The utility of a shock index ≥ 1 as an indication for pre-hospital oxygen carrier administration in major trauma

Factors affecting physicians' decision to start prehospital blood product transfusion in blunt trauma patients: A cohort study of Helsinki Trauma Registry

BACKGROUND

Prehospital blood transfusions are increasing as a treatment for bleeding trauma patients at risk for exsanguination. Triggers for starting transfusion in the field are less studied. We analyzed the factors affecting the decision of physicians to start prehospital blood product transfusion (PHBT) in blunt adult trauma patients.

STUDY DESIGN AND METHODS

Data of all adult blunt trauma patients from the Helsinki Trauma Registry between March 2016 and July 2021 were retrospectively analyzed. Univariate analysis for the identification of predictive factors and multivariate regression analysis for their importance as predictive factors for the initiation of PHBT were applied.

RESULTS

There were 1652 patients registered in the database. A total of 556 of them were treated by a physician-level prehospital emergency care unit, of which by transfusion-capable unit in 394 patients. PHBT (red blood cells and/or plasma) was started in 19.8% of the patients. We identified three statistically highly important clinical triggers for starting PHBT: high crystalloid volume need, shock index ≥0.9, and need for prehospital pleural decompression.

DISCUSSION

PHBT in blunt adult trauma patients is initiated in ~20% of the patients in Southern Finland. High crystalloid volume need, shock index ≥0.9 and prehospital pleural decompression are associated with the initiation of PHBT, probably reflecting patients at high risk for bleeding.

Blood lactate after pre-hospital blood transfusion for major trauma by helicopter emergency medical services

BACKGROUND AND OBJECTIVES

The appropriate use of blood components is essential for ethical use of a precious, donated product. The aim of this study was to report in-hospital red blood cell (RBC) transfusion after pre-hospital transfusion by helicopter emergency medical service paramedics. A secondary aim was to assess the potential for venous blood lactate to predict ongoing transfusion.

MATERIALS AND METHODS

All patients who received RBC in air ambulance were transported to a single adult major trauma centre, had venous blood lactate measured on arrival and did not die before ability to transfuse RBC were included. The association of venous blood lactate with ongoing RBC transfusion was assessed using multi-variable logistic regression analysis and reported using adjusted odds ratios (aOR). The discriminative ability of venous blood lactate was assessed using area under receiver operating characteristics curve (AUROC).

RESULTS

From 1 January 2016 to 15 May 2019, there were 165 eligible patients, and 128 patients were included. In-hospital transfusion occurred in 97 (75.8%) of patients. Blood lactate was associated with ongoing RBC transfusion (aOR: 2.00; 95% confidence interval [CI]: 1.36-2.94). Blood lactate provided acceptable discriminative ability for ongoing transfusion (AUROC: 0.78; 95% CI: 0.70-0.86).

CONCLUSIONS

After excluding patients with early deaths, a quarter of those who had prehospital RBC transfusion had no further transfusion in hospital. Venous blood lactate appears to provide value in identifying such patients. Lactate levels after pre-hospital transfusion could be used as a biomarker for transfusion requirement after trauma.

Shock index as predictor of massive transfusion and mortality in patients with trauma: a systematic review and meta-analysis

BACKGROUND

Management of bleeding trauma patients is still a difficult challenge. Massive transfusion (MT) requires resources to ensure the safety and timely delivery of blood products. Early prediction of MT need may be useful to shorten the time process of blood product preparation. The primary aim of this study was to assess the accuracy of shock index to predict the need for MT in adult patients with trauma. For the same population, we also assessed the accuracy of SI to predict mortality.

METHODS

This systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. We performed a systematic search on MEDLINE, Scopus, and Web of Science from inception to March 2022. Studies were included if they reported MT or mortality with SI recorded at arrival in the field or the emergency department. The risk of bias was assessed using the QUADAS-2.

RESULTS

Thirty-five studies were included in the systematic review and meta-analysis, for a total of 670,728 patients. For MT the overall sensibility was 0.68 [0.57; 0.76], the overall specificity was 0.84 [0.79; 0.88] and the AUC was 0.85 [0.81; 0.88]. Positive and Negative Likelihood Ratio (LR+; LR-) were 4.24 [3.18-5.65] and 0.39 [0.29-0.52], respectively. For mortality the overall sensibility was 0.358 [0.238; 0.498] the overall specificity 0.742 [0.656; 0.813] and the AUC 0.553 (confidence region for sensitivity given specificity: [0.4014; 0.6759]; confidence region for specificity given sensitivity: [0.4799; 0.6332]). LR+ and LR- were 1.39 [1.36-1.42] and 0.87 [0.85-0.89], respectively.

CONCLUSIONS

Our study demonstrated that SI may have a limited role as the sole tool to predict the need for MT in adult trauma patients. SI is not accurate to predict mortality but may have a role to identify patients with a low risk of mortality.

Longitudinal analysis of neutrophil-to-lymphocyte ratio over time after major trauma

Background

The neutrophil-to-lymphocyte ratio has been proposed as a marker of systemic inflammation in major trauma patients that is associated with in-hospital mortality. However, the initial neutrophil-to-lymphocyte ratio does not appear to be predictive of in-hospital mortality. The aim of this study is to determine the discriminative ability of the neutrophil-to-lymphocyte ratio profile over 48 h as a predictor of in-hospital mortality following major trauma.

Methods

This was a case-control study involving all major trauma patients meeting the criteria for inclusion into the Alfred Health Trauma Registry who presented directly from the scene of injury over a 24-month period. Patients were then divided into two groups, cases being major trauma patients who died at hospital discharge and controls being patients who survived. We extracted data for Day 0, Day 1 and Day 2 neutrophil-to-lymphocyte ratio values for each patient. The primary outcome was mortality at hospital discharge.

Results

Data were extracted for 1689 major trauma patients, of which 72% were male, the median age was 49 years (IQR 31–68) and most (90%) patients presented after a blunt mechanism of injury. There were 165 cases that were compared to 1524 controls. Patients who died were older ( p < 0.001), and had higher injury severity scores ( p < 0.001) and lower revised trauma scores ( p < 0.001). Analysis of response profiles demonstrated a significant difference between the trajectories of the neutrophil-to-lymphocyte ratio over time ( p < 0.001).

Conclusions

The profile of neutrophil-to-lymphocyte ratio over 48 h after injury shows promise as a prognostic tool in trauma and warrants further investigation.

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.

Tranexamic acid for major trauma patients in Ireland

BACKGROUND

The Clinical Randomisation of an Anti-fibrinolytic in Significant Hemorrhage-2 (CRASH-2) is the largest randomized control trial (RCT) examining circulatory resuscitation for trauma patients to date and concluded a statistically significant reduction in all-cause mortality in patients administered tranexamic acid (TXA) within 3 hours of injury. Since the publication of CRASH-2, significant geographical variance in the use of TXA for trauma patients exists. This study aims to assess TXA use for major trauma patients with hemorrhagic shock in Ireland after the publication of CRASH-2.

METHODS

A retrospective cohort study was conducted using data derived from the Trauma Audit and Research Network (TARN). All injured patients in Ireland between January 2013 and December 2018 who had evidence of hemorrhagic shock on presentation (as defined by systolic blood pressure [SBP] <100 mmHg [1 mmHg=0.133 kPa] and administration of blood products) were eligible for inclusion. Death at hospital discharge was the primary outcome.

RESULTS

During the study period, a total of 234 patients met the inclusion criteria. Among injured patients presenting with hemorrhagic shock, 133 (56.8%; 95% confidence interval [CI] 50.2%-63.3%) received TXA. Of patients that received TXA, a higher proportion of patients presented with shock index >1 (70.68% vs.57.43%) and higher Injury Severity Score (ISS >25; 49.62% vs. 23.76%). Administration of TXA was not associated with mortality at hospital discharge (odds ratio [OR] 0.86, 95% CI 0.31-2.38).

CONCLUSIONS

Among injured Irish patients presenting with hemorrhagic shock, TXA was administered to 56.8% of patients. Patients administered with TXA were on average more severely injured. However, a mortality benefit could not be demonstrated.

Outcomes of Trauma Patients Present to the Emergency Department with a Shock Index of ≥1.0

Introduction

The study aimed primarily to evaluate the association between the initial shock index (SI) ≥1.0 with blood transfusion requirement in the emergency department (ED) after acute trauma. The study's secondary aim was to look at the outcomes regarding patients' disposition from ED, intensive care unit (ICU) and hospital length of stay, and deaths.

Methods

It was a retrospective, cross-sectional study and utilized secondary data from the Saudi Trauma Registry (STAR) between September 2017 and August 2020. We extracted the data related to patient demographics, mechanism of injuries, the intent of injuries, mode of arrival at the hospital, characteristics on presentation to ED, length of stay, and deaths from the database and compared between two groups of SI <1.0 and SI ≥1.0. A P < 0.05 was statistically considered significant.

Results

Of 6667 patients in STAR, 908 (13.6%) had SI ≥1.0. With SI ≥1.0, there was a significantly higher incidence of blood transfusion in ED compared to SI <1.0 (8.9% vs. 2.4%, P < 0.001). Furthermore, SI ≥ 1.0 was associated with significant ICU admission (26.4% vs. 12.3%, P < 0.001), emergency surgical intervention (8.5% vs. 2.8%, P < 0.001), longer ICU stay (5.0 ± 0.36 vs. 2.2 ± 0.11days, P < 0.001), longer hospital stays (14.8 ± 0.61 vs. 13.3 ± 0.24 days, P < 0.001), and higher deaths (8.4% vs. 2.8%, P < 0.001) compared to the patient with SI <1.0.

Conclusions

In our cohort, a SI ≥ 1.0 on the presentation at the ED carried significantly worse outcomes. This simple calculation based on initial vital signs may be used as a screening tool and therefore incorporated into initial assessment protocols to manage trauma patients.

Monitoring the tissue perfusion during hemorrhagic shock and resuscitation: tissue-to-arterial carbon dioxide partial pressure gradient in a pig model

Background

Despite much evidence supporting the monitoring of the divergence of transcutaneous partial pressure of carbon dioxide (tcPCO₂) from arterial partial pressure carbon dioxide (artPCO₂) as an indicator of the shock status, data are limited on the relationships of the gradient between tcPCO₂ and artPCO₂ (tc-artPCO₂) with the systemic oxygen metabolism and hemodynamic parameters. Our study aimed to test the hypothesis that tc-artPCO₂ can detect inadequate tissue perfusion during hemorrhagic shock and resuscitation.

Methods

This prospective animal study was performed using female pigs at a university-based experimental laboratory. Progressive massive hemorrhagic shock was induced in mechanically ventilated pigs by stepwise blood withdrawal. All animals were then resuscitated by transfusing the stored blood in stages. A transcutaneous monitor was attached to their ears to measure tcPCO₂. A pulmonary artery catheter (PAC) and pulse index continuous cardiac output (PiCCO) were used to monitor cardiac output (CO) and several hemodynamic parameters. The relationships of tc-artPCO₂ with the study parameters and systemic oxygen delivery (DO₂) were analyzed.

Results

Hemorrhage and blood transfusion precisely impacted hemodynamic and laboratory data as expected. The tc-artPCO₂ level markedly increased as CO decreased. There were significant correlations of tc-artPCO₂ with DO₂ and COs (DO₂: r = − 0.83, CO by PAC: r = − 0.79; CO by PiCCO: r = − 0.74; all P < 0.0001). The critical level of oxygen delivery (DO_2crit) was 11.72 mL/kg/min according to transcutaneous partial pressure of oxygen (threshold of 30 mmHg). Receiver operating characteristic curve analyses revealed that the value of tc-artPCO₂ for discrimination of DO_2crit was highest with an area under the curve (AUC) of 0.94, followed by shock index (AUC = 0.78; P < 0.04 vs tc-artPCO₂), and lactate (AUC = 0.65; P < 0.001 vs tc-artPCO₂).

Conclusions

Our observations suggest the less-invasive tc-artPCO₂ monitoring can sensitively detect inadequate systemic oxygen supply during hemorrhagic shock. Further evaluations are required in different forms of shock in other large animal models and in humans to assess its usefulness, safety, and ability to predict outcomes in critical illnesses.

Prehospital Hemorrhage Assessment Criteria: A Concise Review

OBJECTIVE

Early assessment of the clinical status of trauma patients is crucial for guiding the treatment strategy, and it requires a rapid and systematic approach. The aim of this report is to critically review the assessment parameters currently used in the prehospital setting to quantify blood loss in trauma.

DATA SOURCES

Studies regarding hemorrhagic shock in trauma were pooled from PubMed, EMBASE, and Cochrane databases using key words such as "hemorrhagic shock," "vital signs evaluation," "trauma," "blood loss," and "emergency medical service," alone or combined.

STUDY SELECTION

Articles published since 2009 in English and Italian were considered eligible if containing data on assessment parameters in blood loss in adults.

DATA EXTRACTION

Sixteen articles matching the inclusion criteria were considered in our study.

DATA SYNTHESIS

Current prehospital assessment measures lack precise correlation with blood loss.

CONCLUSIONS

Traditional assessment parameters such as heart rate, systolic blood pressure, shock index, and Glasgow Coma Scale score often lag in providing accurate blood loss assessment. The current literature supports the need for a noninvasive, continuously monitored assessment parameter to identify early shock in the prehospital setting.

Association of the neutrophil–lymphocyte ratio to patient outcomes after trauma: A systematic review

Introduction

Early identification of trauma injury severity is important for prognostication. The neutrophil–lymphocyte ratio (NLR) has been proposed as a marker of systemic inflammation in major trauma patients that is associated with in-hospital mortality. The aim of this systematic review is to compile all the best evidence available to determine the prognostic capabilities of the NLR in trauma and to assess the NLR as a predictor of mortality in adult major trauma patients. Additionally, comparing NLR and hospital length of stay (LOS), ICU LOS, mechanical ventilation and transfusion requirements.

Methods

We conducted a search of online information sources to identify manuscripts observing the NLR in adult major trauma patients. Outcomes of interest include mortality as defined by the author, hospital LOS, ICU LOS, mechanical ventilation and transfusion requirements. Quality was assessed using the Newcastle–Ottawa Scale. We aimed to conduct a meta-analysis if there were sufficient manuscripts included.

Results

Eight studies fulfilled our inclusion criteria. Trials were of good methodological quality. Substantial heterogeneity present between the studies prevented a meta-analysis from being conducted. Overall, five studies demonstrated the NLR as a significantly predictive marker of mortality. NLR was observed to be significantly associated with increased ICU LOS and longer duration of mechanical ventilation. Mixed results were observed between NLR and hospital LOS and transfusion requirements.

Conclusions

A potential association between NLR and mortality, ICU LOS and duration of mechanical ventilation has been reported. However, clinical utility of this measure during trauma resuscitation remains unknown.

A Simple Cardiovascular Model for the Study of Hemorrhagic Shock

Hemorrhagic shock is the number one cause of death on the battlefield and in civilian trauma as well. Mathematical modeling has been applied in this context for decades; however, the formulation of a satisfactory model that is both practical and effective has yet to be achieved. This paper introduces an upgraded version of the 2007 Zenker model for hemorrhagic shock termed the ZenCur model that allows for a better description of the time course of relevant observations. Our study provides a simple but realistic mathematical description of cardiovascular dynamics that may be useful in the assessment and prognosis of hemorrhagic shock. This model is capable of replicating the changes in mean arterial pressure, heart rate, and cardiac output after the onset of bleeding (as observed in four experimental laboratory animals) and achieves a reasonable compromise between an overly detailed depiction of relevant mechanisms, on the one hand, and model simplicity, on the other. The former would require considerable simulations and entail burdensome interpretations. From a clinical standpoint, the goals of the new model are to predict survival and optimize the timing of therapy, in both civilian and military scenarios.

Utility of triage shock index in predicting patient outcome in calcium channel blocker poisoning

Introduction:

Shock index is defined as heart rate divided by systolic blood pressure. It is reported as a predictor of morbidity and mortality in trauma and acute myocardial infarction in previous studies. It may be valuable in evaluation of calcium channel blocker poisoning. The objective of this study is to examine the probability of serious outcome based on first measured shock index in patients who presented to emergency department with calcium channel blocker poisoning.

Methods:

A retrospective chart review was conducted on calcium channel blocker poisoning cases in Hong Kong Poison Information Centre from 1 July 2008 to 30 June 2017. Shock index was calculated with blood pressure and pulse measurement at emergency department triage. Odds ratios of various variables for major outcome, mortality, intensive care unit admission, length of stay in acute hospital were calculated by multivariate analysis or negative binomial regression where appropriate. The performance of shock index in predicting major outcome was evaluated with receiver operating characteristic curve.

Results:

A total of 390 cases were identified, of whom 25.1% developed major outcome and 5.6% died. Shock index showed significant association with major outcome (odds ratio: 17.017, 95% confidence interval: 5.521–52.455). The area under the receiver operating characteristic curve for shock index in predicting major outcome was 0.7008 (95% confidence interval: 0.64–0.76).

Conclusion:

Higher shock index is associated with worse patient outcome in calcium channel blocker poisoning. However, shock index alone is not reliable in predicting patient outcome. Further research is needed before shock index can be incorporated for use in patient management in poisoning with calcium channel blocker or other anti-hypertensives.

The ratio of shock index to pulse oxygen saturation predicting mortality of emergency trauma patients

OBJECTIVE

To test the following hypothesis: the ratio of shock index to pulse oxygen saturation can better predict the mortality of emergency trauma patients than shock index.

METHODS

1723 Patients of trauma admitted to the Emergency Department of the First Affiliated Hospital of Soochow University from 1 November 2016 to 30 November 2019 were retrospectively evaluated. We defined SS as the ratio of SI to SPO2, and the mortality of trauma patients in the emergency department as end-point of outcome. We calculated the crude HR of SS and adjusted HR with the adjustment for risk factors including sex, age, revised trauma score (RTS) by Cox regression model. ROC curve analyses were performed to compare the area under the curve (AUC) of SS and SI.

RESULTS

The crude HR of SS was: 4.31, 95%CI (2.89-6.42) and adjusted HR: 3.01, 95%CI(1.86-4.88); ROC curve analyses showed that AUC of SS was higher than that of shock index (SI), and the difference was statistically significant: 0.69, 95%CI(0.55-0.83) vs 0.65, 95%CI (0.51-0.79), P = 0.001.

CONCLUSION

The ratio of shock index to pulse oxygen saturation is good predictor for emergency trauma patients, which has a better prognostic value than shock index.

Comparisons of Trauma Outcomes and Injury Severity Score

Trauma is a global health problem and a leading cause of mortality. One of the major predictors of trauma mortality is the Injury Severity Score (ISS). Theoretically, as the ISS increases, the probability of survival decreases; ISS = 75 is considered to be not survivable. Studies have shown that some deaths are preventable and some potentially preventable. Hemorrhagic shock is a potentially preventable cause of trauma mortality. A retrospective database review was conducted of the Mississippi Trauma Registry and point-by-serial correlational analyses were conducted to determine the direction of any significant relations between blood product usage, traditional vital signs, and shock index. Pearson correlation, logistic regressions, and odds ratio calculation results revealed that shock index can signal impending hemorrhagic compromise better than traditional vital signs; thus, facilitating early intervention, specifically, as heart rate and shock index increase, the use of blood products increases, and as blood pressure increases, the use of blood products decreases. Independent t tests for shock index and ISS revealed significant differences in the means with relationship to the subgroups "Dead" and "Alive." Higher ISS were found to correlate with higher shock indices. Evaluation of ISS and survivability demonstrates that ISS = 75 is survivable and should not lead one to reflexively assume otherwise. A total mortality finding of only 1.58% (n = 2,010) was unexpected but very encouraging.

The use of the shock index to predict hemodynamic collapse in hypotensive sepsis patients: A cross-sectional analysis

Objectives:

Septic shock, defined as sepsis with hypotension not responding to fluid resuscitation or requiring vasopressor support, results in the worst outcomes in sepsis patients. This subtype of the patient is often difficult to detect. The shock index (SI) has demonstrated the potential for predicting hemodynamic compromise and collapse and predicting patient outcomes in multiple medical and surgical settings. In our study, we assessed the utility of the SI as a hemodynamic screening tool to identify patients likely to fail to respond to fluids and ultimately to be diagnosed with septic shock.

Methodology:

A single-center cross-sectional analysis of patients presenting with hypotension and septicemia over 1 year. The study was conducted using the electronic medical records of the emergency department patients presenting to King Saud University Medical City. The charts were reviewed from 2 May 2015 to 24 April 2016 using the local medical registry. The study was approved by the hospital institutional review board (IRB). Data extraction was performed using a standardized form.

Results:

The area under the curve was 0.77 (P < 0.001) for the prediction of hemodynamic collapse. An initial SI ≥0.875 had a sensitivity of 81% and a specificity of 72% for the identification of patients in whom fluid resuscitation would fail.

Conclusions:

Based on our findings, we found that the SI was a reliable screening tool for the identification of hypotensive patients with sepsis who would ultimately be diagnosed with septic shock.

Reverse shock index multiplied by Glasgow Coma Scale (rSIG) predicts mortality in severe trauma patients with head injury

The reverse shock index (rSI), a ratio of systolic blood pressure (SBP) to heart rate (HR), is used to identify prognosis in trauma patients. Multiplying rSI by Glasgow Coma Scale (rSIG) can possibly predict better in-hospital mortality in patients with trauma. However, rSIG has never been used to evaluate the mortality risk in adult severe trauma patients (Injury Severity Score [ISS] ≥ 16) with head injury (head Abbreviated Injury Scale [AIS] ≥ 2) in the emergency department (ED). This retrospective case control study recruited adult severe trauma patients (ISS ≥ 16) with head injury (head AIS ≥ 2) who presented to the ED of two major trauma centers between January 01, 2014 and May 31, 2017. Demographic data, vital signs, ISS scores, injury mechanisms, laboratory data, managements, and outcomes were included for the analysis. Logistic regression and receiver operating characteristic analysis were used to evaluate the accuracy of rSIG score in predicting in-hospital mortality. In total, 438 patients (mean age: 56.48 years; 68.5% were males) were included in this study. In-hospital mortality occurred in 24.7% patients. The median (interquartile range) ISS score was 20 (17-26). Patients with rSIG ≤ 14 had seven-fold increased risks of mortality than those without rSIG ≤ 14 (odds ratio: 7.64; 95% confidence interval: 4.69-12.42). Hosmer-Lemeshow goodness-of-fit test and area under the curve values for rSIG score were 0.29 and 0.76, respectively. The sensitivity, specificity, positive predictive value, and negative predictive values of rSIG ≤ 14 were 0.71, 0.75, 0.49, and 0.89, respectively. The rSIG score is a prompt and simple tool to predict in-hospital mortality among adult severe trauma patients with head injury.

Pre-hospital modified shock index for prediction of massive transfusion and mortality in trauma patients

BACKGROUND

Modified shock index (MSI) is a useful predictor in trauma patients. However, the value of prehospital MSI (preMSI) in trauma patients is unknown. The aim of this study was to investigate the accuracy of preMSI in predicting massive transfusion (MT) and hospital mortality among trauma patients.

METHODS

This was a retrospective, observational, single-center study. Patients presenting consecutively to the trauma center between January 2016 and December 2017, were included. The predictive ability of both prehospital shock index (preSI) and preMSI for MT and hospital mortality was assessed by calculating the areas under the receiver operating characteristic curves (AUROCs).

RESULTS

A total of 1007 patients were included. Seventy-eight (7.7%) patients received MT, and 30 (3.0%) patients died within 24 h of admission to the trauma center. The AUROCs for predicting MT with preSI and preMSI were 0.773 (95% confidence interval [CI], 0.746-0.798) and 0.765 (95% CI, 0.738-0.791), respectively. The AUROCs for predicting 24-hour mortality with preSI and preMSI were 0.584 (95% CI, 0.553-0.615) and 0.581 (95% CI, 0.550-0.612), respectively.

CONCLUSIONS

PreSI and preMSI showed moderate accuracy in predicting MT. PreMSI did not have higher predictive power than preSI. Additionally, in predicting hospital mortality, preMSI was not superior to preSI.

Feasibility study for implementation of resuscitative balloon occlusion of the aorta in peri-arrest, exsanguinating trauma at an adult level 1 Australian trauma centre

OBJECTIVE

This prospective, observational, interventional study sought to determine if the introduction of resuscitative balloon occlusion of the aorta (REBOA) at an Australian adult major trauma centre would improve survival for major trauma patients.

METHODS

Patients aged 18-60 years, transported directly from scene with exsanguinating, sub-diaphragmatic haemorrhage and hypovolaemic shock (systolic BP <70 mmHg or hypovolaemic cardiac arrest) were eligible for recruitment and followed up until hospital discharge (ACTRN12618000550202).

RESULTS

During the 14-month study period (17 January 2015 to 12 March 2016) 3032 patients were admitted direct from scene with an overall mortality of 97 (3.71%). Of these patients 3019 had trauma centre vital signs recorded in the data set (99.57%) and 1523 were between the ages of 18-60, including 143 patients with a shock index of >1.0 (4.74%). There were 13 (0.43%) patients with a systolic BP <70 mmHg and/or cardiorespiratory arrest on arrival. The mortality in this group was six out of 13 (46.15%). Of these 13 patients, there were two (0.07% of the total cohort) where REBOA was attempted. There were no eligible patients for whom REBOA was achieved. None of the six patients who died would have benefited from REBOA deployment.

CONCLUSIONS

Despite considerable training and resource allocation to ensure 24-h availability, the introduction of REBOA failed to effectively demonstrate any impact on patient outcome. Despite retrospective literature supporting the introduction of REBOA, in this 14-month prospective study there was no evidence of benefit. Further studies may define indications and subgroups of patients who may benefit.

Optimal Hemodynamic Parameter to Predict the Neurological Outcome in Out-of-Hospital Cardiac Arrest Survivors Treated with Target Temperature Management

Current guidelines suggest the maintenance of systolic blood pressure (SBP) at >90 mmHg and mean arterial pressure (MAP) at >65 mmHg in postcardiac arrest patients. There remains a lack of clarity regarding optimal values and timing of blood pressure parameters associated with the improvement of neurologic outcome. We investigated the association of time-weighted average (TWA) blood pressure parameters with favorable neurological outcome (FO) in postcardiac arrest patients. This was a registry-based observational study with consecutive adult out-of-hospital cardiac arrest (OHCA) survivors who were treated using targeted temperature management (TTM). During 72 hours of TTM period, we abstracted hemodynamic parameters such as SBP, diastolic blood pressure, pulse rate (PR), and MAP. Shock index (SI; PR/SBP) and modified shock index (MSI; PR/MAP) were calculated from each measured hemodynamics. Logistic regression was performed to assess the associations between TWA blood pressure parameters and FO, defined as cerebral performance category 1 or 2 at hospital discharge. Among the 173 patients (median age: 58 years; 64% male), 51 (29.3%) had FO in this study. MAP, SI, and MSI at 6 hours after return of spontaneous circulation (ROSC) showed considerable differences in patients with FO (MAP: 89.1 ± 14.7 vs. 83.6 ± 15.8 mmHg, p = 0.033, SI: 0.7 ± 0.2 vs. 0.9 ± 0.9, p = 0.002, MSI: 1.0 ± 0.3 vs. 1.2 ± 0.3, p ≤ 0.001). Among them, MSI, especially at 6 hours, had the highest area under the curve for prediction of FO (0.685; 95% confidence interval: 0.597-0.772, p < 0.001). Also, MSI <1.0 had a sensitivity of 64.7%, a specificity of 64.2% to predict FO. In comatose survivors of OHCA with TTM, MSI at 6 hours after ROSC had the highest prognostic value for neurologic outcome among blood pressure parameters.

Can the shock index be a reliable predictor of early mortality after trauma in older patients? A retrospective cohort study

Aim

Older patients have different physiological characteristics; thus, the reliability of the shock index (SI) to predict mortality could depend on age. We investigated whether the SI is a reliable predictor of early mortality in older patients and evaluated the clinical benefit of age in the interpretation of the SI.

Methods

Using data from the Japan Trauma Data Bank, we identified injured patients aged 20–84 years. Area under the receiver operating characteristic curve (AUC) was used to evaluate the discrimination ability of the SI to predict early mortality. A formula to determine the cut‐off for each age was derived using linear regression analysis. Performance of the new method was compared with that of the traditional SI cut‐off of ≥0.9 AUC.

Results

We analyzed data from 146,802 patients. Early mortality was observed in 4% of patients. The AUC showed a significant negative correlation with age (Spearman's ρ = –0.97, P < 0.001), and it decreased from 0.788 (95% confidence interval [CI], 0.761–0.815) in the 20–24 years age group to 0.660 (95% CI, 0.643–0.676) in those aged 80–84 years. By adjusting for age in the SI interpretation, AUC significantly improved from 0.681 (95% CI, 0.675–0.688) to 0.695 (95% CI, 0.688–0.701) (P < 0.001).

Conclusions

The performance of the SI to predict mortality after trauma was significantly worse in older patients. Even if the SI cut‐off value was adjusted based on age, the decrease in performance was not sufficiently prevented. Our results indicated that clinicians should be cautious when using the SI in older patients.

The Reverse Shock Index Multiplied by Glasgow Coma Scale Score (rSIG) and Prediction of Mortality Outcome in Adult Trauma Patients: A Cross-Sectional Analysis Based on Registered Trauma Data

The reverse shock index (rSI) multiplied by Glasgow Coma Scale (GCS) score (rSIG), calculated by multiplying the GCS score with systolic blood pressure (SBP)/hear rate (HR), was proposed to be a reliable triage tool for identifying risk of in-hospital mortality in trauma patients. This study was designed to externally validate the accuracy of the rSIG in the prediction of mortality in our cohort of trauma patients, in comparison with those that were predicted by the Revised Trauma Score (RTS), shock index (SI), and Trauma and Injury Severity Score (TRISS). Adult trauma patients aged ≥20 years who were admitted to the hospital from 1 January 2009 to 31 December 2017, were included in this study. The rSIG, RTS, and SI were calculated according to the initial vital signs and GCS scores of patients upon arrival at the emergency department (ED). The end-point of primary outcome is in-hospital mortality. Discriminative power of each score to predict mortality was measured using area under the curve (AUC) by plotting the receiver operating characteristic (ROC) curve for 18,750 adult trauma patients, comprising 2438 patients with isolated head injury (only head Abbreviated Injury Scale (AIS) ≥ 2) and 16,312 without head injury (head AIS ≤ 1). The predictive accuracy of rSIG was significantly lower than that of RTS in all trauma patients (AUC 0.83 vs. AUC 0.85, p = 0.02) and in patients with isolated head injury (AUC 0.82 vs. AUC 0.85, p = 0.02). For patients without head injury, no difference was observed in the predictive accuracy between rSIG and RTS (AUC 0.83 vs. AUC 0.83, p = 0.97). Based on the cutoff value of 14.0, the rSIG can predict the probability of dying in trauma patients without head injury with a sensitivity of 61.5% and specificity of 94.5%. The predictive accuracy of both rSIG and RTS is significantly poorer than that of TRISS, in all trauma patients (AUC 0.93) or in patients with (AUC 0.89) and without head injury (AUC 0.92). In addition, SI had the significantly worse predictive accuracy than all of the other three models in all trauma patients (AUC 0.57), and the patients with (AUC 0.53) or without (AUC 0.63) head injury. This study revealed that rSIG had a significantly higher predictive accuracy of mortality than SI in all of the studied population but a lower predictive accuracy of mortality than RTS in all adult trauma patients and in adult patients with isolated head injury. In addition, in the adult patients without head injury, rSIG had a similar performance as RTS to the predictive risk of mortality of the patients.

Optimizing transfusion strategies in damage control resuscitation: current insights

From clinical and laboratory studies of specific coagulation defects induced by injury, damage control resuscitation (DCR) emerged as the most effective management strategy for hemorrhagic shock. DCR of the trauma patient who has sustained massive blood loss consists of 1) hemorrhage control; 2) permissive hypotension; and 3) the prevention and correction of trauma-induced coagulopathies, referred to collectively here as acute coagulopathy of trauma (ACOT). Trauma patients with ACOT have higher transfusion requirements, may eventually require massive transfusion, and are at higher risk of exsanguinating. Distinct impairments in the hemostatic system associated with trauma include acquired quantitative and qualitative platelet defects, hypocoagulable and hypercoagulable states, and dysregulation of the fibrinolytic system giving rise to hyperfibrinolysis or a phenomenon referred to as fibrinolytic shutdown. Furthermore, ACOT is a component of a systemic host defense dysregulation syndrome that bears several phenotypic features comparable with other acute systemic physiological insults such as sepsis, myocardial infarction, and postcardiac arrest syndrome. Progress in the science of resuscitation has been continuing at an accelerated rate, and clinicians who manage catastrophic blood loss may be incompletely informed of important advances that pertain to DCR. Therefore, we review recent findings that further characterize the pathophysiology of ACOT and describe the application of this new information to optimization of resuscitation strategies for the patient in hemorrhagic shock.

Improving Accuracy of Noninvasive Hemoglobin Monitors: A Functional Regression Model for Streaming SpHb Data

OBJECTIVE

The purpose of this paper is to develop a method for improving the accuracy of SpHb monitors, which are noninvasive hemoglobin monitoring tools, leading to better critical care protocols in trauma care.

METHODS

The proposed method is based on fitting smooth spline functions to SpHb measurements collected over a time window and then using a functional regression model to predict the true HgB value for the end of the time window.

RESULTS

The accuracy of the proposed method is compared to traditional methods. The mean absolute error between the raw SpHb measurements and the gold standard hemoglobin measurements was 1.26 g/Dl. The proposed method reduced the mean absolute error to 1.08 g/Dl. [1] Conclusion: Fitting a smooth function to SpHb measurements improves the accuracy of Hgb predictions.

SIGNIFICANCE

Accurate prediction of current and future HgB levels can lead to sophisticated decision models that determine the optimal timing and amount of blood product transfusions.

Identification of Pancreatic Injury in Patients with Elevated Amylase or Lipase Level Using a Decision Tree Classifier: A Cross-Sectional Retrospective Analysis in a Level I Trauma Center

Background: In trauma patients, pancreatic injury is rare; however, if undiagnosed, it is associated with high morbidity and mortality rates. Few predictive models are available for the identification of pancreatic injury in trauma patients with elevated serum pancreatic enzymes. In this study, we aimed to construct a model for predicting pancreatic injury using a decision tree (DT) algorithm, along with data obtained from a population-based trauma registry in a Level I trauma center. Methods: A total of 991 patients with elevated serum levels of amylase (>137 U/L) or lipase (>51 U/L), including 46 patients with pancreatic injury and 865 without pancreatic injury between January 2009 and December 2016, were allocated in a ratio of 7:3 to training (n = 642) or test (n = 269) sets. Using the data on patient and injury characteristics as well as laboratory data, the DT algorithm with Classification and Regression Tree (CART) analysis was performed based on the Gini impurity index, using the rpart function in the rpart package in R. Results: Among the trauma patients with elevated amylase or lipase levels, three groups of patients were identified as having a high risk of pancreatic injury, using the DT model. These included (1) 69% of the patients with lipase level ≥306 U/L; (2) 79% of the patients with lipase level between 154 U/L and 305 U/L and shock index (SI) ≥ 0.72; and (3) 80% of the patients with lipase level <154 U/L with abdomen injury, glucose level <158 mg/dL, amylase level <90 U/L, and neutrophil percentage ≥76%; they had all sustained pancreatic injury. With all variables in the model, the DT achieved an accuracy of 97.9% (sensitivity of 91.4% and specificity of 98.3%) for the training set. In the test set, the DT achieved an accuracy of 93.3%, sensitivity of 72.7%, and specificity of 94.2%. Conclusions: We established a DT model using lipase, SI, and additional conditions (injury to the abdomen, glucose level <158 mg/dL, amylase level <90 U/L, and neutrophils ≥76%) as important nodes to predict three groups of patients with a high risk of pancreatic injury. The proposed decision-making algorithm may help in identifying pancreatic injury among trauma patients with elevated serum amylase or lipase levels.

Resuscitation Resequenced: A Rational Approach to Patients with Trauma in Shock

Trauma resuscitation is a complex and dynamic process that requires a high-performing team to optimize patient outcomes. More than 30 years ago, Advanced Trauma Life Support was developed to formalize and standardize trauma care; however, the sequential nature of the algorithm that is used can lead to ineffective prioritization. An improved understanding of shock mandates an updated approach to trauma resuscitation. This article proposes a resequenced approach that (1) addresses immediate threats to life and (2) targets strategies for the diagnosis and management of shock causes. This updated approach emphasizes evidence-based resuscitation principles that align with physiologic priorities.

Utility of the Shock Index for Risk Stratification in Patients with Acute Upper Gastrointestinal Bleeding

OBJECTIVES

Patients with upper gastrointestinal bleeding (UGIB) frequently require hospitalization, and a small but significant percentage of these patients have adverse outcomes. Risk-scoring tools can help clinicians organize care and make predictions about outcomes. The shock index (heart rate divided by systolic blood pressure) has been used in multiple acute disorders and has the potential to identify patients with UGIB who are at risk for adverse outcomes.

METHODS

We retrospectively reviewed the electronic medical records of patients admitted with UGIB between January 1, 2012 and December 31, 2015. We collected information about patient demographics, presenting symptoms, underlying clinical disorders, endoscopic results, and outcomes. We calculated risk scores using the Glasgow-Blatchford score, the pre-endoscopy Rockall score, the full Rockall score, the AIMS65 (albumin, international normalized ratio, mental status, systolic blood pressure, age older than 65 years) score, and the shock index.

RESULTS

This study included 214 admissions for acute UGIB. The mean age was 59.0 ± 15.9 years, 64.5% were men, the mean hemoglobin was 9.2 ± 3.1 g/dL, and the mean shock index was 0.78 ± 0.21 bpm/mm Hg. The mean shock index was significantly increased in patients requiring endoscopic therapy, admission to the intensive care unit, blood component transfusion, and red blood cell transfusion. Classification of patients by a shock index >0.7 preferentially selected patients with these adverse short-term outcomes. Among the scoring tools evaluated in this study, the shock index was the best predictor of the need for endoscopic therapy.

CONCLUSIONS

The shock index is a good tool to identify patients with the potential for short-term adverse outcomes when they present with UGIB. It performs as well as other risk-scoring tools for GI bleeding and has the potential for serial use during hospitalization to identify changes in the clinical course.

Damage Control Resuscitation for Catastrophic Bleeding

The timely recognition of shock secondary to hemorrhage from severe facial trauma or as a complication of complex oral and maxillofacial surgery presents formidable challenges. Specific hemostatic disorders are induced by hemorrhage and several extreme homeostatic imbalances may appear during or after resuscitation. Damage control resuscitation has evolved from massive transfusion to a more complex therapeutic paradigm that includes hemodynamic resuscitation, hemostatic resuscitation, and homeostatic resuscitation. Definitive control of bleeding is the principal objective of any comprehensive resuscitation scheme for hemorrhagic shock.

Pelvic trauma mortality reduced by integrated trauma care

OBJECTIVES

A multidisciplinary approach that emphasised improved triage, early pelvic binder application, early administration of blood and blood products, adherence to algorithmic pathways, screening with focused sonography (FAST), early computed tomography scanning with contrast angiography, angio-embolisation and early operative intervention by specialist pelvic surgeons was implemented in the last decade to improve outcomes after pelvic trauma. The manuscript evaluated the effect of this multi-faceted change over a 12-year period.

METHODS

A retrospective cohort study was conducted comparing patients presenting with serious pelvic injury in 2002 to those presenting in 2013. The primary exposure and comparator variables were the year of presentation and the primary outcome variable was mortality at hospital discharge. Potential confounders were evaluated using multivariable logistic regression analysis.

RESULTS

There were 1213 patients with a serious pelvic injury (Abbreviated Injury Scale ≥3), increasing from 51 in 2002 to 156 in 2013. Demographics, injury severity and presenting clinical characteristics were similar between the two time periods. There was a statistically significant difference in mortality from 20% in 2002 to 7.7% in 2013 (P = 0.02). The association between the primary exposure variable of being injured in 2013 and mortality remained statistically significant (adjusted odds ratio 0.10; 95% confidence interval: 0.02-0.60) when adjusted for potential clinically important confounders.

CONCLUSIONS

Multi-faceted interventions directed at the spectrum of trauma resuscitation from pre-hospital care to definitive surgical management were associated with significant reduction in mortality of patients with severe pelvic injury from 2002 to 2013. This demonstrates the effectiveness of an integrated, inclusive trauma system in achieving improved outcomes.

The Clinical Efficacy of Fibrinogen Concentrate in Massive Obstetric Haemorrhage with Hypofibrinogenaemia

Massive obstetric haemorrhage remains a major cause of maternal death attributable to hypofibrinogenaemia. Transfusion of large volumes of fresh frozen plasma (FFP) is required to normalise fibrinogen levels. We compared the efficacy of FFP (F group) with that of FFP plus fibrinogen concentrate (F + F group) in massive obstetric haemorrhage. In this retrospective study, we compared the medical charts (2004–2016) of 137 patients with <150 mg/dl fibrinogen treated with F + F (n = 47; after August 2009) or F (n = 56; before August 2009). Although fibrinogen concentrate was only administered in severe cases, the FFP/red blood cell concentrate (RCC) ratio was significantly lower in the F + F group than in the F group. A sub-group analysis of cases requiring ≥18 RCC units showed that the F + F group received significantly less FFP than the F group (40.2 ± 19.6 versus 53.4 ± 18.5 units; P = 0.047) and showed significantly less pulmonary oedema (24.0% vs 57.1%; P < 0.05) in the absence of any significant differences in pre-transfusion coagulation, estimated blood loss, or RCC transfusion volume. Administration of fibrinogen concentrate increased the rate of fibrinogen supplementation five-fold and reduced FFP dosage, the FFP/RCC ratio, and the incidence of pulmonary oedema.

Plasma micro-RNA biomarkers for diagnosis and prognosis after traumatic brain injury: A pilot study

Prediction of post-concussive syndrome after apparent mild traumatic brain injury (TBI) and subsequent cognitive recovery remains challenging, with substantial limitations of current methods of cognitive testing. This pilot study aimed to determine if levels of micro ribonucleic acids (RNAs) circulating in plasma are altered following TBI, and if changes to levels of such biomarkers over time could assist in determination of prognosis after TBI. Patients were enrolled after TBI on presentation to the Emergency Department and allocated to three groups: A - TBI (physical trauma to the head), witnessed loss of consciousness, amnesia, GCS=15, a normal CT Brain and a recorded first pass after post-traumatic amnesia (PTA) scale; B TBI, witnessed LOC, amnesia, GCS=15, a normal CT brain and a PTA scale test fail and: C - TBI and initial GCS <13 on arrival to the ED. Venous blood was collected at three time points (arrival, day 5 and day 30). Isolation of cell-free total RNA was then assayed using a custom miRNA PCR array. Two micro-RNAs, mir142-3p and mir423-3p demonstrated potential clinical utility differentiating patients after mild head injury into those at greater risk of developing amnesia and therefore, post-concussive syndromes. In addition, these miRNA demonstrated a decrease in expression over time, possibly indicative of brain healing after the injury. Further evaluation of these identified miRNA markers with larger patient cohorts, correlation with clinical symptoms and analysis over longer time periods are essential next steps in developing objective markers of severity of TBI.

Validation of the Shock Index, Modified Shock Index, and Age Shock Index for Predicting Mortality of Geriatric Trauma Patients in Emergency Departments

The shock index (SI), modified shock index (MSI), and age multiplied by SI (Age SI) are used to assess the severity and predict the mortality of trauma patients, but their validity for geriatric patients is controversial. The purpose of this investigation was to assess predictive value of the SI, MSI, and Age SI for geriatric trauma patients. We used the Emergency Department-based Injury In-depth Surveillance (EDIIS), which has data from 20 EDs across Korea. Patients older than 65 years who had traumatic injuries from January 2008 to December 2013 were enrolled. We compared in-hospital and ED mortality of groups categorized as stable and unstable according to indexes. We also assessed their predictive power of each index by calculating the area under the each receiver operating characteristic (AUROC) curve. A total of 45,880 cases were included. The percentage of cases classified as unstable was greater among non-survivors than survivors for the SI (36.6% vs. 1.8%, P < 0.001), the MSI (38.6% vs. 2.2%, P < 0.001), and the Age SI (69.4% vs. 21.3%, P < 0.001). Non-survivors had higher median values than survivors on the SI (0.84 vs. 0.57, P < 0.001), MSI (0.79 vs. 1.14, P < 0.001), and Age SI (64.0 vs. 41.5, P < 0.001). The predictive power of the Age SI for in-hospital mortality was higher than SI (AUROC: 0.740 vs. 0.674, P < 0.001) or MSI (0.682, P < 0.001) in geriatric trauma patients.

Prediction of Massive Transfusion in Trauma Patients with Shock Index, Modified Shock Index, and Age Shock Index

Objectives: The shock index (SI) and its derivations, the modified shock index (MSI) and the age shock index (Age SI), have been used to identify trauma patients with unstable hemodynamic status. The aim of this study was to evaluate their use in predicting the requirement for massive transfusion (MT) in trauma patients upon arrival at the hospital. Participants: A patient receiving transfusion of 10 or more units of packed red blood cells or whole blood within 24 h of arrival at the emergency department was defined as having received MT. Detailed data of 2490 patients hospitalized for trauma between 1 January 2009, and 31 December 2014, who had received blood transfusion within 24 h of arrival at the emergency department, were retrieved from the Trauma Registry System of a level I regional trauma center. These included 99 patients who received MT and 2391 patients who did not. Patients with incomplete registration data were excluded from the study. The two-sided Fisher exact test or Pearson chi-square test were used to compare categorical data. The unpaired Student t-test was used to analyze normally distributed continuous data, and the Mann-Whitney U-test was used to compare non-normally distributed data. Parameters including systolic blood pressure (SBP), heart rate (HR), hemoglobin level (Hb), base deficit (BD), SI, MSI, and Age SI that could provide cut-off points for predicting the patients’ probability of receiving MT were identified by the development of specific receiver operating characteristic (ROC) curves. High accuracy was defined as an area under the curve (AUC) of more than 0.9, moderate accuracy was defined as an AUC between 0.9 and 0.7, and low accuracy was defined as an AUC less than 0.7. Results: In addition to a significantly higher Injury Severity Score (ISS) and worse outcome, the patients requiring MT presented with a significantly higher HR and lower SBP, Hb, and BD, as well as significantly increased SI, MSI, and Age SI. Among these, only four parameters (SBP, BD, SI, and MSI) had a discriminating power of moderate accuracy (AUC > 0.7) as would be expected. A SI of 0.95 and a MSI of 1.15 were identified as the cut-off points for predicting the requirement of MT, with an AUC of 0.760 (sensitivity: 0.563 and specificity: 0.876) and 0.756 (sensitivity: 0.615 and specificity: 0.823), respectively. However, in the groups of patients with comorbidities such as hypertension, diabetes mellitus, or coronary artery disease, the discriminating power of these three indices in predicting the requirement of MT was compromised. Conclusions: This study reveals that the SI is moderately accurate in predicting the need for MT. However, this predictive power may be compromised in patients with HTN, DM or CAD. Moreover, the more complex calculations of MSI and Age SI failed to provide better discriminating power than the SI.

The use of the reverse shock index to identify high-risk trauma patients in addition to the criteria for trauma team activation: a cross-sectional study based on a trauma registry system

OBJECTIVES

The presentation of decrease blood pressure with tachycardia is usually an indicator of significant blood loss. In this study, we used the reverse shock index (RSI), a ratio of systolic blood pressure (SBP) to heart rate (HR), to evaluate the haemodynamic status of trauma patients. As an SBP lower than the HR (RSI<1) may indicate haemodynamic instability, the objective of this study was to assess whether RSI<1 can help to identify high-risk patients with potential shock and poor outcome, even though these patients do not yet meet the criteria for multidisciplinary trauma team activation (TTA).

DESIGN

Cross-sectional study.

SETTING

Taiwan.

PARTICIPANTS

We retrospectively reviewed the data of 20 106 patients obtained from the trauma registry system of a level I trauma centre for trauma admissions from January 2009 through December 2014. Patients for whom a trauma team was not activated (regular patients) and who had RSI<1 were compared with regular patients with RSI≥1. The ORs of the associated conditions and injuries were calculated with 95% CIs.

MAIN OUTCOME MEASURES

In-hospital mortality.

RESULTS

Among regular patients with RSI<1, significantly more patients had an Injury Severity Score (ISS) ≥25 (OR 2.4, 95% CI 1.58 to 3.62; p<0.001) and the mortality rate was also higher (2.1% vs 0.5%; OR 3.9, 95% CI 2.10 to 7.08; p<0.001) than in regular patients with RSI≥1. The intensive care unit length of stay was longer in regular patients with RSI<1 than in regular patients with RSI≥1.

CONCLUSIONS

Among patients who did not reach the criteria for TTA, RSI<1 indicates a potentially worse outcome and a requirement for more attention and aggressive care in the emergency department.

Systolic Blood Pressure Lower than Heart Rate upon Arrival at and Departure from the Emergency Department Indicates a Poor Outcome for Adult Trauma Patients

BACKGROUND

Hemorrhage is a leading cause of preventable trauma death. In this study, we used the reverse shock index (RSI), a ratio of systolic blood pressure (SBP) to heart rate (HR), to evaluate the hemodynamic stability of trauma patients. As an SBP lower than the HR (RSI < 1) may indicate hemodynamic instability, the objective of this study was to assess the associated complications in trauma patients with an RSI < 1 upon arrival at the emergency department (ED) (indicated as (A)RSI) and at the time of departure from the ED (indicated as (L)RSI) to the operative room or for admission.

METHODS

Data obtained from all 16,548 hospitalized patients recorded in the trauma registry system at a Level I trauma center between January 2009 and December 2013 were retrospectively reviewed. A total of 10,234 adult trauma patients aged ≥20 were enrolled and subsequently divided into four groups: Group I, (A)RSI ≥ 1 and (L)RSI ≥ 1 (n = 9827); Group II, (A)RSI ≥ 1 and (L)RSI < 1 (n = 76); Group III, (A)RSI < 1 and (L)RSI ≥ 1 (n = 251); and Group IV, (A)RSI < 1 and (L)RSI < 1 (n = 80). Pearson's χ² test, Fisher's exact test, or independent Student's t-test was conducted to compare trauma patients in Groups II, III, and IV with those in Group I.

RESULTS

Patients in Groups II, III, and IV had a higher injury severity score and underwent a higher number of procedures, including intubation, chest tube insertion, and blood transfusion, than Group I patients. Additionally, patients of these groups had increased hospital length of stay (16.3 days, 14.9 days, and 22.0 days, respectively), proportion of patients admitted to the intensive care unit (ICU) (48.7%, 43.0%, and 62.5%, respectively), and in-hospital mortality (19.7%, 7.6%, and 27.5%, respectively). Although the trauma patients who had a SBP < 90 mmHg either upon arrival at or departure from the ED also present a more severe injury and poor outcome, those patients who had a SBP ≥ 90 mmHg but an RSI < 1 had a more severe injury and poor outcome than those patients who had a SBP ≥ 90 mmHg and an RSI ≥ 1.

CONCLUSIONS

SBP lower than heart rate (RSI < 1) either upon arrival at or departure from the ED may indicate a detrimental sign of poor outcome in adult trauma patients even in the absence of noted hypotension.

Using the Reverse Shock Index at the Injury Scene and in the Emergency Department to Identify High-Risk Patients: A Cross-Sectional Retrospective Study

BACKGROUND

The ratio of systolic blood pressure (SBP) to heart rate (HR), called the reverse shock index (RSI), is used to evaluate the hemodynamic stability of trauma patients. A SBP lower than the HR (RSI < 1) indicates the probability of hemodynamic shock. The objective of this study was to evaluate whether the RSI as evaluated by emergency medical services (EMS) personnel at the injury scene (EMS RSI) and the physician in the emergency department (ED RSI) could be used as an additional variable to identify patients who are at high risk of more severe injury.

METHODS

Data obtained from all 16,548 patients added to the trauma registry system at a Level I trauma center between January 2009 and December 2013 were retrospectively reviewed. Only patients transferred by EMS were included in this study. A total of 3715 trauma patients were enrolled and subsequently divided into four groups: group I patients had an EMS RSI ≥1 and an ED RSI ≥1 (n = 3485); group II an EMS RSI ≥ 1 and an ED RSI < 1 (n = 85); group III an EMS RSI < 1 and an ED RSI ≥ 1 (n = 98); and group IV an EMS RSI < 1 and a ED RSI < 1 (n = 47). A Pearson's χ² test, Fisher's exact test, or independent Student's t-test was conducted to compare trauma patients in groups II, III, and IV with those in group I.

RESULTS

Group II and IV patients had a higher injury severity score, a higher incidence of commonly associated injuries, and underwent more procedures (including intubation, chest tube insertion, and blood transfusion in the ED) than patients in group I. Group II and IV patients were also more likely to receive a severe injury to the thoracoabdominal area. These patients also had worse outcomes regarding the length of stay in hospital and intensive care unit (ICU), the proportion of patients admitted to ICU, and in-hospital mortality. Group II patients had a higher adjusted odds ratio for mortality (5.8-times greater) than group I patients.

CONCLUSIONS

Using an RSI < 1 as a threshold to evaluate the hemodynamic condition of the patients at the injury scene and upon arrival to the ED provides valid information regarding deteriorating outcomes for certain subgroups of patients in the ED setting. Particular attention and additional resources should be provided to patients with an EMS RSI ≥ 1 that deteriorates to an RSI < 1 upon arrival to the ED since a higher odds of mortality was found in these patients.

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.

Use of the reverse shock index for identifying high-risk patients in a five-level triage system

BACKGROUND

The ratio of systolic blood pressure (SBP) to heart rate (HR), called the reverse shock index (RSI), is used to evaluate the hemodynamic stability of trauma patients. To minimize undertriage in emergency departments (EDs), we evaluated whether RSI < 1 (i.e., SBP lower than HR) could be used as an additional variable to identify patients at high risk for more severe injury within a level category of the five-level Taiwan Triage and Acuity Scales (TTAS) system.

METHODS

Data obtained from the Trauma Registry System, including triage level according to the TTAS system, were retrospectively reviewed for trauma admissions from January 2009 through December 2013 in a Level I trauma center. In our study, the primary outcomes were injury severity as measured using different scoring systems, including the Glasgow coma scale (GCS), abbreviated injury scale scores, and the injury severity score (ISS), and in-hospital mortality. The secondary outcomes were hospital and intensive care unit (ICU) length of stay (LOS).

RESULTS

Of 10,814 trauma patients, 348 patients (3.2%) had RSI < 1, whereas 10,466 (96.8%) had RSI ≥ 1. Those with RSI < 1 had greater injury severity, a higher incidence of commonly associated injuries, lower GCS scores, greater deterioration of vital signs, and a higher incidence of procedures those with RSI ≥ 1. Patients with RSI < 1 also worse outcomes including hospital and ICU LOS, a greater frequency of ICU admission, and higher in-hospital mortality. Although the five-level TTAS system provides good prioritization of patients with major trauma, using the additional criterion of RSI < 1 could identify the patients at higher risk within the same triage level (I-III).

DISCUSSION

The alert of a trauma patient's SBP being lower than his/her HR (RSI < 1) without the requirement of any additional equipment makes the concept of RSI particularly valuable in crowded EDs for identifying high-risk patients. RSI < 1 may serve as a principle trigger for action in the ED to alert trauma surgeons to the need for early intervention and timely preparation upon patient arrival particularly for those patients triaged in levels II and III of the TTAS system.

CONCLUSIONS

RSI < 1 upon arrival at an ED is an alarming sign of an associated worse outcome. Within the same triage level from level I to level III, patients with RSI < 1 had worse outcomes than those with RSI ≥ 1. The inclusion of RSI in the TTAS system may help to identify patients with more serious injuries who need an upgraded management level.

Peritoneal Breach as an Indication for Exploratory Laparotomy in Penetrating Abdominal Stab Injury: Operative Findings in Haemodynamically Stable Patients

Introduction. Management of haemodynamically stable patients with penetrating abdominal injuries varies from nonoperative to operative management. The aim was to investigate whether peritoneal breach when used as an indication for exploratory laparotomy appropriately identified patients with intra-abdominal visceral injury. Methods. We conducted retrospective cohort study of all patients presenting with PAI at a major trauma centre from January 2007 to December 2011. We measured the incidence of peritoneal breach and correlated this with intra-abdominal visceral injury diagnosed at surgery. Results. 252 patients were identified with PAI. Of the included patients, 71 were managed nonoperatively and 118 operatively. The operative diagnoses included nonperitoneal-breaching injuries, intraperitoneal penetration without organ damage, or intraperitoneal injury with organ damage. The presenting trauma CT scan was reported as normal in 63%, 34%, and 2% of these groups, respectively. The total negative laparotomy/laparoscopy rate for all patients presented with PAI was 21%, almost half of whom had a normal CT scan. Conclusion. We found that peritoneal breach on its own does not necessarily always equate to intra-abdominal visceral injury. Observation with sequential examination for PAI patients with a normal CT scan may be more important than exclusion of peritoneal breach via laparoscopy.

Massive transfusion prediction with inclusion of the pre-hospital Shock Index

BACKGROUND

Detecting occult bleeding can be challenging and may delay resuscitation. The Shock Index (SI) defined as heart rate divided by systolic blood pressure has attracted attention. Prediction models using combinations of pre-hospital SI (phSI) and the trauma centre SI (tcSI) values may be effective in identifying patients requiring massive blood transfusions (MT).

AIM

To explore whether combinations of the phSI and the tcSI augment MT prediction.

METHODS

The scores were retrospectively developed using all major trauma patients that presented to The Alfred Hospital between 2006 and 2012. The first PH and TC observations were used. To avoid exclusion of the 'sickest' patients, the SI was imputed to 2 where SBP was missing, but HR was present. We developed 4 models. (i) 'Dichotomised', defined as positive when both phSI and tcSI were ≥1. (ii) 'Formulaic', defined by logistic regression analysis. (iii) 'Combination', defined pragmatically based on the logistic regression. (iv) 'Trending', defined as: tcSI minus phSI.

RESULTS

There were 6990 major trauma patients and 360 (5.2%) received MT. There were 1371 cases with either phSI or tcSI missing and were thus excluded from the analysis. The 'Dichotomised' had higher positive predictive value than the tcSI with a further 5 per 100 patients identified. The 'Formulaic' model, defined as: log Odds (MT)=2.16×tcSI+0.89×phSI-5.42, and the 'Combination' model, defined as: phSI×0.5+tcSI, performed equally (AUROC 0.83 versus 0.83, χ(2)=0.86, p=0.35). The 'Formulaic' performed marginally, but statistically significantly, more accurate than the tcSI alone (AUROC 0.83 versus 0.82, χ(2)=6.89, p<0.01). An 'Upward Trending' SI was observed in 1758 patients, revealing a 4.6-fold univariate association with MT (OR 4.55; 95%CI 2.64-7.83), and an AUROC of 0.79 (95%CI 0.74-0.83). The 'Downward Trending' SI was protective against MT (OR 0.44; 95%CI 0.34-0.57).

CONCLUSION

The initial pre-hospital SI is associated with MT. However, this relationship did not clinically augment MT decision when combined with the in-hospital SI. The simplicity of the SI makes it a favourable option to explore further. Computer-assisted technology in data capturing, analysis and prognostication presents avenues for further research.

'Big data' approaches to trauma outcome prediction and autonomous resuscitation

Massive clinical digital data routinely collected by high throughput biomedical devices provide opportunities and challenges for optimal use. This article discusses how such data are used in learning prediction models at level 1 trauma centres to support decision making in trauma patients.

Indications for blood transfusion following trauma - a pilot study

Background: Indications for blood transfusion during trauma resuscitation remain poorly understood. This study aimed to objectively determine the range of factors that lead to initiation of blood transfusion during trauma resuscitation. Design and method: This was a prospective, observational pilot study. A questionnaire was distributed to all clinicians following any transfusion of packed red blood cells during trauma resuscitation. The questionnaire focused on the clinicians’ opinion regarding the indication for red cell transfusion. Results: Complete data on 37 individual episodes of transfusion initiation in the Emergency Department were collected. The most commonly used pre-hospital factors that influenced initiation of transfusion was a pre-hospital systolic blood pressure (SBP) of < 100 mm Hg (65%), pre-hospital tachycardia (38%) or estimated blood loss of >1 L (30%) by paramedics. On arrival to hospital, the activation of a massive transfusion protocol was the commonest indication for transfusion, followed by a positive FAST examination (43%), low systolic blood pressure (35%), tachycardia (32%) or pallor (35%). Blood tests to guide initiation of transfusion were less commonly used with 9 (24%) patients transfused for a low haemoglobin level and 6 (16%) patients transfused for coagulopathy. Conclusions: A combination of objective pre- and in-hospital vital signs, together with subjective indicators such as pallor and estimation of blood loss guided initiation of transfusion following injury.

Potentially avoidable blood transfusion during trauma resuscitation

INTRODUCTION

Red blood cell (RBC) transfusion is often essential during trauma resuscitation but is associated with high cost and potential adverse outcomes. This study aimed to determine the incidence of potentially avoidable RBC transfusions (PAT) among adult major trauma patients.

MATERIALS AND METHODS

A retrospective review of data collected by <name blinded> Registry on patients presenting between Jan 2006 and Dec 2011 was conducted. Eligible patients received at least 1 unit of RBC in the first 24h following presentation to the Emergency Department (ED). Episodes of PAT were determined according to haemodynamic stability and post-transfusion haemoglobin levels.

RESULTS

There were 621 patients included, of whom 224 (36.1%; 95% CI: 32.3-40.0) received PAT. Of them, 132 (58.9%) were haemodynamically stable on arrival and did not require a surgical procedure. Patients with PAT had significantly lower injury severity scores (30 vs 34, p<0.01), higher presenting systolic blood pressure (129 vs 112mm Hg, p<0.01) and a lower frequency of a shock index ≥1 (24.1 vs 65.0%, p<0.01), compared to those without PAT. They also had a significantly lower mortality (13.4 vs 21.7%, p<0.01).

CONCLUSIONS

PAT after trauma was common and often delivered to haemodynamically stable patients who did not require surgical procedures. Clinical decision pathways for trauma resuscitation should aim to limit PAT.

Red blood cell storage duration and trauma

Numerous retrospective clinical studies suggest that transfusion of longer stored red blood cells (RBCs) is associated with an independent risk of poorer outcomes for certain groups of patients, including trauma, intensive care, and cardiac surgery patients. Large multicenter randomized controlled trials are currently underway to address the concern about RBC storage duration. However, none of these randomized controlled trials focus specifically on trauma patients with hemorrhage. Major trauma, particularly due to road accidents, is the leading cause of critical injury in the younger-than-40-year-old age group. Severe bleeding associated with major trauma induces hemodynamic dysregulation that increases the risk of hypoxia, coagulopathy, and potentially multiorgan failure, which can be fatal. In major trauma, a multitude of stress-associated changes occur to the patient's RBCs, including morphological changes that increase cell rigidity and thereby alter blood flow hemodynamics, particularly in the microvascular vessels, and reduce RBC survival. Initial inflammatory responses induce deleterious cellular interactions, including endothelial activation, RBC adhesion, and erythrophagocytosis that are quickly followed by profound immunosuppressive responses. Stored RBCs exhibit similar biophysical characteristics to those of trauma-stressed RBCs. Whether transfusion of RBCs that exhibit storage lesion changes exacerbates the hemodynamic perturbations already active in the trauma patient is not known. This article reviews findings from several recent nonrandomized studies examining RBC storage duration and clinical outcomes in trauma patients. The rationale for further research on RBC storage duration in the trauma setting is provided.