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.

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.

Boehler's angle and the critical angle of Gissane are of limited use in diagnosing calcaneus fractures in the ED.

STUDY OBJECTIVES: The aim of this study was to determine the use of Boehler's angle (BA) and the critical angle of Gissane (CAG) in diagnosing calcaneus fractures in the ED. DESIGN: The study was conducted as a randomized, blinded, case-control trial. CASES: One hundred thirty-three patients older than 15 years were included in the study. Sixty-five patients with computed tomography-verified calcaneus fractures (gold standard) and 68 ED patients with lateral foot or ankle x-rays without calcaneus fractures were included in the study. METHODS: One second-year emergency medicine resident, 1 third-year emergency medicine resident, 2 board-certified emergency medicine attending physicians, and 1 board-certified radiologist prospectively reviewed all films using the Picture Archival and Communication System digital radiology system. Cases and controls were randomized and the participants were blinded to final radiographic diagnoses. Participants determined whether there was a fracture on each x-ray and measured BA and the CAG using the digital angle tool in the Picture Archival and Communication System. RESULTS: Emergency physicians were 97.9% accurate in diagnosing calcaneus fractures (range, 97% to 99%). The mean kappa value for emergency physicians was 0.96 (range, 0.94-0.985). Receiver operating characteristic curves were constructed for BA and the CAG. When compared with the gold standard, the area under the curve for BA ranged from 0.82 to 0.88. The area under the curve for the CAG ranged from 0.45 to 0.67. BA had an interclass correlation coefficient of 0.84 (95% confidence interval, 0.79-0.87). The CAG interclass correlation was 0.52 (95% confidence interval, 0.43-0.60). One fracture was missed by the radiologist and all of the emergency physicians because it was only visible on computed tomography. CONCLUSION: BA is somewhat helpful and the CAG is not useful in diagnosing calcaneus fractures in the ED. Interrater reliability for BA is excellent, but for the CAG, it is poor. Emergency physicians were 97.9% accurate in making the diagnosis by reviewing the plain films without "assistance" of the angle measurements.