A Simpler Method for Choosing Adult i-gel Size: An Evaluation of Real-World Prehospital Data.

OBJECTIVE: The i-gel supraglottic airway device (Intersurgical, Berkshire, UK) is commonly used in the United States and worldwide for prehospital airway management. Previous research has suggested that a sex-based method of size selection (4.0 for female patients and 5.0 for male patients) is superior to a weight-based method in patients undergoing elective anesthesia. Our objective was to compare a sex-based i-gel size selection strategy with a weight-based strategy using real-world prehospital data. METHODS: The ESO Data Collaborative 2018 to 2022 dataset was used. All initial i-gel insertion attempts in patients > 18 years of age were evaluated for inclusion. Insertion attempts were excluded if age, sex, weight, success, or device size was not documented. Logistic regression was used to compare the rate of insertion failure on the first attempt for the group placed in alignment with the weight-based but not sex-based method with the group placed in alignment with the sex-based but not weight-based method. RESULTS: After the application of the exclusion criteria, 39,867 initial i-gel insertion attempts were included. The overall rate of failure was 6.5% (2,585/39,867). The rate of unsuccessful i-gel placement was similar when i-gel devices were placed in alignment with a sex-based size selection method in comparison to i-gel placement in alignment with a weight-based selection strategy (6.0% vs. 6.4%). Logistic regression analysis did not reveal a significant difference between groups (odds ratio: 1.08; 95% confidence interval: 0.95-1.23). CONCLUSION: The use of a sex-based method of i-gel size selection may be equivalent with respect to the rate of unsuccessful i-gel placement on the first attempt in comparison to a weight-based method.

A retrospective, multi-agency 'target trial emulation' for the comparison of post-resuscitation epinephrine to norepinephrine.

INTRODUCTION: Epinephrine and norepinephrine are the two most commonly used prehospital vasopressors in the United States. Prior studies have suggested that use of a post-ROSC epinephrine infusion may be associated with increased rearrest and mortality in comparison to use of norepinephrine. We used target trial emulation methodology to compare the rates of rearrest and mortality between the groups of OHCA patients receiving these vasopressors in the prehospital setting. METHODS: Adult (18-80 years of age) non-traumatic OHCA patients in the 2018-2022 ESO Data Collaborative datasets with a documented post-ROSC norepinephrine or epinephrine infusion were included in this study. Logistic regression modeling was used to evaluate the association between vasopressor agent and outcome using two sets of covariables. The first set of covariables included standard Utstein factors, the dispatch to ROSC interval, the ROSC to vasopressor interval, and the follow-up interval. The second set added prehospital systolic blood pressure and SpO2 values. Kaplan-Meier time-to-event analysis was also conducted and the vasopressor groups were compared using a multivariable Cox regression model. RESULTS: Overall, 1,893 patients treated by 309 EMS agencies were eligible for analysis. 1,010 (53.4%) received an epinephrine infusion and 883 (46.7%) received a norepinephrine infusion as their initial vasopressor. Adjusted analyses did not discover an association between vasopressor agent and rearrest (aOR: 0.93 [0.72, 1.21]) or mortality (aOR: 1.00 [0.59, 1.69]). CONCLUSIONS: In this multi-agency target trial emulation, the use of a post-resuscitation epinephrine infusion was not associated with increased odds of rearrest in comparison to the use of a norepinephrine infusion.

The association of clinical, treatment, and demographic characteristics with rearrest in a national dataset.

INTRODUCTION: Following initial resuscitation from out-of-hospital cardiac arrest, rearrest frequently occurs and has been associated with adverse outcomes. We aimed to identify clinical, treatment, and demographic characteristics associated with prehospital rearrest at the encounter and agency levels. METHODS: Adult non-traumatic cardiac arrest patients who achieved ROSC following EMS resuscitation in the 2018-2021 ESO annual datasets were included in this study. Patients were excluded if they had a documented DNR/POLST or achieved ROSC after bystander CPR only. Rearrest was defined as post-ROSC CPR initiation, administration of ≥ 1 milligram of adrenaline, defibrillation, or a documented non-perfusing rhythm on arrival at the receiving hospital. Multivariable logistic regression modeling was used to evaluate the association between rearrest and case characteristics. Linear regression modeling was used to evaluate the association between agency-level factors (ROSC rate, scene time, and scene termination rate), and rearrest rate. RESULTS: Among the 53,027 cases included, 16,116 (30.4%) experienced rearrest. Factors including longer response intervals, longer 'low-flow' intervals, unwitnessed OHCA, and a lack of bystander CPR were associated with rearrest. Among agencies that treated ≥ 30 patients with outcome data, the agency-level rate of rearrest was inversely associated with agency-level rate of survival to discharge to home (R2 = -0.393, p < 0.001). CONCLUSIONS: This multiagency retrospective study found that factors associated with increased ischaemic burden following OHCA were associated with rearrest. Agency-level rearrest frequency was inversely associated with agency-level survival to home. Interventions that decrease the burden of ischemia sustained by OHCA patients may decrease the rate of rearrest and increase survival.

Association of prehospital post-resuscitation peripheral oxygen saturation with survival following out-of-hospital cardiac arrest.

BACKGROUND: Hypoxia and hyperoxia following resuscitation from out-of-hospital cardiac arrest (OHCA)may cause harm by exacerbating secondary brain injury. Our objective was to retrospectively examine theassociationof prehospital post-ROSC hypoxia and hyperoxia with the primary outcome of survival to discharge home. METHODS: We utilized the 2019-2021 ESO Data Collaborative public use research datasets for this study (ESO, Austin, TX). Average prehospital SpO2, lowest recorded prehospital SpO2, and hypoxia dose were calculated for each patient. Theassociationof these measures with survival was explored using multivariable logistic regression. We also evaluated theassociationof American Heart Association (AHA) and European Resuscitation Council (ERC) recommended post-ROSC SpO2 target ranges with outcome. RESULTS: After application of exclusion criteria, 19,023 patients were included in this study. Of these, 52.3% experienced at least one episode of post-ROSC hypoxia (lowest SpO2 < 90%) and 19.6% experienced hyperoxia (average SpO2 > 98%). In comparison to normoxic patients, patients who were hypoxic on average (AHA aOR: 0.31 [0.25, 0.38]; ERC aOR: 0.34 [0.28, 0.42]) and patients who had a hypoxic lowest recorded SpO2 (AHA aOR: 0.48 [0.39, 0.59]; ERC aOR: 0.52 [0.42, 0.64]) had lower adjusted odds of survival. Patients who had a hyperoxic average SpO2 (AHA aOR: 0.75 [0.59, 0.96]; ERC aOR: 0.68 [0.53, 0.88]) and patients who had a hyperoxic lowest recorded SpO2 (AHA aOR: 0.66 [0.48, 0.92]; ERC aOR: 0.65 [0.46, 0.92]) also had lower adjusted odds of survival. CONCLUSION: Prehospital post-ROSC hypoxia and hyperoxia were associated with worse outcomes in this dataset.

Prehospital time for patients with acute cardiac complaints: A rural health disparity.

OBJECTIVE: Delays in care for patients with acute cardiac complaints are associated with increased morbidity and mortality. The objective of this study was to quantify rural and urban differences in prehospital time intervals for patients with cardiac complaints. METHODS: The ESO Data Collaborative dataset consisting of records from 1332 EMS agencies was queried for 9-1-1 encounters with acute cardiac problems among adults (age ≥ 18) from 1/1/2013-6/1/2018. Location was classified as rural or urban using the 2010 United States Census. The primary outcome was total prehospital time. Generalized estimating equations evaluated differences in the average times between rural and urban encounters while controlling for age, sex, race, transport mode, loaded mileage, and patient stability. RESULTS: Among 428,054 encounters, the median age was 62 (IQR 50-75) years with 50.7% female, 75.3% white, and 10.3% rural. The median total prehospital, response, scene, and transport times were 37.0 (IQR 29.0-48.0), 6.0 (IQR 4.0-9.0), 16.0 (IQR 12.0-21.0), and 13.0 (IQR 8.0-21.0) minutes. Rural patients had an average total prehospital time that was 16.76 min (95%CI 15.15-18.38) longer than urban patients. After adjusting for covariates, average total time was 5.08 (95%CI 4.37-5.78) minutes longer for rural patients. Average response and transport time were 4.36 (95%CI 3.83-4.89) and 0.62 (95%CI 0.33-0.90) minutes longer for rural patients. Scene time was similar in rural and urban patients (0.09 min, 95%CI -0.15-0.33). CONCLUSION: Rural patients with acute cardiac complaints experienced longer prehospital time than urban patients, even after accounting for other key variables, such as loaded mileage.

Point-of-Care Troponin Testing during Ambulance Transport to Detect Acute Myocardial Infarction.

Objective: Use of point-of-care (POC) troponin (cTn) testing in the Emergency Department (ED) is well established. However, data examining POC cTn measurement in the prehospital setting, during ambulance transport, are limited. The objective of this study was to prospectively test the performance of POC cTn measurement by paramedics to detect myocardial infarction (MI) among patients transported to the ED for acute chest pain. Methods: A prospective cohort study of adults with non-traumatic chest pain was conducted in three Emergency Medical Services agencies (December 2016 to January 2018). Patients with ST-elevation MI on ECG were excluded. During ambulance transport paramedics initiated intravenous access, collected blood, and used a POC device (i-STAT; Abbott Laboratories) to measure cTn. Following ED arrival, participants received standard evaluations including clinical blood draws for cTn measurement in the hospital central lab (AccuTnI +3 assay; Beckman Coulter, or cTnI-Ultra assay; Siemens). Blood collected during ambulance transport was also analyzed for cTn in the central lab. Index visit MI was adjudicated by 3 experts using central lab cTn measures from the patient's clinical blood draws. Test characteristics (sensitivity, specificity, and predictive values) for detection of MI were calculated for POC and central lab cTn measurement of prehospital blood and compared with McNemar's test. Results: During the study period prehospital POC cTn results were obtained on 421 patients, of which 5.0% (21/421) had results >99th percentile upper reference limit. MI was adjudicated in 16.2% (68/421) during the index visit. The specificity and positive predictive value of the POC cTn measurement were 99.2% (95% CI 97.5-99.8%) and 85.7% (95% CI 63.7-97.0%) for MI. However, the sensitivity and NPV of prehospital POC cTn were 26.5% (95% CI 16.5-38.6%) and 87.5% (95% CI 83.9-90.6%). Compared to POC cTn, the central lab cTn measurement of prehospital blood resulted in a higher sensitivity of 67.9% (95% CI 53.7-80.1%, p < 0.0001), but lower specificity of 92.4% (95% CI 88.4-95.4%, p = 0.0001). Conclusions: Prehospital POC i-STAT cTn measurement in patients transported with acute chest pain was highly specific for MI but had low sensitivity. This suggests that prehospital i-STAT POC cTn could be useful to rule-in MI, but should not be used to exclude MI.