Pre-hospital shock index correlates with transfusion, resource utilization and mortality; The role of patient first vitals

Hyperkalaemia in bleeding trauma patients: A potential marker of disease severity - A retrospective cohort study

Background

Hyperkalaemia is a common electrolyte abnormality seen in critically ill patients. In haemorrhagic shock, it may contribute to cardiac arrest and has been identified as a potential marker for tissue hypoxia. However, the significance of its role in haemorrhagic shock and its contribution to mortality remains unclear. This study aimed to examine the potential underlying pathophysiology and evaluate the incidence and characteristics of patients with hyperkalaemia on hospital arrival in bleeding trauma patients before transfusions and its mortality.

Methods

A retrospective cohort study was conducted on adult patients with traumatic bleeding admitted to a European Major Trauma Centre between January 2016 and December 2021. Patients were classified according to their serum potassium levels on arrival, and relevant clinical parameters between non-hyperkalaemic and hyperkalaemic patients were compared.

Results

Among the 83 patients in this study, 8 (9.6 %) presented with hyperkalaemia on arrival. The median shock index showed a higher tendency in the hyperkalaemic group. Hyperkalaemia was found to be more common among younger patients who sustained penetrating trauma. Mortality rates were higher in the hyperkalaemic group, but the difference was not statistically significant.

Conclusion

Our results suggest that hyperkalaemia occurs frequently in bleeding trauma patients on hospital arrival pre-transfusions, indicating a more severe illness. Our findings provide insights into the pathophysiology and characteristics of hyperkalaemia in bleeding trauma patients. Further studies are required to investigate the mechanisms by which hyperkalaemia contributes to mortality in haemorrhagic shock patients.

The shock index predicts in-flight blood transfusion in aeromedical trauma patients

OBJECTIVE

To define the utility of the Triage Revised Trauma Score (TRTS), GCS/Age/arterial Pressure (GAP) score, and shock index (SI) in predicting the need for in-flight blood product administration in civilian trauma patients transported by an aeromedical platform.

METHODS

A retrospective chart review of 3582 aeromedical trauma cases was conducted. An initial TRTS, GAP score and SI were calculated for each patient, and the administration of in-flight blood products was also recorded. Receiver operating characteristic (ROC) curves were used to quantify the predictive discrimination of the TRTS, GAP score and SI on the need for in-flight blood product administration.

RESULTS

The SI showed a superior predictive value compared to the TRTS and GAP score. The SI showed an area under the curve on the ROC curve of 0.85 in both primary and inter-hospital transfer cases, indicating reasonable predictive value.

CONCLUSION

The SI demonstrates favourable test characteristics for predicting the need for in-flight blood product administration. Prospective validation of these results is warranted.

Sodium bicarbonate Ringer's solution for hemorrhagic shock: A meta-analysis comparing crystalloid solutions

BACKGROUND

The choice of fluid resuscitation in Traumatic Hemorrhagic shock (THS) remains a critical aspect of patient management. Bicarbonated Ringers solution (BRS) has shown promise due to its composition resembling human Extracellular Fluid and its potential benefits on hemodynamics.

OBJECTIVE

To evaluate the efficacy, mortality rates, hemodynamic effects, and adverse outcomes of Sodium Bicarbonate Ringer's Solution in the treatment of hemorrhagic shock, as compared to other relevant interventions.

METHOD

A comprehensive examination of the available literature was performed by conducting systematic searches in prominent databases such as Cochrane, EMBASE, MEDLINE, and PubMed. The process employed predefined criteria to extract relevant data and evaluate the quality of the studies. The outcome measures considered encompassed survival rates, mortality, mean arterial pressure (MAP), heart rate (HR), and adverse events.

RESULT

The meta-analysis of three studies showed that compared to the other crystalloids, the use of BRS had an odds ratio for survival of 1.86 (95% CI: 0.94, 3.71; p = 0.08; I2 = 0%), an odds ratio for total adverse events of 0.14 (95% CI: 0.06, 0.35; p < 0.0001; I2 = 22%), a mean difference in heart rate of -4.49 (95% CI: -7.55, -1.44; p = 0.004; I2 = 13%), and a mean difference in mean arterial pressure of 2.31 (95% CI: -0.85, 5.47; p = 0.15; I2 = 66%).

CONCLUSION

BRS demonstrated a significant reduction in complications, including adult respiratory distress syndrome (ARDS), Multiple Organ Dysfunction (MODS), and Total Adverse Effects, when compared to other solutions in the treatment of THS. Additionally, THS patients resuscitated with BRS experienced a notable decrease in heart rate. The findings suggest BRS may contribute to organ stability and potential survival improvement due to its similarity to human Extracellular Fluid and minimal impact on the liver.

Prehospital Time Following Traumatic Injury Is Independently Associated With the Need for In-Hospital Blood and Early Mortality for Specific Injury Types

OBJECTIVE

Treating traumatic hemorrhage is time sensitive. Prehospital care and transport modes (eg, helicopter and ground) may influence in-hospital events. We hypothesized that prehospital time (on-scene time [OST] and total prehospital time [TPT]) and transport mode are associated with same-day transfusion and mortality. Furthermore, we sought to identify regions of anatomic injury that modify the relationship between prehospital time and outcomes in strata corresponding to transport types.

METHODS

We obtained prehospital, in-hospital, and trauma registry data from an 8-center cohort of adult nonburn trauma patients from 2017 to 2022 directly transported from the scene to the hospital and having an Injury Severity Score (ISS) > 9 for the Task Order 1 project of the Linking Investigators in Trauma and Emergency Services research network. We excluded patients missing prehospital times, patients < 18 years of age, patients from interfacility transfers, and recipients of prehospital blood. Our same-day outcomes were in-hospital transfusions within 4 hours and 24-hour mortality. Each outcome was adjusted using multivariable logistic regression for covariates of prehospital phases (OST and TPT), mode of transport (helicopter and ground), age, sex, ISS, Glasgow Coma Scale motor subscale score < 6, and field hypotension (systolic blood pressure < 90 mm Hg). We evaluated the association of prehospital time on outcomes for scene missions by transport mode across severe injury patterns defined by Abbreviated Injury Scale > 2 body regions.

RESULTS

Of 78,198 subjects, 34,504 were eligible for the study with a mean age of 47.6 ± 20.3 years, ISS of 18 ± 11, OST of 15.9 ± 9.5 minutes, and TPT of 48.7 ± 20.3 minutes. Adjusted for injury severity and demographic factors, transport type significantly modified the relationship between prehospital time and outcomes. The association of OST and TPT with the odds of 4-hour transfusion was absent for the ground emergency medical services (GEMS) cohort and present for the helicopter emergency medical services (HEMS) ambulance cohort, whereas these times were associated with decreased 24-hour mortality for both transport types. When stratifying by injury to most anatomic regions, OST and TPT were associated with a decreased need for 4-hour transfusions in the GEMS cohort. However, OST was associated with increased early transfusion only among patients with severe injuries of the thorax, and this association persisted after adjusting additionally for injury type (odds ratio [OR] = 1.03; 95% confidence interval [CI], 1.00-1.05; P = .02). The presence of polytrauma supported an association between prehospital time and decreased 24-hour mortality for the GEMS cohort (OST: OR = 0.97; 95% CI, 0.95-0.99; P < .01; TPT: OR = 0.99; 95% CI, 0.98-0.99; P = .02), whereas no injuries showed significant association of helicopter prehospital time on mortality after adjustment.

CONCLUSION

We determined that transport type affects the relationship between prehospital time and hospital outcomes (4-hour transfusion: positive relationship for HEMS and negative for GEMS, 24-hour mortality: negative for both transport types). Furthermore, we identified regions of anatomic injury that modify the relationship between prehospital time and outcomes in strata corresponding to transport types. Of these regions, most notable were severe isolated injuries to the thorax that supported a positive relationship between HEMS OST and 4-hour transfusions and polytrauma that showed a negative relationship between GEMS OST or TPT and 24-hour mortality after adjustment.

Is a Positive Prehospital FAST Associated with Severe Bleeding? A Multicenter Retrospective Study

INTRODUCTION

Severe hemorrhage is the leading cause of early preventable death in severe trauma patients. Delayed diagnosis is a poor prognostic factor, and severe hemorrhage prediction is essential. The aim of our study was to investigate if there was an association between the detection of peritoneal or pleural fluid on prehospital sonography for trauma and posttraumatic severe hemorrhage.

METHODS

We retrospectively studied data from records of thoracic or abdominal trauma patients managed in mobile intensive care units from January 2017 to December 2021 in four centers in France. Severe hemorrhage was defined as a condition necessitating transfusion of at least four packed red blood cells or surgical intervention/radioembolization for hemostasis within the first 24 h. Using a multivariate analysis, we investigated the predictive performance of focused assessment with sonography for trauma (FAST) alone or in combination with the five Red Flags criteria validated by Hamada et al.

RESULTS

Among the 527 patients analyzed, 371 (71%) were men, the mean age was 41 ± 19 years, and the Injury Severity Score was 11 (Interquartile range = [5; 22]). Seventy-three (14%) patients had severe hemorrhage - of whom 28 (38%) had a positive FAST, compared to 61 (13%) without severe hemorrhage (p < 0.01). For severe hemorrhage prediction, FAST had a sensitivity of 38% (95%CI = [27%; 50%]) and a specificity of 87% (95%CI = [83%; 90%]) (AUC = 0.62, 95%CI = [0.57; 0.68]). The comparison of the other outcomes between positive and negative FAST was: hemostatic procedure, 22 (25%) vs 28 (6%), p < 0.01; intensive care unit admission 71 (80%) vs 190 (43%), p < 0.01; mean length of hospital stay 11 [4; 27] vs 4 [0; 14] days, p = 0.02; 30-day mortality 13 (15%) vs 22 (5%), p < 0.01.

CONCLUSION

A positive FAST performed in the prehospital setting is associated with severe hemorrhage and all prognostic criteria we studied.

Emergency Department Shock Index Outperforms Prehospital and Delta Shock Indices in Predicting Outcomes of Trauma Patients

INTRODUCTION

Multiple shock indices (SIs), including prehospital, emergency department (ED), and delta (ED SI - Prehospital SI) have been developed to predict outcomes among trauma patients. This study aims to compare the predictive abilities of these SIs for outcomes of polytrauma patients on a national level.

METHODS

This was a retrospective analysis of the American College of Surgeons Trauma Quality Improvement Program (2017-2018). We included adult (≥18 y) trauma patients and excluded patients who were transferred, had missing vital signs, and those with severe head injuries (Head-Abbreviated Injury Scale>3). Outcome measures were 24-h and in-hospital mortality, 24-h packed red blood cells transfusions, and intensive care unit and hospital length of stay. Predictive performances of these SIs were evaluated by the Area Under the Receiver Operating Characteristics for the entire study cohort and across all injury severities.

RESULTS

A total of 750,407 patients were identified. Meanstandard deviation age and lowest systolic blood pressure were 53 ± 21 y, and 81 ± 32 mmHg, respectively. Overall, 24-h and in-hospital mortality were 1.2% and 2.5%, respectively. On multivariable analysis, all three SIs were independently associated with higher rates of 24-h and in-hospital mortality, blood product requirements, intensive care unit and hospital length of stay (P < 0.001). ED SI was superior to prehospital and delta SIs (P < 0.001) for all outcomes. On subanalysis of patients with moderate injuries, severe injuries, and positive delta SI, the results remained the same.

CONCLUSIONS

ED SI outperformed both prehospital and delta SIs across all injury severities. Trauma triage guidelines should prioritize ED SI in the risk stratification of trauma patients who may benefit from earlier and more intense trauma activations.

Use of prehospital reverse shock index times Glasgow Coma Scale to identify children who require the most immediate trauma care

BACKGROUND

Appropriate prehospital trauma triage ensures transport of children to facilities that provide specialized trauma care. There are currently no objective and generalizable scoring tool for emergency medical services to facilitate such decisions. An abnormal reverse shock index times Glasgow Coma Scale (rSIG), which is calculated using readily available parameters, has been shown to be associated with severely injured children. This study sought to determine if rSIG could be used in the prehospital setting to identify injured children who require the highest levels of care.

METHODS

Patients (1-18 years old) transferred from the scene to a level 1 pediatric trauma center from 2010 to 2020 with complete prehospital and emergency department vital signs, and Glasgow Coma Scale (GCS) scores were included. Reverse shock index times GCS was calculated as previously described ((systolic blood pressure/heart rate) × GCS), and the following cutoffs were used: ≤13.1, ≤16.5, and ≤20.1 for 1- to 6-, 7- to 12-, and 13- to 18-year-old patients, respectively. Trauma activation level and clinical outcomes upon arrival to the pediatric trauma center were collected.

RESULTS

There were 247 patients included in the analysis; 66.0% (163) had an abnormal prehospital rSIG. Patients with an abnormal rSIG had a higher rate of highest-level trauma activation compared with those with a normal rSIG (38.7% vs. 20.2%, p = 0.013). Patients with an abnormal prehospital rSIG also had higher rates of intubation (28.8% vs. 9.52%, p < 0.001), intracranial pressure monitor (9.20 vs. 1.19%, p = 0.032), need for blood (19.6% vs. 8.33%, p = 0.034), laparotomy (7.98% vs. 1.19%, p = 0.039), and intensive care unit admission (54.6% vs. 40.5%, p = 0.049).

CONCLUSION

Reverse shock index times GCS may assist emergency medical service providers in early identification and triage of severely injured children. An abnormal rSIG in the emergency department is associated with higher rates of intubation, need for blood transfusion, intracranial pressure monitoring, laparotomy, and intensive care unit admission. Use of this metric may help to speed the identification, care, and treatment of any injured child.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level IV.

Prehospital shock index predicts 24-h mortality in trauma patients with a normal shock index upon emergency department arrival

BACKGROUND

The shock index (heart rate divided by systolic blood pressure) of trauma patients upon emergency department arrival predicts blood loss and death. However, some patients with normal shock indices (0.4 < shock index <0.9) upon emergency department arrival also have poor prognoses. This study aimed to determine whether abnormal prehospital shock indices in trauma patients with normal shock indices upon emergency department arrival were predictors of a high risk of mortality.

METHODS

We conducted a retrospective cohort study of emergency department-admitted trauma patients from 2004 to 2017. The study included 89,495 consecutive trauma patients aged ≥16 years, with Abbreviated Injury Scale score of ≥3, who were transported to the emergency department directly from the field and had a normal shock index upon emergency department arrival. According to the prehospital shock index scores, the patients were categorized into low shock index (≤ 0.4), normal shock index, and high shock index (≥0.9) groups. Odds ratios and 95% confidence intervals were calculated using logistic regression analysis.

RESULTS

The 89,495 patients had a median age of 64 (interquartile range: 43-79) years, and 55,484 (62.0%) of the patients were male. There were 1350 (1.5%) 24-h deaths in total; 176/4263 (4.1%), 1017/78,901 (1.3%), and 157/6331 (2.5%) patients were in the low, normal, and high prehospital shock index groups, respectively. The adjusted odds ratios for 24-h mortality compared with the normal shock index group were 1.63 (95% confidence interval: 1.34-1.99) in the low shock index group and 1.62 (95% confidence interval: 1.31-1.99) in the high shock index group.

CONCLUSION

Trauma patients with abnormal prehospital shock indices but normal shock indices upon emergency department arrival are at a higher risk of 24-h mortality. Identifying these indices could improve triage and targeted care for patients.

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.

Prediction of pre-hospital blood transfusion in trauma patients based on scoring systems

BACKGROUND

Pre-hospital blood transfusion (PHBT) is a safe and gradually expanding procedure applied to trauma patients. A proper decision to activate PHBT with the presently limited diagnostic options at the site of an incident poses a challenge for pre-hospital crews. The purpose of this study was to compare the selected scoring systems and to determine whether they can be used as valid tools in identifying patients with PHBT requirements.

METHODS

A retrospective single-center study was conducted between June 2018 and December 2020. Overall, 385 patients (aged [median; IQR]: 44; 24-60; 73% males) were included in this study. The values of five selected scoring systems were calculated in all patients. To determine the accuracy of each score for the prediction of PHBT, the Receiver Operating Characteristic (ROC) analysis was used and to measure the association, the odds ratio with 95% confidence intervals was counted (Fig. 1).

RESULTS

Regarding the proper indication of PHBT, shock index (SI) and pulse pressure (PP) revealed the highest value of AUC and sensitivity/specificity ratio (SI: AUC 0.88; 95% CI 0.82-0.93; PP: AUC 0.85 with 95% CI 0.79-0.91).

CONCLUSION

Shock index and pulse pressure are suitable tools for predicting PHBT in trauma patients.

The effect of time of measurement on the discriminant ability for mortality in trauma of a pre-hospital shock index multiplied by age and divided by the Glasgow Coma Score: a registry study

BACKGROUND

The shock index (SI) and its derivatives have been shown to predict mortality in severely injured patients, both in pre-hospital and in-hospital settings. However, the impact of the time of measurement on the discriminative ability of the pre-hospital SI is unknown. The aim of this study was to evaluate whether the time of measurement influences the discriminative ability of the SI multiplied by age (SIA) and divided by the Glasgow Coma Score (SIA/G).

METHODS

Registry data were obtained from the national helicopter emergency medical services (HEMS) on trauma patients aged ≥ 18 years. The SI values were calculated based on the first measured vitals of the trauma patients by the HEMS unit. The discriminative ability of the SIA/G, with 30-day mortality as the endpoint, was evaluated according to different delay times (0 - 19, 20 - 39 and ≥ 40 min) from the initial incident. Sub-group analyses were performed for trauma patients without a traumatic brain injury (TBI), patients with an isolated TBI and patients with polytrauma, including a TBI.

RESULTS

In total, 3,497 patients were included in the study. The SIA/G was higher in non-survivors (median 7.8 [interquartile range 4.7-12.3] vs. 2.4 [1.7-3.6], P < 0.001). The overall area under the receiver operator characteristic curve (AUROC) for the SIA/G was 0.87 (95% CI: 0.85-0.89). The AUROC for the SIA/G was similar in the short (0.88, 95% CI: 0.85-0.91), intermediate (0.86, 95% CI: 0.84-0.89) and long (0.86, 95% CI: 0.82-0.89) measurement delay groups. The findings were similar in the three trauma sub-groups.

CONCLUSIONS

The discriminative ability of the SIA/G in predicting 30-day mortality was not significantly affected by the measurement time of the index in the pre-hospital setting. The SIA/G is a simple and reliable tool for assessing the risk of mortality among severely injured patients in the pre-hospital setting.

Predictive value of shock index variants on 30-day mortality of trauma patients in helicopter emergency medical services: a nationwide observational retrospective multicenter study

The original shock index (SI) has been further developed to increase its prognostic value. We aimed to evaluate the predictive value of different SI variants on 30-day mortality among severely injured trauma patients in pre-hospital critical care settings. Adult trauma patients in the national Helicopter Emergency Medical Services (HEMS) registry were evaluated based on the primary outcome of 30-day mortality. SI, SIA (SI multiplied by age), SI/G (SI divided by Glasgow Coma Scale (GCS)), SIA/G (SI multiplied by age and divided by GCS), and SS (SI divided by oxygen saturation) were calculated based on the first vital signs measured at the time of HEMS contact. The area under the receiver operating curve (AUROC) was calculated for each SI variant. In total 4108 patients were included in the study. The overall 30-day mortality was 13.5%. The SIA/G and SI/G had the highest predictive ability (AUROC 0.884 [95% CI 0.869-0.899] and 0.8000 [95% CI 0.7780-0.8239], respectively). The SIA/G yielded good predictive performance between 30-day survivors and non-survivors in the pre-hospital critical care setting.

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.

Emergency Transport Refusal during the Early Stages of the COVID-19 Pandemic in Gyeonggi Province, South Korea

We analyzed the changes in patients’ clinical characteristics and transport refusal pre- and post-COVID-19 and identified the reasons for transport refusal using emergency medical services run sheet data from pre-COVID-19 (April−December 2019) and post-COVID-19 (April−December 2020) in Gyeonggi Province, South Korea. We included patients aged ≥18 years. Univariate and multivariate logistic regression analyses were performed to identify the relationship between patients’ personal factors and clinical characteristics and emergency transport refusal. During the control and study periods, 612,681 cases were reported; the transport refusal rates during the control and study periods were 6.7% and 8.2%, respectively. Emergency transport refusal was associated with younger age, the male sex, a normal mental status, a shock index < 1, and trauma in both the pre- and post-COVID-19 periods. Although fever prevented transport refusal during the pre-COVID-19 period (aOR, 0.620; 95% CI, 0.567−0.679), it became a significant risk factor for transport refusal during the post-COVID-19 period (aOR, 1.619; 95% CI, 1.534−1.709). The most common reason for transport refusal by critically ill patients was “because it was not accepted within the jurisdiction and remote transport was required.” It is necessary to expand the response capacity of patients with fever in the community to reduce the refusal of transport by critically ill patients.

Nationwide estimates of the need for prehospital blood products after injury

INTRODUCTION

Prehospital blood product resuscitation after injury significantly decreases risk of mortality. However, the number of patients who may potentially benefit from this life-saving intervention is currently unknown. The primary objective of this study was to estimate the number of patients who may potentially benefit from prehospital blood product resuscitation after injury in the United States. The secondary objective was to estimate the amount of blood products needed for prehospital resuscitation of injured patients.

METHODS

Patients ≥16 years with blunt/penetrating injuries included in National Emergency Medical Services Information System 2019 were identified and classified into four separate cohorts of hemodynamic instability: Cohort 1 (systolic blood pressure [SBP] <90 mmHg), Cohort 2 (SBP <90 and/or heart rate [HR] >120), Cohort 3 (SBP <90 and HR >108 or SBP <70), and Cohort 4 (shock index ≥1). The need for prehospital blood was estimated by multiplying number of patients in each cohort with average number of blood products used for prehospital resuscitation.

RESULTS

After exclusions, 3.7 million adult trauma patients were included. The number of patients who may potentially benefit from prehospital blood products was estimated as 89,391 (Cohort 1), 901,346 (Cohort 2), 54,160 (Cohort 3), and 300,475 (Cohort 4). Assuming 1 unit of whole blood is needed per patient, a lower-bound estimate of 54,160 additional whole blood units (0.6% of current collections) will be need for prehospital resuscitation of the injured.

CONCLUSIONS

Annually, between 54,000 and 900,000 patients may potentially benefit from prehospital blood product resuscitation after injury in the United States. Prehospital blood utilization and collection of blood products will need to be increased to scale-up this life-saving intervention nationwide.

Effectiveness of massive transfusion protocol activation in pre-hospital setting for major trauma

INTRODUCTION

Hemorrhage in major trauma is life-threatening and the activation of the Massive Transfusion Protocol (MTP) was found to reduce the time to transfusion and mortality. The purpose was (i) to verify whether MTP activation identifies patients that require massive transfusions once admitted to the Emergency Department (ED), (ii) to establish whether pre-hospital MTP activation reduces the time to transfusion on arrival at the ED, (iii) to identify the variable that best predicts MTP activation.

MATERIALS AND METHODS

This is a retrospective, single-center study. The MTP was implemented at the end of 2012; it was activated for major trauma in pre-hospital setting on the basis on established criteria. Pre-hospital MTP activation aimed to make blood products available prior to the patients' arrival at the ED. The blood products are transfused when the patient arrives at the hospital.

RESULTS

The MTP was activated in pre-hospital setting in 219 patients. On arrival at the hospital, the Trauma Team Leader confirmed MTP activation in 146 (66.7%) patients. Patients with MTP criteria received a higher amount of blood products than the patients without MTP criteria, median 7 (IQR 2-13) units versus 2 (0-6) units, respectively (P < 0.001). At the same time, patients with a Shock Index ≥ 0.9 received more transfusions (5.5 [2-13] units) compared with patients characterized by a lower SI (2 [0-7.25] units, P = 0.009). 146 patients were transfused in the first hour of ED admission. Poisson's multiple regression shows that the SI is the variable that better predicted MTP activation compared to age, gender and the number of injured sites.

CONCLUSIONS

Pre-hospital MTP activation is useful to identify patients that require an urgent blood transfusion on arrival at the ED. Further analysis should be considered to evaluate the implementation of the Shock Index as a criterion to activate MTP.

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.

Comparison of 4 Different Threshold Values of Shock Index in Predicting Mortality of COVID-19 Patients

OBJECTIVE

The object of this study was to examine the accuracy in prehospital shock index (SI) for predicting intensive care unit (ICU) requirement and 30-d mortality among from coronavirus disease 2019 (COVID-19) patients transported to the hospital by ambulance.

METHODS

All consecutive patients who were the age ≥18 y, transported to the emergency department (ED) by ambulance with a suspected or confirmed COVID-19 in the prehospital frame were included in the study. Four different cutoff points were compared (0.7, 0.8, 0.9, and 1.0) to examine the predictive performance of both the mortality and ICU requirement of the SI. The receiver operating characteristic (ROC) curve and the area under the curve (AUC) was used to evaluate each cut-off value discriminatory for predicting 30-d mortality and ICU admission.

RESULTS

The total of 364 patients was included in this study. The median age in the study population was 69 y (range, 55-80 y), of which 196 were men and 168 were women. AUC values for 30-d mortality outcome were calculated as 0.672, 0.674, 0.755, and 0.626, respectively, for threshold values of 0.7, 0.8, 0.9 and 1.0. ICU admission was more likely for the patients with prehospital SI > 0.9. Similarly, the mortality rate was higher in patients with prehospital SI > 0.9.

CONCLUSIONS

Early triage of COVID-19 patients will ensure efficient use of health-care resources. The SI could be a helpful, fast, and powerful tool for predicting mortality status and ICU requirements of adult COVID-19 patients. It was concluded that the most useful threshold value for the shock index in predicting the prognosis of COVID-19 patients is 0.9.

Comparison of Shock Index With the Assessment of Blood Consumption Score for Association With Massive Transfusion During Hemorrhage Control for Trauma

BACKGROUND

Hemorrhage is a leading cause of early mortality following trauma. A massive transfusion protocol (MTP) to guide resuscitation while bleeding is definitively controlled may improve outcomes. Prompts to initiate massive transfusion (MT) include shock index (SI) and the Assessment of Blood Consumption (ABC) score.

OBJECTIVE

To compare SI with the ABC score for association with transfusion requirement, need for emergency hemorrhage interventions, and early mortality.

METHODS

A retrospective cohort analysis of trauma MTP activations at our Level I trauma center was conducted from January 1, 2012, to December 31, 2016. The study data were obtained from the Trauma Registry and the blood bank. An SI cutoff of 1.0 was chosen for comparison with the positive ABC score.

RESULTS

The study cohort included 146 patients. Shock index ≥ 1 had significant association with MT requirement (p = .002) whereas a positive ABC score did not (p = .65). More patients with SI ≥ 1 required bleeding control interventions (67% surgery, 47% interventional radiology) than patients having a positive ABC score (49% surgery, 29% interventional radiology). For geriatric patients who received MT, 65% had SI ≥ 1 but only 30% had a positive ABC score. Three-hour mortality following emergency department arrival was similar (60% SI ≥ 1, 62% positive ABC score).

CONCLUSION

Shock index ≥ 1 outperformed a positive ABC score for association with MT requirement. Shock index is a simple tool registered nurses can independently utilize to anticipate MT.

Shock index as a predictor for short-term mortality in helicopter emergency medical services: A registry study

BACKGROUND

The value of shock-index has been demonstrated in hospital triage, but few studies have evaluated its prehospital use. The aim of our study was to evaluate the association between shock-index in prehospital critical care and short-term mortality.

METHODS

We analyzed data from the national helicopter emergency medical services database and the Population Register Centre. The shock-index was calculated from the patients' first measured parameters. The primary outcome measure was 1- and 30-day mortality.

RESULTS

A total of 22 433 patients were included. The 1-day mortality was 7.5% and 30-day mortality was 16%. The median shock-index was 0.68 (0.55/0.84) for survivors and 0.67 (0.49/0.93) for non-survivors (P = .316) at 30-days. Association between shock-index and mortality followed a U-shaped curve in trauma (shock-index < 0.5: odds ratio 2.5 [95% confidence interval 1.8-3.4], shock-index > 1.3: odds ratio 4.4 [2.7-7.2] at 30 days). Patients with neurological emergencies with a low shock-index had an increased risk of mortality (shock-index < 0.5: odds ratio 1.8 [1.5-2.3]) whereas patients treated after successful resuscitation from out-of-hospital cardiac arrest, a higher shock-index was associated with higher mortality (shock-index > 1.3: odds ratio 3.5 [2.3-5.4). The association was similar for all ages, but older patients had higher mortality in each shock-index category.

CONCLUSION

The shock-index is associated with short time mortality in most critical patient categories in the prehospital setting. However, the marked overlap of shock-index in survivors and non-survivors in all patient categories limits its predictive value.

Predicting the need for blood transfusion requirement in postpartum hemorrhage

OBJECTIVE

We aimed to assess the role of lactate and hemoglobin levels as predictors for the need for blood transfusion in post-partum hemorrhage (PPH).

METHODS

A retrospective cohort study of women with PPH in a single university-affiliated tertiary medical center between August 2018 and June 2020. PPH was defined as an estimated excessive blood loss (of more than 500 ml following vaginal delivery and 1000 ml following a cesarean delivery) requiring at least one uterotonic drug and fluid resuscitation. Women were stratified by the need of requiring blood transfusion due to hemorrhage. The criteria for blood transfusion were: (1) clinically severe uncontrollable ongoing hemorrhage; (2) symptomatic anemia (maternal tachycardia >110 beats per minute, dizziness, syncope or presyncope) in the presence of Hb 7-8 g/dL^; or (3) postpartum Hb level < 7 g/dL regardless of maternal symptoms or signs of anemia. Demographic, labor characteristics as well as laboratory data were collected. For all women the Shock Index (SI: heart rate divided by systolic blood pressure) was calculated. Women without available data on immediate (more than 15 min from the bleeding initiation) hemoglobin (Hb) level and lactate concentrations were excluded.

RESULTS

Overall, out of 22,241 deliveries during the study, 94 women were included, of them 26 (23.4%) required blood transfusion. The antepartum Hb level was lower in the transfused group (11.7 ± vs 12.4 ± 1.0 re/dL, p = .01). No significant differences were found in demographic and labor characteristics. In multivariate logistic regression analysis, a lower immediate postpartum Hb and a higher SI higher were associated with blood transfusion requirement (adjusted odds ratio (aOR) 3.45 [CI] 1.82-7.69, p < .001] and aOR 1.25 [CI 1.03-1.55, p = .03], respectively). The combination of SI, immediate postpartum Hb and lactate concentration provided the best integration, with an area under the curve of 0.86, sensitivity 92.65%, specificity 61.54%, positive and negative predictive values of 86.3% and 76.2%, respectively.

CONCLUSION

The combination of SI, immediate postpartum Hb and lactate levels is a good predictor for the need of blood requirement in PPH.

A comparison of frailty indices in predicting length of inpatient stay and discharge destination following angiogram-negative subarachnoid hemorrhage

BACKGROUND AND PURPOSE

While patients with angiogram-negative subarachnoid hemorrhages (ANSAH) have better prognoses than those with aneurysmal SAH, frailty's impact on outcomes in ANSAH is unclear. We previously showed that the modified frailty index (mFI-11) is associated with poor outcomes following ANSAH. Here, we compared the mFI-5, mFI-11, Charlson Comorbidity Index (CCI), and temporalis thickness (TMT) to determine which index was the best predictor of ANSAH outcomes and mortality rates.

METHODS

In this retrospective cohort analysis between 2014 and 2018, patients with non-traumatic, angiogram negative SAH (ANSAH) were identified. The admission mFI-5, mFI-11, CCI, and TMT were calculated for each patient. Primary outcomes were mortality rate, discharge location, and prolonged length of stay (PLOS; LOS >85^th percentile). Multivariate logistic regression and receiver operating characteristic (ROC) curves were used to evaluate frailty as predictors of primary endpoints.

RESULTS

We included 75 patients with a mean age of 55.4 ± 1.5 years. There were 4 patient deaths (5.3%), 53 patients (70.7%) discharged home, and 11 patients (14.7%) with PLOS. On ROC analysis, the mFI-5 had the highest discriminatory value for mortality (AUC = 0.97) while the mFI-11 was most discriminatory for discharge home (AUC = 0.85) and PLOS (AUC = 0.78). On multivariate analysis, the only independent predictor of mortality was the mFI-11 (OR = 0.46; 95%CI: 1.45-14.23; p = 0.009) while the mFI-5 was the best predictor of discharge home (OR = 0.21; 95% CI: 0.08-0.61; p = 0.004). On multivariate analysis, the only independent predictor of PLOS was the Hunt and Hess score (OR = 2.63; 95%CI: 1.38-5.00; p = 0.003). The CCI and TMT were inferior to either mFI for predicting primary endpoints.

CONCLUSIONS

Increasing frailty is associated with poorer outcomes and higher mortality following ANSAH. The mFI-5 and mFI-11 were found to be superior predictors of discharge home and mortality rate. While larger prospective study is needed, frailty, as measured by mFI-11 and -5, should be considered when evaluating ANSAH prognosis.