Pulse Pressure: A Predictor of Intervention in Blunt Abdominal Trauma

BACKGROUND

Patients with life-threatening hemorrhages due to blunt torso trauma are at a particularly high risk of being underdiagnosed. The pulse pressure (PP) starts narrowing down before the traditional parameters start changing, making it a useful tool for assessing and planning early intervention.

OBJECTIVE

To assess the utility of low PP in predicting massive transfusion (MT) or operative intervention in patients with isolated blunt abdominal trauma.

MATERIAL AND METHODS

A total of 186 patients were included. The PP and mean arterial pressure (MAP) were calculated. Vitals, PP, and MAP were monitored every 15 min during the first 6 h, then every 30 min during the next 6 h, and afterward, every 4 h until discharge. A Chi-square test and an independent t-test (as appropriate) were applied to compare variables with PP at the time of presentation. Differences were considered statistically significant at p-value ≤ 0.05.

RESULTS

A total of 55.9% of these patients had injuries due to road traffic accidents (RTA). Emergency operative intervention was provided to 26.3% of the patients. Death was 4.3%. MT was required by 26.3% of the patients. There was a statistically significant association between low PP and sex, length of stay, repeat extended focused assessment with sonography in trauma (eFAST), emergency operational intervention, outcome, MT, number of crystalloids consumed within the first four hours after presentation, injury severity score, systolic blood pressure (SBP), and pulse rate.

CONCLUSION

The PP <30 mmHg was observed as a useful predictor for increased blood loss requiring blood transfusion or operative intervention.

A prediction model for massive hemorrhage in trauma: a retrospective observational study

Background

Massive hemorrhage is the main cause of preventable death after trauma. This study aimed to establish prediction models for early diagnosis of massive hemorrhage in trauma.

Methods

Using the trauma database of Chinese PLA General Hospital, two logistic regression (LR) models were fit to predict the risk of massive hemorrhage in trauma. Sixty-two potential predictive variables, including clinical symptoms, vital signs, laboratory tests, and imaging results, were included in this study. Variable selection was done using the least absolute shrinkage and selection operator (LASSO) method. The first model was constructed based on LASSO feature selection results. The second model was constructed based on the first vital sign recordings of trauma patients after admission. Finally, a web calculator was developed for clinical use.

Results

A total of 2353 patients were included in this study. There were 377 (16.02%) patients with massive hemorrhage. The selected predictive variables were heart rate (OR: 1.01; 95% CI: 1.01–1.02; P<0.001), pulse pressure (OR: 0.99; 95% CI: 0.98–0.99; P = 0.004), base excess (OR: 0.90; 95% CI: 0.87–0.93; P<0.001), hemoglobin (OR: 0.95; 95% CI: 0.95–0.96; P<0.001), displaced pelvic fracture (OR: 2.13; 95% CI: 1.48–3.06; P<0.001), and a positive computed tomography scan or positive focused assessment with sonography for trauma (OR: 1.62; 95% CI: 1.21–2.18; P = 0.001). Model 1, which was developed based on LASSO feature selection results and LR, displayed excellent discrimination (AUC: 0.894; 95% CI: 0.875–0.912), good calibration (P = 0.405), and clinical utility. In addition, the predictive power of model 1 was better than that of model 2 (AUC: 0.718; 95% CI: 0.679–0.757). Model 1 was deployed as a public web tool (http://82.156.217.249:8080/).

Conclusions

Our study developed and validated prediction models to assist medical staff in the early diagnosis of massive hemorrhage in trauma. An open web calculator was developed to facilitate the practical application of the research results.

Predictors of transfusion in trauma and their utility in the prehospital environment: a scoping review

Background: Hemorrhage is a leading cause of preventable mortality from trauma, necessitating resuscitation through blood product transfusions. Early and accurate identification of patients requiring transfusions in the prehospital setting may reduce delays in time to transfusion upon arrival to hospital, reducing mortality. The purpose of this study is to characterize existing literature on predictors of transfusion and analyze their utility in the prehospital context.Objectives: The objectives of this study are to characterize the existing quantity and quality of literature regarding predictor scores for transfusion in injured patients, and to analyse the utility of predictor scores for massive transfusions in the prehospital setting and identify prehospital predictor scores for future research.Methods: A search strategy was developed in consultation with information specialists. A literature search of OVID MEDLINE from 1946 to present was conducted for primary studies evaluating the predictive ability of scoring systems or single variables in predicting transfusion in all trauma settings.Results: Of the 5824 studies were identified, 5784 studies underwent title and abstract screening, 94 studies underwent full text review, and 72 studies were included in the final review. We identified 16 single variables and 52 scoring systems for predicting transfusion. Amongst single predictor variables, fluids administered and systolic blood pressure had the highest reported sensitivity (100%) and specificity (89%) for massive transfusion protocol (MTP) activation respectively. Amongst scoring systems for transfusion, the Shock Index and Modified Shock Index had the highest reported sensitivity (96%), while the Pre-arrival Model had the highest reported specificity (95%) for MTP activation. Overall, 20 scores were identified as being applicable to the prehospital setting, 25 scores were identified as being potentially applicable, and seven scores were identified as being not applicable.Conclusions: We identified an extensive list of predictive single variables, validated scoring systems, and derived models for massive transfusion, presented their properties, and identified those with potential utility in the prehospital setting. By further validating applicable scoring tools in the prehospital setting, we may begin to administer more timely transfusions in the trauma population.

Shock Index as a Predictor for Angiographic Hemostasis in Life-Threatening Traumatic Oronasal Bleeding

The objective of this retrospective study was to identify predictors of angiographic hemostasis among patients with life-threatening traumatic oronasal bleeding (ONB) and determine the threshold for timely referral or intervention. The diagnosis of traumatic, life-threatening ONB was made if the patient suffered from craniofacial trauma presenting at triage with unstable hemodynamics or required a definitive airway due to ONB, without other major bleeding identified. There were 4404 craniofacial trauma patients between January 2015 and December 2019, of which 72 (1.6%) fulfilled the diagnosis of traumatic life-threatening ONB. Of these patients, 39 (54.2%) received trans-arterial embolization (TAE), 11 (15.3%) were treated with other methods, and 22 (30.5%) were excluded. Motor vehicle accidents were the most common cause of life-threatening ONB (52%), and the internal maxillary artery was the most commonly identified hemorrhaging artery requiring embolization (84%). Shock index (SI) was significantly higher in the angiographic hemostasis group (p < 0.001). The AUC-ROC was 0.87 (95% CI, 0.88-1.00) for SI to predict angiographic hemostasis. Early recognition and timely intervention are crucial in post-traumatic, life-threatening ONB management. Patients initially presenting with SI > 0.95 were more likely to receive TAE, with the TAE group having statistically higher SI than the non-TAE group whilst receiving significantly more packed red blood cells. Hence, for patients presenting with life-threatening traumatic ONB and a SI > 0.95, TAE should be considered if preliminary attempts at hemostasis have failed.

Major Prehospital Trauma and In-Hospital Emergencies: Massive Transfusion Triggers

BACKGROUND

Massive transfusion (MT) in trauma is initiated on the basis of factors of different natures and depending on protocols and scales used both in prehospital and in-hospital care areas.

OBJECTIVE

The main goal was to analyze and relate factors and predictive variables for MT requirements considering both health care areas.

METHOD

This was a retrospective cohort study that included patients who were treated either at the emergency department of a large hospital or through prehospital care before arrival at the hospital. The patients included were adults who received MT, defined as a blood bank request of 10 or more units of red cells in the first 24 hours or 5 or more within 4 hours of trauma, from January 1, 2009, to January 1, 2017. The variables included were individual characteristics and those associated with the trauma, clinical-analytical assessment, resuscitation, timing, and survival.

RESULTS

A total of 52 patients who received MT were included. The average age of the patients was 41.23 ± 16.06 years, a mean of 19.56 ± 12.77 units was administered, and the mortality rate was 21.2%.

DISCUSSION

Injury mechanism, clinical-analytical variables, and resuscitation strategies have a significant influence on the need for MT; therefore, early identification is fundamental for performing quality management and addressing avoidable factors during MT processes.

Massive Blood Transfusion for Trauma Score to Predict Massive Blood Transfusion in Trauma

Background

Massive blood loss is the most common cause of immediate death in trauma. A massive blood transfusion (MBT) score is a prediction tool to activate blood banks to prepare blood products. The previously published scoring systems were mostly developed from settings that had mature prehospital systems which may lead to a failure to validate in settings with immature prehospital systems. This research aimed to develop a massive blood transfusion for trauma (MBTT) score that is able to predict MBT in settings that have immature prehospital care.

Methods

This study was a retrospective cohort that collected data from trauma patients who met the trauma team activation criteria. The predicting parameters included in the analysis were retrieved from the history, physical examination, and initial laboratory results. The significant parameters from a multivariable analysis were used to develop a clinical scoring system. The discrimination was evaluated by the area under a receiver operating characteristic (AuROC) curve. The calibration was demonstrated with Hosmer–Lemeshow goodness of fit, and an internal validation was done.

Results

Among 867 patients, 102 (11.8%) patients received MBT. Four factors were associated with MBT: a score of 3 for age ≥60 years; 2.5 for base excess ≤–10 mEq/L; 2 for lactate >4 mmol/L; and 1 for heart rate ≥105 /min. The AuROC was 0.85 (95% CI: 0.78–0.91). At the cut point of ≥4, the positive likelihood ratio of the score was 6.72 (95% CI: 4.7–9.6, p < 0.001), the sensitivity was 63.6%, and the specificity was 90.5%. Internal validation with bootstrap replications had an AuROC of 0.83 (95% CI: 0.75–0.91).

Conclusions

The MBTT score has good discrimination to predict MBT with simple and rapidly obtainable parameters.

The FASILA Score: A Novel Bio-Clinical Score to Predict Massive Blood Transfusion in Patients with Abdominal Trauma

Background

Early identification of patients who may need massive blood transfusion remains a major challenge in trauma care. This study proposed a novel and easy-to-calculate prediction score using clinical and point of care laboratory findings in patients with abdominal trauma (AT).

Methods

Patients with AT admitted to a trauma center in Qatar between 2014 and 2017 were retrospectively analyzed. The FASILA score was proposed and calculated using focused assessment with sonography in trauma (0 = negative, 1 = positive), Shock Index (SI) (0 = 0.50–0.69, 1 = 0.70–0.79, 2 = 0.80–0.89, and 3 ≥ 0.90), and initial serum lactate (0 ≤ 2.0, 1 = 2.0–4.0, and 2 ≥ 4.0 mmol/l). Outcome variables included mortality, laparotomy, and massive blood transfusion (MT). FASILA was compared to other prediction scores using receiver operating characteristics and areas under the curves. Bootstrap procedure was employed for internal validation.

Results

In 1199 patients with a mean age of 31 ± 13.5 years, MT, MT protocol (MTP) activation, exploratory laparotomy (ExLap), and hospital mortality were related linearly with the FASILA score, Injury Severity Score, and total length of hospital stay. Initial hemoglobin, Revised Trauma Score (RTS), and Trauma Injury Severity Score (TRISS) were inversely proportional. FASILA scores correlated significantly with the Assessment of Blood Consumption (ABC) (r = 0.65), Revised Assessment of Bleeding and Transfusion (RABT) (r = 0.63), SI (r = 0.72), RTS (r = − 0.34), and Glasgow Coma Scale (r = − 0.32) and outperformed other predictive systems (RABT, ABC, and SI) in predicting MT, MTP, ExLap, and mortality.

Conclusions

The novel FASILA score performs well in patients with abdominal trauma and offers advantages over other scores.

Electronic supplementary material

The online version of this article (10.1007/s00268-019-05289-0) contains supplementary material, which is available to authorized users.

Predictive Factors for Massive Transfusion in Trauma: A Novel Clinical Score from an Italian Trauma Center and German Trauma Registry

Early management of critical bleeding and coagulopathy can improve patient survival. The aim of our study was to identify independent predictors of critical bleeding and to build a clinical score for early risk stratification. A prospective analysis was performed on a cohort of trauma patients with at least one hypotensive episode during pre-hospital (PH) care or in the Emergency Department (ED). Patients who received massive transfusion (MT+) (≥4 blood units during the first hour) were compared to those who did not (MT−). Hemodynamics, Glagow Coma Score (GCS), diagnostics and blood tests were evaluated. Using multivariate analysis, we created and validated a predictive score for MT+ patients. The predictive score was validated on a matched cohort of patients of the German Trauma Registry TR-DGU. One hundred thirty-nine patients were included. Independent predictors of MT+ included a prehospital (PH) GCS of 3, PH administration of tranexamic acid, hypotension and tachycardia upon admission, coagulopathy and injuries with significant bleeding such as limb amputation, hemoperitoneum, pelvic fracture, massive hemothorax. The derived predictive score revealed an area under the curve (AUC) of 0.854. Massive transfusion is essential to damage control resuscitation. Altered GCS, unstable hemodynamics, coagulopathy and bleeding injuries can allow early identification of patients at risk for critical hemorrhage.

Review of Existing Scoring Systems for Massive Blood Transfusion in Trauma Patients: Where Do We Stand?

BACKGROUND

Uncontrolled bleeding is the main cause of the potential preventable death in trauma patients. Accordingly, we reviewed all the existing scores for massive transfusion posttraumatic hemorrhage and summarized their characteristics, thus making it easier for the reader to have a global view of these scores-how they were created, their accuracy and to which population they apply.

METHODS

A narrative review with a systematic search method to retrieve the journal articles on the predictive scores or models for massive transfusion was carried out. A literature search using PubMed, SCOPUS, and Google scholar was performed using relevant keywords in different combinations. The keywords used were "massive transfusion," "score," "model," "trauma," and "hemorrhage" in different combinations. The search was limited for full-text articles published in English language, human species and for the duration from January 1, 1998 to November 30, 2018.

RESULTS

The database search yielded 295 articles. The search was then restricted to the inclusion criteria which retrieved 241 articles. Duplicates were removed and full-texts were assessed for the eligibility to include in the review which resulted in inclusion of 24 articles. These articles identified 24 scoring systems including modified or revised scores. Different models and scores for identifying patients requiring massive transfusion in military and civilian settings have been described. Many of these scorings were complex with difficult calculation, while some were simple and easy to remember.

CONCLUSIONS

The current prevailing practice that is best described as institutional or provider centered should be supplemented with score-based protocol with auditing and monitoring tools to refine it. This review summarizes the current scoring models in predicting the need for MT in civilian and military trauma. Several questions remain open; i.e., do we need to develop new score, merge scores, modify scores, or adopt existing score for certain trauma setting?

Systematic reviews of scores and predictors to trigger activation of massive transfusion protocols

BACKGROUND

The use of massive transfusion protocols (MTPs) in the resuscitation of hemorrhaging trauma patients ensures rapid delivery of blood products to improve outcomes, where the decision to trigger MTPs early is important. Scores and tools to predict the need for MTP activation have been developed for use to aid with clinical judgment. We performed a systematic review to assess (1) the scores and tools available to predict MTP in trauma patients, (2) their clinical value and diagnostic accuracies, and (3) additional predictors of MTP.

METHODS

MEDLINE, EMBASE, and CENTRAL were searched from inception to June 2017. All studies that utilized scores or predictors of MTP activation in adult (age, ≥18 years) trauma patients were included. Data collection for scores and tools included reported sensitivities and specificities and accuracy as defined by the area under the curve of the receiver operating characteristic.

RESULTS

Forty-five articles were eligible for analysis, with 11 validated and four unvalidated scores and tools assessed. Of four scores using clinical assessment, laboratory values, and ultrasound assessment the modified Traumatic Bleeding Severity Score had the best performance. Of those scores, the Trauma Associated Severe Hemorrhage score is most well validated and has higher area under the curve of the receiver operating characteristic than the Assessment of Blood Consumption and Prince of Wales scores. Without laboratory results, the Assessment of Blood Consumption score balances accuracy with ease of use. Without ultrasound use, the Vandromme and Schreiber scores have the highest accuracy and sensitivity respectively. The Shock Index uses clinical assessment only with fair performance. Other clinical variables, laboratory values, and use of point-of-care testing results were identified predictors of MTP activation.

CONCLUSION

The use of scores or tools to predict MTP need to be individualized to hospital resources and skill set to aid clinical judgment. Future studies for triggering nontrauma MTP activations are needed.

LEVEL OF EVIDENCE

Systematic review, level III.

Early coagulation support protocol: A valid approach in real-life management of major trauma patients. Results from two Italian centres

INTRODUCTION

Early coagulation support (ECS) includes prompt infusion of tranexamic acid, fibrinogen concentrate, and packed red blood cells for initial resuscitation of major trauma patients. The aim of this study was to determine the effects, in terms of blood product consumption, length of stay, and in-hospital mortality, of the ECS protocol, compared to the massive transfusion protocol (MTP) in the treatment of major trauma patients.

PATIENTS AND METHODS

A retrospective analysis was conducted using the registry data of two Italian trauma centres. Adult major trauma patients with, or at risk of, active bleeding who were managed according to the MTP during the years 2011-2012, or the ECS protocol during the years 2013-2014 and were considered at risk of multiple transfusions, were enrolled. The primary endpoint was to determine whether the ECS protocol reduces the use of blood products in the acute management of trauma patients. Secondary endpoints were the outcome measures of length of stay in ICU, length of stay in hospital, and mortality at 24-hours and 28-days after hospital admission.

RESULTS

Among the 518 major trauma patients admitted to the trauma centres during the study period, 235 patients (118 in the pre-ECS period and 117 in the ECS period) matched one of the inclusion criteria and were enrolled in the study. Compared with the pre-ECS period, the ECS period showed a reduction in the average consumption of packed red blood cells (-1.87 units, 95% confidence interval [CI], -2.40, -1.34), platelets (-1.28 units; 95% CI, -1.64, -0.91), and fresh frozen plasma (-1.69; 95% CI, -2.14, -1.25) in the first 24-hours. Furthermore, during the ECS period, we recorded a 10-day reduction in the hospital length of stay (-10 days, 95% CI, -11.6, -8.4) and a non-significant 28-day mortality increase.

CONCLUSIONS

The ECS protocol was effective in reducing blood product consumption compared to the MTP and confirmed the importance of early fibrinogen administration as a strategy of rapid coagulation. This novel approach may be adopted in real-life management of major trauma patients.

Pulse Pressure as an Early Warning of Hemorrhage in Trauma Patients

BACKGROUND

Hypotension based on low systolic blood pressure (SBP) is a well-documented indicator of ongoing blood loss. However, the utility of pulse pressure (PP) for detection of hemorrhage has not been well studied. The purpose of this study was to determine whether a narrowed PP in nonhypotensive patients is an independent predictor of critical administration threshold (CAT+) hemorrhage requiring surgical or endovascular control.

STUDY DESIGN

We performed a retrospective single-center study (January 2010 to October 2014), including trauma patients ≥16 years old with SBP ≥ 90 mmHg upon emergency department (ED) admission. We identified patients who were both CAT+ and required either surgical or interventional radiology for definitive hemorrhage control as the active hemorrhage (AH) group. Analyses were then performed to elucidate the association between PP and hemorrhage.

RESULTS

Of the total 18,015 patients identified, 283 (1.6%) met the criteria for clinically significant hemorrhage. Mean PP was significantly lower in the AH group compared with the non-AH group (39 ± 18 mmHg vs 53 ± 19 mmHg, p < 0.0001). Multivariate analysis revealed that narrowed initial ED PP is an independent predictor of AH (adjusted odds ratio [AOR] 0.975) along with age (AOR 1.01), penetrating mechanism (AOR 9.476), field SBP (AOR 0.985), ED heart rate (AOR 1.024), and Injury Severity Score (AOR 1.126). Cutoff analysis of PP values identified a significantly higher risk of AH at a PP cutoff of 55 mmHg (AOR 3.44, p = 0.005, AUC 0.955) in patients 61 years or older vs 40 mmHg (AOR 2.73, p < 0.0001, AUC 0.940) for patients 16 to 60 years old. The predicted probability of AH increases as PP narrows.

CONCLUSIONS

In patients who are nonhypotensive, a narrowed PP is an independent early predictor of active hemorrhage requiring blood product transfusion and intervention for hemorrhage control.

External validation of a smartphone app model to predict the need for massive transfusion using five different definitions

BACKGROUND

Previously, a model to predict massive transfusion protocol (MTP) (activation) was derived using a single-institution data set. The PRospective, Observational, Multicenter, Major Trauma Transfusion database was used to externally validate this model's ability to predict both MTP activation and massive transfusion (MT) administration using multiple MT definitions.

METHODS

The app model was used to calculate the predicted probability of MTP activation or MT delivery. The five definitions of MT used were: (1) 10 units packed red blood cells (PRBCs) in 24 hours, (2) Resuscitation Intensity score ≥ 4, (3) critical administration threshold, (4) 4 units PRBCs in 4 hours; and (5) 6 units PRBCs in 6 hours. Receiver operating curves were plotted to compare the predicted probability of MT with observed outcomes.

RESULTS

Of 1,245 patients in the data set, 297 (24%) met definition 1, 570 (47%) met definition 2, 364 (33%) met definition 3, 599 met definition 4 (49.1%), and 395 met definition 5 (32.4%). Regardless of the outcome (MTP activation or MT administration), the predictive ability of the app model was consistent: when predicting activation of the MTP, the area under the curve for the model was 0.694 and when predicting MT administration, the area under the curve ranged from 0.695 to 0.711.

CONCLUSION

Regardless of the definition of MT used, the app model demonstrates moderate ability to predict the need for MT in an external, homogenous population. Importantly, the app allows the model to be iteratively recalibrated ("machine learning") and thus could improve its predictive capability as additional data are accrued.

LEVEL OF EVIDENCE

Diagnostic test study/Prognostic study, level III.

Massive transfusion triggers in severe trauma: Scoping review

OBJECTIVE

to identify the predictive variables or the massive transfusion triggers in severely traumatized patients through the existing scales.

METHOD

a review of the literature was carried out using the Scoping Review method across the electronic databases CINAHL, MEDLINE, LILACS, the Cochrane and IBECS libraries, and the Google Scholar search tool.

RESULTS

in total, 578 articles were identified in the search and the 36 articles published in the last ten years were included, of which 29 were original articles and 7 review articles. From the analysis, scales for massive transfusion and their predictive triggers were examined.

CONCLUSION

the absence of universal criteria regarding the massive transfusion triggers in traumatized patients has led to the development of different scales, and the studies on their validation are considered relevant for the studies about when to initiate this strategy.

Massive Transfusion: The Revised Assessment of Bleeding and Transfusion (RABT) Score

BACKGROUND

Massive transfusion (MT) is a lifesaving treatment for trauma patients with hemorrhagic shock, assessed by Assessment of Blood Consumption (ABC) Score based on mechanism of injury, systolic blood pressure (SBP), tachycardia, and FAST exam. The aim of this study was to assess the performance of ABC score by replacing hypotension and tachycardia; with Shock Index (SI) > 1.0 and including pelvic fractures.

METHODS

We performed a 2-year (2014-2015) analysis of all high-level trauma activations and excluded patients dead on arrival. The ABC score was calculated using the 4-point score [blunt (0)/penetrating trauma (1), HR ≥ 120 (1), SBP ≤ 90 mmHg (1), and FAST positive (1)]. The Revised Assessment of Bleeding and Transfusion (RABT) score also included 4 points, calculated by replacing HR and SBP with SI > 1.0 and including pelvic fracture. AUROC compared performances of the two scores.

RESULTS

A total of 380 patients were included. The overall MT was 27%. Patients receiving MT had higher median ABC scores [1.1 (0-2) vs. 1 (0-2), p = 0.15] and RABT scores [2 (1-3) vs. 1 (0-2), p < 0.001]. The RABT score had better discriminative power (AUROC = 0.828) compared to ABC score (AUROC = 0.617) for predicting the need for MT. Cutoff of RABT score ≥ 2 had a sensitivity of 84% and specificity of 77% for predicting need for MT compared to ABC score with 39% sensitivity and 72% specificity.

CONCLUSION

Replacement of hypotension and tachycardia with a SI > 1.0 and inclusion of pelvic fracture enhanced discrimination of ABC score for predicting the need for MT. The current ABC score would benefit from revision to more appropriately identify patients requiring MT.

Prediction of Massive Transfusion in Trauma

Hemorrhage is the leading cause of preventable death in trauma. Damage control resuscitation relies on permissive hypotension, minimizing crystalloid use, and early implementation of massive transfusion protocols with established blood component ratios. These protocols improve the survival of the severely injured patient. Trauma physicians must quickly and accurately predict when a massive transfusion protocol should be activated. Several validated transfusion scores have been developed for this purpose. Many of these scores are useful for resuscitation research. One option, the ABC score, is an accurate, validated, and clinically useful score that is simple to calculate and rapidly obtained.

FDP/fibrinogen ratio reflects the requirement of packed red blood cell transfusion in patients with blunt trauma

PURPOSE

To find factors that predict the requirement of packed red blood cells (pRBC) transfusion in patients with blunt trauma on arrival at the hospital.

METHODS

We conducted blood tests in trauma patients whose trauma severity was suspected as being 3 and over in the Abbreviated Injury Scale. Patients were divided into the blood transfusion (BT) and control groups according to the requirement of pRBC transfusion within 24h after arrival.

RESULTS

We analyzed 347 patients (BT group, n=14; control group, n=333). On univariate analysis, there were significant differences in Glasgow Coma Scale (GCS), rate of positive FAST (focused assessment with sonography for trauma) finding, hematocrit, international normalized ratio of prothrombin time, activated partial thromboplastin time, fibrinogen (Fib), and level of fibrin degradation products (FDP). On multivariable analysis, positive FAST finding, GCS, Fib, and FDP influenced the requirement of pRBC transfusion. In the area under the receiver operating characteristic curve analysis, Fib and FDP were markers that predicted the requirement of pRBC transfusion. The FDP/Fib ratio had a better correlation with the requirement of pRBC transfusion than FDP or Fib.

CONCLUSIONS

The FDP/Fib ratio can be easily measured and may be a predictor of the need for pRBC transfusion.

Fibrinogen level on admission is a predictor for massive transfusion in patients with severe blunt trauma: Analyses of a retrospective multicentre observational study

INTRODUCTION

In the early phase of trauma, fibrinogen (Fbg) plays an important role in clot formation. However, to the best of our knowledge, few studies have analysed methods of predicting the need for massive transfusion (MT) based on Fbg levels using multiple logistic regression. Therefore, the present study aimed to evaluate whether Fbg levels on admission can be used to predict the need for MT in patients with trauma.

METHODS

We conducted a retrospective multicentre observational study. Patients with blunt trauma with ISS ≥16 who were admitted to 15 tertiary emergency and critical care centres in Japan participating in the J-OCTET were enrolled in the present study. MT was defined as the transfusion of packed red blood cells (PRBC) ≥10 units or death caused by bleeding within 24h after admission. Patients were divided into non-MT and MT groups. Multiple logistic-regression analysis was used to assess the predictive value of the variables age, sex, vital signs, Glasgow Coma Scale (GCS) score, and Fbg levels for MT. We also evaluated the discrimination threshold of MT prediction via receiver operating characteristic curve (ROC) analysis for each variable.

RESULTS

Higher heart rate (HR; per 10 beats per minutes [bpm]), systolic blood pressure (SBP; per 10mm Hg), GCS, and Fbg levels (per 10mg/dL) were independent predictors of MT (odds ratio [OR] 1.480, 95% confidence interval [CI] 1.326-1.668; OR 0.851, 95% CI 0.789-0.914; OR 0.907, 95% CI 0.855-0.962; and OR 0.931, 95% CI 0.898-0.963, respectively). The optimal cut-off values for HR, SBP, GCS, and Fbg levels were ≥100 bpm (sensitivity 62.4%, specificity 79.8%), ≤120mm Hg (sensitivity 61.5%, specificity 70.5%), ≤12 points (sensitivity 63.3%, specificity 63.6%), and ≤190mg/dL (sensitivity 55.1%, specificity 78.6%), respectively.

CONCLUSIONS

Our findings suggest that vital signs, GCS, and decreased Fbg levels can be regarded as predictors of MT. Therefore, future studies should consider Fbg levels when devising models for the prediction of MT.

[Trauma bay haemoglobin level. Predictor of coagulation disorder in major trauma]

BACKGROUND

Trauma-induced coagulopathy is common in patients with major trauma and requires early and appropriate treatment for bleeding control. Even in emergency laboratory, the availability of standard coagulation tests is associated with certain latencies and devices for viscoelastic haemostasis diagnosis (thromboelastometry) are not routinely established in major trauma centres.

PURPOSE

We searched for a laboratory parameter with fast availability by point of care blood gas analysis and reliable correlation with coagulation parameters.

METHODS

We analyzed the trauma patients of a single level one trauma centre from 2005-2011 and particularly evaluated the correlation between haemoglobin (Hb) and coagulation parameters and the correlation of Hb and parameters indicating tissue perfusion. All patients who were directly admitted from the scene of an accident to the trauma centre had an injury severity score (ISS) > 9, had a complete revised injury severity classification (RISC) and blood samples that were taken in the emergency department (ED) immediately after admission were included. Correlations were tested using the Pearson test (r) with a two-tailed significance level of p < 0.05.

RESULTS

A total of 425 patients met inclusion criteria presenting with a mean age of 43 years, 76% male gender and mean ISS of 30.4. Significant correlation (p < 0.01) between Hb and prothrombin time (Quick) (r = 0.652), Hb and partial thromboplastin time (PTT) (r = - 0.434), Hb and platelet count (r = 0.501) and Hb and base excess (BE) (0.408) was found. No significant correlation between Hb and lactate was found.

CONCLUSION

We found a robust correlation of Hb and Quick in a single centre trauma population. These data suggest that especially severely injured trauma patients with persistent bleeding might benefit from an Hb-based algorithm for early correction of coagulation disorders. Further studies with larger trauma populations are required to confirm our findings.

Prediction of extravasation in pelvic fracture using coagulation biomarkers

PURPOSE

To evaluate the usefulness of coagulation biomarkers, which are easy and quick to analyze in emergency settings, for prediction of arterial extravasation due to pelvic fracture.

PATIENTS AND METHODS

The medical records of pelvic fracture patients transferred to the emergency department of Gunma University Hospital between December 2009 and May 2015 were reviewed. Patients were divided into two groups, those with (Extra(+)) and without (Extra(-)) arterial extravasation on enhanced CT or angiography. Levels of fibrin degradation products (FDP), D-dimer, fibrinogen, the ratio of FDP to fibrinogen, the ratio of D-dimer to fibrinogen, systolic blood pressure, heart rate, the Glasgow Coma Scale, pH, base excess, hemoglobin and lactate levels, the pattern of pelvic injury, and injury severity score were measured at hospital admission, and compared between the two groups. Parameters with a significant difference between the two groups were used to construct receiver operating characteristic (ROC) curves.

RESULTS

The study included 29 patients with pelvic fracture. FDP, D-dimer, the ratio of FDP to fibrinogen and the ratio of D-dimer to fibrinogen were the most useful parameters for predicting arterial extravasation due to pelvic fracture. FDP, D-dimer, the ratio of FDP to fibrinogen, the ratio of D-dimer to fibrinogen, and hemoglobin and lactate levels were significantly higher in the Extra(+) group than in the Extra(-) group (FDP, 354.8μg/mL [median] versus 96.6μg/mL; D-dimer, 122.3μg/mL versus 42.1μg/mL; the ratio of FDP to fibrinogen, 3.39 versus 0.42; the ratio of D-dimer to fibrinogen, 1.14 versus 0.18; hemoglobin, 10.5g/dL versus 13.5g/dL; lactate, 3.5mmol/L versus 1.7mmol/L). The area under the ROC curves for FDP, D-dimer, the ratio of FDP to fibrinogen, the ratio of D-dimer to fibrinogen, hemoglobin and lactate levels were 0.900, 0.882, 0.918, 0.900, 0.815 and 0.765, respectively.

CONCLUSION

Coagulation biomarkers, and hemoglobin and lactate levels could be useful to predict the existence of arterial extravasation due to pelvic fracture. The ratio of FDP to fibrinogen and the ratio of D-dimer to fibrinogen were the most accurate markers. Coagulation biomarkers may enable more rapid and specific treatment for pelvic fracture.

Early Prediction of Ongoing Hemorrhage in Severe Trauma: Presentation of the Existing Scoring Systems

Early prediction of ongoing hemorrhage may reduce mortality via the earlier delivery of blood products, adequate orientation of the patient in a dedicated highly specialized and trained infrastructure, and by earlier correction of acute traumatic coagulopathy. We identified 14 scores or algorithms developed for the prediction of ongoing hemorrhage and the need for massive transfusion in severe trauma patients.

Influence of surgical bleeding on the relationship between admission coagulopathy and risk of massive transfusion: lesson from 704 severe trauma patients

BACKGROUND

This study hypothesized that the relationship between early coagulopathy and massive transfusion (MT) in trauma was highly dependent on the presence of surgical bleeding.

METHODS

Consecutive severe trauma patients admitted to our institution over a 4-year period were included in this retrospective study. Surgical bleeding was defined as an injury requiring an invasive endovascular or surgical haemostatic procedure. The ability of prothrombin time ratio (PTr) and activated partial thromboplastin time ratio (aPTTr) to predict MT (≥10 units of packed red blood cells during the first 24 h) was determined by ROC curves. The strength of association and interaction between PTr, surgical bleeding and MT was assessed using a logistic regression analysis.

RESULTS

Among the 704 patients included (ISS 21·0 ± 16·2), MT rate was higher in patients with surgical bleeding than in those with no surgical bleeding (47% vs. 5%; P < 0·001). The global performance of PTr and aPTTr to predict MT was only fair in our study population (AUCs 0·83 and 0·81). MT rate was widely higher in the surgical bleeding group whatever the severity of coagulopathy (P < 0·001). PTr was found to be significantly associated with TM [PTr ≥ 1·5, OR 23·6 (95% CI 13·4-41·7); PTr 1·2-1·5, OR 3·0 (95% CI 1·7-5·3)]. Corresponding ORs were reduced after adjusting for the surgical bleeding: 12·1 (95% CI 6·5-22·5) and 2·1 (95% CI 1·2-4·0), respectively. However, no significant interaction was found regression models.

CONCLUSION

The strength of association between MT and coagulation status on admission was found strongly influenced by surgical bleeding. The admission coagulopathy monitoring in trauma patients without considering the surgical bleeding does not allow a reliable determination of MT probability.

Recursive partitioning identifies greater than 4 U of packed red blood cells per hour as an improved massive transfusion definition

BACKGROUND

Massive transfusion (MT) is classically defined as greater than 10 U of packed red blood cells (PRBCs) in 24 hours. This fails to capture the most severely injured patients. Extending the previous work of Savage and Rahbar, a rolling hourly rate-based definition of MT may more accurately define critically injured patients requiring early, aggressive resuscitation.

METHODS

The Prospective Observational Multicenter Major Trauma Transfusion (PROMMTT) trial collected data from 10 Level 1 trauma centers. Patients were placed into rate-based transfusion groups by maximal number of PRBCs transfused in any hour within the first 6 hours. A nonparametric analysis using classification trees partitioned data according to mortality at 24 hours using a predictor variable of maximum number PRBC units transfused in an hour. Dichotomous variables significant in previous scores and models as predictors of MT were used to identify critically ill patients: a positive finding on Focused Assessment with Sonography in Trauma (FAST) examination, Glasgow Coma Scale (GCS) score less than 8, heart rate greater than 120 beats/min, systolic blood pressure less than 90 mm Hg, penetrating mechanism of injury, international normalized ratio greater than 1.5, hemoglobin less than 11, and base deficit greater than 5. These critical indicators were then compared among the nodes of the classification tree. Patients omitted included those who did not receive PRBCs (n = 24) and those who did not have all eight critical indicators reported (n = 449).

RESULTS

In a population of 1,245 patients, the classification tree included 772 patients. Analysis by recursive partitioning showed increased mortality among patients receiving greater than 13 U/h (73.9%, p < 0.01). In those patients receiving less than or equal to 13 U/h, mortality was greater in patients who received more than 4 U/h (16.7% vs. 6.0%, p < 0.01) (Fig. 1). Nodal analysis showed that the median number of critical indicators for each node was 3 (2-4) (≤4 U/h), 4 (3-5) (>4 U/h and ≤13 U/h), and 5 (4-5.5) (>13 U/h).

CONCLUSION

A rate-based transfusion definition identifies a difference in mortality in patients who receive greater than 4 U/h of PRBCs. Redefining MT to greater than 4 U/h allows early identification of patients with a significant mortality risk who may be missed by the current definition.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level III.

Modified traumatic bleeding severity score: early determination of the need for massive transfusion

BACKGROUND

Determination of the need for massive transfusion (MT) is essential for early activation of a MT protocol. The Traumatic Bleeding Severity Score (TBSS) predicts the need for MT accurately, but takes time to determine because systolic blood pressure after a 1000mL of crystalloid infusion is used. The aim of this study is to determine the how well the Modified TBSS (age, sonography, pelvic fracture, serum lactate and systolic blood pressure on arrival) predicts the need for MT (accuracy).

METHODS

This is a single-center retrospective study of trauma patients (Injury Severity Score ≧16) admitted between 2010 and 2014. The TBSS, the Trauma Associated Severe Hemorrhage (TASH) Score, and the Modified TBSS were calculated. MT is defined as ≧10 U packed red blood cell transfusion within 24hours of injury, and the predictive value of the need for MT was compared by area under the receiver operating characteristic curve (AUC) analysis among three scores.

RESULTS

Three hundred patients were enrolled, and MT given to 25% of patients. Although the AUC of the TBSS was higher than that of the TASH score (0.956 vs 0.912, P=.006) and the Modified TBSS (0.956 vs 0.915, P=.001), there was no difference between the AUC of the Modified TBSS and the TASH score. The Modified TBSS has high accuracy, within an AUC >0.9.

CONCLUSION

The predictive value of the Modified TBSS of the need for MT is still high and is equivalent to the TASH score. The Modified TBSS is calculated earlier in resuscitation than the original TBSS.

Prediction of critical haemorrhage following trauma: A narrative review

Introduction: Traumatic haemorrhagic shock can be difficult to diagnose. Models for predicting critical bleeding and massive transfusion have been developed to aid clinicians. The aim of this review is to outline the various available models and report on their performance and validation. Methods: A review of the English and non-English literature in Medline, PubMed and Google Scholar was conducted from 1990 to September 2015. We combined several terms for i) haemorrhage AND ii) prediction, in the setting of iii) trauma. We included models that had at least two data points. We extracted information about the models, their developments, performance and validation. Results: There were 36 different models identified that diagnose critical bleeding, which included a total of 36 unique variables. All models were developed retrospectively. The models performed with variable predictive abilities–the most superior with an area under the receiver operating characteristics curve of 0.985, but included detailed findings on imaging and was based on a small cohort. The most commonly included variable was systolic blood pressure, featuring in all but five models. Pattern or mechanism of injury were used by 16 models. Pathology results were used by 15 models, of which nine included base deficit and eight models included haemoglobin. Imaging was utilised in eight models. Thirteen models were known to be validated, with only one being prospectively validated. Conclusions: Several models for predicting critical bleeding exist, however none were deemed accurate enough to dictate treatment. Potential areas of improvement identified include measures of variability in vital signs and point of care imaging and pathology testing.

[Multidisciplinary consensus document on the management of massive haemorrhage (HEMOMAS document)]

Massive haemorrhage is common and often associated with high morbidity and mortality. We perform a systematic review of the literature, with extraction of the recommendations from the existing evidences because of the need for its improvement and the management standardization. From the results we found, we wrote a multidisciplinary consensus document. We begin with the agreement in the definitions of massive haemorrhage and massive transfusion, and we do structured recommendations on their general management (clinical assessment of bleeding, hypothermia management, fluid therapy, hypotensive resuscitation and damage control surgery), blood volume monitoring, blood products transfusion (red blood cells, fresh frozen plasma, platelets and their best transfusion ratio), and administration of hemostatic components (prothrombin complex, fibrinogen, factor VIIa, antifibrinolytic agents).

Protocols for massive blood transfusion: when and why, and potential complications

PURPOSE

An update paper on massive bleeding after major trauma. A review of protocols to address massive bleeding, and its possible complications, including coagulation abnormalities, complications related to blood storage, immunosuppression and infection, lung injury associated with transfusion, and hypothermia is carried out.

METHODS

Literature review and discussion with authors' experience.

RESULTS

Massive bleeding is an acute life-threatening complication of major trauma, and consequently its prompt diagnosis and treatment is of overwhelming importance. Treatment requires rapid surgical management together with the massive infusion of colloid and blood.

CONCLUSIONS

Since massive transfusion provokes further problems in patients who are already severely traumatized and anaemic, once this course of action has been decided upon, a profound knowledge of its potential complications, careful monitoring and proper follow-up are all essential. To diagnose this bleeding, most authors favour, as the main first choice tool, a full-body CT scan (head to pelvis), in non-critical severe trauma cases. In addition, focused abdominal sonography for trauma (FAST, an acronym that highlights the necessity of rapid performance) is a very important diagnostic test for abdominal and thoracic bleeding. Furthermore, urgent surgical intervention should be undertaken for patients with significant free intraabdominal fluid and haemodynamic instability. Although the clinical situation and the blood haemoglobin concentration are the key factors considered in this rapid decision-making context, laboratory markers should not be based on a single haematocrit value, as its sensitivity to significant bleeding may be very low. Serum lactate and base deficit are very sensitive markers for detecting and monitoring the extent of bleeding and shock, in conjunction with repeated combined measurements of prothrombin time, activated partial thromboplastin time, fibrinogen and platelets.

Multidisciplinary consensus document on the management of massive haemorrhage (HEMOMAS document)

Massive haemorrhage is common and often associated with high morbidity and mortality. We perform a systematic review of the literature, with extraction of the recommendations from the existing evidences because of the need for its improvement and the management standardization. From the results we found, we wrote a multidisciplinary consensus document. We begin with the agreement in the definitions of massive haemorrhage and massive transfusion, and we do structured recommendations on their general management (clinical assessment of bleeding, hypothermia management, fluid therapy, hypotensive resuscitation and damage control surgery), blood volume monitoring, blood products transfusion (red blood cells, fresh frozen plasma, platelets and their best transfusion ratio), and administration of hemostatic components (prothrombin complex, fibrinogen, factor VIIa, antifibrinolytic agents).

Analysis of risk classification for massive transfusion in severe trauma using the gray zone approach

BACKGROUND

The Traumatic Bleeding Severity Score (TBSS) was developed to predict the need for massive transfusion (MT). The aim of this study is evaluation of clinical thresholds for activation of a MT protocol using the gray zone approach based on TBSS.

METHODS

This is a single-center retrospective study of trauma patients, admitted from 2010 to 2013. The TBSS on admission was calculated, and the accuracy of predicting MT was analyzed using area under the receiver operating characteristic curve. Risk classification for MT was made using sensitivity/specificity. The gray zone (indeterminate risk) was defined from a sensitivity of 95% to a specificity of 95%, patients were separated into MT and non-MT groups, and their clinical characteristics were compared.

RESULTS

A total of 264 patients were enrolled, with an area under the TBSS curve of 0.967 (95% confidence interval, 0.94-0.99). A TBSS of 10 points or less resulted in a sensitivity of 96.5% with 146 patients in this group, and 3.4% (5/146) of them received MT. A TBSS of 17 points or higher had a specificity of 97.8%, which included 72 patients, and 94.4% (68/72) of them received MT. Forty-six patients had a TBSS from 11 to 16 points (gray zone), and 26.1% (12/46) of them received MT. Comparing the MT group (12/46) and non-MT group (34/46), coagulopathy and extravasation on computed tomographic scan were more prevalent in the MT group.

CONCLUSION

The TBSS is highly accurate in predicting the need for MT, and a risk classification for needing MT was created based on TBSS.

Damage control resuscitation

The early recognition and management of hemorrhage shock are among the most difficult tasks challenging the clinician during primary assessment of the acutely bleeding patient. Often with little time, within a chaotic setting, and without sufficient clinical data, a decision must be reached to begin transfusion of blood components in massive amounts. The practice of massive transfusion has advanced considerably and is now a more complete and, arguably, more effective process. This new therapeutic paradigm, referred to as damage control resuscitation (DCR), differs considerably in many important respects from previous management strategies for catastrophic blood loss. We review several important elements of DCR including immediate correction of specific coagulopathies induced by hemorrhage and management of several extreme homeostatic imbalances that may appear in the aftermath of resuscitation. We also emphasize that the foremost objective in managing exsanguinating hemorrhage is always expedient and definitive control of the source of bleeding.

Prehospital identification of trauma patients with early acute coagulopathy and massive bleeding: results of a prospective non-interventional clinical trial evaluating the Trauma Induced Coagulopathy Clinical Score (TICCS)

Introduction

Identifying patients who need damage control resuscitation (DCR) early after trauma is pivotal for adequate management of their critical condition. Several trauma-scoring systems have been developed to identify such patients, but most of them are not simple enough to be used in prehospital settings in the early post-traumatic phase. The Trauma Induced Coagulopathy Clinical Score (TICCS) is an easy-to-measure and strictly clinical trauma score developed to meet this medical need.

Methods

TICCS is a 3-item clinical score (range: 0 to 18) based on the assessment of general severity, blood pressure and extent of body injury and calculated by paramedics on-site for patients with severe trauma. This non-interventional prospective study was designed to assess the ability of TICCS to discern patients who need DCR. These patients were patients with early acute coagulopathy of trauma (EACT), haemorrhagic shock, massive transfusion and surgical or endovascular haemostasis during hospitalization. Diagnosis of EACT was assessed by both thromboelastometry and conventional coagulation tests.

Results

During an 18-month period, 89 severe trauma patients admitted to the general emergency unit at our hospital were enrolled in the study, but 7 were excluded for protocol violations. Of the 82 remaining patients, 8 needed DCR and 74 did not. With receiver operating characteristic curve analysis, TICCS proved to be a powerful discriminant test (area under the curve = 0.98; 95% CI: 0.92 to 1.0). A cutoff of 10 on the TICCS scale provided the best balance between sensitivity (100%; 95% CI: 53.9 to 100) and specificity (95.9%; 95% CI: 88.2 to 99.2). The positive predictive value was 72.7%, and the negative predictive value was 100.0%.

Conclusion

TICCS can be easily and rapidly measured by paramedics at the trauma site. In this study of blunt trauma patients, TICCS was able to discriminate between patients with and without need for DCR. TICCS on-site evaluation should allow initiation of optimal care immediately upon hospital admission of patients with severe trauma in need of DCR. However, a larger multicentre prospective study is needed for in-depth validation of TICCS.

Trial registration

Clinicaltrials.gov ID: NCT02132208 (registered 6 May 2014)

Low level of procoagulant platelet microparticles is associated with impaired coagulation and transfusion requirements in trauma patients

BACKGROUND

Following activation, platelets release small vesicles called platelet-derived microparticles (PMPs). PMPs accelerate thrombin generation and thus clot formation at sites of injury by exposing the procoagulant membrane phospholipid phosphatidylserine (PS). The role of PMPs in coagulopathy and hemorrhage following trauma remains elusive. We hypothesized that low levels of PS-positive PMPs (PS + PMPs) would be associated with impaired clot formation.

METHODS

This is a prospective observational study of 210 trauma patients admitted directly to a Level 1 trauma center. Plasma levels of PS + PMPs were determined by flow cytometry. Coagulation status was assessed by rotational thrombelastometry, and impaired clot formation was defined by an α angle less than 63 degrees using the tissue factor-based EXTEM reagent. Transfusion requirement was assessed by number of units of red blood cells (RBCs) transfused within 24 hours of admission; platelet aggregation capacity was evaluated by the Multiplate assay; and injury severity was determined by the Injury Severity Score (ISS).

RESULTS

The median ISS was 17, and blood samples were obtained after a median of 65 minutes following injury. Significantly lower levels of PS + PMPs were found in patients with impaired clot formation (p < 0.001). A low level of PS + PMPs was associated with a higher number of RBCs transfused during the initial 24 hours after admission (p < 0.03) when corrected for risk factors, for example, platelet count, hemoglobin level, and ISS. Platelet aggregation and PS + PMPs did not correlate significantly.

CONCLUSION

Low levels of PMPs were associated with impaired clot formation in trauma patients at admission and also with the number of RBC transfusions. This suggests that PMPs may play an important and not previously investigated role in trauma-induced coagulopathy.

LEVEL OF EVIDENCE

Prognostic study, level III.

Redefining massive transfusion when every second counts

BACKGROUND

The massive transfusion (MT) concept (>10-U packed red blood cells per 24 hours) is retrospective, arbitrary, and prone to survivor bias. Accounting for rate and timing is a more accurate conceptual framework. We redefined MT as a critical administration threshold (CAT) of 3 U/h, which is clinically pertinent and reflects hemorrhagic shock. The purpose of this study was to compare the traditional form of MT to a CAT definition in predicting mortality.

METHODS

Patients receiving transfusion in the first 24 hours were included. Precise transfusion times for each unit, in minutes, were calculated from time of injury. MT and CAT were compared to determine risk of death. Univariate and multivariate analyses were used to examine inpatient mortality.

RESULTS

A total of 169 patients(70%, >10 New Injury Severity Score [NISS]) were studied; 46% were CAT+; 22% met the MT criteria. With logistic regression, a CAT of 3 U/h (CAT+) was more predictive of death compared with 2, 4, 5, or 6 U/h. CAT was met once (CAT 1), twice (CAT 2) or more than 3 times (CAT 3) in 21%, 14%, and 11%, respectively. Increasing CAT was associated with increased mortality. CAT identified 75% of all deaths; MT only identified 33% and failed to identify 42% of CAT+ deaths. CAT (relative risk [RR] 3.58; 95% confidence interval [CI] 1.80-7.15) had a stronger association with mortality compared with MT(RR, 1.82; 95% confidence interval, 1.02-3.26).

CONCLUSION

The traditional definition of MT is inadequate to reflect illness severity. Using CATs allows prospective identification of critically ill trauma patients and eliminates survivor bias. CAT may serve as an activation trigger for transfusion protocols, allowing early identification of patients with critical transfusion requirements. Clinical trials involving transfusion strategies should consider CAT as an instrument for evaluating outcomes.

LEVEL OF EVIDENCE

Diagnostic/prognostic study, level II.

The acute coagulopathy of trauma: mechanisms and tools for risk stratification

Trauma remains the leading cause of death, with bleeding as the primary cause of preventable mortality. When death occurs, it happens quickly, typically within the first 6 h after injury. The principal drivers of the acute coagulopathy of trauma have been characterized, but another group of patients with early evidence of coagulopathy both physiologically and mechanistically distinct from this systemic acquired coagulopathy has been identified. This distinct phenotype is present in 25% to 30% of patients with major trauma without being exposed to the traditional triggers and is associated with higher morbidity and a 4-fold increase in mortality. Despite improvements in the resuscitation of exsanguinating patients, one of the remaining keys is to expeditiously and reproducibly identify the patients most likely to require transfusion including massive transfusion with damage control resuscitation principles. Several predictive scoring systems/algorithms for transfusion including massive transfusion in both civilian and military trauma populations have been introduced. The models developed usually suggest combinations of physiologic, hemodynamic, laboratory, injury severity, and demographic triggers identified on the initial evaluation. Many use a combination of dichotomous variables that are readily accessible after the patient's arrival to the trauma bay, but others rely on time-consuming mathematical calculations and may thus have limited real-time application. Weighted and more sophisticated systems including higher numbers of variables perform superiorly. A common limitation to all models is their retrospective nature, and prospective validations are needed. Point-of-care viscoelastic testing may be an alternative to early recognize trauma-induced coagulopathy with the risk of ongoing hemorrhage and transfusion.

A systematic review of the relationship between blood loss and clinical signs

INTRODUCTION

This systematic review examines the relationship between blood loss and clinical signs and explores its use to trigger clinical interventions in the management of obstetric haemorrhage.

METHODS

A systematic review of the literature was carried out using a comprehensive search strategy to identify studies presenting data on the relationship of clinical signs & symptoms and blood loss. Methodological quality was assessed using the STROBE checklist and the general guidelines of MOOSE.

RESULTS

30 studies were included and five were performed in women with pregnancy-related haemorrhage (other studies were carried in non-obstetric populations). Heart rate (HR), systolic blood pressure (SBP) and shock index were the parameters most frequently studied. An association between blood loss and HR changes was observed in 22 out of 24 studies, and between blood loss and SBP was observed in 17 out of 23 studies. An association was found in all papers reporting on the relationship of shock index and blood loss. Seven studies have used Receiver Operating Characteristic Curves to determine the accuracy of clinical signs in predicting blood loss. In those studies the AUC ranged from 0.56 to 0.74 for HR, from 0.56 to 0.79 for SBP and from 0.77 to 0.84 for shock index. In some studies, HR, SBP and shock index were associated with increased mortality.

CONCLUSION

We found a substantial variability in the relationship between blood loss and clinical signs, making it difficult to establish specific cut-off points for clinical signs that could be used as triggers for clinical interventions. However, the shock index can be an accurate indicator of compensatory changes in the cardiovascular system due to blood loss. Considering that most of the evidence included in this systematic review is derived from studies in non-obstetric populations, further research on the use of the shock index in obstetric populations is needed.

Defining when to initiate massive transfusion: a validation study of individual massive transfusion triggers in PROMMTT patients

BACKGROUND

Early predictors of massive transfusion (MT) would prevent undertriage of patients likely to require MT. This study validates triggers using the Prospective Observational Multicenter Major Trauma Transfusion (PROMMTT) study.

METHODS

All enrolled patients in PROMMTT were analyzed. The initial emergency department value for each trigger (international normalized ratio [INR], systolic blood pressure, hemoglobin, base deficit, positive result for Focused Assessment for the Sonography of Trauma examination, heart rate, temperature, and penetrating injury mechanism) was compared for patients receiving MT (≥ 10 U of packed red blood cells in 24 hours) versus no MT. Adjusted odds ratios (ORs) for MT are reported using multiple logistic regression. If all triggers were known, a Massive Transfusion Score (MTS) was created, with 1 point assigned for each met trigger.

RESULTS

A total of 1,245 patients were prospectively enrolled with 297 receiving an MT. Data were available for all triggers in 66% of the patients including 67% of the MTs (199 of 297). INR was known in 87% (1,081 of 1,245). All triggers except penetrating injury mechanism and heart rate were valid individual predictors of MT, with INR as the most predictive (adjusted OR, 2.5; 95% confidence interval, 1.7-3.7). For those with all triggers known, a positive INR trigger was seen in 49% receiving MT. Patients with an MTS of less than 2 were unlikely to receive MT (negative predictive value, 89%). If any two triggers were present (MTS ≥ 2), sensitivity for predicting MT was 85%. MT was present in 33% with an MTS of 2 greater compared with 11% of those with MTS of less than 2 (OR, 3.9; 95% confidence interval, 2.6-5.8; p < 0.0005).

CONCLUSION

Parameters that can be obtained early in the initial emergency department evaluation are valid predictors for determining the likelihood of MT.

LEVEL OF EVIDENCE

Diagnostic, level II.

Debunking the survival bias myth: characterization of mortality during the initial 24 hours for patients requiring massive transfusion

BACKGROUND

Controversy surrounds the optimal ratios of blood (packed red blood cell [PRBC]), plasma (fresh frozen plasma [FFP]) and platelet (PLT) use for patients requiring massive transfusion (MT) owing to possible survival bias in previous studies. We sought to characterize mortality during the first 24 hours while controlling for time varying effects of transfusion to minimize survival bias.

METHODS

Data were obtained from a multicenter prospective cohort study of adults with blunt injury and hemorrhagic shock. MT was defined as 10 U of PRBC or more over 24 hours. High FFP/PRBC (≥1:1.5) and PLT/PRBC (≥1:9) ratios at 6, 12, and 24 hours were compared with low ratio groups. Cox proportional hazards regression was used to determine the independent association of high versus low ratios with mortality at 6, 12, and 24 hours while controlling for important confounders. Cox proportional hazards regression was repeated with FFP/PRBC and PLT/PRBC ratios analyzed as time-dependent covariates to account for fluctuation over time. Mortality for more than 24 hours was treated as survival.

RESULTS

In the MT cohort (n = 604), initial base deficit, lactate, and international normalized ratio were similar across high and low ratio groups. High 6-hour FFP/PRBC and PLT/PRBC ratios were independently associated with a reduction in mortality risk at 6, 12, and 24 hours (hazard ratio [HR] range, 0.20-0.41, p < 0.05). These findings were consistent for 12-hour and 24-hour ratios. When analyzed as time-dependent covariates, a high FFP/PRBC ratio was associated with a 68% (HR, 0.32; 95% confidence interval [CI], 0.12-0.87, p = 0.03) reduction in 24-hour mortality, and a high PLT/PRBC ratio was associated with a 96% (HR, 0.04; 95% CI, 0.01-0.94, p = 0.04) reduction in 24-hour mortality. Subgroup analysis revealed that a high 1:1 ratio (≥1:1.5) had a significant 24-hour survival benefit relative to a high 1:2 (1:1.51-1:2.50) ratio group at both 6 hours (HR, 0.19; 95% CI, 0.03-0.86, p = 0.03) and 24 hours (HR, 0.25; 95% CI, 0.06-0.95, p = 0.04), suggesting a dose-response relationship. A high FFP/PRBC or PLT/PRBC ratio was not associated with development of multiple-organ failure, nosocomial infection, or adult respiratory distress syndrome in a 28-day Cox proportional hazards regression.

CONCLUSION

Despite similar degrees of early shock and coagulopathy, high FFP/PRBC and PLT/PRBC ratios are associated with a survival benefit as early as 6 hours and throughout the first 24 hours, even when time-dependent fluctuations of component transfusion are accounted for. This suggests that the observed mortality benefit associated with high component transfusion ratios is unlikely owing to survivor bias and that early attainment of high transfusion ratios may significantly lower the risk of mortality in MT patients.