EMS Treatment Guidelines in Major Traumatic Brain Injury With Positive Pressure Ventilation.

Importance: The Excellence in Prehospital Injury Care (EPIC) study demonstrated improved survival in patients with severe traumatic brain injury (TBI) following implementation of the prehospital treatment guidelines. The impact of implementing these guidelines in the subgroup of patients who received positive pressure ventilation (PPV) is unknown. Objective: To evaluate the association of implementation of prehospital TBI evidence-based guidelines with survival among patients with prehospital PPV. Design, Setting, and Participants: The EPIC study was a multisystem, intention-to-treat study using a before/after controlled design. Evidence-based guidelines were implemented by emergency medical service agencies across Arizona. This subanalysis was planned a priori and included participants who received prehospital PPV. Outcomes were compared between the preimplementation and postimplementation cohorts using logistic regression, stratified by predetermined TBI severity categories (moderate, severe, or critical). Data were collected from January 2007 to June 2017, and data were analyzed from January to February 2023. Exposure: Implementation of the evidence-based guidelines for the prehospital care of patient with TBI. Main Outcomes and Measures: The primary outcome was survival to hospital discharge, and the secondary outcome was survival to admission. Results: Among the 21 852 participants in the main study, 5022 received prehospital PPV (preimplementation, 3531 participants; postimplementation, 1491 participants). Of 5022 included participants, 3720 (74.1%) were male, and the median (IQR) age was 36 (22-54) years. Across all severities combined, survival to admission improved (adjusted odds ratio [aOR], 1.59; 95% CI, 1.28-1.97), while survival to discharge did not (aOR, 0.94; 95% CI, 0.78-1.13). Within the cohort with severe TBI but not in the moderate or critical subgroups, survival to hospital admission increased (aOR, 6.44; 95% CI, 2.39-22.00), as did survival to discharge (aOR, 3.52; 95% CI, 1.96-6.34). Conclusions and Relevance: Among patients with severe TBI who received active airway interventions in the field, guideline implementation was independently associated with improved survival to hospital admission and discharge. This was true whether they received basic airway interventions or advanced airways. These findings support the current guideline recommendations for aggressive prevention/correction of hypoxia and hyperventilation in patients with severe TBI, regardless of which airway type is used.

Haboob Dust Storms and Motor Vehicle Collision-related Trauma in Phoenix, Arizona.

BACKGROUND: The Sonoran Desert region, encompassing most of southern Arizona, has an extreme climate that is famous for dust storms known as haboobs. These storms lead to decreased visibility and potentially hazardous driving conditions. In this study we evaluate the relationship between haboob events and emergency department (ED) visits due to motor vehicle collisions (MVCs) in Phoenix, Arizona. METHODS: This study is a retrospective analysis of MVC-related trauma presentations to Phoenix, AZ, hospitals before and following haboob dust storms. These events were identified from 2009-2017 primarily using Phoenix International Airport weather data. De-identified trauma data were obtained from the Arizona Department of Health Services (ADHS) Arizona State Trauma Registry (ASTR) from seven trauma centers within a 10-mile radius of the airport. We compared MVC-related trauma using six- and 24-hour windows before and following the onset of haboob events. RESULTS: There were 31,133 MVC-related trauma encounters included from 2009-2017 and 111 haboob events meeting meteorological criteria during that period. There was a 17% decrease in MVC-related ED encounters in the six hours following haboob onset compared to before onset (235 vs 283, P = 0.04), with proportionally more injuries among males (P < 0.001) and higher mortality (P = 0.02). There was no difference in frequency of presentations (P = 0.82), demographics, or outcomes among the 24-hour pre-and post-haboob groups. CONCLUSION: Haboob dust storms in Phoenix, Arizona, are associated with a decrease in MVC-related injuries during the six-hour period following storm onset, likely indicating the success of public safety messaging efforts. Males made up a higher proportion of those injured during the storms, suggesting a target for future interventions. Future public-targeted weather-safety initiatives should be accompanied more closely by monitoring and evaluation efforts to assess for effectiveness.

Correlation between prehospital and in-hospital hypotension and outcomes after traumatic brain injury.

BACKGROUND AND OBJECTIVE: Hypotension has a powerful effect on patient outcome after traumatic brain injury (TBI). The relative impact of hypotension occurring in the field versus during early hospital resuscitation is unknown. We evaluated the association between hypotension and mortality and non-mortality outcomes in four cohorts defined by where the hypotension occurred [neither prehospital nor hospital, prehospital only, hospital only, both prehospital and hospital]. METHODS: Subjects ≥10 years with major TBI were included. Standard statistics were used for unadjusted analyses. We used logistic regression, controlling for significant confounders, to determine the adjusted odds (aOR) for outcomes in each of the three cohorts. RESULTS: Included were 12,582 subjects (69.8% male; median age 44 (IQR 26-61). Mortality by hypotension status: No hypotension: 9.2% (95%CI: 8.7-9.8%); EMS hypotension only: 27.8% (24.6-31.2%); hospital hypotension only: 45.6% (39.1-52.1%); combined EMS/hospital hypotension 57.6% (50.0-65.0%); (p < 0.0001). The aOR for death reflected the same progression: 1.0 (reference-no hypotension), 1.8 (1.39-2.33), 2.61 (1.73-3.94), and 4.36 (2.78-6.84), respectively. The proportion of subjects having hospital hypotension was 19.0% (16.5-21.7%) in those with EMS hypotension compared to 2.0% (1.8-2.3%) for those without (p < 0.0001). Additionally, the proportion of patients with TC hypotension was increased even with EMS "near hypotension" up to an SBP of 120 mmHg [(aOR 3.78 (2.97, 4.82)]. CONCLUSION: While patients with hypotension in the field or on arrival at the trauma center had markedly increased risk of death compared to those with no hypotension, those with prehospital hypotension that was not resolved before hospital arrival had, by far, the highest odds of death. Furthermore, TBI patients who had prehospital hypotension were five times more likely to arrive hypotensive at the trauma center than those who did not. Finally, even "near-hypotension" in the field was strongly and independently associated the risk of a hypotensive hospital arrival (<90 mmHg). These findings are supportive of the prehospital guidelines that recommend aggressive prevention and treatment of hypotension in major TBI.

Optimal Out-of-Hospital Blood Pressure in Major Traumatic Brain Injury: A Challenge to the Current Understanding of Hypotension.

STUDY OBJECTIVE: Little is known about the out-of-hospital blood pressure ranges associated with optimal outcomes in traumatic brain injuries (TBI). Our objective was to evaluate the associations between out-of-hospital systolic blood pressure (SBP) and multiple hospital outcomes without assuming any predefined thresholds for hypotension, normotension, or hypertension. METHODS: This was a preplanned secondary analysis from the Excellence in Prehospital Injury Care (EPIC) TBI study. Among patients (age ≥10 years) with major TBIs (Barell Matrix type 1 and/or Abbreviated Injury Scale-head severity ≥3) and lowest out-of-hospital SBPs of 40 to 299 mmHg, we utilized generalized additive models to summarize the distributions of various outcomes as smoothed functions of SBP, adjusting for important and significant confounders. The subjects who were enrolled in the study phase after the out-of-hospital TBI guideline implementation were used to validate the models developed from the preimplementation cohort. RESULTS: Among 12,169 included cases, the mortality model revealed 3 distinct ranges: (1) a monotonically decreasing relationship between SBP and the adjusted probability of death from 40 to 130 mmHg, (2) lowest adjusted mortality from 130 to 180 mmHg, and (3) rapidly increasing mortality above 180 mmHg. A subanalysis of the cohorts with isolated TBIs and multisystem injuries with TBIs revealed SBP mortality patterns that were similar to each other and to that of the main analysis. While the specific SBP ranges varied somewhat for the nonmortality outcomes (hospital length of stay, ICU length of stay, discharge to skilled nursing/inpatient rehabilitation, and hospital charges), the patterns were very similar to that of mortality. In each model, validation was confirmed utilizing the postimplementation cohort. CONCLUSION: Optimal adjusted mortality was associated with a surprisingly high SBP range (130 to 180 mmHg). Below this level, there was no point or range of inflection that would indicate a physiologically meaningful threshold for defining hypotension. Nonmortality outcomes showed very similar patterns. These findings highlight how sensitive the injured brain is to compromised perfusion at SBP levels that, heretofore, have been considered adequate or even normal. While the study design does did not allow us to conclude that the currently recommended treatment threshold (<90 mmHg) should be increased, the findings imply that the definition of hypotension in the setting of TBI is too low. Randomized trials evaluating treatment levels significantly higher than 90 mmHg are needed.

Effect of Implementing the Out-of-Hospital Traumatic Brain Injury Treatment Guidelines: The Excellence in Prehospital Injury Care for Children Study (EPIC4Kids).

STUDY OBJECTIVE: We evaluate the effect of implementing the out-of-hospital pediatric traumatic brain injury guidelines on outcomes in children with major traumatic brain injury. METHODS: The Excellence in Prehospital Injury Care for Children study is the preplanned secondary analysis of the Excellence in Prehospital Injury Care study, a multisystem, intention-to-treat study using a before-after controlled design. This subanalysis included children younger than 18 years who were transported to Level I trauma centers by participating out-of-hospital agencies between January 1, 2007, and June 30, 2015, throughout Arizona. The primary and secondary outcomes were survival to hospital discharge or admission for children with major traumatic brain injury and in 3 subgroups, defined a priori as those with moderate, severe, and critical traumatic brain injury. Outcomes in the preimplementation and postimplementation cohorts were compared with logistic regression, adjusting for risk factors and confounders. RESULTS: There were 2,801 subjects, 2,041 in preimplementation and 760 in postimplementation. The primary analysis (postimplementation versus preimplementation) yielded an adjusted odds ratio of 1.16 (95% confidence interval 0.70 to 1.92) for survival to hospital discharge and 2.41 (95% confidence interval 1.17 to 5.21) for survival to hospital admission. In the severe traumatic brain injury cohort (Regional Severity Score-Head 3 or 4), but not the moderate or critical subgroups, survival to discharge significantly improved after guideline implementation (adjusted odds ratio = 8.42; 95% confidence interval 1.01 to 100+). The improvement in survival to discharge among patients with severe traumatic brain injury who received positive-pressure ventilation did not reach significance (adjusted odds ratio = 9.13; 95% confidence interval 0.79 to 100+). CONCLUSION: Implementation of the pediatric out-of-hospital traumatic brain injury guidelines was not associated with improved survival when the entire spectrum of severity was analyzed as a whole (moderate, severe, and critical). However, both adjusted survival to hospital admission and discharge improved in children with severe traumatic brain injury, indicating a potential severity-based interventional opportunity for guideline effectiveness. These findings support the widespread implementation of the out-of-hospital pediatric traumatic brain injury guidelines.

Prehospital Protocols Reducing Long Spinal Board Use Are Not Associated with a Change in Incidence of Spinal Cord Injury.

Introduction: Many emergency medical services (EMS) agencies have de-emphasized or eliminated the use of long spinal boards (LSB) for patients with possible spinal injury. We sought to determine if implementation of spinal motion restriction (SMR) protocols, which reduce LSB use, was associated with an increase in spinal cord injury (SCI). Methods: This retrospective observational study includes EMS encounters from January 1, 2013 to December 31, 2015 submitted by SMR-adopting ground-based agencies to a state EMS database with hospital discharge data. Encounters were excluded if SMR implementation date was unknown, occurred during a 3-month run-in period, or were duplicates. Study samples include patients with traumatic injury (TI), possible spinal trauma (P-ST), and verified spinal trauma (V-ST) using hospital discharge ICD-9/10 diagnosis codes. The incidence of SCI before and after implementation of SMR was compared using Chi-squared and logistic regression. Results: From 1,005,978 linked encounters, 104,315 unique encounters with traumatic injury and known SMR implementation date were identified with 51,199 cases of P-ST and 5,178 V-ST cases. The incidence of SCI in the pre-SMR and post-SMR interval for each group was: TI, 0.20% vs. 0.22% (p = 0.390); P-ST, 0.40% vs. 0.45% (p = 0.436); and V-ST, 4.04% vs. 4.37% (p = 0.561). Age and injury severity adjusted odds ratio of SCI in the highest risk cohort of patients with V-ST was 1.097 after SMR implementation (95% CI 0.818-1.472). Conclusion: In this limited study, no change in the incidence of SCI was identified following implementation of SMR protocols. Prospective evaluation of this question is necessary to evaluate the safety of SMR protocols.

Improving the Continuum of Care by Bridging the Gap between Prehospital and Hospital Discharge Data through Stepwise Deterministic Linkage.

Objective: To describe the process, benefits, and challenges of linking Arizona's prehospital registry to hospital discharge data. Methods: Data were queried from the Arizona Prehospital Information and Emergency Medical Services Registry System (AZ-PIERS) and the Arizona Hospital Discharge Database (HDD) for the calendar year 2015. To maximize the number of matched records, the databases were deterministically linked in 17 steps using different combinations/variations of patient personal identifiers. Random samples of at least 1% of matched pairs from each of 16 linkage steps (excluding Step 1) were manually reviewed to assess the rate of false positive matches. Results: A total of 626,413 records were reported to AZ-PIERS in 2015. Of those, 503,715 qualified for linkage. These records were matched against 3,125,689 discharge records reported to the HDD in 2015. The first step, which involved exact matching on first name, last name, date of birth, gender, and date of incident/date of admission, yielded a linkage of 64.6% (n = 325,156). The 16 successive steps yielded a further linkage of 26.6% (n = 134,006) for a total linkage of 91.2% (n = 459,162). The manual review indicated an overall false positive match rate for the 16 reviewed steps of 6.96% (n = 99). The 2 steps with the highest false positive match rates were Step 16 (43.02%, n = 77) and Step 17 (31.43%, n = 11). Conclusion: It is feasible to link prehospital and hospital data using stepwise deterministic linkage; this method returns a high linkage rate with a low false positive error rate. Data linkage is vital to identifying and bridging gaps in the continuum of care and is a useful tool in statewide and agency-specific research and quality improvement.

Association of Statewide Implementation of the Prehospital Traumatic Brain Injury Treatment Guidelines With Patient Survival Following Traumatic Brain Injury: The Excellence in Prehospital Injury Care (EPIC) Study.

Importance: Traumatic brain injury (TBI) is a massive public health problem. While evidence-based guidelines directing the prehospital treatment of TBI have been promulgated, to our knowledge, no studies have assessed their association with survival. Objective: To evaluate the association of implementing the nationally vetted, evidence-based, prehospital treatment guidelines with outcomes in moderate, severe, and critical TBI. Design, Setting, and Participants: The Excellence in Prehospital Injury Care (EPIC) Study included more than 130 emergency medical services systems/agencies throughout Arizona. This was a statewide, multisystem, intention-to-treat study using a before/after controlled design with patients with moderate to critically severe TBI (US Centers for Disease Control and Prevention Barell Matrix-Type 1 and/or Abbreviated Injury Scale Head region severity ≥3) transported to trauma centers between January 1, 2007, and June 30, 2015. Data were analyzed between October 25, 2017, and February 22, 2019. Interventions: Implementation of the prehospital TBI guidelines emphasizing avoidance/treatment of hypoxia, prevention/correction of hyperventilation, and avoidance/treatment of hypotension. Main Outcomes and Measures: Primary: survival to hospital discharge; secondary: survival to hospital admission. Results: Of the included patients, the median age was 45 years, 14 666 (67.1%) were men, 7181 (32.9%) were women; 16 408 (75.1% ) were white, 1400 (6.4%) were Native American, 743 (3.4% ) were Black, 237 (1.1%) were Asian, and 2791 (12.8%) were other race/ethnicity. Of the included patients, 21 852 met inclusion criteria for analysis (preimplementation phase [P1]: 15 228; postimplementation [P3]: 6624). The primary analysis (P3 vs P1) revealed an adjusted odds ratio (aOR) of 1.06 (95% CI, 0.93-1.21; P = .40) for survival to hospital discharge. The aOR was 1.70 (95% CI, 1.38-2.09; P < .001) for survival to hospital admission. Among the severe injury cohorts (but not moderate or critical), guideline implementation was significantly associated with survival to discharge (Regional Severity Score-Head 3-4: aOR, 2.03; 95% CI, 1.52-2.72; P < .001; Injury Severity Score 16-24: aOR, 1.61; 95% CI, 1.07-2.48; P = .02). This was also true for survival to discharge among the severe, intubated subgroups (Regional Severity Score-Head 3-4: aOR, 3.14; 95% CI, 1.65-5.98; P < .001; Injury Severity Score 16-24: aOR, 3.28; 95% CI, 1.19-11.34; P = .02). Conclusions and Relevance: Statewide implementation of the prehospital TBI guidelines was not associated with significant improvement in overall survival to hospital discharge (across the entire, combined moderate to critical injury spectrum). However, adjusted survival doubled among patients with severe TBI and tripled in the severe, intubated cohort. Furthermore, guideline implementation was significantly associated with survival to hospital admission. These findings support the widespread implementation of the prehospital TBI treatment guidelines. Trial Registration: ClinicalTrials.gov identifier: NCT01339702.

Death by Suicide-The EMS Profession Compared to the General Public.

BACKGROUND: In 2016, nearly 45,000 deaths in the United States were attributed to suicide making this the 10th leading cause of death for all ages. National survey data suggest that among Emergency Medical Technicians (EMTs), including firefighters and Paramedics, rates of suicide are significantly higher than among the general public. EMTs face high levels of acute and chronic stress as well as high rates of depression and substance abuse, which increase their risk of suicide. OBJECTIVE/AIM: To determine the statewide Mortality Odds Ratio (MOR) of suicide completion among EMTs as compared to non-EMTs in Arizona. METHODS: We analyzed the Arizona Vital Statistics Information Management System Electronic Death Registry of all adult (≥18) deaths between January 1, 2009 and December 31, 2015. Manual review of decedent occupation was performed to identify the EMT cohort; all other deaths were included in the non-EMT cohort. Using the underlying cause of death as the outcome, we calculated the MOR of both the EMT and non-EMT cohorts. RESULTS: There were a total of 350,998 deaths during the study period with 7,838 categorized as suicide. The proportion of deaths attributed to suicide among EMTs was 5.2% (63 of 1,205 total deaths) while the percentage among non-EMTs was 2.2% (7,775/349,793) (p < 0.0001). The crude Mortality Odds Ratio for EMTs compared with non-EMTs was [cMOR 2.43; 95% CI (1.88-3.13)]. After adjusting for gender, age, race, and ethnicity, EMTs had higher odds that their death was by suicide than non-EMTs [aMOR: 1.39; 95% CI (1.06-1.82)]. CONCLUSION: In this statewide analysis, we found that EMTs had a significantly higher Mortality Odds Ratio due to suicide compared to non-EMTs. Further research is necessary to identify the underlying causes of suicide among EMTs and to develop effective prevention strategies.

Trends in overdose-related out-of-hospital cardiac arrest in Arizona.

AIM: Opioid overdose mortality has increased in North America; however, recent regional trends in the proportion of treated overdose-related out-of-hospital cardiac arrest (OD-OHCA) compared to out-of-hospital cardiac arrest of presumed cardiac etiology (C-OHCA) are largely unknown. Our aim is to assess trends in the prevalence and outcomes of OD-OHCAs compared to C-OHCAs in Arizona. METHODS: Statewide, observational study utilizing an Utstein-style database with EMS-first care reports linked with hospital records, and vital statistics data from 2010 to 2015. RESULTS: There were 21,658 OHCAs during the study period. After excluding non-C-OHCAs, non-OD-OHCAs, and cases missing outcome data, 18,562 cases remained. Of these remaining cases, 17,591 (94.8%) were C-OHCAs and 971 (5.2%) were OD-OHCAs. There was a significant increase in the proportion of OD-OHCAs from 2010, 4.7% (95% CI: 3.9-5.5) to 2015, 6.6% (95% CI: 5.8-7.5). Mean age for OD-OHCAs was 38 years compared to 66 years for C-OHCAs, (p < 0.0001). Initial shockable rhythm was present in 7.1% of OD-OHCAs vs. 22.6% of C-OHCAs (p < 0.0001). Overall survival to discharge in the OD-OHCA group was 18.6% vs. 11.9% in C-OHCA (p < 0.0001). After risk adjustment, we found an aOR of 2.1 (95% CI: 1.8-2.6) for survival in OD-OHCA compared to C-OHCA. CONCLUSION: There has been a significant increase in the proportion of OD-OHCAs in Arizona between 2010-2015. OD-OHCA patients were younger, were less likely to present with a shockable rhythm, and more likely to survive than patients with C-OHCA. These data should be considered in prevention and treatment efforts.

Quantification of ventilation volumes produced by compressions during emergency department cardiopulmonary resuscitation.

BACKGROUND: Clinical investigations have shown improved outcomes with primary compression cardiopulmonary resuscitation strategies. It is unclear whether this is a result of passive ventilation via chest compressions, a low requirement for any ventilation during the early aspect of resuscitation or avoidance of inadvertent over-ventilation. OBJECTIVES: To quantify whether chest compressions with guideline-compliant depth (>2 in) produce measurable and substantial ventilation volumes during emergency department resuscitation of out-of-hospital cardiac arrest. METHODS: This was a prospective, convenience sampling of adult non-traumatic out-of-hospital cardiac arrest patients receiving on-going cardiopulmonary resuscitation in an academic emergency department from June 1, 2011 to July 30, 2013. Cardiopulmonary resuscitation quality files were analyzed using R-Series defibrillator/monitors (ZOLL Medical) and ventilation data were measured using a Non-Invasive Cardiac Output monitor (Philips/Respironics, Wallingford, CT). RESULTS: cardiopulmonary resuscitation quality data were analyzed from 21 patients (17 males, median age 59). The median compression depth was 2.2 in (IQR = 1.9, 2.5) and the median chest compression fraction was 88.4% (IQR = 82.2, 94.1). We were able to discern 580 ventilations that occurred during compressions. The median passive tidal volume recorded during compressions was 7.5 ml (IQR 3.5, 12.6). While the highest volume recorded was 45.8 ml, 81% of the measured tidal volumes were <20 ml. CONCLUSION: Ventilation volume measurements during emergency department cardiopulmonary resuscitation after out-of-hospital cardiac arrest suggest that chest compressions alone, even those meeting current guideline recommendations for depth, do not provide physiologically significant tidal volumes.

Association between coronary angiography with or without percutaneous coronary intervention and outcomes after out-of-hospital cardiac arrest.

AIM: The aim of our study was to assess the impact of coronary angiography (CAG) after out-of-hospital cardiac arrest (OHCA) without ST-elevation (STE). METHODS: Prospective observational study of adult (age ≥ 18) OHCA of presumed cardiac etiology from 1/01/2010-12/31/2014 admitted to one of 40 recognized cardiac receiving centers within a statewide resuscitation network. RESULTS: Among 11,976 cases, 1881 remained for analysis after exclusions. Of the 1230 non-STE cases, 524 (43%) underwent CAG with resultant PCI in 157 (30%). Survival in non-STE cases was: 56% in cases without CAG; 82% in cases with CAG but without PCI; and 78% in those with PCI (p < 0.0001). In cases without STE the aOR for survival with CAG alone was 2.34 (95% CI 1.69-3.24) and for CAG plus PCI was 1.98 (95% CI 1.26-3.09). The aOR for CPC 1/2 with CAG alone was 6.89 (95% CI 3.99-11.91) and for CAG plus PCI was 2.95 (95% CI 1.59-5.47). After propensity matching, CAG was associated with an aOR for survival of 2.10 (95% CI 1.30-3.55) and for CPC 1/2 it was 5.06 (95% CI 2.29-11.19). CONCLUSION: In OHCA without STE, CAG was strongly and independently associated with survival regardless of whether PCI was performed. The association between CAG and positive outcomes remained after propensity matching.

Description of Abnormal Breathing Is Associated With Improved Outcomes and Delayed Telephone Cardiopulmonary Resuscitation Instructions.

BACKGROUND: Emergency 9-1-1 callers use a wide range of terms to describe abnormal breathing in persons with out-of-hospital cardiac arrest (OHCA). These breathing descriptors can obstruct the telephone cardiopulmonary resuscitation (CPR) process. METHODS AND RESULTS: We conducted an observational study of emergency call audio recordings linked to confirmed OHCAs in a statewide Utstein-style database. Breathing descriptors fell into 1 of 8 groups (eg, gasping, snoring). We divided the study population into groups with and without descriptors for abnormal breathing to investigate the impact of these descriptors on patient outcomes and telephone CPR process. Callers used descriptors in 459 of 2411 cases (19.0%) between October 1, 2010, and December 31, 2014. Survival outcome was better when the caller used a breathing descriptor (19.6% versus 8.8%, P<0.0001), with an odds ratio of 1.63 (95% confidence interval, 1.17-2.25). After exclusions, 379 of 459 cases were eligible for process analysis. When callers described abnormal breathing, the rates of telecommunicator OHCA recognition, CPR instruction, and telephone CPR were lower than when callers did not use a breathing descriptor (79.7% versus 93.0%, P<0.0001; 65.4% versus 72.5%, P=0.0078; and 60.2% versus 66.9%, P=0.0123, respectively). The time interval between call receipt and OHCA recognition was longer when the caller used a breathing descriptor (118.5 versus 73.5 seconds, P<0.0001). CONCLUSIONS: Descriptors of abnormal breathing are associated with improved outcomes but also with delays in the identification of OHCA. Familiarizing telecommunicators with these descriptors may improve the telephone CPR process including OHCA recognition for patients with increased probability of survival.

Association of Out-of-Hospital Hypotension Depth and Duration With Traumatic Brain Injury Mortality.

STUDY OBJECTIVE: Out-of-hospital hypotension has been associated with increased mortality in traumatic brain injury. The association of traumatic brain injury mortality with the depth or duration of out-of-hospital hypotension is unknown. We evaluated the relationship between the depth and duration of out-of-hospital hypotension and mortality in major traumatic brain injury. METHODS: We evaluated adults and older children with moderate or severe traumatic brain injury in the preimplementation cohort of Arizona's statewide Excellence in Prehospital Injury Care study. We used logistic regression to determine the association between the depth-duration dose of hypotension (depth of systolic blood pressure <90 mm Hg integrated over duration [minutes] of hypotension) and odds of inhospital death, controlling for significant confounders. RESULTS: There were 7,521 traumatic brain injury cases included (70.6% male patients; median age 40 years [interquartile range 24 to 58]). Mortality was 7.8% (95% confidence interval [CI] 7.2% to 8.5%) among the 6,982 patients without hypotension (systolic blood pressure ≥90 mm Hg) and 33.4% (95% CI 29.4% to 37.6%) among the 539 hypotensive patients (systolic blood pressure <90 mm Hg). Mortality was higher with increased hypotension dose: 0.01 to 14.99 mm Hg-minutes 16.3%; 15 to 49.99 mm Hg-minutes 28.1%; 50 to 141.99 mm Hg-minutes 38.8%; and greater than or equal to 142 mm Hg-minutes 50.4%. Log2 (the logarithm in base 2) of hypotension dose was associated with traumatic brain injury mortality (adjusted odds ratio 1.19 [95% CI 1.14 to 1.25] per 2-fold increase of dose). CONCLUSION: In this study, the depth and duration of out-of-hospital hypotension were associated with increased traumatic brain injury mortality. Assessments linking out-of-hospital blood pressure with traumatic brain injury outcomes should consider both depth and duration of hypotension.

Body Temperature after EMS Transport: Association with Traumatic Brain Injury Outcomes.

INTRODUCTION: Low body temperatures following prehospital transport are associated with poor outcomes in patients with traumatic brain injury (TBI). However, a minimal amount is known about potential associations across a range of temperatures obtained immediately after prehospital transport. Furthermore, a minimal amount is known about the influence of body temperature on non-mortality outcomes. The purpose of this study was to assess the correlation between temperatures obtained immediately following prehospital transport and TBI outcomes across the entire range of temperatures. METHODS: This retrospective observational study included all moderate/severe TBI cases (CDC Barell Matrix Type 1) in the pre-implementation cohort of the Excellence in Prehospital Injury Care (EPIC) TBI Study (NIH/NINDS: 1R01NS071049). Cases were compared across four cohorts of initial trauma center temperature (ITCT): <35.0°C [Very Low Temperature (VLT)]; 35.0-35.9°C [Low Temperature (LT)]; 36.0-37.9°C [Normal Temperature (NT)]; and ≥38.0°C [Elevated Temperature (ET)]. Multivariable analysis was performed adjusting for injury severity score, age, sex, race, ethnicity, blunt/penetrating trauma, and payment source. Adjusted odds ratios (aORs) with 95% confidence intervals (CI) for mortality were calculated. To evaluate non-mortality outcomes, deaths were excluded and the adjusted median increase in hospital length of stay (LOS), ICU LOS and total hospital charges were calculated for each ITCT group and compared to the NT group. RESULTS: 22,925 cases were identified and cases with interfacility transfer (7361, 32%), no EMS transport (1213, 5%), missing ITCT (2083, 9%), or missing demographic data (391, 2%) were excluded. Within this study cohort the aORs for death (compared to the NT group) were 2.41 (CI: 1.83-3.17) for VLT, 1.62 (CI: 1.37-1.93) for LT, and 1.86 (CI: 1.52-3.00) for ET. Similarly, trauma center (TC) LOS, ICU LOS, and total TC charges increased in all temperature groups when compared to NT. CONCLUSION: In this large, statewide study of major TBI, both ETs and LTs immediately following prehospital transport were independently associated with higher mortality and with increased TC LOS, ICU LOS, and total TC charges. Further study is needed to identify the causes of abnormal body temperature during the prehospital interval and if in-field measures to prevent temperature variations might improve outcomes.

Mortality and Prehospital Blood Pressure in Patients With Major Traumatic Brain Injury: Implications for the Hypotension Threshold.

IMPORTANCE: Current prehospital traumatic brain injury guidelines use a systolic blood pressure threshold of less than 90 mm Hg for treating hypotension for individuals 10 years and older based on studies showing higher mortality when blood pressure drops below this level. However, the guidelines also acknowledge the weakness of the supporting evidence. OBJECTIVE: To evaluate whether any statistically supportable threshold between systolic pressure and mortality emerges from the data a priori, without assuming that a cut point exists. DESIGN, SETTING, AND PARTICIPANTS: Observational evaluation of a large prehospital database established as a part of the Excellence in Prehospital Injury Care Traumatic Brain Injury Study. Patients from the preimplementation cohort (January 2007 to March 2014) 10 years and older with moderate or severe traumatic brain injury (Barell Matrix Type 1 classification, International Classification of Diseases, Ninth Revision head region severity score of 3 or greater, and/or Abbreviated Injury Scale head-region severity score of 3 or greater) and a prehospital systolic pressure between 40 and 119 mm Hg were included. The generalized additive model and logistic regression were used to determine the association between systolic pressure and probability of death, adjusting for significant/important confounders. MAIN OUTCOMES AND MEASURES: The main outcome measure was in-hospital mortality. RESULTS: Among the 3844 included patients, 2565 (66.7%) were male, and the median (range) age was 35 (10-99) years. The model revealed a monotonically decreasing association between systolic pressure and adjusted probability of death across the entire range (ie, from 40 to 119 mm Hg). Each 10-point increase of systolic pressure was associated with a decrease in the adjusted odds of death of 18.8% (adjusted odds ratio, 0.812; 95% CI, 0.748-0.883). Thus, the adjusted odds of mortality increased as much for a drop from 110 to 100 mm Hg as for a drop from 90 to 80 mm Hg, and so on throughout the range. CONCLUSIONS AND RELEVANCE: We found a linear association between lowest prehospital systolic blood pressure and severity-adjusted probability of mortality across an exceptionally wide range. There is no identifiable threshold or inflection point between 40 and 119 mm Hg. Thus, in patients with traumatic brain injury, the concept that 90 mm Hg represents a unique or important physiological cut point may be wrong. Furthermore, clinically meaningful hypotension may not be as low as current guidelines suggest. Randomized trials evaluating treatment levels significantly above 90 mm Hg are needed.

The Effect of Combined Out-of-Hospital Hypotension and Hypoxia on Mortality in Major Traumatic Brain Injury.

STUDY OBJECTIVE: Survival is significantly reduced by either hypotension or hypoxia during the out-of-hospital management of major traumatic brain injury. However, only a handful of small studies have investigated the influence of the combination of both hypotension and hypoxia occurring together. In patients with major traumatic brain injury, we evaluate the associations between mortality and out-of-hospital hypotension and hypoxia separately and in combination. METHODS: All moderate or severe traumatic brain injury cases in the preimplementation cohort of the Excellence in Prehospital Injury Care study (a statewide, before/after, controlled study of the effect of implementing the out-of-hospital traumatic brain injury treatment guidelines) from January 1, 2007, to March 31, 2014, were evaluated (exclusions: <10 years, out-of-hospital oxygen saturation ≤10%, and out-of-hospital systolic blood pressure <40 or >200 mm Hg). The relationship between mortality and hypotension (systolic blood pressure <90 mm Hg) or hypoxia (saturation <90%) was assessed with multivariable logistic regression, controlling for Injury Severity Score, head region severity, injury type (blunt versus penetrating), age, sex, race, ethnicity, payer, interhospital transfer, and trauma center. RESULTS: Among the 13,151 patients who met inclusion criteria (median age 45 years; 68.6% men), 11,545 (87.8%) had neither hypotension nor hypoxia, 604 (4.6%) had hypotension only, 790 (6.0%) had hypoxia only, and 212 (1.6%) had both hypotension and hypoxia. Mortality for the 4 study cohorts was 5.6%, 20.7%, 28.1%, and 43.9%, respectively. The crude and adjusted odds ratios for death within the cohorts, using the patients with neither hypotension nor hypoxia as the reference, were 4.4 and 2.5, 6.6 and 3.0, and 13.2 and 6.1, respectively. Evaluation for an interaction between hypotension and hypoxia revealed that the effects were additive on the log odds of death. CONCLUSION: In this statewide analysis of major traumatic brain injury, combined out-of-hospital hypotension and hypoxia were associated with significantly increased mortality. This effect on survival persisted even after controlling for multiple potential confounders. In fact, the adjusted odds of death for patients with both hypotension and hypoxia were more than 2 times greater than for those with either hypotension or hypoxia alone. These findings seem supportive of the emphasis on aggressive prevention and treatment of hypotension and hypoxia reflected in the current emergency medical services traumatic brain injury treatment guidelines but clearly reveal the need for further study to determine their influence on outcome.

Duration of Coma in Out-of-Hospital Cardiac Arrest Survivors Treated With Targeted Temperature Management.

STUDY OBJECTIVE: We evaluate the time to awakening after out-of-hospital cardiac arrest in patients treated with targeted temperature management and determine whether there was an association with any patient or event characteristics. METHODS: This was a prospective, observational cohort study of consecutive adult survivors of out-of-hospital cardiac arrest of presumed cardiac cause who were treated with targeted temperature management between January 1, 2008, and March 31, 2014. Data were obtained from hospitals and emergency medical services agencies responding to approximately 90% of Arizona's population as part of a state-sponsored out-of-hospital cardiac arrest quality improvement initiative. RESULTS: Among 573 out-of-hospital cardiac arrest patients who completed targeted temperature management, 316 became responsive, 60 (19.0%) of whom woke up at least 48 hours after rewarming. Eight patients (2.5%) became responsive more than 7 days after rewarming, 6 of whom were discharged with a good Cerebral Performance Category score (1 or 2). There were no differences in standard Utstein variables between the early and late awakeners. The early awakeners were more likely to be discharged with a good Cerebral Performance Category score (odds ratio 2.93; 95% confidence interval 1.09 to 7.93). CONCLUSION: We found that a substantial proportion of adult out-of-hospital cardiac arrest survivors treated with targeted temperature management became responsive greater than 48 hours after rewarming, with a resultant good neurologic outcome.

Barriers to telephone cardiopulmonary resuscitation in public and residential locations.

AIM: Emergency medical telecommunicators can play a key role in improving outcomes from out-of-hospital cardiac arrest (OHCA) by providing instructions for cardiopulmonary resuscitation (CPR) to callers. Telecommunicators, however, frequently encounter barriers that obstruct the Telephone CPR (TCPR) process. The nature and frequency of these barriers in public and residential locations have not been well investigated. The aim of this study is to identify the barriers to TCPR in public and residential locations. METHODS: We conducted a retrospective study of audio recordings of EMS-confirmed OHCAs from eight regional 9-1-1 dispatch centers between January 2012 and December 2013. RESULTS: We reviewed 1850 eligible cases (public location OHCAs: N=223 and residential location OHCAs: N=1627). Telecommunicators less frequently encountered barriers such as inability to calm callers in public than in residential locations (2.1% vs 8.5%, p=0.002) or inability to place victims on a hard flat surface (13.9% vs 25.4%, p<0.001). However, the barrier where callers were not with patients was more frequently observed in public than in residential locations (11.8% vs 2.7%, p<0.001). CONCLUSIONS: This study revealed that barriers to TCPR are distributed differently across public and residential locations. Understanding these differences can aid in the development of strategies to enhance bystander CPR and improve overall patient outcomes.

Racial/Ethnic Disparities in Rates of Traumatic Injury in Arizona, 2011-2012.

OBJECTIVE: The purpose of this study was to compare the rates of traumatic injury among five racial/ethnic groups in Arizona and to identify which mechanisms and intents of traumatic injury were predominant in each group. METHODS: We obtained 2011 and 2012 data on traumatic injury from Arizona's trauma registry and data on mortality from Arizona's death registry. We calculated location- and age-adjusted rates (aRs) of traumatic injury and rates of mortality per 100,000 Arizona residents and rate ratios (RRs) for each racial/ethnic group. We also calculated race/ethnicity specific aRs and RRs by mechanism of injury, intent of injury, and alcohol use. RESULTS: We analyzed data on 58,034 cases of traumatic injury. After adjusting for age and location, American Indians/Alaska Natives (AI/ANs) had the highest overall rate of traumatic injury (n = 6,287; aR = 729) and Asian Americans/Pacific Islanders had the lowest overall rate of traumatic injury (n = 553; aR = 141). By intent, AI/ANs had the highest rate of homicide/assault-related traumatic injury (n = 2,170; aR = 221) and by mechanism, non-Hispanic black/African American people had the highest rate of firearm-related traumatic injury (n = 265; aR = 40). In 2011-2012, 8,868 deaths in Arizona were related to traumatic injury. AI/ANs had the highest adjusted mortality rate (n = 716; aR = 95). CONCLUSION: Racial/ethnic disparities in traumatic injuries persisted after adjusting for age and injury location. Understanding how these disparities differ by mechanism, intent, and alcohol use may lead to the development of more effective initiatives to prevent traumatic injury.