins appeared to be the population that benefited.

Whole blood for old blood: Use of whole blood for resuscitation in older trauma patients.

INTRODUCTION: Older patients are expected to comprise 40 % of trauma admissions in the next 30 years. The use of whole blood (WB) has shown promise in improving mortality while lowering the utilization of blood products. However, the use of WB in older trauma patients has not been examined. The objective of our study is to determine the safety and efficacy of a WB first transfusion strategy in injured older patients. METHODS: Older trauma patients, defined as age ≥55 years old, were reviewed from March 2016-November 2021. Patients that received a WB first resuscitation strategy were compared to those that received a ratio based component strategy. Demographics as well as complications rates, blood product transfusion volumes, and mortality were evaluated. Univariate and multivariable analysis was used to determine independent predictors of mortality. RESULTS: There were 388 older trauma patients that received any blood products during the study period. A majority of patients received a WB first resuscitation strategy (83 %). Compared to patients that received component therapy, patients that received WB first were more likely female, less likely to have a penetrating mechanism, and had a slightly lower injury severity score. The-30 day mortality rate was comparable (WB 36% vs component 37 %, p = 0.914). While rates of AKI were slightly higher in those that received WB, this did not result in increased rates of renal replacement therapy (3 % vs 2 %, p = 1). Further, compared to patients that received components, patients that were resuscitated with a WB first strategy significantly utilized lower median volumes of platelets (0 mL vs 197 mL, p < 0.001), median volumes of plasma (0 mL vs 1253 mL, p < 0.001, and median total volume of blood products (1000 mL vs 2859 mL, p < 0.001). CONCLUSION: The use of WB in the older trauma patient appears safe, with mortality and complication rates comparable to component therapy. Blood product utilization is significantly less in those that are resuscitated with WB first.

Eliminating the benzos: A benzodiazepine-sparing approach to preventing and treating alcohol withdrawal syndrome.

BACKGROUND: Alcohol withdrawal syndrome (AWS) represents significant cost to the hospitalized trauma population from a clinical and financial perspective. Historically, AWS has been managed with benzodiazepines. Despite their efficacy, benzodiazepines carry a heavy adverse effect profile. Recently, benzodiazepine-sparing protocols for the prophylaxis and treatment of AWS have been used in medical patient populations. Most existing benzodiazepine-sparing protocols use phenobarbital, while ours primarily uses gabapentin and clonidine, and no such protocol has been developed and examined for safety and efficacy specifically within a trauma population. METHODS: In December of 2019, we implemented our benzodiazepine-sparing protocol for trauma patients identified at risk for alcohol withdrawal on admission. Trauma patients at risk for AWS admitted to an academic Level 1 trauma center before (conventional) and after (benzodiazepine-sparing [BS]) protocol implementation were compared. Outcomes examined include morphine milligram equivalent dosing rates and lorazepam equivalent dosing rates as well as the Clinical Institute Withdrawal Assessment for Alcohol, revised (CIWA-Ar) scores, hospital length of stay, intensive care unit length of stay, and ventilator days. RESULTS: A total of 387 conventional and 134 benzodiazepine sparing patients were compared. Injury Severity Score (13 vs. 16, p = 0.10) and admission alcohol levels (99 vs. 149, p = 0.06) were similar. Patients in the BS pathway had a lower maximum daily CIWA-Ar (2.7 vs. 1.5, p = 0.04). While mean morphine milligram equivalent per day was not different between groups (31.5 vs. 33.6, p = 0.49), mean lorazepam equivalents per day was significantly lower in the BS group (1.1 vs. 0.2, p < 0.01). Length of stay and vent days were not different between the groups. CONCLUSION: Implementation of a benzodiazepine-sparing pathway that uses primarily clonidine and gabapentin to prevent and treat alcohol withdrawal syndrome in trauma patients is safe, reduces the daily maximum CIWA-Ar, and significantly decreases the need for benzodiazepines. Future studies will focus on outcomes affected by avoiding AWS and benzodiazepines in the trauma population. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

A Novel Taxonomy of Intraoperative Cholangiograms in Suspected Choledocholithiasis: A Tool for Advancing Laparoscopic Common Bile Duct Exploration Outcomes Research.

BACKGROUND: Cholangiography for visualization of the biliary tree during laparoscopic cholecystectomy is an important diagnostic roadmap in the context of suspected choledocholithiasis (CDL). The renewed interest in transcystic laparoscopic common bile duct exploration (LCBDE) necessitates a general description of the range of CDL presentations. Our aim was to establish a novel classification system of intraoperative cholangiograms (IOCs) to advance research efforts in this field. METHODS: A novel cholangiogram classification system, featuring 8 distinct presentations of choledocholithiasis, was applied to a data set of 80 preintervention IOCs for suspected choledocholithiasis. The classification system is as follows: A (no common bile duct stones, duodenal filling present, and concern for air bubbles), B (no common bile duct stones, no duodenal filling, and concern for sludge), C1 (stone(s) < 2x size of cystic duct with duodenal filling), C2 (stone(s) < 2x size of cystic duct without duodenal filling), D1 (stone(s) ≥ 2x size of cystic duct with duodenal filling), D2 (stone(s) ≥ 2x size of cystic duct without duodenal filling), E1 (congenital anatomical variant and/or common duct stricture), and E2 (surgically altered biliary anatomy). RESULTS: Cholangiogram review yielded preintervention classifications for 6 of 8 variants (A-E): A (7.5%), B (3.75%), C1 (23.75%), C2 (42.5%), D1 (15%), and D2 (7.5%). Analysis of cystic duct diameter yielded no significant differences among classification groups, indicating no predominant pattern of cystic duct anatomy within a given classification. DISCUSSION: An IOC classification system for suspected choledocholithiasis is foundational to answering key clinical questions for transcystic laparoscopic common bile duct exploration.

Spontaneous rupture of nontraumatic hepatic artery pseudoaneurysm.

Spontaneous rupture of hepatic artery pseudoaneurysms (HAP) is a rare cause of intra-abdominal hemorrhage. Herein, we present a case of a spontaneous rupture of a nontraumatic HAP. A 61-year-old female, not on any anticoagulant or antiplatelet medications, presented with abdominal pain and hemorrhagic shock. Cross-sectional imaging revealed a left HAP with evidence of active bleeding. Emergent diagnostic angiography was performed, and angioembolization of an actively bleeding pseudoaneurysm was performed. Given the risk of rupture and high mortality rate associated with rupture, aggressive treatment of HAP should be pursued.

Win or lose, nighttime transcystic laparoscopic common bile duct exploration is a win.

Objectives: Although controversial, recent data suggest nighttime versus daytime laparoscopic cholecystectomy (LC) have comparable outcomes. Laparoscopic common bile duct exploration (LCBDE) for choledocholithiasis decreases length of stay (LOS) as compared with LC with endoscopic retrograde cholangiopancreatography (ERCP) but increases case complexity/time. The influence of time of day on LCBDE outcomes has not been evaluated. Our aim was to examine outcomes and LOS for nighttime (PM) compared with daytime LC+LCBDE (DAY). Methods: Consecutive patients who underwent LCBDE were reviewed. Demographics, operative duration, success of LCBDE, time to postoperative ERCP (if required), LOS, and complications were compared. PM procedures were defined as beginning 19:00-07:00 hours. Results: Between 2018 and 2022, sixty patients underwent LCBDE (PM 42%). Groups had equivalent age/sex and preoperative liver function tests (LFTs). LCBDE success was 69% PM versus 71% DAY (p=0.78). Operative duration did not differ (2.8 IQR: 2.2-3.3 hours vs. 2.8 IQR: 2.3-3.2 hours, p=0.9). LOS was compared, and PM LOS was shorter (p=0.03). Time to ERCP after a failed LCBDE at night was compared with daytime (13.8 IQR: 10.6-29.5 hours vs. 19.9 IQR: 18.7-54.4 hours, p=0.07). LOS for failed PM LCBDE requiring ERCP was similar to successful DAY LCBDE (p=0.29). One complication (transient hyperbilirubinemia) was reported in the DAY group, none in PM. Conclusion: PM LCBDE cases are equivalent in safety and success rate to DAY cases but have reduced LOS. Widespread adoption of acute care surgery-driven management of choledocholithiasis via LCBDE during cholecystectomy may decrease LOS, especially in PM cases. Level of evidence: Level IV.