Immediate screening method for predicting the necessity of massive transfusions in trauma patients: a retrospective single-center study

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 mortality in trauma patients: a systematic review and meta-analysis

PURPOSE

The primary aim was to determine whether a shock index (SI) ≥ 1 in adult trauma patients was associated with increased in-hospital mortality compared to an SI < 1.

METHODS

This systematic review including a meta-analysis was performed in accordance with the PRISMA guidelines. EMBASE, MEDLINE, and Cochrane Library were searched, and two authors independently screened articles, performed the data extraction, and assessed risk of bias. Studies were included if they reported in-hospital, 30-day, or 48-h mortality, length of stay, massive blood transfusion or ICU admission in trauma patients with SI recorded at arrival in the emergency department or trauma center. Risk of bias was assessed using the Newcastle-Ottawa Scale, and the strength and quality of the body of evidence according to GRADE. Data were pooled using a random effects model. Inter-rater reliability was assessed with Cohen's kappa.

RESULTS

We screened 1350 citations with an inter-rater reliability of 0.90. Thirty-eight cohort studies were included of which 14 reported the primary outcome. All studies reported a significant higher in-hospital mortality in adult trauma patients with an SI ≥ 1 compared to those having an SI < 1. Twelve studies involving a total of 348,687 participants were included in the meta-analysis. The pooled risk ratio (RR) of in-hospital mortality was 4.15 (95% CI 2.96-5.83). The overall quality of evidence was low.

CONCLUSIONS

This systematic review found a fourfold increased risk of in-hospital mortality in adult trauma patients with an initial SI ≥ 1 in the emergency department or trauma center.

Association of acidosis with coagulopathy and transfusion requirements in liver transplantation

The relationship between acidosis and coagulopathy has long been described in vitro and in trauma patients, but not yet in orthotopic liver transplantation (OLT). The association of metabolic acidosis with coagulopathy and with transfusion requirements was evaluated in patients submitted to OLT. Changes in acid-base and coagulation parameters were analyzed by repeated measures. Regression analyses [adjusted for sex, age, model for end stage liver disease (MELD) score, and baseline values of hemoglobin, fibrinogen, international normalized ratio, platelets] determined the association of acid-base parameters with coagulation markers and transfusion requirement. We included 95 patients, 66% were male, 49.5% of the patients had hepatocellular carcinoma and the mean MELD score was 20.4 (SD 8.9). The values of all the coagulation and acid-base parameters significantly changed during OLT, particularly in the reperfusion phase. After adjustments for baseline parameters, the decrease in pH and base excess (BE) values were associated with a decrease in fibrinogen levels (mean decrease of fibrinogen level = 14.88 mg/dL per 0.1 unit reduction of pH values and 3.6 mg/dL per 1 mmol/L reduction of BE levels) and an increase in red blood cells transfusion (2.16 units of RBC per 0.1 unit reduction of pH and 0.38 units of RBC per 1 mmol/L reduction of BE levels). Among multiple factors potentially associated with adverse outcomes, decreasing pH levels were independently associated with the length of hospitalization but not with in-hospital mortality. Metabolic acidosis is independently associated with decreased fibrinogen levels and increased intraoperative transfusion requirement during OLT. Awareness of that association may improve treatment strategies to reduce intraoperative bleeding risk in OLT.

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.

Higher enhanced computed tomography attenuation value of the aorta is a predictor of massive transfusion in blunt trauma patients

Objective

Several scoring systems have been developed to identify patients who require massive transfusion (MT) after major trauma to improve survival. The primary goal of this study was to investigate the usefulness of enhanced computed tomography attenuation values (CTAVs) of major vessels to determine the need for MT in patients with major blunt trauma.

Methods

This single-center retrospective cohort study evaluated patients aged 16 years or older who underwent contrast-enhanced computed tomography scan of the torso after major blunt trauma. The CTAVs of six major vessel points in both the arterial and portal venous phases at initial computed tomography examination were assessed and compared between the MT and the no MT group. The capability of enhanced CTAVs to predict the necessity for MT was estimated based on the area under the receiver operating characteristic curve.

Results

Of the 254 eligible patients, 36 (14%) were in the MT group. Patients in the MT group had significantly higher CTAVs at all sites except the inferior vena cava in both the arterial and portal venous phases than that in the no MT group. The descending aorta in the arterial phase had the highest accuracy for predicting MT, with an AUROC of 0.901 (95% confidence interval, 0.855 to 0.947; P<0.001).

Conclusion

Initial elevation of enhanced CTAV of the aorta is a predictor for the need for MT. A higher CTAV of the aorta should alert the trauma surgeon or emergency physician to activate their MT protocol.

Handheld Tissue Oximetry for the Prehospital Detection of Shock and Need for Lifesaving Interventions: Technology in Search of an Indication?

Improved prehospital methods for assessing the need for lifesaving interventions (LSIs) are needed to gain critical lead time in the care of the injured. We hypothesized that threshold values using prehospital handheld tissue oximetry would detect occult shock and predict LSI requirements. This was a prospective observational study of adult trauma patients emergently transported by helicopter. Patients were monitored with a handheld tissue oximeter (InSpectra Spot Check; Hutchinson Technology Inc, Hutchinson, MN), continuous vital signs, and 21 laboratory measurements obtained both in the field with a portable analyzer and at the time of admission. Shock was defined as base excess ≥ 4 or lactate > 3 mmol/L. Eighty-eight patients were enrolled with a median Injury Severity Score of 16 (interquartile range, 5-29). The median hemoglobin saturation in the capillaries, venules, and arterioles (StO₂) value for all patients was 82% (interquartile range, 76%-87%; range, 42%-98%). StO₂ was abnormal (< 75%) in 18 patients (20%). Eight were hypotensive (9%) and had laboratory-confirmed evidence of occult shock. StO₂ correlated poorly with shock threshold laboratory values (r = -0.17; 95% confidence interval, -0.33 to 1.0; P = .94). The area under the receiver operating curve was 0.51 (95% confidence interval, 0.39-0.63) for StO₂ < 75% and laboratory-confirmed shock. StO₂ was not associated with LSI need on admission when adjusted for multiple covariates, nor was it independently associated with death. Handheld tissue oximetry was not sensitive or specific for identifying patients with prehospital occult shock. These results do not support prehospital StO₂ monitoring despite its inclusion in several published guidelines.

Initial inferior vena cava diameter predicts massive transfusion requirements in blunt trauma patients: A retrospective cohort study

OBJECTIVES

The inferior vena cava (IVC) diameter is associated with shock and increased mortality in trauma patients. However, there are no reports examining the association between the IVC diameter and massive transfusion (MT) requirements in trauma patients. The aim of this study was to evaluate the association between IVC diameter and MT requirements in patients with blunt trauma.

METHODS

We retrospectively reviewed all patients who were consecutively hospitalized with blunt trauma (Injury Severity Score [ISS] ≥16) between from November 1, 2011 to March 30, 2016. Univariate and multivariate analyzes were performed to identify the independent predictors of MT (defined as >10units of red cell concentrate transfusions within 24h of admission). Receiver operating characteristic curve and the area under the curve (AUC) were estimated.

RESULTS

Of the 222 patients included in this study, MT occurred in 22.5% patients. On multiple regression analysis, IVC diameter [Odds ratio (OR), 0.88; 95% confidence interval (CI), 0.80-0.96; p<0.01], fibrin degradation product (FDP; OR, 1.01; 95% CI, 1.00-1.01; p<0.01), and fibrinogen level (OR, 0.99; 95% CI, 0.98-1.00; p<0.01) were strong predictors of MT. IVC diameter demonstrated moderate accuracy (AUC, 0.74; cutoff level, 13.0mm; sensitivity, 67%; specificity, 73%). Combined cutoff levels of FDP <80.5μg/ml, fibrinogen ≥165mg/dl, and IVC diameter ≥13mm could also determine how unnecessary a MT was with 100% accuracy.

CONCLUSIONS

Initial IVC diameter is a predictor of MT in blunt trauma patients.

Outcomes after concomitant traumatic brain injury and hemorrhagic shock: A secondary analysis from the Pragmatic, Randomized Optimal Platelets and Plasma Ratios trial

BACKGROUND

Often the clinician is faced with a diagnostic and therapeutic dilemma in patients with concomitant traumatic brain injury (TBI) and hemorrhagic shock (HS), as rapid deterioration from either can be fatal. Knowledge about outcomes after concomitant TBI and HS may help prioritize the emergent management of these patients. We hypothesized that patients with concomitant TBI and HS (TBI + HS) had worse outcomes and required more intensive care compared with patients with only one of these injuries.

METHODS

This is a post hoc analysis of the Pragmatic, Randomized Optimal Platelets and Plasma Ratios (PROPPR) trial. TBI was defined by a head Abbreviated Injury Scale score greater than 2. HS was defined as a base excess of -4 or less and/or shock index of 0.9 or greater. The primary outcome for this analysis was mortality at 30 days. Logistic regression, using generalized estimating equations, was used to model categorical outcomes.

RESULTS

Six hundred seventy patients were included. Patients with TBI + HS had significantly higher lactate (median, 6.3; interquartile range, 4.7-9.2) compared with the TBI group (median, 3.3; interquartile range, 2.3-4). TBI + HS patients had higher activated prothrombin times and lower platelet counts. Unadjusted mortality was higher in the TBI + HS (51.6%) and TBI (50%) groups compared with the HS (17.5%) and neither group (7.7%). Adjusted odds of death in the TBI and TBI + HS groups were 8.2 (95% confidence interval, 3.4-19.5) and 10.6 (95% confidence interval, 4.8-23.2) times higher, respectively. Ventilator, intensive care unit-free and hospital-free days were lower in the TBI and TBI + HS groups compared with the other groups. Patients with TBI + HS or TBI had significantly greater odds of developing a respiratory complication compared with the neither group.

CONCLUSION

The addition of TBI to HS is associated with worse coagulopathy before resuscitation and increased mortality. When controlling for multiple known confounders, the diagnosis of TBI alone or TBI+HS was associated with significantly greater odds of developing respiratory complications.

LEVEL OF EVIDENCE

Prognostic study, level II.

A Derivation and Validation Study of an Early Blood Transfusion Needs Score for Severe Trauma Patients

Background

There is no existing adequate blood transfusion needs determination tool that Emergency Medical Services (EMS) personnel can use for prehospital blood transfusion initiation. In this study, a simple and pragmatic prehospital blood transfusion needs scoring system was derived and validated.

Methods

Local trauma registry data were reviewed retrospectively from 2004 through 2013. Patients were randomly assigned to derivation and validation cohorts. Multivariate logistic regression was used to identify the independent approachable risks associated with early blood transfusion needs in the derivation cohort in which a scoring system was derived. Sensitivity, specificity, and area under the receiver operational characteristic (AUC) were calculated and compared using both the derivation and validation data.

Results

A total of 24,303 patients were included with 12,151 patients in the derivation and 12,152 patients in the validation cohorts. Age, penetrating injury, heart rate, systolic blood pressure, and Glasgow coma scale (GCS) were risks predictive of early blood transfusion needs. An early blood transfusion needs score was derived. A score > 5 indicated risk of early blood transfusion need with a sensitivity of 83% and a specificity of 80%. A sensitivity of 82% and a specificity of 80% were also found in the validation study and their AUC showed no statistically significant difference (AUC of the derivation = 0.87 versus AUC of the validation = 0.86, P > 0.05).

Conclusions

An early blood transfusion scoring system was derived and internally validated to predict severe trauma patients requiring blood transfusion during prehospital or initial emergency department resuscitation.

Fibrinogen and base excess levels as predictive markers of the need for massive blood transfusion after blunt trauma

Background

Assessment blood consumption and trauma-associated severe hemorrhage scores are useful for predicting the need for massive transfusion (MT) in severe trauma patients. However, fibrinogen (Fbg) and base excess (BE) levels might also be useful indicators for the need for MT. We evaluated the accuracy of prediction for MT of the scoring system vs. Fbg and BE.

Methods

The subjects of this retrospective single center observational study were patients with injury severity score ≥16 trauma, divided into a non-MT group and an MT group. We compared variables, including the scoring system (comprising vital signs and focused assessment with sonography for trauma; FAST) and Fbg between the groups. We then performed a multiple logistic regression modeling and a receiver operating characteristic analysis to clarify which value was the most useful predictive indicator for MT.

Results

There were 114 patients in the non-MT group and 39 in the MT group. The level of Fbg and BE were independent predictors of MT. The area under the curve values for Fbg and BE were 0.765 and 0.845, respectively, and the optimal cutoff values of Fbg and BE were 211 mg/dL and −1.4, respectively.

Conclusions

Fbg and BE levels can be used as an independent predictor for MT.