The Performance of ChatGPT-4 and Gemini Ultra 1.0 for Quality Assurance Review in Emergency Medical Services Chest Pain Calls.

OBJECTIVES: This study assesses the feasibility, inter-rater reliability, and accuracy of using OpenAI's ChatGPT-4 and Google's Gemini Ultra large language models (LLMs), for Emergency Medical Services (EMS) quality assurance. The implementation of these LLMs for EMS quality assurance has the potential to significantly reduce the workload on medical directors and quality assurance staff by automating aspects of the processing and review of patient care reports. This offers the potential for more efficient and accurate and identification of areas requiring improvement, thereby potentially enhancing patient care outcomesMETHODS: Two expert human reviewers, ChatGPT GPT-4, and Gemini Ultra assessed and rated 150 consecutively sampled and anonymized prehospital records from 2 large urban EMS agencies for adherence to 2020 National Association of State EMS metrics for cardiac care. We evaluated the accuracy of scoring, inter-rater reliability, and review efficiency. The inter-rater reliability for the dichotomous outcome of each EMS metric was measured using the kappa statistic.RESULTS: Human reviewers showed high interrater reliability, with 91.2% agreement and a kappa coefficient, 0.782 (0.654-0.910). ChatGPT-4 achieved substantial agreement with human reviewers in EKG documentation and aspirin administration (76.2% agreement, kappa coefficient, 0.401 (0.334-0.468), but performance varied across other metrics. Gemini Ultra's evaluation was discontinued due to poor performance. No significant differences were observed in median review times: 01:28 minutes (IQR 1:12 - 1:51 min) per human chart review, 01:24 minutes (IQR 01:09 - 01:53 min) per ChatGPT-4 chart review (p = 0.46), and 01:50 minutes (IQR 01:10-03:34 min) per Gemini Ultra review (p = 0.06).CONCLUSIONS: Large language models demonstrate potential in supporting quality assurance by effectively and objectively extracting data elements. However, their accuracy in interpreting non-standardized and time-sensitive details remains inferior to human evaluators. Our findings suggest that current LLMs may best offer supplemental support to the human review processes, but their value remains limited. Enhancements in LLM training and integration are recommended for improved and more reliable performance in the quality assurance processes.

Transesophageal Echocardiography During Cardiopulmonary Resuscitation Is Associated With Shorter Compression Pauses Compared With Transthoracic Echocardiography.

STUDY OBJECTIVE: Point-of-care ultrasonography provides diagnostic information in addition to visual pulse checks during cardiopulmonary resuscitation (CPR). The most commonly used modality, transthoracic echocardiography, has unfortunately been repeatedly associated with prolonged pauses in chest compressions, which correlate with worsened neurologic outcomes. Unlike transthoracic echocardiography, transesophageal echocardiography does not require cessation of compressions for adequate imaging and provides the diagnostic benefit of point-of-care ultrasonography. To assess a benefit of transesophageal echocardiography, we compare the duration of chest compression pauses between transesophageal echocardiography, transthoracic echocardiography, and manual pulse checks on video recordings of cardiac arrest resuscitations. METHODS: We analyzed 139 pulse check CPR pauses among 25 patients during cardiac arrest. RESULTS: Transesophageal echocardiography provided the shortest mean pulse check duration (9 seconds [95% confidence interval {CI} 5 to 12 seconds]). Mean pulse check duration with transthoracic echocardiography was 19 seconds (95% CI 16 to 22 seconds), and it was 11 seconds (95% CI 8 to 14 seconds) with manual checks. Intraclass correlation coefficient between abstractors for a portion of individual and average times was 0.99 and 0.99, respectively (P<.001 for both). CONCLUSION: Our study suggests that pulse check times with transesophageal echocardiography are shorter versus with transthoracic echocardiography for ED point-of-care ultrasonography during cardiac arrest resuscitations, and further emphasizes the need for careful attention to compression pause duration when using transthoracic echocardiography for point-of-care ultrasonography during ED cardiac arrest resuscitations.

Supportive technology in the resuscitation of out-of-hospital cardiac arrest patients.

PURPOSE OF REVIEW: To discuss the increasing value of technological tools to assess and augment the quality of cardiopulmonary resuscitation (CPR) and, in turn, improve chances of surviving out-of-hospital cardiac arrest (OHCA). RECENT FINDINGS: After decades of disappointing survival rates, various emergency medical services systems worldwide are now seeing a steady rise in OHCA survival rates guided by newly identified 'sweet spots' for chest compression rate and chest compression depth, aided by monitoring for unnecessary pauses in chest compressions as well as methods to better ensure full-chest recoil after compressions. Quality-assurance programs facilitated by new technologies that monitor chest compression rate, chest compression depth, and/or frequent pauses have been shown to improve the quality of CPR. Further aided by other technologies that enhance flow or better identify the best location for hand placement, the future outlook for better survival is even more promising, particularly with the potential use of another technology - extracorporeal membrane oxygenation for OHCA. SUMMARY: After 5 decades of focus on manual chest compressions for CPR, new technologies for monitoring, guiding, and enhancing CPR performance may enhance outcomes from OHCA significantly in the coming years.

Development and Implementation of a Comprehensive, Multidisciplinary Emergency Department Extracorporeal Membrane Oxygenation Program.

Despite advances in the medical and surgical management of cardiovascular disease, greater than 350,000 patients experience out-of-hospital cardiac arrest in the United States annually, with only a 12% neurologically favorable survival rate. Of these patients, 23% have an initial shockable rhythm of ventricular fibrillation/pulseless ventricular tachycardia (VF/VT), a marker of high probability of acute coronary ischemia (80%) as the precipitating factor. However, few patients (22%) will experience return of spontaneous circulation and sufficient hemodynamic stability to undergo cardiac catheterization and revascularization. Previous case series and observational studies have demonstrated the successful application of intra-arrest extracorporeal life support, including to out-of-hospital cardiac arrest victims, with a neurologically favorable survival rate of up to 53%. For patients with refractory cardiac arrest, strategies are needed to bridge them from out-of-hospital cardiac arrest to the catheterization laboratory and revascularization. To address this gap, we expanded our ICU and perioperative extracorporeal membrane oxygenation (ECMO) program to the emergency department (ED) to reach this cohort of patients to improve survival. In this report, we illustrate our process and initial experience of developing a multidisciplinary team for rapid deployment of ED ECMO as a template for institutions interested in building their own ED ECMO programs.

Advanced Airway Type and Its Association with Chest Compression Interruptions During Out-of-Hospital Cardiac Arrest Resuscitation Attempts.

OBJECTIVE: To assess interruptions in chest compressions associated with advanced airway placement during cardiopulmonary resuscitation (CPR) of out-of-hospital cardiac arrest (OHCA) victims. METHODS: The method used was observational analysis of prospectively collected clinical and defibrillator data from 339 adult OHCA victims, excluding victims with <5 minutes of CPR. Interruptions in CPR, summarized by chest compression fraction (CCF), longest pause, and the number of pauses greater than 10 seconds, were compared between patients receiving bag valve mask (BVM), supraglottic airway (SGA), endotracheal intubation (ETI) via direct laryngoscopy (DL), and ETI via video laryngoscopy (VL). Secondary outcomes included first pass success and the effect of multiple airway attempts on CPR interruptions. RESULTS: During the study period, paramedics managed 23 cases with BVM, 43 cases with SGA, 148 with DL, and 125 with VL. There were no statistically significant differences between the airway groups with regard to longest compression pause (BVM 18 sec [IQR 11-33], SGA 29 sec [IQR 15-65], DL 26 sec [IQR 12-59], VL 22 sec [IQR 14-41]), median number of pauses greater than 10 seconds (BVM 2 [IQR 1-3], SGA 2 [IQR 1-3], DL 2 [IQR 1-4], VL 2 [IQR 1-3]), or CCF (0.92 for all groups). However, each additional attempt following failed initial DL was associated with an increase in the risk of additional chest compression pauses (relative risk 1.29, 95% confidence interval 1.02-1.64). Such an association was not observed with additional attempts using VL or SGA. First pass success was highest with SGA (77%), followed by between DL (68%) and VL (67%); these differences were not statistically significant. CONCLUSIONS: While summary measures of chest compression delivery did not differ significantly between airway classes in this observational study, repeated attempts following failed initial DL during cardiopulmonary resuscitation were associated with an increase in the number of pauses in chest compression delivery observed.

Predictors of patient adherence to follow-up recommendations after an ED visit.

BACKGROUND: It is unclear whether factors identified during the emergency department (ED) visit predict noncompliance with ED recommendations. STUDY OBJECTIVE: We sought to determine predictors of adherence to medical recommendations after an ED visit. METHODS: We conducted a prospective, observational study at a single urban medical center. Eligible ED patients provided baseline demographic data as well as information regarding insurance status, whether they had a primary care physician (PCP), and the impact of cost of care on their ability to follow medical recommendations. Patients were contacted at least 1 week after the ED visit and answered questions regarding adherence to medical recommendations. RESULTS: Four hundred twenty-two patients agreed to participate in the study. At follow-up, 89.7% of patients reported that they had complied with recommendations made during the ED visit. Patients who were adherent to follow-up recommendations were more likely to have a primary care provider (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.1-6.1), have an annual income of greater than $35000 (OR, 2.9; 95% CI, 1.2-7.2), and report a non-Hispanic ethnicity or race (OR, 2.8; 95% CI, 1.1-7.1). Individuals who reported that cost "sometimes" or "always" impacts their ability to follow their physician's recommendations were significantly less likely to comply with ED recommendations (OR, 2.7; 95% CI, 1.3-5.6). CONCLUSION: Individuals who reported that cost affects their ability to follow their physician's recommendations and those who did not have a PCP were less likely to follow ED recommendations. Identification of predictors of noncompliance during the ED visit may aid in ensuring compliance with ED recommendations.

Emergency physician knowledge of reimbursement rates associated with emergency medical care.

STUDY OBJECTIVE: We investigated emergency physician knowledge of the Centers for Medicare & Medicaid Services (CMS) reimbursement for common tests ordered and procedures performed in the emergency department (ED), determined the relative accuracy of their estimation, and reported the impact of perceived costs on physicians' ordering and prescribing behavior. METHODS: We distributed an online survey to 189 emergency physicians in 11 EDs across multiple institutions. The survey asked respondents to estimate reimbursement rates for a limited set of medical tests and procedures, rate their level of current cost knowledge, and determine the effect of health expenditures on their medical decision making. We calculated relative accuracy of cost knowledge as a percent difference of participant estimation of cost from the CMS reimbursement rate. RESULTS: Ninety-seven physicians participated in the study. Most respondents (65%) perceived their knowledge of costs as inadequate, and 39.3% indicated that beliefs about cost impacted their ordering behavior. Eighty percent of physicians surveyed were unable to estimate 25% of the costs within ±25%, and no physicians estimated at least 50% of costs within 25% of the CMS reimbursement and only 17.3% of medical services were estimated correctly within ±25% by 1 or more physicians. CONCLUSION: Most emergency physicians indicated they should consider cost in their decision making but have a limited knowledge of cost estimates used by CMS to calculate reimbursement rates. Interventions that are easily accessible and applicable in the ED setting are needed to educate physicians about costs, reimbursement, and charges associated with the care they deliver.

The impact of time to defibrillation on return of spontaneous circulation in out-of-hospital cardiac arrest patients with recurrent shockable rhythms.

OBJECTIVE: Optimal timing for subsequent defibrillation attempts for Out-of-hospital cardiac arrest (OHCA) patients with recurrent VF/pVT is uncertain. We investigated the relationship between VF/pVT duration and return of spontaneous circulation (ROSC) in OHCA patients with recurrent shockable rhythms. METHODS: We analyzed data from the Salt Lake City Fire Department (SLCFD) spanning from 2012 to 2023. The implementation of rhythm-filtering technology since 2011 enabled real-time rhythm interpretation during CPR, with local protocols allowing early defibrillation for recurrent/refractory VF/pVT cases. We included patients experiencing four or five episodes of VF and pVT rhythms and employed generalized estimating equation (GEE) regression analysis to examine the association between VF/pVT durations preceding recurrent defibrillation and return of spontaneous circulation (ROSC). RESULTS: Analysis of 622 appropriate shocks showed that patients achieving ROSC had significantly shorter median VF/pVT duration than those who did not achieve ROSC (0.83 minutes vs. 1.2 minutes, p = 0.004). Adjusted analysis of those with 4 VF/pVT episodes (N = 142) revealed that longer VF/pVT durations were associated with lower odds of achieving ROSC (odds ratio: 0.81, 95% CI: 0.72-0.93, p = 0.005). Every one-minute delay in intra-arrest defibrillation is predicted to decrease the likelihood of achieving ROSC by 19%. CONCLUSION: Every one-minute increase in intra-arrest VF/pVT duration was associated with a statistically significant 19% decrease in the chance of achieving ROSC. This highlights the importance of reducing time to shock in managing recurrent VF/pVT. The findings suggest reevaluating the current recommendations of two minutes intervals for rhythm check and shock delivery.

Examining the association between ethnicity and out-of-hospital cardiac arrest interventions in Salt Lake City, Utah.

Aims: Previous research has reported racial disparities in out-of-hospital cardiac arrest (OHCA) interventions, including bystander CPR and AED use. However, studies on other prehospital interventions are limited. The primary objective of this study was to investigate race/ethnic disparities in out-of-hospital cardiac arrest (OHCA) interventions: EMS response times, medication administration, and decisions for intra-arrest transport. The secondary objective was to evaluate differences in the provision of Bystander CPR (CPR) and application of AED. Methods: We retrospectively analyzed data from the Salt Lake City Fire Department (2010-2023). We included adults 18 years or older with EMS-treated OHCA. Race/ethnicity was categorized as White people, Asian people, Black people, Hispanic people, and others. We employed multivariable regression analysis to evaluate the association between race/ethnicity and the outcomes of interest. Results: Unadjusted analyses revealed no significant differences across ethnic groups in EMS response, medication administration, bystander CPR, or intra-arrest transport decisions. However, significant ethnic disparities were observed in Automated External Defibrillator (AED) utilization, Black people having the lowest rate (6.5%) and Asian people the highest (21.8%). The adjusted analysis found no significant association between race/ethnicity and all OHCA intervention measures, nor between race/ethnicity and survival outcomes. Conclusions: Our multivariable analysis found no statistically significant association between race/ethnicity and EMS response time, epinephrine administration, antiarrhythmic medication use, bystander CPR, AED intervention, or intra-arrest transport. These results imply regional variations in ethnic disparities in OHCA may not be consistent across all areas, warranting further research into disparities in other regions and additional influential factors like neighborhood conditions and socioeconomic status.

Early intramuscular adrenaline administration is associated with improved survival from out-of-hospital cardiac arrest.

BACKGROUND: Early administration of adrenaline is associated with improved survival after out-of-hospital cardiac arrest (OHCA). Delays in vascular access may impact the timely delivery of adrenaline. Novel methods for administering adrenaline before vascular access may enhance survival. The objective of this study was to determine whether an initial intramuscular (IM) adrenaline dose followed by standard IV/IO adrenaline is associated with improved survival after OHCA. METHODS STUDY DESIGN: We conducted a before-and-after study of the implementation of an early, first-dose IM adrenaline EMS protocol for adult OHCAs. The pre-intervention period took place between January 2010 and October 2019. The post-intervention period was between November 2019 and May 2024. SETTING: Single-center urban, two-tiered EMS agency. PARTICIPANTS: Adult, nontraumatic OHCA meeting criteria for adrenaline use. INTERVENTION: Single dose (5 mg) IM adrenaline. All other care, including subsequent IV or IO adrenaline, followed international guidelines. MAIN OUTCOMES AND MEASURES: The primary outcome was survival to hospital discharge. Secondary outcomes were time from EMS arrival to the first dose of adrenaline, survival to hospital admission, and favorable neurologic function at discharge. RESULTS: Among 1450 OHCAs, 372 (29.9%) received IM adrenaline and 985 (70.1%) received usual care. Fifty-two patients received the first dose of adrenaline through the IV or IO route within the post-intervention period and were included in the standard care group analysis. Age was younger and bystander CPR was higher in the IM adrenaline group. All other characteristics were similar between IM and standard care cohorts. Time to adrenaline administration was faster for the IM cohort [(median 4.3 min (IQR 3.0-6.0) vs. 7.8 min (IQR 5.8-10.4)]. Compared with standard care, IM adrenaline was associated with improved survival to hospital admission (37.1% vs. 31.6%; aOR 1.37, 95% CI 1.06-1.77), hospital survival (11.0% vs 7.0%; aOR 1.73, 95% CI 1.10-2.71) and favorable neurologic status at hospital discharge (9.8% vs 6.2%; aOR 1.72, 95% CI 1.07-2.76). CONCLUSION: In this single-center before-and-after implementation study, an initial IM dose of adrenaline as an adjunct to standard care was associated with improved survival to hospital admission, survival to hospital discharge, and functional survival. A randomized controlled trial is needed to fully assess the potential benefit of IM adrenaline delivery in OHCA.

Numerical Cincinnati Stroke Scale versus Stroke Severity Screening Tools for the Prehospital Determination of LVO.

Background: Previous research demonstrated that the numerical Cincinnati Prehospital Stroke Scale (CPSS) identifies large vessel occlusion (LVO) at similar rates compared to a limited number of stroke severity screening tools. We aimed to compare numerical CPSS to additional stroke scales using a national EMS database. Methods: Using the ESO Data Collaborative, the largest EMS database with hospital linked data, we retrospectively analyzed prehospital patient records for the year 2022. Stroke and LVO diagnoses were determined by ICD-10 codes from linked hospital discharge and emergency department records. Prehospital CPSS was compared to the Cincinnati Stroke Triage Assessment Tool (C-STAT), the Field Assessment Stroke Triage for Emergency Destination (FAST-ED), and the Balance Eyes Face Arm Speech Time (BE-FAST). The optimal prediction cut-points for LVO screening were determined by intersecting the sensitivity and specificity curves for each scale. To compare the discriminative abilities of each scale among those diagnosed with LVO, we used the area under the receiver operating curve (AUROC). Results: We identified 17,442 prehospital records from 754 EMS agencies with ≥ 1 documented stroke scale of interest: 30.3% (n=5,278) had a hospital diagnosis of stroke, of which 71.6% (n=3,781) were ischemic; of those, 21.6% (n=817) were diagnosed with LVO. CPSS score ≥ 2 was found to be predictive of LVO with 76.9% sensitivity, 68.0% specificity, and AUROC 0.787 (95% CI 0.722-0.801). All other tools had similar predictive abilities, with sensitivity / specificity / AUROC of: C-STAT 62.5% / 76.5% / 0.727 (0.555-0.899); FAST-ED 61.4% / 76.1%/ 0.780 (0.725-0.836); BE-FAST 70.4% / 67.1% / 0.739 (0.697-0.788). Conclusion: The less complex CPSS exhibited comparable performance to three frequently employed LVO detection tools. EMS agency leadership, medical directors, stroke system directors, and other stroke leaders may consider the complexity of stroke severity instruments and challenges with ensuring accurate recall and consistent application when selecting which instrument to implement. Use of the simpler CPSS may enhance compliance with the utilization of LVO screening instruments while maintaining the accuracy of prehospital LVO determination.

GlideScope versus flexible fiber optic for awake upright laryngoscopy.

STUDY OBJECTIVES: We compare laryngoscopic quality and time to highest-grade view between a face-to-face approach with the GlideScope and traditional flexible fiber-optic laryngoscopy in awake, upright volunteers. METHODS: This was a prospective, randomized, crossover study in which we performed awake laryngoscopy under local anesthesia on 23 healthy volunteers, using both a GlideScope video laryngoscopy face-to-face technique with the blade held upside down and flexible fiber-optic laryngoscopy. Operator reports of Cormack-Lehane laryngoscopic views and video-reviewed time to highest-grade view, as well as number of attempts, were recorded. RESULTS: Ten women and 13 men participated. A grade II or better view was obtained with GlideScope video laryngoscopy in 22 of 23 (95.6%) participants and in 23 of 23 (100%) participants with flexible fiber-optic laryngoscopy (relative risk GlideScope video laryngoscopy versus flexible fiber-optic laryngoscopy 0.96; 95% confidence interval 0.88 to 1.04). Median time to highest-grade view for GlideScope video laryngoscopy was 16 seconds (interquartile range 9 to 34) versus 51 seconds (interquartile range 35 to 96) for flexible fiber-optic laryngoscopy. A distribution of interindividual differences demonstrated that GlideScope video laryngoscopy was, on average, 39 seconds faster than flexible fiber-optic laryngoscopy (95% confidence interval 0.2 to 76.9 seconds). CONCLUSION: GlideScope video laryngoscopy can be used to obtain a Cormack-Lehane grade II or better view in the majority of awake, healthy volunteers when an upright face-to-face approach is used and was slightly faster than traditional flexible fiber-optic laryngoscopy. However, flexible fiber-optic laryngoscopy may be more reliable at obtaining high-grade views of the larynx. Awake, face-to-face GlideScope use may offer an alternative approach to the difficulty airway, particularly among providers uncomfortable with flexible fiber-optic laryngoscopy.

Part 19: What is a P value?

This review represents a nontechnical explanation of P values intended for the statistical novice.

Experimental studies in air medical research.

This article is the 18th in a multipart series designed to assist readers, particularly novices, in the area of clinical research. This article is focused on the process of developing a new research project. It provides tools to help those involved in beginning their own research projects.

Automated aortic endovascular balloon volume titration prevents re-arrest immediately after return of spontaneous circulation in a swine model of nontraumatic cardiac arrest.

Objectives: Endovascular aortic occlusion as an adjunct to cardiopulmonary resuscitation (CPR) for non-traumatic cardiac arrest is gaining interest. In a recent clinical trial, return of spontaneous circulation (ROSC) was achieved despite prolonged no-flow times. However, 66% of patients re-arrested upon balloon deflation. We aimed to determine if automated titration of endovascular balloon volume following ROSC can augment diastolic blood pressure (DBP) to prevent re-arrest. Methods: Twenty swine were anesthetized and placed into ventricular fibrillation (VF). Following 7 minutes of no-flow VF and 5 minutes of mechanical CPR, animals were subjected to complete aortic occlusion to adjunct CPR. Upon ROSC, the balloon was either deflated steadily over 5 minutes (control) or underwent automated, dynamic adjustments to maintain a DBP of 60 mmHg (Endovascular Variable Aortic Control, EVAC). Results: ROSC was obtained in ten animals (5 EVAC, 5 REBOA). Sixty percent (3/5) of control animals rearrested while none of the EVAC animals rearrested (p = 0.038). Animals in the EVAC group spent a significantly higher proportion of the post-ROSC period with a DBP > 60 mmHg [median (IQR)] [control 79.7 (72.5-86.0)%; EVAC 97.7 (90.8-99.7)%, p = 0.047]. The EVAC group had a statistically significant reduction in arterial lactate concentration [7.98 (7.4-8.16) mmol/L] compared to control [9.93 (8.86-10.45) mmol/L, p = 0.047]. There were no statistical differences between the two groups in the amount of adrenaline (epinephrine) required. Conclusion: In our swine model of cardiac arrest, automated aortic endovascular balloon titration improved DBP and prevented re-arrest in the first 20 minutes after ROSC.

Paramedic rhythm interpretation misclassification is associated with poor survival from out-of-hospital cardiac arrest.

BACKGROUND: Early recognition and rapid defibrillation of shockable rhythms is strongly associated with survival in out of hospital cardiac arrest (OHCA). Little is known about the accuracy of paramedic rhythm interpretation and its impact on survival. We hypothesized that inaccurate paramedic interpretation of initial rhythm would be associated with worse survival. METHODS: This is a retrospective cohort analysis of prospectively collected OHCA data over a nine-year period within a single, urban, fire-based EMS system that utilizes manual defibrillators equipped with rhythm-filtering technology. We compared paramedic-documented initial rhythm with a reference standard of post-event physician interpretation to estimate sensitivity and specificity of paramedic identification of and shock delivery to shockable rhythms. We assessed the association between misclassification of initial rhythm and neurologically intact survival to hospital discharge using multivariable logistic regression. RESULTS: A total of 863 OHCA cases were available for analysis with 1,756 shocks delivered during 542 (63%) resuscitation attempts. Eleven percent of shocks were delivered to pulseless electrical activity (PEA). Sensitivity and specificity for paramedic initial rhythm interpretation were 176/197 (0.89, 95% CI 0.84-0.93) and 463/504 (0.92, 95% CI 0.89-0.94) respectively. No patient survived to hospital discharge when paramedics misclassified the initial rhythm. CONCLUSIONS: Paramedics achieved high sensitivity for shock delivery to shockable rhythms, but with an 11% shock delivery rate to PEA. Misclassification of initial rhythm was associated with poor survival. Technologies that assist in rhythm identification during CPR, rapid shock delivery, and minimal hands-off time may improve outcomes.

The association of modifiable mechanical ventilation settings, blood gas changes and survival on extracorporeal membrane oxygenation for cardiac arrest.

RESEARCH QUESTION: Given the relative independence of ventilator settings from gas exchange and plasticity of blood gas values during extracorporeal cardiopulmonary resuscitation (ECPR), do mechanical ventilation parameters and blood gas values influence survival? METHODS: Observational cohort study of 7488 adult patients with ECPR from the Extracorporeal Life Support Organization (ELSO) Registry. We performed case-mix adjustment for severity of illness and patient type using generalized estimating equation logistic regression to determine factors associated with hospital survival accounting for clustering by center, standardizing variables by 1 standard deviation (SD) of their values. We examined non-linear relationships between ventilatory and blood gas values with hospital survival. RESULTS: Hospital survival was decreased with higher PaO2 on ECMO (OR 0.69, per 1SD increase [95% CI 0.64, 0.74]; p < 0.001) and with any relative changes in PaCO2 (pre-arrest to on-ECMO) in a non-linear fashion. Survival was worsened with any peak inspiratory pressure >20 cmH20 (OR 0.69, per 1SD [0.64, 0.75]; p < 0.001) and above 40% fraction of inspired oxygen (OR 0.75, per 1SD [0.69, 0.82]; p < 0.001), and with higher dynamic driving pressure (OR 0.72, per 1 SD increase [0.65, 0.79]; <0.001). Ventilation settings and blood gas values varied widely across hospitals, but were not associated with annual hospital ECPR case volume. CONCLUSION: Lower ventilatory pressures, avoidance of hyperoxia, and relatively unchanged CO2 (pre- to on-ECMO) were all associated with survival in patients after ECPR, yet varied across hospitals. Our findings represent potential targets for prospective trials for this rapidly growing therapy to test if these associations have causality.

The Association of Modifiable Postresuscitation Management and Annual Case Volume With Survival After Extracorporeal Cardiopulmonary Resuscitation.

It is not know if hospital-level extracorporeal cardiopulmonary resuscitation (ECPR) case volume, or postcannulation clinical management associate with survival outcomes. OBJECTIVES: To describe variation in postresuscitation management practices, and annual hospital-level case volume, for patients who receive ECPR and to determine associations between these management practices and hospital survival. DESIGN: Observational cohort study using case-mix adjusted survival analysis. SETTING AND PARTICIPANTS: Adult patients greater than or equal to 18 years old who received ECPR from the Extracorporeal Life Support Organization Registry from 2008 to 2019. MAIN OUTCOMES AND MEASURES: Generalized estimating equation logistic regression was used to determine factors associated with hospital survival, accounting for clustering by center. Factors analyzed included specific clinical management interventions after starting extracorporeal membrane oxygenation (ECMO) including coronary angiography, mechanical unloading of the left ventricle on ECMO (with additional placement of a peripheral ventricular assist device, intra-aortic balloon pump, or surgical vent), placement of an arterial perfusion catheter distal to the arterial return cannula (to mitigate leg ischemia); potentially modifiable on-ECMO hemodynamics (arterial pulsatility, mean arterial pressure, ECMO flow); plus hospital-level annual case volume for adult ECPR. RESULTS: Case-mix adjusted patient-level management practices varied widely across individual hospitals. We analyzed 7,488 adults (29% survival); median age 55 (interquartile range, 44-64), 68% of whom were male. Adjusted hospital survival on ECMO was associated with mechanical unloading of the left ventricle (odds ratio [OR], 1.3; 95% CI, 1.08-1.55; p = 0.005), performance of coronary angiography (OR, 1.34; 95% CI, 1.11- 1.61; p = 0.002), and placement of an arterial perfusion catheter distal to the return cannula (OR, 1.39; 95% CI, 1.05-1.84; p = 0.022). Survival varied by 44% across hospitals after case-mix adjustment and was higher at centers that perform more than 12 ECPR cases/yr (OR, 1.23; 95% CI, 1.04-1.45; p = 0.015) versus medium- and low-volume centers. CONCLUSIONS AND RELEVANCE: Modifiable ECMO management strategies and annual case volume vary across hospitals, appear to be associated with survival and should be the focus of future research to test if these hypothesis-generating associations are causal in nature.

Establishing a multicenter, preclinical consortium in resuscitation: A pilot experimental trial evaluating epinephrine in cardiac arrest.

BACKGROUND: Large animal studies are an important step in the translation pathway, but single laboratory experiments do not replicate the variability in patient populations. Our objective was to demonstrate the feasibility of performing a multicenter, preclinical, randomized, double-blinded, placebo-controlled cardiac arrest trial. We evaluated the effect of epinephrine on coronary perfusion pressure (CPP) as previous single laboratory studies have reported mixed results. METHODS: Forty-five swine from 5 different laboratories (Ann Arbor, MI; Baltimore, MD; Los Angeles, CA; Pittsburgh, PA; Toronto, ON) using a standard treatment protocol. Ventricular fibrillation was induced and left untreated for 6 min before starting continuous cardiopulmonary resuscitation (CPR). After 2 min of CPR, 9 animals from each lab were randomized to 1 of 3 interventions given over 12 minutes: (1) Continuous IV epinephrine infusion (0.00375 mg/kg/min) with placebo IV normal saline (NS) boluses every 4 min, (2) Continuous placebo IV NS infusion with IV epinephrine boluses (0.015 mg/kg) every 4 min or (3) Placebo IV NS for both infusion and boluses. The primary outcome was mean CPP during the 12 mins of drug therapy. RESULTS: There were no significant differences in mean CPP between the three groups: 14.4 ± 6.8 mmHg (epinephrine Infusion), 16.9 ± 5.9 mmHg (epinephrine bolus), and 14.4 ± 5.5 mmHg (placebo) (p = NS). Sensitivity analysis demonstrated inter-laboratory variability in the magnitude of the treatment effect (p = 0.004). CONCLUSION: This study demonstrated the feasibility of performing a multicenter, preclinical, randomized, double-blinded cardiac arrest trials. Standard dose epinephrine by bolus or continuous infusion did not increase coronary perfusion pressure during CPR when compared to placebo.

Helicopter emergency medical services utilization for winter resort injuries.

INTRODUCTION: Helicopter and ground emergency medical services (EMS) units are frequently called to transport patients from winter resorts to area trauma centers. OBJECTIVE: The purpose of this study was to examine helicopter EMS (HEMS) utilization for such patients, and to investigate out-of-hospital clinical variables that might help providers determine the most appropriate utilization of HEMS. METHODS: The study included patients aged ≥ 12 years who were transported by ground EMS (GEMS) or HEMS to a regional trauma center with an acute injury sustained at a winter resort. The decision to transport via HEMS was based on field provider judgment. Injury information was prospectively obtained and combined with emergency department (ED) and hospital data abstracted from trauma registry and hospital records. For the purpose of this study, appropriate HEMS utilization was defined according to two different schemes. Limited utilization of HEMS was defined as the need for an emergent ED or out-of-hospital intervention (intubation, chest tube or needle thoracostomy, central line placement, or cardiopulmonary resuscitation). Expanded utilization of HEMS was defined as the need for an emergent intervention and/or an Injury Severity Score (ISS) ≥ 16 and/or need for emergent nonorthopedic surgery. Provider judgment alone was compared with results of recursive partitioning to predict the need for HEMS. RESULTS: Of 815 patients enrolled between 2006 and 2009, 65 (8.0%) patients met the expanded criteria for appropriate HEMS utilization. Of these, 30 (46.2%) were transported by GEMS and 35 (53.8%) were transported by HEMS. Twenty-seven of the 65 patients (41.5%) required an emergent ED or out-of-hospital intervention. Activation of HEMS by out-of-hospital providers was (at best) 55.6% sensitive and 89.1% specific (85.2% overtriage rate) for predicting the need for an emergent out-of-hospital or ED intervention. Recursive partitioning, using a Glasgow Coma Scale score (GCS) ≤ 13 or pulse oximetry value <89%, was superior to provider judgment in predicting the need for an emergent procedure (57.9% sensitive, 98.6% specific, 45% overtriage rate). CONCLUSION: Use of a simple prediction rule was superior to provider judgment in predicting the need for an emergent ED or out-of-hospital procedure in patients injured at winter resorts. If validated, this rule may be a resource to help out-of-hospital providers decide when to activate HEMS in these unique areas.