Early Vital Sign Thresholds Associated with 24-Hour Mortality among Trauma Patients: A Trauma Quality Improvement Program (TQIP) Study

BACKGROUND

Identifying patients at imminent risk of death is critical in the management of trauma patients. This study measures the vital sign thresholds associated with death among trauma patients.

METHODS

This study included data from patients ≥15 years of age in the American College of Surgeons Trauma Quality Improvement Program (TQIP) database. Patients with vital signs of zero were excluded. Documented prehospital and emergency department (ED) vital signs included systolic pressure, heart rate, respiratory rate, and calculated shock index (SI). The area under the receiver operator curves (AUROC) was used to assess the accuracy of these variables for predicting 24-hour survival. Optimal thresholds to predict mortality were identified using Youden's Index, 90% specificity, and 90% sensitivity. Additional analyses examined patients 70+ years of age.

RESULTS

There were 1,439,221 subjects in the 2019-2020 datasets that met inclusion for this analysis with <0.1% (10,270) who died within 24 hours. The optimal threshold for prehospital systolic pressure was 110, pulse rate was 110, SI was 0.9, and respiratory rate was 15. The optimal threshold for the ED systolic was 112, pulse rate was 107, SI was 0.9, and respiratory rate was 21. Among the elderly sub-analysis, the optimal threshold for prehospital systolic was 116, pulse rate was 100, SI was 0.8, and respiratory rate was 21. The optimal threshold for ED systolic was 121, pulse rate was 95, SI was 0.8, and respiratory rate was 0.8.

CONCLUSIONS

Systolic blood pressure (SBP) and SI offered the best predictor of mortality among trauma patients. The SBP values predictive of mortality were significantly higher than the traditional 90mmHg threshold. This dataset highlights the need for better methods to guide resuscitation as initial vital signs have limited accuracy in predicting subsequent mortality.

Blood consumption in the Role 2 setting: A Department of Defense Trauma Registry analysis

BACKGROUND

The Role 2 setting represents the most far-forward military treatment facility with limited surgical and holding capabilities. There are limited data to guide recommendations on blood product utilization at the Role 2. We describe the consumption of blood products in this setting.

STUDY DESIGN AND METHODS

We analyzed data from 2007 to 2023 from the Department of Defense Trauma Registry (DODTR) that received care at a Role 2. We used descriptive and inferential statistics to characterize the volumes of blood products consumed in this setting. We also performed a secondary analysis of US military, Coalition, and US contractor personnel.

RESULTS

Within our initial cohort analysis of 15,581 encounters, 17% (2636) received at least one unit of PRBCs or whole blood, of which 11% received a submassive transfusion, 4% received a massive transfusion, and 1% received a supermassive transfusion. There were 6402 encounters that met inclusion for our secondary analysis. With this group, 5% received a submassive transfusion, 2% received a massive transfusion, and 1% received a supermassive transfusion.

CONCLUSIONS

We described volumes of blood products consumed at the Role 2 during recent conflicts. The maximum number of units consumed among survivors exceeds currently recommended available blood supply. Our findings suggest that rapid resupply and cold-stored chain demands may be higher than anticipated in future conflicts.

Clinical Assessment of Low Calcium In traUMa (CALCIUM)

Major trauma frequently occurs in the deployed, combat setting and is especially applicable in the recent conflicts with explosives dominating the combat wounded. In future near-peer conflicts, we will likely face even more profound weapons including mortars and artillery. As such, the number of severely wounded will likely increase. Hypocalcemia frequently occurs after blood transfusions, secondary to the preservatives in the blood products; however, recent data suggests major trauma in and of itself is a risk factor for hypocalcemia. Calcium is a major ion involved in heart contractility; thus, hypocalcemia can lead to poor contractility. Smaller studies have linked hypocalcemia to worse outcomes, but it remains unclear what causes hypocalcemia and if intervening could potentially save lives. The objective of this study is to determine the incidence of hypocalcemia on hospital arrival and the association with survival. We are seeking to address the following scientific questions, (1) Is hypocalcemia present following traumatic injury prior to transfusion during resuscitation? (2) Does hypocalcemia influence the amount of blood products transfused? (3) To what extent is hypocalcemia further exacerbated by transfusion? (4) What is the relationship between hypocalcemia following traumatic injury and mortality? We will conduct a multicenter, prospective, observational study. We will gather ionized calcium levels at 0, 3, 6, 12, 18, and 24 hours as part of scheduled calcium measurements. This will ensure we have accurate data to assess the early and late effects of hypocalcemia throughout the course of resuscitation and hemorrhage control. These data will be captured by a trained study team at every site. Our findings will inform clinical practice guidelines and optimize the care delivered in the combat and civilian trauma setting. We are seeking 391 patients with complete data to meet our a priori inclusion criteria. Our study will have major immediate short-term findings including risk prediction modeling to assess who is at risk for hypocalcemia, data assessing interventions associated with the incidence of hypocalcemia, and outcome data including mortality and its link to early hypocalcemia.

Clinical Assessment of Low Calcium In traUMa (CALCIUM)

Major trauma frequently occurs in the deployed, combat setting and is especially applicable in the recent conflicts with explosives dominating the combat wounded. In future near-peer conflicts, we will likely face even more profound weapons including mortars and artillery. As such, the number of severely wounded will likely increase. Hypocalcemia frequently occurs after blood transfusions, secondary to the preservatives in the blood products; however, recent data suggests major trauma in and of itself is a risk factor for hypocalcemia. Calcium is a major ion involved in heart contractility; thus, hypocalcemia can lead to poor contractility. Smaller studies have linked hypocalcemia to worse outcomes, but it remains unclear what causes hypocalcemia and if intervening could potentially save lives. The objective of this study is to determine the incidence of hypocalcemia on hospital arrival and the association with survival. We are seeking to address the following scientific questions, (1) Is hypocalcemia present following traumatic injury prior to transfusion during resuscitation? (2) Does hypocalcemia influence the amount of blood products transfused? (3) To what extent is hypocalcemia further exacerbated by transfusion? (4) What is the relationship between hypocalcemia following traumatic injury and mortality? We will conduct a multicenter, prospective, observational study. We will gather ionized calcium levels at 0, 3, 6, 12, 18, and 24 hours as part of scheduled calcium measurements. This will ensure we have accurate data to assess the early and late effects of hypocalcemia throughout the course of resuscitation and hemorrhage control. These data will be captured by a trained study team at every site. Our findings will inform clinical practice guidelines and optimize the care delivered in the combat and civilian trauma setting. We are seeking 391 patients with complete data to meet our a priori inclusion criteria. Our study will have major immediate short-term findings including risk prediction modeling to assess who is at risk for hypocalcemia, data assessing interventions associated with the incidence of hypocalcemia, and outcome data including mortality and its link to early hypocalcemia.

Temporal trends in myocardial infarction case fatality: methodological challenges and prevention targets

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Health and Medical Research Council of AustraliaHealy Medical Research Foundation

Background

Case fatality is an important indicator of severity and quality of care for myocardial infarction (MI). Most studies focus on hospitalised case fatality, which does not capture the total burden of MI deaths. Additionally, changes in diagnostic criteria and acute clinical care, and evidence that identifying all coronary heart disease (CHD) events better captures this patient group,1 have led to suggestions that a different definition of case fatality is required.

Purpose

The aim of the study was to determine the impact of different definitions of case fatality on the composition of fatal cases, and to measure trends in case fatality across a range of case definitions.

Methods

A whole-state linked hospital/death dataset was used to identify all MI, acute coronary syndromes (ACS) and CHD events (fatal + nonfatal) from 1997-2015. The traditional MI case fatality definition included all MI deaths as the numerator, stratified as MI hospitalisation with death ≤28 days, non-MI hospitalisation with MI death ≤28 days, or pre-hospital MI deaths. The denominator was all MIs (fatal plus nonfatal MI). ACS and a broader CHD definition were trialled, with ACS or CHD deaths as the numerator respectively, stratified in a similar manner as MI. Case fatality was age-standardised by 5-year age group using the internal age distribution of each definition as the standard.

Results

From 1997 to 2015, there were 76,928 MI events, 126,470 ACS events, and 235,100 CHD events. Of the MI cohort, 64.1% were men, and 13.0% had a prior MI, with a similar pattern in the ACS and CHD cohorts. For the traditional definition of MI case fatality, 10,819 deaths (53.9%) occurred pre-hospital, 4990 deaths in those hospitalised for MI and dying ≤28 days (24.8%), and 4271 MI deaths (21.3%) ≤28 days of a non-MI hospitalisation (Figure). Using the broadest CHD definition of case fatality, there was a similar proportion of pre-hospital deaths, but a higher proportion of CHD deaths in those with a non-CHD hospitalisation.

In men, age-standardised MI case fatality declined from 40.0% in 1997 to 17.3% by 2015; in women, the decline was from 41.9% to 18.2%. In contrast, using the ACS and broad CHD definitions, age-standardised case fatality was lower than for MI throughout the study period, with a smaller temporal decline (ACS: men 22.2% to 13.1%, women 20.5% to 13.0%; CHD: men 20.6% to 12.4%, women 19.3% to 12.3%).

Conclusion

Despite substantial falls in MI case fatality, the fatal burden remains high. Regardless of the case fatality definition, pre-hospital deaths from acute or all CHD have remained high over time, highlighting the need to target the pre-hospital setting. Caution is needed when using different definitions of case fatality to ensure relevant statistics are used, particularly for temporal trends.

Figure Legend. Proportion of MI deaths occurring ≤28 days after MI hospitalisation (2), ≤28 days after non-MI hospitalisation (3), and pre-hospital (4).

An Analysis of the Incidence of Hypocalcemia in Wartime Trauma Casualties

OBJECTIVE

Background: Massive transfusion protocols implement the use of blood products to restore homeostasis. Citrated blood products are required for massive transfusions and can induce hypocalcemia, resulting in decreased cardiac contractility. Recent data suggests that major trauma alone is associated with hypocalcemia. This phenomenon remains poorly described. We seek to characterize the incidence and risk factors for early hypocalcemia in the setting of combat trauma.

MATERIALS AND METHODS

This is a secondary analysis of previously described data from the Department of Defense Trauma Registry from January 2007 to March 2020. In this sub-analysis, we selected only casualties that had at least one ionized calcium measurement. We defined hypocalcemia as an ionized calcium level of less than 1.2mmol/L.

RESULTS

Within our study database, there were 142 adult casualties that met inclusion with at least one calcium value documented. We found 72 (51%) experienced at least one episode of hypocalcemia. Median composite injury severity score (ISS) was significantly lower in the control cohort compared to those with hypocalcemia (9 versus 15, p=0.010). Survival was similar between the two groups (97% versus 90%, p=0.166). On multivariable analysis when evaluating serious injuries by body region, only serious injuries to the extremities were significantly associated with developing hypocalcemia (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.00-2.21). When comparing prehospital interventions, only intravenous (IV) fluid administration was associated with high proportions experiencing hypocalcemia (25% versus 43%, p=0.029). In the multivariable model adjusted for ISS, mechanism of injury, and patient category, IV fluids were associated with the development of hypocalcemia (OR 2.48, 95% CI 1.03-5.94). When comparing vital signs, only respiratory rates were noted to be higher in the hypocalcemia cohort (18.6 versus 20.4, p=0.048).

CONCLUSIONS

Approximately half of combat casualties with available ionized calcium (iCa) level were hypocalcemic. Prehospital IV fluid use was associated with the development of hypocalcemia. Our study has implications for forward-staged medical teams with limited laboratory analysis capabilities. Additional research is needed to determine whether calcium replacement improves survival from traumatic injury and to identify the specific indications and timing for calcium replacement. This study will help inform a clinical study intended to aid in the development of clinical practice guidelines for deployed medical personnel.

MUlticenter STudy of tissue plasminogen activator (alteplase) use in COVID‐19 severe respiratory failure (MUST COVID): A retrospective cohort study

Background

Few therapies exist to treat severe COVID‐19 respiratory failure once it develops. Given known diffuse pulmonary microthrombi on autopsy studies of COVID‐19 patients, we hypothesized that tissue plasminogen activator (tPA) may improve pulmonary function in COVID‐19 respiratory failure.

Methods

A multicenter, retrospective, observational study of patients with confirmed COVID‐19 and severe respiratory failure who received systemic tPA (alteplase) was performed. Seventy‐nine adults from seven medical centers were included in the final analysis after institutional review boards' approval; 23 were excluded from analysis because tPA was administered for pulmonary macroembolism or deep venous thrombosis. The primary outcome was improvement in the PaO₂/FiO₂ ratio from baseline to 48 h after tPA. Linear mixed modeling was used for analysis.

Results

tPA was associated with significant PaO₂/FiO₂ improvement at 48 h (estimated paired difference = 23.1 ± 6.7), which was sustained at 72 h (interaction term p < 0.00). tPA administration was also associated with improved National Early Warning Score 2 scores at 24, 48, and 72 h after receiving tPA (interaction term p = 0.00). D‐dimer was significantly elevated immediately after tPA, consistent with lysis of formed clot. Patients with declining respiratory status preceding tPA administration had more marked improvement in PaO₂/FiO₂ ratios than those who had poor but stable (not declining) respiratory status. There was one intracranial hemorrhage, which occurred within 24 h following tPA administration.

Conclusions

These data suggest tPA is associated with significant improvement in pulmonary function in severe COVID‐19 respiratory failure, especially in patients whose pulmonary function is in decline, and has an acceptable safety profile in this patient population.

The patient's voice matters: The impact of advance directives on elderly trauma patients

BACKGROUND

Geriatric trauma rates are increasing, yet trauma centers often struggle to provide autonomy regarding decision making to these patients. Advance care planning can assist with this process. Currently, there are limited data on the impact of advance directives (ADs) in elderly trauma patients. The purpose of this study was to evaluate the prevalence of preinjury AD in geriatric trauma patients and its impact on outcomes, with the hypothesis that ADs would not be associated with an increase in mortality.

METHODS

A multicenter retrospective review was conducted on patients older than 65 years with traumatic injury between 2017 and 2019. Three Level I trauma centers and one Level II trauma center were included. Exclusion criteria were readmission, burn injury, transfer to another facility, discharge from emergency department, and mortality prior to being admitted.

RESULTS

There were 6,135 patients identified; 751 (12.2%) had a preinjury AD. Patients in the AD+ group were older (86 vs. 77 years, p < 0.0001), more likely to be women (67.0% vs. 54.8%, p < 0.0001), and had more comorbidities. Hospital length of stay and ventilator days were similar. In-hospital mortality occurred in 236 patients, and 75.4% of them underwent withdrawal of care (WOC). The mortality rate was higher in AD+ group (10.5% vs. 2.9%, p < 0.0001). No difference was seen in the rate of AD between the WOC+ and WOC- group (31.5% vs. 39.6%, p = 0.251). A preinjury AD was identified as an independent predictor of mortality, but not a predictor of WOC.

CONCLUSION

Despite a high WOC rate in patients older than 65 years, most patients did not have an AD prior to injury. As the elderly trauma population grows, advance care planning should be better integrated into geriatric care to encourage a patient-centered approach to end-of-life care.

LEVEL OF EVIDENCE

Prognostic and epidemiological, level IV.

Whole Blood Versus Conventional Blood Component Massive Transfusion Protocol Therapy in Civilian Trauma Patients

BACKGROUND

Military data demonstrating an improved survival rate with whole blood (WB) have led to a shift toward the use of WB in civilian trauma. The purpose of this study is to compare a low-titer group O WB (LTOWB) massive transfusion protocol (MTP) to conventional blood component therapy (BCT) MTP in civilian trauma patients.

METHODS

Trauma patients 15 years or older who had MTP activations from February 2019 to December 2020 were included. Patients with a LTOWB MTP activation were compared to BCT MTP patients from a historic cohort.

RESULTS

299 patients were identified, 169 received LTOWB and 130 received BCT. There were no differences in age, gender, or injury type. The Injury Severity Score was higher in the BCT group (27 vs 25, P = .006). The LTOWB group had a longer transport time (33 min vs 26 min, P < .001) and a lower arrival temperature (35.8 vs 36.1, P < .001). Other hemodynamic parameters were similar between the groups. The LTOWB group had a lower in-hospital mortality rate compared to the BCT group (19.5% vs 30.0%, P = .035). There were no differences in total transfusion volumes at 4 hours and 24 hours. No differences were seen in transfusion reactions or hospital complications. Multivariable logistic regression identified ISS, age, and 24-hour transfusion volume as predictors of mortality.

DISCUSSION

Resuscitating severely injured trauma patient with LTOWB is safe and may be associated with an improved survival.

Study of Alteplase for Respiratory Failure in SARS-CoV-2 COVID-19: A Vanguard Multicenter, Rapidly Adaptive, Pragmatic, Randomized Controlled Trial

Background

Pulmonary vascular microthrombi are a proposed mechanism of COVID-19 respiratory failure. We hypothesized that early administration of tissue plasminogen activator (tPA) followed by therapeutic heparin would improve pulmonary function in these patients.

Research Question

Does tPA improve pulmonary function in severe COVID-19 respiratory failure, and is it safe?

Study Design and Methods

Adults with COVID-19-induced respiratory failure were randomized from May14, 2020 through March 3, 2021, in two phases. Phase 1 (n = 36) comprised a control group (standard-of-care treatment) vs a tPA bolus (50-mg tPA IV bolus followed by 7 days of heparin; goal activated partial thromboplastin time [aPTT], 60-80 s) group. Phase 2 (n = 14) comprised a control group vs a tPA drip (50-mg tPA IV bolus, followed by tPA drip 2 mg/h plus heparin 500 units/h over 24 h, then heparin to maintain aPTT of 60-80 s for 7 days) group. Patients were excluded from enrollment if they had not undergone a neurologic examination or cross-sectional brain imaging within the previous 4.5 h to rule out stroke and potential for hemorrhagic conversion. The primary outcome was Pao₂ to Fio₂ ratio improvement from baseline at 48 h after randomization. Secondary outcomes included Pao₂ to Fio₂ ratio improvement of > 50% or Pao₂ to Fio₂ ratio of ≥ 200 at 48 h (composite outcome), ventilator-free days (VFD), and mortality.

Results

Fifty patients were randomized: 17 in the control group and 19 in the tPA bolus group in phase 1 and eight in the control group and six in the tPA drip group in phase 2. No severe bleeding events occurred. In the tPA bolus group, the Pao₂ to Fio₂ ratio values were significantly (P < .017) higher than baseline at 6 through 168 h after randomization; the control group showed no significant improvements. Among patients receiving a tPA bolus, the percent change of Pao₂ to Fio₂ ratio at 48 h (16.9% control [interquartile range (IQR), –8.3% to 36.8%] vs 29.8% tPA bolus [IQR, 4.5%-88.7%]; P = .11), the composite outcome (11.8% vs 47.4%; P = .03), VFD (0.0 [IQR, 0.0-9.0] vs 12.0 [IQR, 0.0-19.0]; P = .11), and in-hospital mortality (41.2% vs 21.1%; P = .19) did not reach statistically significant differences when compared with those of control participants. The patients who received a tPA drip did not experience benefit.

Interpretation

The combination of tPA bolus plus heparin is safe in severe COVID-19 respiratory failure. A phase 3 study is warranted given the improvements in oxygenation and promising observations in VFD and mortality.

Trial Registry

ClinicalTrials.gov; No.: NCT04357730; URL: www.clinicaltrials.gov

A quasiexperimental study of targeted normoxia in critically ill trauma patients

BACKGROUND

Avoidance of hypoxia and hyperoxia may reduce morbidity and mortality in critically ill civilian and military trauma patients. The objective of this study was to determine if a multimodal quality improvement intervention increases adherence to a consensus-based, targeted normoxia strategy. We hypothesized that this intervention would safely improve compliance with targeted normoxia.

METHODS

This is a pre/postquasiexperimental pilot study to improve adherence to normoxia, defined as a pulse oximetry (SpO2) of 90% to 96% or an arterial partial pressure oxygen (PaO2) of 60 to 100 mm Hg. We used a multimodal informatics and educational intervention guiding clinicians to safely titrate supplemental oxygen to normoxia based on SpO2 monitoring in critically ill trauma patients admitted to the surgical-trauma or neurosurgical intensive care unit within 24 hours of emergency department arrival. The primary outcome was effectiveness in delivering targeted normoxia (i.e., an increase in the probability of being in the targeted normoxia range and/or a reduction in the probability of being on a higher fraction-inspired oxygen concentration [FiO2]).

RESULTS

Analysis included 371 preintervention subjects and 201 postintervention subjects. Preintervention and postintervention subjects were of similar age, race/ethnicity, and sex and had similar comorbidities and Acute Physiologic and Chronic Health Evaluation II scores. Overall, the adjusted probability of being hyperoxic while on supplemental oxygen was reduced during the postintervention period (adjusted odds ratio, 0.74; 95% confidence interval, 0.57-0.97). There was a higher probability of being on room air (FiO2, 0.21) in the postintervention period (adjusted odds ratio, 1.38; 95% confidence interval, 0.83-2.30). In addition, there was a decreased amount of patient time spent on higher levels of FiO2 (FiO2, >40%) without a concomitant increase in hypoxia.

CONCLUSION

A multimodal intervention targeting normoxia in critically ill trauma patients increased normoxia and lowered the use of supplemental oxygen. A large clinical trial is needed to validate the impact of this protocol on patient-centered clinical outcomes.

LEVEL OF EVIDENCE

Therapeutic/care management, level II.

Early ventilator liberation and decreased sedation needs after tracheostomy in patients with COVID-19 infection

Background

Since the outset of the coronavirus disease 2019 (COVID-19) pandemic, published tracheostomy guidelines have generally recommended deferral of the procedure beyond the initial weeks of intubation given high mortality as well as concerns about transmission of the infection to providers. It is unclear whether tracheostomy in patients with COVID-19 infection facilitates ventilator weaning, and long-term outcomes are not yet reported in the literature.

Methods

This is a retrospective study of tracheostomy outcomes in patients with COVID-19 infection at a single-center academic tertiary referral intensive care unit. Patients underwent percutaneous tracheostomy at the bedside; the procedure was performed with limited staffing to reduce risk of disease transmission.

Results

Between March 1 and June 30, 2020, a total of 206 patients with COVID-19 infection required mechanical ventilation and 26 underwent tracheostomy at a mean of 25±5 days after initial intubation. Overall, 81% of tracheostomy patients were liberated from the ventilator at a mean of 9±6 days postprocedure, and 54% were decannulated prior to hospital discharge at a mean of 21±10 days postprocedure. Sedation and pain medication requirements decreased significantly in the week after the procedure. In-hospital mortality was 15%. Among tracheostomy survivors, 68% were discharged to a facility.

Discussion

The management of patients with COVID-19 related respiratory failure can be challenging due to prolonged ventilator dependency. In our initial experience, outcomes post-tracheostomy in this population are encouraging, with short time to liberation from the ventilator, a high rate of decannulation prior to hospital discharge, and similar mortality to tracheostomy performed for other indications. Barriers to weaning ventilation in this cohort may be high sedation needs and ventilator dyssynchrony.

Level of evidence

Level V-Therapeutic/care management.

The diamond of death: Hypocalcemia in trauma and resuscitation

INTRODUCTION

Early recognition and management of hemorrhage, damage control resuscitation, and blood product administration have optimized management of severe trauma. Recent data suggest hypocalcemia exacerbates the ensuing effects of coagulopathy in trauma.

OBJECTIVE

This narrative review of available literature describes the physiology and role of calcium in trauma resuscitation. Authors did not perform a systematic review or meta-analysis.

DISCUSSION

Calcium is a divalent cation found in various physiologic forms, specifically the bound, inactive state and the unbound, physiologically active state. While calcium plays several important physiologic roles in multiple organ systems, the negative hemodynamic effects of hypocalcemia are crucial to address in trauma patients. The negative ramifications of hypocalcemia are intrinsically linked to components of the lethal triad of acidosis, coagulopathy, and hypothermia. Hypocalcemia has direct and indirect effects on each portion of the lethal triad, supporting calcium's potential position as a fourth component in this proposed lethal diamond. Trauma patients often present hypocalcemic in the setting of severe hemorrhage secondary to trauma, which can be worsened by necessary transfusion and resuscitation. The critical consequences of hypocalcemia in the trauma patient have been repeatedly demonstrated with the associated morbidity and mortality. It remains poorly defined when to administer calcium, though current data suggest that earlier administration may be advantageous.

CONCLUSIONS

Calcium is a key component of trauma resuscitation and the coagulation cascade. Recent data portray the intricate physiologic reverberations of hypocalcemia in the traumatically injured patient; however, future research is needed to further guide the management of these patients.

Fibrinolysis Shutdown Correlation with Thromboembolic Events in Severe COVID-19 Infection

Background

COVID-19 predisposes patients to a prothrombotic state with demonstrated microvascular involvement. The degree of hypercoagulability appears to correlate with outcomes; however, optimal criteria to assess for the highest-risk patients for thrombotic events remain unclear; we hypothesized that deranged thromboelastography measurements of coagulation would correlate with thromboembolic events.

Study Design

Patients admitted to an ICU with COVID-19 diagnoses who had thromboelastography analyses performed were studied. Conventional coagulation assays, d-dimer levels, and viscoelastic measurements were analyzed using a receiver operating characteristic curve to predict thromboembolic outcomes and new-onset renal failure.

Results

Forty-four patients with COVID-19 were included in the analysis. Derangements in coagulation laboratory values, including elevated d-dimer, fibrinogen, prothrombin time, and partial thromboplastin time, were confirmed; viscoelastic measurements showed an elevated maximum amplitude and low lysis of clot at 30 minutes. A complete lack of lysis of clot at 30 minutes was seen in 57% of patients and predicted venous thromboembolic events with an area under the receiver operating characteristic curve of 0.742 (p = 0.021). A d-dimer cutoff of 2,600 ng/mL predicted need for dialysis with an area under the receiver operating characteristic curve of 0.779 (p = 0.005). Overall, patients with no lysis of clot at 30 minutes and a d-dimer > 2,600 ng/mL had a venous thromboembolic event rate of 50% compared with 0% for patients with neither risk factor (p = 0.008), and had a hemodialysis rate of 80% compared with 14% (p = 0.004).

Conclusions

Fibrinolysis shutdown, as evidenced by elevated d-dimer and complete failure of clot lysis at 30 minutes on thromboelastography predicts thromboembolic events and need for hemodialysis in critically ill patients with COVID-19. Additional clinical trials are required to ascertain the need for early therapeutic anticoagulation or fibrinolytic therapy to address this state of fibrinolysis shutdown.

The Extremity/Mechanism/Shock Index/GCS (EMS-G) score: A novel pre-hospital scoring system for early and appropriate MTP activation

BACKGROUND

Numerous in-hospital scoring systems to activate massive transfusion protocols (MTP) have been proposed; however, to date, pre-hospital scoring systems have not been robustly validated. Many trauma centers do not have blood or pre-thawed plasma available in the trauma bay, leading to delays in balanced transfusion. This study aims to assess pre-hospital injury and physiologic parameters to develop a pre-hospital scoring system predictive of need for massive transfusion (MT) prior to patient arrival.

METHODS

A retrospective review of all adult full and partial trauma team activations from July 2014-July 2018 from an urban level 2 trauma center was performed utilizing our trauma registry. Stepwise logistic regression analysis was performed to develop a new scoring system, with point totals assigned proportional to the odds ratios of requiring MT for each variable. Internal validation of the EMS-G score was performed using a subset of the data which was not utilized for development of the scoring system, and sensitivity and specificity were compared to previously validated in-hospital scoring systems applied in the pre-hospital setting.

RESULTS

763 patients were included with 94 patients (12.3%) receiving early MT, defined as 4 units pRBC in 4 h or ED death. In-hospital models for predicting MT such as Assessment of Blood Consumption (ABC) or Shock Index (SI) have sensitivities and specificities of 46/85% and 94/79% respectively for early MTP utilization based on pre-hospital data. Pre-hospital variables found to be predictive of MT were used to develop the EMS-G (Extremity, Mechanism, Shock Index, GCS) score. This system assigns obvious extremity injury-1-point, penetrating mechanism -2 points, shock index ≥0.9-2 points, GCS ≤8-3 points. A score of 3 or greater was chosen to maximize sensitivity and specificity for pre-hospital MT activation. EMS-G score based on pre-hospital report is 89% sensitive, 84% specific, with a PPV of 44% and NPV of 98% for early MT. Using this system, 25% of full and partial trauma team activations met criteria for pre-hospital MTP activation.

CONCLUSION

The EMS-G Score has increased sensitivity and specificity compared to the ABC Score in the pre-hospital setting and appears more appropriate than shock index alone at predicting massive transfusion. This scoring system allows trauma centers to activate MTP prior to patient arrival to ensure early and appropriate blood product administration without blood product wastage.

Effect of Pre-Hospital Use of the Assessment of Blood Consumption Score and Pre-Thawed Fresh Frozen Plasma on Resuscitation and Trauma Mortality

BACKGROUND

Early blood product resuscitation reduces trauma patient mortality from hemorrhage. This mortality benefit depends on a system that can rapidly identify actively bleeding patients, initiate massive transfusion protocol (MTP), and mobilize resources to the bedside. We hypothesized that process improvement efforts that identify patients early and mobilize appropriate blood products to the bedside for immediate use would improve mortality.

STUDY DESIGN

Pre-implementation, MTP activation was at the discretion of the trauma surgeon, and only PRBCs were immediately available. In June 2016, the Assessment of Blood Consumption (ABC) score was incorporated in our pre-hospital triage process, and a process for thawed plasma to be available was developed. We performed a retrospective review of patients who were hypotensive on arrival or had MTP activated. We compared mortality and MTP component ratios 15 months pre- vs 15 months post-implementation.

RESULTS

Activations of MTP increased 6-fold, while the specificity of the process remained the same. In patients receiving MTP, appropriate blood product transfusion ratios increased 44%. Overall and penetrating trauma mortality improved by 23% and 41%, respectively. When divided by the Injury Severity Score (ISS), penetrating trauma mortality decreased by 65% for the ISS subgroup 15 to 24 and by 38% for ISS subgroup ≥ 25. Length of stay, ICU length of stay, and readmission rates were not significantly different.

CONCLUSIONS

Delivery of balanced blood product resuscitation is essential to confer mortality benefits. Process improvement directed at early recognition of the hemorrhagic patient, immediate product availability, and product delivery to the bedside for transfusion allows for mortality reduction without increased resource use.

Hyperosmolarity invokes distinct anti-inflammatory mechanisms in pulmonary epithelial cells: evidence from signaling and transcription layers

Hypertonic saline (HTS) has been used intravenously to reduce organ dysfunction following injury and as an inhaled therapy for cystic fibrosis lung disease. The role and mechanism of HTS inhibition was explored in the TNFα and IL-1β stimulation of pulmonary epithelial cells. Hyperosmolar (HOsm) media (400 mOsm) inhibited the production of select cytokines stimulated by TNFα and IL-1β at the level of mRNA translation, synthesis and release. In TNFα stimulated A549 cells, HOsm media inhibited I-κBα phosphorylation, NF-κB translocation into the nucleus and NF-κB nuclear binding. In IL-1β stimulated cells HOsm inhibited I-κBα phosphorylation without affecting NF-κB translocation or nuclear binding. Incubation in HOsm conditions inhibited both TNFα and IL-1β stimulated nuclear localization of interferon response factor 1 (IRF-1). Additional transcription factors such as AP-1, Erk-1/2, JNK and STAT-1 were unaffected by HOsm. HTS and sorbitol supplemented media produced comparable outcomes in all experiments, indicating that the effects of HTS were mediated by osmolarity, not by sodium. While not affecting MAPK modules discernibly in A549 cells, both HOsm conditions inhibit IRF-1 against TNFα or IL-1β, but inhibit p65 NF-kB translocation only against TNFα but not IL-1β. Thus, anti-inflammatory mechanisms of HTS/HOsm appear to disrupt cytokine signals at distinct intracellular steps.

Behavioural profile of exendin-4/naltrexone dose combinations in male rats during tests of palatable food consumption

RATIONALE

The glucagon-like peptide 1 receptor (GLP-1R) agonist exendin-4 potently suppresses food intake in animals and humans. However, little is known about the behavioural specificity of this effect either when administered alone or when co-administered with another anorectic agent.

OBJECTIVES

The present study characterises the effects of exendin-4, both alone and in combination with naltrexone, on behaviours displayed by male rats during tests with palatable mash.

METHODS

Experiment 1 examined the dose-response effects of exendin-4 (0.025-2.5 μg/kg, IP), while experiment 2 profiled the effects of low-dose combinations of the peptide (0.025 and 0.25 μg/kg) and naltrexone (0.1 mg/kg).

RESULTS

In experiment 1, exendin-4 dose dependently suppressed food intake as well as the frequency and rate of eating. However, these effects were accompanied by dose-dependent reductions in all active behaviours and, at 2.5 μg/kg, a large increase in resting and disruption of the behavioural satiety sequence (BSS). In experiment 2, while exendin-4 (0.25 μg/kg) and naltrexone each produced a significant reduction in intake and feeding behaviour (plus an acceleration in the BSS), co-treatment failed to produce stronger effects than those seen in response to either compound alone.

CONCLUSION

Similarities between the behavioural signature of exendin-4 and that previously reported for the emetic agent lithium chloride would suggest that exendin-4 anorexia is related to the aversive effects of the peptide. Furthermore, as low-dose combinations of the peptide with naltrexone failed to produce an additive/synergistic anorectic effect, this particular co-treatment strategy would not appear to have therapeutic significance.

On the behavioural specificity of hypophagia induced in male rats by mCPP, naltrexone, and their combination

RATIONALE

Serotonergic (5-hydroxytryptamine, 5-HT) and opioidergic mechanisms are intimately involved in appetite regulation.

OBJECTIVES

In view of recent evidence of positive anorectic interactions between opioid and various non-opioid substrates, our aim was to assess the behavioural specificity of anorectic responses to the opioid receptor antagonist naltrexone, the 5-HT2C/1B receptor agonist mCPP and their combination.

METHODS

Behavioural profiling techniques, including the behavioural satiety sequence (BSS), were used to examine acute drug effects in non-deprived male rats tested with palatable mash. Experiment 1 characterised the dose-response profile of mCPP (0.1-3.0 mg/kg), while experiment 2 assessed the effects of combined treatment with a sub-anorectic dose of mCPP (0.1 mg/kg) and one of two low doses of naltrexone (0.1 and 1.0 mg/kg).

RESULTS

Experiment 1 confirmed the dose-dependent anorectic efficacy of mCPP, with robust effects on intake and feeding-related measures observed at 3.0 mg/kg. However, that dose was also associated with other behavioural alterations including increased grooming, reductions in locomotion and sniffing, and disruption of the BSS. In experiment 2, naltrexone dose-dependently reduced food intake and time spent feeding, effects accompanied by a behaviourally selective acceleration in the BSS. However, the addition of 0.1 mg/kg mCPP did not significantly alter the behavioural changes observed in response to either dose of naltrexone given alone.

CONCLUSIONS

In contrast to recently reported positive anorectic interactions involving low-dose combinations of opioid receptor antagonists or mCPP with cannabinoid CB1 receptor antagonists, present results would not appear to provide any support for potentially clinically relevant anorectic interactions between opioid and 5-HT2C/1B receptor mechanisms.

Low dose naloxone attenuates the pruritic but not anorectic response to rimonabant in male rats

RATIONALE

Previous research suggests that the acute anorectic effect of cannabinoid CB1 receptor antagonist/inverse agonists may be secondary to response competition from the compulsive scratching and grooming syndrome characteristic of these agents.

OBJECTIVES

As the pruritic effect of rimonabant can be attenuated by the opioid receptor antagonist naloxone, these studies test the prediction that naloxone co-treatment should prevent acute rimonabant anorexia.

METHODS

Two experiments comprehensively profiled the behavioural effects of an anorectic dose of rimonabant (1.5 mg/kg) in the absence or presence of naloxone (experiment 1: 0.01 or 0.1 mg/kg; experiment 2: 0.05 mg/kg).

RESULTS

In both experiments, rimonabant not only significantly suppressed food intake and time spent eating but also induced compulsive scratching and grooming. In experiment 1, although the lower dose of naloxone seemed to weakly attenuate the effects of rimonabant both on ingestive and compulsive behaviours, the higher dose more strongly suppressed the compulsive elements but did not significantly affect the anorectic response. The results of experiment 2 showed that naloxone at a dose which markedly attenuated rimonabant-induced grooming and scratching did not alter the effects of the compound on food intake or time spent feeding. The apparent independence of the ingestive and compulsive effects of rimonabant was confirmed by the observation that despite a 'normalising' effect of naloxone co-treatment on behavioural structure (BSS), the opioid antagonist did not impact the suppressant effect of rimonabant on peak feeding.

CONCLUSION

The acute anorectic response to rimonabant would not appear to be secondary to compulsive scratching and grooming.

Patients' and practice nurses' perceptions of secondary preventive care for established ischaemic heart disease: a qualitative study

A significant proportion of patients with established ischaemic heart disease remain unrecognized in general practice and those who are receiving treatment are experiencing sub-optimal care. The provision of coronary prevention by practice nurses may be an important strategy to improve the quality of this care, and this is feasible and effective. This study explored what occurred during patients' initial assessment for secondary prevention of ischaemic heart disease with a practice nurse and investigated patients' and practice nurses' views ofnurse-led clinics in primary care. Nurses were effective in history taking and offering reassurance and dietary advice, yet were less confident in discussing patients' understandings of heart disease and related medication. Practice nurse-led coronary preventive care is acceptable to both nurses and patients. Further practice nurse education is required in heart disease, cardiac medications and skills necessary for exploring and challenging patients' understandings of these issues.