Vasopressors in Trauma: A Never Event?

Vasopressor use in severely injured trauma patients is discouraged due to concerns that vasoconstriction will worsen organ perfusion and result in increased mortality and organ failure in hypotensive trauma patients. Hypotensive resuscitation is advocated based on limited data that lower systolic blood pressure and mean arterial pressure will result in improved mortality. It is classically taught that hypotension and hypovolemia in trauma are associated with peripheral vasoconstriction. However, the pathophysiology of traumatic shock is complex and involves multiple neurohormonal interactions that are ultimately manifested by an initial sympathoexcitatory phase that attempts to compensate for acute blood loss and is characterized by vasoconstriction, tachycardia, and preserved mean arterial blood pressure. The subsequent hypotension observed in hemorrhagic shock reflects a sympathoinhibitory vasodilation phase. The objectives of hemodynamic resuscitation in hypotensive trauma patients are restoring adequate intravascular volume with a balanced ratio of blood products, correcting pathologic coagulopathy, and maintaining organ perfusion. Persistent hypotension and hypoperfusion are associated with worse coagulopathy and organ function. The practice of hypotensive resuscitation would appear counterintuitive to the goals of traumatic shock resuscitation and is not supported by consistent clinical data. In addition, excessive volume resuscitation is associated with adverse clinical outcomes. Therefore, in the resuscitation of traumatic shock, it is necessary to target an appropriate balance with intravascular volume and vascular tone. It would appear logical that vasopressors may be useful in traumatic shock resuscitation to counteract vasodilation in hemorrhage as well as other clinical conditions such as traumatic brain injury, spinal cord injury, multiple organ dysfunction syndrome, and vasodilation of general anesthetics. The purpose of this article is to discuss the controversy of vasopressors in hypotensive trauma patients and advocate for a nuanced approach to vasopressor administration in the resuscitation of traumatic shock.

The Bitter and the Sweet: Relationship of Lactate, Glucose, and Mortality After Severe Blunt Trauma.

BACKGROUND: Hyperglycemia is associated with mortality after trauma; however, few studies have simultaneously investigated the association of depth of shock and acute hyperglycemia. We evaluated lactate, as a surrogate measure for depth of shock, and glucose levels on mortality following severe blunt trauma. We hypothesize that measurements of both lactate and glucose are associated with mortality when considered simultaneously. METHODS: This is a retrospective cohort study at a single academic trauma center. Inclusion criteria are age 18-89 years, blunt trauma, injury severity score (ISS) ≥15, and transferred from the scene of injury. All serum blood glucose and lactate values were analyzed within the first 24 hours of admission. Multiple metrics of glucose and lactate were calculated: first glucose (Glucadm) and lactate (Lacadm) at hospital admission, mean 24-hour after hospital admission glucose (Gluc24-hMean) and lactate (Lac24-hMean), maximum 24-hour after hospital admission glucose (Gluc24-hMax) and lactate (Lac24-hMax), and time-weighted 24-hour after hospital admission glucose (Gluc24-hTW) and lactate (Lac24-hTW). Primary outcome was in-hospital mortality. Multivariable logistic regression modeling assessed the odds ratio (OR) of mortality, after adjusting for confounding variables. RESULTS: A total of 1439 trauma patients were included. When metrics of both glucose and lactate were analyzed, after adjusting for age, ISS, and admission shock index, only lactate remained significantly associated with mortality: Lacadm (OR, 1.28; 95% confidence interval [CI], 1.13-1.44); Lac24-hMean (OR, 1.86; 95% CI, 1.52-2.28); Lac24-hMax (OR, 1.39; 95% CI, 1.23-1.56); and Lac24-hTW (OR, 1.86; 95% CI, 1.53-2.26). CONCLUSIONS: Lactate is associated with mortality in severely injured blunt trauma patients, after adjusting for injury severity, age, and shock index. However, we did not find evidence for an association of glucose with mortality after adjusting for lactate.

Musculoskeletal Trauma in Critically Injured Patients: Factors Leading to Delayed Operative Fixation and Multiple Organ Failure.

BACKGROUND: Musculoskeletal injuries are common following trauma and variables that are associated with late femur fracture fixation are important to perioperative management. Furthermore, the association of late fracture fixation and multiple organ failure (MOF) is not well defined. METHODS: We performed a retrospective cohort investigation from 2 academic trauma centers. INCLUSION CRITERIA: age 18-89 years, injury severity score (ISS) >15, femoral shaft fracture requiring operative fixation, and admission to the intensive care unit >2 days. Admission physiology variables and abbreviated injury scale (AIS) scores were obtained. Lactate was collected as a marker of shock and was described as admission lactate (LacAdm) and as 24-hour time-weighted lactate (LacTW24h), which reflects an area under the curve and is considered a marker for the overall depth of shock. The primary aim was to evaluate clinical variables associated with late femur fracture fixation (defined as ≥24 hours after admission). A multivariable logistic regression model tested variables associated with late fixation and is reported by odds ratio (OR) with 95% confidence interval (CI). The secondary aim evaluated the association between late fixation and MOF, defined by the Denver MOF score. The summation of scores (on a scale from 0 to 3) from the cardiac, pulmonary, hepatic, and renal systems was calculated and MOF was confirmed if the total daily sum of the worst scores from each organ system was >3. We assessed the association between late fixation and MOF using a Cox proportional hazards model adjusted for confounding variables by inverse probability weighting (a propensity score method). A P value <.05 was considered statistically significant. RESULTS: One hundred sixty of 279 (57.3%) patients received early fixation and 119 of 279 (42.7%) received late fixation. LacTW24h (OR = 1.66 per 1 mmol/L increase, 95% CI, 1.24-2.21; P < .001) and ISS (OR = 1.07 per 1-point increase, 95% CI, 1.03-1.10; P < .001) were associated with higher odds of late fixation. Late fixation was associated with a 3-fold increase in the odds of MOF (hazard ratio [HR] = 3.21, 95% CI, 1.48-7.00; P < .01). CONCLUSIONS: In a cohort of multisystem trauma patients with femur fractures, greater injury severity and depth of shock, as measured by LacTW24h, were associated with late operative fixation. Late fixation was also associated with MOF. Strategies to reduce the burden of MOF in this population require further investigation.

Viscoelastic Signals for Optimal Resuscitation in Trauma: Kaolin Thrombelastography Cutoffs for Diagnosing Hypofibrinogenemia (VISOR Study).

BACKGROUND: Acute traumatic coagulopathy is common in trauma patients. Prompt diagnosis of hypofibrinogenemia allows for early treatment with cryoprecipitate or fibrinogen concentrate. At present, optimal cutoffs for diagnosing hypofibrinogenemia with kaolin thrombelastography (TEG) have not been established. We hypothesized that kaolin kaolin-TEG parameters, such as kinetic time (K-time), α-angle, and maximum amplitude (MA), would accurately diagnose hypofibrinogenemia (fibrinogen <200 mg/dL) and severe hypofibrinogenemia (fibrinogen <100 mg/dL). METHODS: Adult trauma patients (injury severity score >15) presenting to our trauma center between October 2015 and October 2017 were identified retrospectively. All patients had a traditional plasma fibrinogen measurement and kaolin-TEG performed within 15 minutes of each other and within 1 hour of admission. Some patients had additional measurements after. Receiver operating characteristic (ROC) curve analysis was performed to evaluate whether K-time, α-angle, and MA could diagnose hypofibrinogenemia and severe hypofibrinogenemia. Area under the ROC curve (AUROC) was calculated for each TEG parameter with a bootstrapped 99% confidence interval (CI). Further, ROC analysis was used to estimate ideal cutoffs for diagnosing hypofibrinogenemia and severe hypofibrinogenemia by maximizing sensitivity and specificity. In addition, likelihood ratios were also calculated for different TEG variable cutoffs to diagnose hypofibrinogenemia and severe hypofibrinogenemia. RESULTS: Seven hundred twenty-two pairs of TEGs and traditional plasma fibrinogen measurements were performed in 623 patients with 99 patients having additional pairs of tests after the first hour. MA (AUROC = 0.84) and K-time (AUROC = 0.83) better diagnosed hypofibrinogenemia than α-angle (AUROC = 0.8; P = .03 and P < .001 for AUROC comparisons, respectively). AUROCs statistically improved for each parameter when severe hypofibrinogenemia was modeled as the outcome (P < .001). No differences were found between parameters for diagnosing severe hypofibrinogenemia (P > .05 for all comparisons). The estimated optimal cutoffs for diagnosing hypofibrinogenemia were 1.5 minutes for K-time (95% CI, 1.4-1.6), 70.0° for α-angle (95% CI, 69.8-71.0), and 60.9 mm for MA (95% CI, 59.2-61.8). The estimated optimal cutoffs for diagnosing severe hypofibrinogenemia were 2.4 minutes for K-time (95% CI, 1.7-2.8), 60.6° for α-angle (95% CI, 57.2-67.3), and 51.2 mm for MA (95% CI, 49.0-56.2). Currently recommended K-time and α-angle cutoffs from the American College of Surgeons had low sensitivity for diagnosing hypofibrinogenemia (3%-29%), but sensitivity improved to 74% when using optimal cutoffs. CONCLUSIONS: Kaolin-TEG parameters can accurately diagnose hypofibrinogenemia and severe hypofibrinogenemia in trauma patients. Currently recommended cutoffs for the treatment of hypofibrinogenemia are skewed toward high specificity and low sensitivity. Many patients are likely to be undertreated for hypofibrinogenemia using current national guidelines.

Does Lactate Affect the Association of Early Hyperglycemia and Multiple Organ Failure in Severely Injured Blunt Trauma Patients?

BACKGROUND: Early hyperglycemia is associated with multiple organ failure (MOF) after traumatic injury; however, few studies have considered the contribution of depth of clinical shock. We hypothesize that when considered simultaneously, glucose and lactate are associated with MOF in severely injured blunt trauma patients. METHODS: We performed a retrospective investigation at a single tertiary care trauma center. Inclusion criteria were patient age ≥18 years, injury severity score (ISS) >15, blunt mechanism of injury, and an intensive care unit length of stay >48 hours. Patients with a history of diabetes or who did not survive the initial 48 hours were excluded. Demographics, injury severity, and physiologic data were recorded. Blood glucose and lactate values were collected from admission through the initial 24 hours of hospitalization. Multiple metrics of glucose and lactate were calculated: the first glucose (Glucadm, mg/dL) and lactate (Lacadm, mmol/L) at hospital admission, the mean initial 24-hour glucose (Gluc24hMean, mg/dL) and lactate (Lac24hMean, mmol/L), and the time-weighted initial 24-hour glucose (Gluc24hTW) and lactate (Lac24hTW). These metrics were divided into quartiles. The primary outcome was MOF. Separate Cox proportional hazard models were generated to assess the association of each individual glucose and lactate metric on MOF, after controlling for ISS, admission shock index, and disposition to the operating room after hospital admission. We assessed the interaction between glucose and lactate metrics in the multivariable models. Results are reported as hazard ratios (HRs) for an increase in the quartile level of glucose and lactate measurements, with 95% confidence intervals (CIs). RESULTS: A total of 507 severely injured blunt trauma patients were evaluated. MOF occurred in 46 of 507 (9.1%) patients and was associated with a greater median ISS (33.5, interquartile range [IQR]: 22-41 vs 27, IQR: 21-34; P < .001) and a greater median admission shock index (0.82, IQR: 0.68-1.1 vs 0.73, IQR: 0.60-0.91; P = .02). Patients who were transferred to the operating room after the initial trauma resuscitation were also more likely to develop MOF (20 of 119, 14.4% vs 26 of 369, 7.1%; P = .01). Three separate Cox proportional regression models demonstrated the following HR for an increase in the individual glucose metric quartile and MOF, while controlling for confounding variables: Glucadm HR: 1.35, 95% CI, 1.02-1.80; Gluc24hMean HR: 1.63, 95% CI, 1.14-2.32; Gluc24hTW HR: 1.14, 95% CI, 0.86-1.50. Three separate Cox proportional hazards models also demonstrated the following HR for each individual lactate metric quartile while controlling for the same confounders, with MOF again representing the dependent variable: Lacadm HR: 1.94, 95% CI, 1.38-2.96; Lac24hMean HR: 1.68, 95% CI, 1.22-2.31; Lac24hTW HR: 1.49, 95% CI, 1.10-2.02. When metrics of both glucose and lactate were entered into the same model only lactate remained significantly associated with MOF: Lacadm HR: 1.86, 95% CI, 1.29-2.69, Lac24hMean HR: 1.54, 95% CI, 1.11-2.12, and Lac24hTW HR: 1.48, 95% CI, 1.08-2.01. There was no significant interaction between lactate and glucose variables in relation to the primary outcome. CONCLUSIONS: When glucose and lactate are considered simultaneously, only lactate remained significantly associated with MOF in severely injured blunt trauma patients.

Association of Early Norepinephrine Administration With 24-Hour Mortality Among Patients With Blunt Trauma and Hemorrhagic Shock.

Importance: Hemorrhagic shock is a common cause of preventable death after injury. Vasopressor administration for patients with blunt trauma and hemorrhagic shock is often discouraged. Objective: To evaluate the association of early norepinephrine administration with 24-hour mortality among patients with blunt trauma and hemorrhagic shock. Design, Setting, and Participants: This retrospective, multicenter, observational cohort study used data from 3 registries in the US and France on all consecutive patients with blunt trauma from January 1, 2013, to December 31, 2018. Patients were alive on admission with hemorrhagic shock, defined by prehospital or admission systolic blood pressure less than 100 mm Hg and evidence of hemorrhage (ie, prehospital or resuscitation room transfusion of packed red blood cells, receipt of emergency treatment for hemorrhage control, transfusion of >10 units of packed red blood cells in the first 24 hours, or death from hemorrhage). Blunt trauma was defined as any exposure to nonpenetrating kinetic energy, collision, or deceleration. Statistical analysis was performed from January 15, 2021, to February 22, 2022. Exposure: Continuous administration of norepinephrine in the prehospital environment or resuscitation room prior to hemorrhage control, according to European guidelines. Main Outcomes and Measures: The primary outcome was 24-hour mortality, and the secondary outcome was in-hospital mortality. The average treatment effect (ATE) of early norepinephrine administration on 24-hour mortality was estimated according to the Rubin causal model. Inverse propensity score weighting and the doubly robust approach with 5 distinct analytical strategies were used to determine the ATE. Results: A total of 52 568 patients were screened for inclusion, and 2164 patients (1508 men [70%]; mean [SD] age, 46 [19] years; median Injury Severity Score, 29 [IQR, 17-36]) presented with acute hemorrhage and were included. A total of 1497 patients (69.1%) required emergency hemorrhage control, 128 (5.9%) received a prehospital transfusion of packed red blood cells, and 543 (25.0%) received a massive transfusion. Norepinephrine was administered to 1498 patients (69.2%). The 24-hour mortality rate was 17.8% (385 of 2164), and the in-hospital mortality rate was 35.6% (770 of 2164). None of the 5 analytical strategies suggested any statistically significant association between norepinephrine administration and 24-hour mortality, with ATEs ranging from -4.6 (95% CI, -11.9 to 2.7) to 2.1 (95% CI, -2.1 to 6.3), or between norepinephrine administration and in-hospital mortality, with ATEs ranging from -1.3 (95% CI, -9.5 to 6.9) to 5.3 (95% CI, -2.1 to 12.8). Conclusions and Relevance: The findings of this study suggest that early norepinephrine infusion was not associated with 24-hour or in-hospital mortality among patients with blunt trauma and hemorrhagic shock. Randomized clinical trials that study the effect of early norepinephrine administration among patients with trauma and hypotension are warranted to further assess whether norepinephrine is safe for patients with hemorrhagic shock.

Does hypoxia affect intensive care unit delirium or long-term cognitive impairment after multiple trauma without intracranial hemorrhage?

BACKGROUND: Within the traumatic brain injury population, outcomes are affected by hypoxic events in the early injury period. Previous work shows a high prevalence of cognitive deficits in patients with multiple injuries who do not have intracranial hemorrhage identified on admission head computed tomography scan. We hypothesize that intensive care unit (ICU) delirium and long-term cognitive impairment (LTCI) are more likely in patients who have a hypoxic event within the first 48 hours of ICU admission. METHODS: A total of 173 patients with multiple injuries (Injury Severity Score [ISS] >15) who presented to a Level I trauma center from July 2006 to July 2007 were enrolled in a study on long-term cognitive deficit. Ninety-seven patients required ICU management and all had continuous oxygen saturation data collected. The Confusion Assessment Method for the ICU was collected twice a day on all patients in ICU. Of the total enrolled population, 108 (62%) were evaluated 12 months after discharge by neuropsychological tests. Cognitive impairment was defined as having 2 neuropsychological test scores, 1.5 standard deviations below the mean or 1 neuropsychological test score, and 2 standard deviations below the mean. Demographic data, ISS, initial 24-hour blood requirements, presence of hypoxia (SpO(2) <90% and <85%) or hypotension (systolic blood pressure <90 mm Hg), emergency department (ED) pulse, Glasgow Coma Scale score, ventilator and ICU days were recorded. Significant univariate identification of clinical variables was used for multivariate analysis. RESULTS: Fifty-five of 97 ICU patients (57%) were Confusion Assessment Method-ICU positive for delirium and 59 of 108 (55%) demonstrated cognitive impairment at 12-month follow-up. There was no significant association between hypoxia and ICU delirium (74.5% vs. 74%; p = 0.9) or LTCI (89% vs. 83%; p = 0.5). Ventilator days (8.7 ± 8.9 vs. 2.9 ± 4.6; p < 0.0001), ED pulse (109 ± 28.5 vs. 94 ± 22.8; p = 0.01), and blood transfusions (10 U ± 10.8 U vs. 5 U ± 5.3 U; p = 0.015) were significant independent predictors of delirium. Ventilator days (odds ratio, 1.16; 95% confidence interval, 1.05-1.29; p = 0.004) and ED pulse (odds ratio, 1.02; 95% confidence interval, 1.00-1.04; p = 0.03) remained significant predictors of ICU delirium after adjusting for ISS, hypoxic state, blood transfusions, and ED blood pressure. Among ED Glasgow Coma Scale score (10.5 ± 5.1 vs. 11.4 ±5.5; p = 0.7), ISS (33.3 ± 10.1 vs. 32.2 ± 9.0; p = 0.5), ventilator days (6.5 ± 7.5 vs. 6.2 ± 8.8; p = 0.4), blood transfusions (8.1 ± 6.8 vs. 9.4 ± 8.1; p = 0.4), and delirium (62% vs. 62.5%; p = 0.9), there were no significant univariate associations with LTCI. CONCLUSIONS: Hypoxic events in the ICU do not have a direct correlation with ICU delirium or LTCI in the patients with multiple injuries without evidence of intracranial hemorrhage.

Admission Hyperglycemia Is a Risk Factor for Deep Surgical-Site Infection in Orthopaedic Trauma Patients.

OBJECTIVES: To evaluate the association of admission blood glucose ≥200 mg/dL and surgical site infection in orthopaedic trauma surgery. DESIGN: Retrospective, case control study. SETTING: Academic trauma center. PATIENTS: Four hundred sixty-five nondiabetic, noncritically ill orthopaedic trauma patients with an extremity, pelvic, or acetabular fracture and requiring open reduction and internal fixation or intramedullary nailing. INTERVENTION: None. MAIN OUTCOME MEASUREMENTS: Ninety-day deep surgical site infection. RESULTS: Admission blood glucose ≥200 mg/dL was significantly associated with the primary outcome (8/128, 6.3% vs. 35/337, 1.8%; P = 0.01). Multivariable logistic regression modeling demonstrated that admission blood glucose ≥200 mg/dL was a significant risk factor for deep surgical site infections [odds ratio (OR): 4.7, 95% confidence interval (CI) 1.4-15.7], after controlling for male gender (OR: 1.8, 95% CI: 1.1-3.1), prior drug or alcohol abuse (OR: 1.9, 95% CI 0.9-4.0), open fracture (OR: 6.4, 95% CI 3.7-11.0), and fracture region (upper extremity OR: reference; pelvis/hip OR: 3.9, 95% CI 1.6-9.7; femur OR: 2.0, 95% CI 0.88-4.8; tibia/ankle OR: 3.3, 95% CI 1.7-6.2; and foot OR: 2.7, 95% CI 1.2-6.3). CONCLUSIONS: Admission glucose ≥200 mg/dL was a significant independent risk factor for 90-day deep surgical site infections in orthopaedic trauma patients and may serve as an important marker for infection risk. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Is Tranexamic Acid Associated With Mortality or Multiple Organ Failure Following Severe Injury?

BACKGROUND: Tranexamic acid (TXA) administration is recommended in severely injured trauma patients. We examined TXA administration, admission fibrinolysis phenotypes, and clinical outcomes following traumatic injury and hypothesized that TXA was associated with increased multiple organ failure (MOF). METHODS: Two-year, single-center, retrospective investigation. Inclusion criteria were age ≥ 18 years, Injury Severity Score (ISS) >16, admitted from scene of injury, thromboelastography within 30 min of arrival. Fibrinolysis was evaluated by lysis at 30 min (LY30) and fibrinolysis phenotypes were defined as: Shutdown: LY30 ≤ 0.8%, Physiologic: LY30 0.81-2.9%, Hyperfibrinolysis: LY30 ≥ 3.0%. Primary outcomes were 28-day mortality and MOF. The association of TXA with mortality and MOF was assessed among the entire study population and in each of the fibrinolysis phenotypes. RESULTS: Four hundred twenty patients: 144/420 Shutdown (34.2%), 96/420 Physiologic (22.9%), and 180/410 Hyperfibrinolysis (42.9%). There was no difference in 28-day mortality by TXA administration among the entire study population (P = 0.52). However, there was a significant increase in MOF in patients who received TXA (11/46, 23.9% vs 16/374, 4.3%; P < 0.001). TXA was associated MOF (OR: 3.2, 95% CI 1.2-8.9), after adjusting for confounding variables. There was no difference in MOF in patients who received TXA in the Physiologic (1/5, 20.0% vs 7/91, 7.7%; P = 0.33) group. There was a significant increase in MOF among patients who received TXA in the Shutdown (3/11, 27.3% vs 5/133, 3.8%; P = 0.001) and Hyperfibrinolysis (7/30, 23.3% vs 5/150, 3.3%; P = 0.001) groups. CONCLUSIONS: Administration of TXA following traumatic injury was associated with MOF in the fibrinolysis shutdown and hyperfibrinolysis phenotypes and warrants continued evaluation.

The Algorithm Examining the Risk of Massive Transfusion (ALERT) Score Accurately Predicts Massive Transfusion at the Scene of Injury and on Arrival to the Trauma Bay: A Retrospective Analysis.

BACKGROUND: Massive transfusion (MT) is required to resuscitate traumatically injured patients with complex derangements. Scoring systems for MT typically require laboratory values and radiological imaging that may delay the prediction of MT. STUDY DESIGN: The Trauma ALgorithm Examining the Risk of massive Transfusion (Trauma ALERT) study was an observational cohort study. Prehospital and admission ALERT scores were constructed with logistic regression of prehospital and admission vitals, and FAST examination results. Internal validation was performed with bootstrap analysis and cross-validation. RESULTS: The development cohort included 2,592 patients. Seven variables were included in the prehospital ALERT score: systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), respiratory rate (RR), SpO2, motor Glasgow Coma Scale (GCS) score, and penetrating mechanism. Eight variables from 2,307 patients were included in the admission ALERT score: admission SBP, HR, RR, GCS score, temperature, FAST examination result, and prehospital SBP and DBP.The area under the receiving operator characteristic curve for the prehospital and admission models were 0.754 (95% bootstrapped CI 0.735-0.794, P < 0.001) and 0.905 (95% bootstrapped CI 0.867-0.923, P < 0.001), respectively. The prehospital ALERT score had equivalent diagnostic accuracy to the ABC score (P = 0.97), and the admission ALERT score outperformed both the ABC and the prehospital ALERT scores (P < 0.0001). CONCLUSION: The prehospital and admission ALERT scores can accurately predict massive transfusion in trauma patients without the use of time-consuming laboratory studies, although prospective studies need to be performed to validate these findings. Early identification of patients who will require MT may allow for timely mobilization of scarce resources and could benefit patients by making blood products available for treating hemorrhagic shock.

Thromboelastography Reaction-Time Thresholds for Optimal Prediction of Coagulation Factor Deficiency in Trauma.

BACKGROUND: Coagulopathy is common in multitrauma patients and repletion of procoagulant factor deficiency with fresh frozen plasma (FFP) improves hemostasis. Optimal kaolin-thromboelastography thresholds for FFP transfusion in trauma patients have not been well established. STUDY DESIGN: Adult trauma patients with an Injury Severity Score ≥15 were included in this retrospective observational cohort study. The primary end point was area under the receiver operating characteristic curve (AUROC) for reaction time (R-time) to detect procoagulant factor deficiency, as reflected by an elevated international normalized ratio (INR) or aPTT. Test characteristics for the optimal R-time threshold calculated in our study were compared against thresholds recommended by the American College of Surgeons for FFP transfusion. RESULTS: Six hundred and ninety-four pairs of thromboelastography and conventional coagulation tests were performed in 550 patients, with 144 patients having additional pairs of tests after the first hour. The R-time was able to detect procoagulant factor deficiency (INR ≥1.5 AUROC 0.80; 95% CI, 0.75 to 0.85; aPTT ≥40 seconds AUROC 0.85; 95% 0.80 to 0.89) and severe procoagulant factor deficiency (INR ≥2.0 AUROC 0.82; 95% CI, 0.73 to 0.99; aPTT ≥60 seconds AUROC 0.89; 95% CI, 0.81 to 0.98) with good accuracy. Optimal thresholds to maximize sensitivity and specificity were 3.9 minutes for detection of INR ≥1.5, 4.1 minutes for detection of aPTT ≥40 seconds, 4.3 minutes for detection of INR ≥2.0, and 4.3 for detection of aPTT ≥60 seconds. Currently recommended R-time thresholds for FFP transfusion had 100% specificity for detecting procoagulant factor deficiency, but low sensitivity (3% to 7%). CONCLUSIONS: R-time can detect procoagulant factor deficiency in multitrauma patients with good accuracy, but currently recommended R-time thresholds are highly specific and not sensitive. Use of low-sensitivity thresholds might result in undertreatment of many patients with procoagulant factor deficiency.

Prehospital Point of Care Testing for the Early Detection of Shock and Prediction of Lifesaving Interventions.

INTRODUCTION: Early diagnosis and treatment are essential for enhancing outcomes for the traumatically injured. In this prospective prehospital observational study, we hypothesized that a variety of laboratory results measured in the prehospital environment would predict both the presence of early shock and the need for lifesaving interventions (LSIs) for adult patients with traumatic injuries. METHODS: Adult trauma patients flown by a helicopter emergency medical service were prospectively enrolled. Using an i-STAT portable analyzer, data from 16 laboratory tests were collected. Vital signs data were also collected. Outcomes of interest included detection of shock, mortality, and requirement for LSIs. Logistic regression, including a Bayesian analysis, was performed. RESULTS: Among 300 patients screened for enrollment, 261 had complete laboratory data for analysis. The majority of patients were male (75%) with blunt trauma (91.2%). The median injury severity score was 29 (IQR, 25-75) and overall mortality was 4.6%. A total of 170 LSIs were performed. The median lactate for patients who required an LSI was 4.1 (IQR, 3-5.4). The odds of requiring an LSI within the first hour of admission to the trauma center was highly associated with increases in lactate and glucose. A lactate level > 4 mmol/L was statistically associated with greater sensitivity and specificity for predicting the need for a LSI compared with shock index. CONCLUSIONS: In this prospective observational trial, lactate outperformed static vital signs, including shock index, for detecting shock and predicting the need for LSIs. A lactate level > 4 mmol/L was found to be highly associated with the need for LSIs.

Resuscitative Endovascular Balloon Occlusion of the Aorta and the Anesthesiologist: A Case Report and Literature Review.

The most common preventable cause of death after trauma is exsanguination due to uncontrolled hemorrhage. Traditionally, anterolateral emergency department thoracotomy is used for temporary control of noncompressible torso hemorrhage and to increase preload after trauma. Resuscitative endovascular balloon occlusion of the aorta is a minimally invasive technique that achieves similar goals. It is therefore imperative for the anesthesiologist to understand physiologic implications during resuscitative endovascular aortic occlusion and after balloon deflation. We report a case of a patient with significant pelvic and lower-extremity trauma who required acute resuscitative endovascular balloon occlusion of the aorta deployment, aggressive resuscitation, and extensive intraoperative hemorrhage control.

The Role of Elevated Lactate as a Risk Factor for Pulmonary Morbidity After Early Fixation of Femoral Shaft Fractures.

OBJECTIVES: To evaluate lactate levels before reamed intramedullary nailing (IMN) of femur fractures treated with early fixation. DESIGN: Retrospective study. SETTING: Three academic, tertiary care trauma centers. PATIENTS: Age ≥18 years, injury severity score ≥17, admission lactate ≥ 2.5 mmol/L, elevated preoperative lactate = preoperative lactate ≥ 2.5 mmol/L. INTERVENTION: Reamed IMN of femur fracture within 24 hours. MAIN OUTCOME MEASURE: Total duration of mechanical ventilation, pulmonary complications (PC) = duration of mechanical ventilation ≥5 days. RESULTS: Four hundred and fourteen patients identified; 294/414 (71.0%) with admission lactate ≥ 2.5 mmol/L. No difference in PC among the groups (86/294, 29.3% vs. 28/120, 23.3%; P = 0.22). Median admission lactate: 3.7 (interquartile range: 3.0-4.6); median preoperative lactate: 2.8 (interquartile range: 1.9-3.5). 184/294 (62.6%) demonstrated an elevated preoperative lactate (≥ 2.5 mmol/L) before fracture fixation. No difference in elevated preoperative lactate and vent days (4.8 ± 9.9 vs. 3.9 ± 6.0, P = 0.41) or PC (50/86, 58.1% vs. 134/208, 64.4%; P = 0.31). There was no difference in PC when preoperative lactate was considered separately for a lactate ≥3.0 (34/123, 27.6% vs. 52/171, 30.4%; P = 0.61), ≥3.5 (21/79, 26.6% vs. 65/215, 30.2%; P = 0.54), or ≥4.0 (14/50, 28.0% vs. 72/244, 29.5%; P = 0.83). Multivariable linear regression modeling demonstrated that admission lactate [coefficient of variation: 0.84, standard error: 0.33, 95% confidence interval (CI): 0.20-1.49] was correlated with duration of mechanical ventilation, after adjusting for emergency department Glasgow Coma Scale, age, chest Abbreviated Injury Scale (AIS) score, abdominal AIS, and admission glucose. Logistic regression demonstrated admission lactate was also significantly associated with PC (odds ratio: 1.26, 95% CI: 1.03-1.53) after controlling for age, admission Glasgow Coma Scale, chest AIS, abdominal AIS, admission pulse and admission glucose; preoperative lactate was not a risk factor (odds ratio: 0.84, 95% CI: 0.65-1.09) for PC. CONCLUSION: Median admission lactate of 3.7 mmol/L was associated with duration of mechanical ventilation ≥5 days, whereas median preoperative lactate of 2.8 mmol/L was not, when multisystem trauma patients with a femoral shaft fracture were treated with reamed IMN within 24 hours after admission. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The effect of body mass index on posttraumatic transfusion after pelvic trauma.

The impact of body mass index (BMI) on posttraumatic blood transfusion after pelvic trauma is not well known. We conducted a retrospective review of trauma registry data over a 5-year period. Patients were stratified by BMI as normal: less than 25 kg/m(2), overweight: 25 to 29.9 kg/m(2), obese: 30 to 39.9 kg/m(2), and morbidly obese: 40 kg/m(2) or greater. Fractures were identified as "likely to receive transfusion" based on literature. Multivariable logistic regression modeling evaluated the relationship between BMI and initial posttraumatic transfusion. A second regression model was created to test the effect of BMI after adjusting for fractures "less likely to receive transfusion." Sixty-six of 244 patients (27.3%) received transfusion (mean: 1.1 ± 2.3 units). Morbid obesity was associated with transfusion (less than 55.6 vs 24.8%; P < 0.05) and units of total blood transfused (2.2 ± 2.9 vs 1.0 ± 2.2 mL; P < 0.05). The average age of patients who received a blood transfusion was significantly older compared with patients who did not receive a transfusion (45.4 ± 18.8 vs 36.1 ± 16.1 years; P < 0.05). After adjusting for potential confounders, morbid obesity was a significant risk factor for transfusion (odds ratio [OR], 4.1; 95% confidence interval [CI], 1.4 to 12.0). Adjusting by age and fracture patterns "less likely to receive transfusion," morbid obesity remained a risk factor for transfusion (OR, 4.5; 95% CI, 1.5 to 12.9). Morbid obesity represented a significant risk factor for posttraumatic transfusion in isolated pelvic trauma, even for fracture patterns "less likely to receive transfusion."