Standard Advanced Cardiac Life Support Research Articles

Outcomes of Out-of-Hospital Cardiac Arrest Patients Who Received Naloxone in an EMS System with a High Prevalence of Opioid Overdose

BackgroundOpioid-associated out-of-hospital cardiac arrest (OA-OHCA) is a subset of cardiac arrests that could benefit from measures outside of standard Advanced Cardiac Life Support (ACLS), such as naloxone. ObjectivesIn this study, we sought to examine whether OHCA patients chosen for naloxone therapy by EMS clinicians in a system with high rates of opioid overdose would have increased rates of return of spontaneous circulation (ROSC) and survival to hospital discharge. MethodsThe study took place in an urban EMS system with a high prevalence of opioid overdose. Paramedics could administer naloxone in cardiac arrest in addition to ACLS. It was often administered based on clinical gestalt for suspected OA-OHCA. The outcomes of OHCA patients who received naloxone were compared against those who received usual care in both an adjusted and unadjusted fashion. Lastly, we created a logistic regression model to test for an independent association of naloxone administration on ROSC and survival to hospital discharge. ResultsA consecutive sample of 769 OHCA patients was obtained, of which 175 (23%) received naloxone. On average, patients who received naloxone had significantly fewer comorbidities and were younger. There was no difference in ROSC, survival to hospital discharge, or modified Rankin Scores. Using logistic regression modeling, there was no statistically significant effect of naloxone administration on these outcomes. ConclusionOHCA patients who received naloxone, despite being younger and having fewer comorbidities, had similar outcomes compared to those who received usual care. The difference in baseline characteristics suggests that paramedic gestalt reasonably selected for OA-OHCA.

Health-related quality of life and cognitive function after out-of-hospital cardiac arrest; a comparison of prehospital return-of-spontaneous circulation and refractory arrest managed with extracorporeal cardiopulmonary resuscitation

BackgroundExtracorporeal cardiopulmonary resuscitation (ECPR) for selected refractory out-of-hospital cardiac arrest (OHCA) is increasingly used. Detailed knowledge of health-related quality of life (HRQoL) and long-term cognitive function is limited. HRQoL and cognitive function were assessed in ECPR-survivors and OHCA-survivors with prehospital return of spontaneous circulation after standard advanced cardiac life support (sACLS). MethodsFifteen ECPR-survivors and 22 age-matched sACLS-survivors agreed to participate in this follow-up study. Participants were examined with echocardiography, 6-minute walk test, and neuropsychological testing, and answered HRQoL (EQ-5D-5L and Short Form 36 (SF-36)), and mental health questionnaires. ResultsMost patients were male (73 % and 82 %) and median age at follow-up was similar between groups (55 years and 60 years). Low flow time was significantly longer for ECPR-survivors (86 min vs. 15 min) and lactate levels were significantly higher (14.1 mmol/l vs. 3.9 mmol/l). No between-group difference was found in physical function nor in cognitive function with scores corresponding to the 23rd worst percentile of the general population. SACLS-survivors had HRQoL on level with the Danish general population while ECPR-survivors scored lower in both EQ-5D-5L (index score 0.73 vs. 0.86, p = 0.03, visual analog scale: 70 vs. 84, p = 0.04) and in multiple SF-36 health domains (role physical, bodily pain, general health, and mental health). ConclusionsDespite substantially longer low flow times with thrice as high lactate levels, ECPR-survivors were similar in cognitive and physical function compared to sACLS-survivors. Nonetheless, ECPR-survivors reported lower HRQoL overall and related to mental health, pain management, and the perception of limitations in physical role.

Spontaneous Coronary Artery Dissection Presenting as Electrical Storm: A Case Report.

Spontaneous coronary artery dissection (SCAD) is an important cause of myocardial infarction in patients of younger age without typical atherosclerotic risk factors and can present with ventricular arrhythmia such as ventricular tachycardia (VT) or ventricular fibrillation (VF). Electrical storm (ES) is defined as greater than or equal to 3 episodes of VT or VF occurring within 24 hours. A healthy 38-year-old-male developed chest pain while exercising at the gym and presented to the emergency department unresponsive in a ventricular arrhythmia defined as ES. The patient's cardiac arrest was initially refractory to standard defibrillation and Advanced Cardiac Life Support medications. He was ultimately diagnosed with SCAD of the left anterior descending artery, which was stented. The patient survived neurologically intact after a 13-day hospital stay. Spontaneous coronary artery dissection is a significant cause of acute coronary syndrome and occurs in healthier patients without cardiac risk factors. Electrical storm represents a unique manifestation of SCAD. Emergency physicians should maintain a heightened suspicion for SCAD for accurate diagnosis and treatment.

Long-term survival and return to work after refractory out-of-hospital cardiac arrest managed with extracorporeal cardiopul-monary resuscitation; a nationwide follow-up study

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Rigshospitalets and Odense Universitetshospitals common foundation Background Survival after refractory out-of-hospital cardiac arrest (OHCA) is low. Extracorporeal cardiopulmonary resuscitation (ECPR) is increasingly used for selected patients aiming to increase survival after refractory OHCA. However, ECPR is resource heavy and carries risk of poor functional status. Previous studies have shown favorable neurological outcome in the majority of survivors of OHCA managed with ECPR; yet the share of patients able to return to work has not previously been explored. Purpose The purpose of this study is to investigate the fraction of patients returning to work after OHCA managed with ECPR in a national cohort of refractory OHCA-patients. Methods Of about 44,000 OHCAs during the period of 2011-2020, this nationwide registry-based study included 812 refractory OHCA-patients in the working age between 18 years and 65 years (as 65 was the current age of retirement) who were in employment prior to the event. We excluded 113 ECPR-patients and 3,536 refractory OHCA-patients managed with standard advanced cardiac life support (sACLS) due to age or unemployment. We defined refractory OHCA as patients with OHCA brought to hospital with on-going CPR. Information on demographics, OHCA circumstances, status at hospital arrival, and survival were retrieved through the Danish Cardiac Arrest Register. Employment status were retrieved through the Danish Research Institute for Economic Analysis and Modelling database. Maintenance of work was defined as return to work without any sick leave relapse (>4 weeks) during six months of employment. Results Of 812 included refractory OHCA-patients, 137 patients received ECPR while 675 were managed with sACLS. ECPR-patients were slightly younger than sACLS-patients (median 51 vs. 53 years), a higher percentage male sex (84% vs. 79%), and more had favorable OHCA circumstances (witnessed arrest [80% vs. 64%], bystander CPR [75% vs. 67%], and shockable presenting rhythm [59% vs. 37%]). One-year survival was higher for ECPR-patients compared with sACLS-patients (24% vs. 7%, p<0.001). Of one-year survivors, less ECPR-patients were in employment one year after OHCA compared with sACLS-patients (48% vs. 77%, p=0.01). No difference in maintenance of work were found between ECPR- and sACLS-patients after OHCA (88% vs. 79%, p=0.7). Conclusion Survival was higher for refractory OHCA-patients receiving ECPR- compared to sACLS-therapy, which may reflect selection bias. One out of two ECPR patients returned to work and the majority maintained employment for at least six months. More sACLS-survivors returned to work compared with ECPR-survivors likely reflecting survival bias.

Intraarrest transport, extracorporeal cardiopulmonary resuscitation, and early invasive management in refractory out-of-hospital cardiac arrest: an individual patient data pooled analysis of two randomised trials.

Refractory out-of-hospital cardiac arrest (OHCA) treated with standard advanced cardiac life support (ACLS) has poor outcomes. Transport to hospital followed by in-hospital extracorporeal cardiopulmonary resuscitation (ECPR) initiation may improve outcomes. We performed a pooled individual patient data analysis of two randomised controlled trials evaluating ECPR based approach in OHCA. The individual patient data from two published randomised controlled trials (RCTs) were pooled: ARREST (enrolled Aug 2019-June 2020; NCT03880565) and PRAGUE-OHCA (enrolled March 1, 2013-Oct 25, 2020; NCT01511666). Both trials enrolled patients with refractory OHCA and compared: intra-arrest transport with in-hospital ECPR initiation (invasive approach) versus continued standard ACLS. The primary outcome was 180-day survival with favourable neurological outcome (defined as Cerebral Performance Category 1-2). Secondary outcomes included: cumulative survival at 180 days, 30-day favourable neurological survival, and 30-day cardiac recovery. Risk of bias in each trial was assessed by two independent reviewers using the Cochrane risk-of-bias tool. Heterogeneity was assessed via Forest plots. The two RCTs included 286 patients. Of those randomised to the invasive (n=147) and standard (n=139) groups, respectively: the median age was 57 (IQR 47-65) and 58 years (IQR 48-66), and the median duration of resuscitation was 58 (IQR 43-69) and 49 (IQR 33-71) minutes (p=0.17). In a modified intention to treat analysis, 45 (32.4%) in the invasive and 29 (19.7%) patients in the standard arm survived to 180 days with a favourable neurological outcome [absolute difference (AD), 95% CI: 12.7%, 2.6-22.7%, p=0.015]. Forty-seven (33.8%) and 33 (22.4%) patients survived to 180 days [HR 0.59 (0.43-0.81); log rank test p=0.0009]. At 30 days, 44 (31.7%) and 24 (16.3%) patients had favourable neurological outcome (AD 15.4%, 5.6-25.1%, p=0.003), 60 (43.2%), and 46 (31.3%) patients had cardiac recovery (AD: 11.9%, 0.7-23%, p=0.05), in the invasive and standard arms, respectively. The effect was larger in patients presenting with shockable rhythms (AD 18.8%, 7.6-29.4; p=0.01; HR 2.26 [1.23-4.15]; p=0.009) and prolonged CPR (>45min; HR 3.99 (1.54-10.35); p=0.005). In patients with refractory OHCA, the invasive approach significantly improved 30- and 180-day neurologically favourable survival. None.

Early Extracorporeal CPR for Refractory Out-of-Hospital Cardiac Arrest

BackgroundExtracorporeal cardiopulmonary resuscitation (CPR) restores perfusion and oxygenation in a patient who does not have spontaneous circulation. The evidence with regard to the effect of extracorporeal CPR on survival with a favorable neurologic outcome in refractory out-of-hospital cardiac arrest is inconclusive.MethodsIn this multicenter, randomized, controlled trial conducted in the Netherlands, we assigned patients with an out-of-hospital cardiac arrest to receive extracorporeal CPR or conventional CPR (standard advanced cardiac life support). Eligible patients were between 18 and 70 years of age, had received bystander CPR, had an initial ventricular arrhythmia, and did not have a return of spontaneous circulation within 15 minutes after CPR had been initiated. The primary outcome was survival with a favorable neurologic outcome, defined as a Cerebral Performance Category score of 1 or 2 (range, 1 to 5, with higher scores indicating more severe disability) at 30 days. Analyses were performed on an intention-to-treat basis.ResultsOf the 160 patients who underwent randomization, 70 were assigned to receive extracorporeal CPR and 64 to receive conventional CPR; 26 patients who did not meet the inclusion criteria at hospital admission were excluded. At 30 days, 14 patients (20%) in the extracorporeal-CPR group were alive with a favorable neurologic outcome, as compared with 10 patients (16%) in the conventional-CPR group (odds ratio, 1.4; 95% confidence interval, 0.5 to 3.5; P=0.52). The number of serious adverse events per patient was similar in the two groups.ConclusionsIn patients with refractory out-of-hospital cardiac arrest, extracorporeal CPR and conventional CPR had similar effects on survival with a favorable neurologic outcome. (Funded by the Netherlands Organization for Health Research and Development and Maquet Cardiopulmonary [Getinge]; INCEPTION ClinicalTrials.gov number, NCT03101787.)

Esmolol, vector change, and dose-capped epinephrine for prehospital ventricular fibrillation or pulseless ventricular tachycardia

BackgroundRefractory ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) cardiac arrest describes a subset of patients who do not respond to standard Advanced Cardiac Life Support (ACLS) interventions and are associated with poor outcomes. Esmolol administration and vector change defibrillation have shown promise in improving outcomes in these patients, however evidence is limited. ObjectivesThis study compares clinical outcomes between patients with prehospital refractory VF/pVT who received an Emergency Medical Service (EMS) bundle, comprised of esmolol administration, vector change defibrillation, and dose-capped epinephrine at 3 mg, to patients who received standard ACLS interventions. MethodsThis multicenter, retrospective, cohort study evaluated medical records between October 18, 2017 and March 15, 2022. Patients were enrolled if they experienced a prehospital cardiac arrest with the rhythm VF or pVT, had received at least three standard defibrillations, at least 3 mg of epinephrine, and 300 mg of amiodarone. Patients who received the EMS bundle after its implementation were compared to patients who received standard ACLS interventions prior to its implementation. The primary outcome was sustained return of spontaneous circulation (ROSC), defined as ROSC lasting 20 min without recurrence of cardiac arrest. Secondary outcomes included the incidence of any ROSC, survival to hospital arrival, survival at hospital discharge, and neurologically intact survival at hospital discharge. ResultsEighty-three patients were included in the study. Thirty-six were included in the pre-EMS bundle group and 47 patients were included in the post-EMS bundle group. Patients in the pre-EMS bundle group achieved significantly higher rates of sustained ROSC (58.3% vs 17%, p < 0.001), any ROSC (66.7% vs 19.1%, p < 0.001), and survival to hospital arrival (55.6% vs 17%, p < 0.001). The rates of survival to hospital discharge (16.7% vs 6.4%, p = 0.17) and neurologically intact survival at hospital discharge (5.9% vs 4.3%, p = 1.00) were not significantly different between groups. ConclusionsPatients who received the EMS bundle achieved sustained ROSC significantly less often and were less likely to have pulses at hospital arrival. The incidence of neurologically intact survival was low and similar between groups.

LUNG HERNIATION: A RARE RESULT OF CPR

TOPIC: Lung Pathology TYPE: Medical Student/Resident Case Reports INTRODUCTION: Lung herniation as a result of cardiopulmonary resuscitation (CPR) is a rare condition whereby the pleura-covered lung parenchyma protrudes through a defect in the chest wall. CASE PRESENTATION: A 70-year-old male with a history of end stage renal disease on dialysis and heart failure presented to the hospital with three weeks of progressive dyspnea and diagnosed with pulmonary edema. He was started on hemodialysis for volume removal. On hospital day four, the patient developed cardiac arrest, and was found to be in hemorrhagic shock, with massive hemorrhage from his dialysis fistula. The patient underwent high quality chest compressions while receiving standard advanced cardiac life support and a massive transfusion protocol. After return of spontaneous circulation and control of the bleeding, a right chest mass was palpated. Imaging demonstrated multiple consecutive right anterior rib and costochondral junction fractures resulting in flail chest and a large anterior herniation of the lung with an associated moderate hemothorax. A thoracostomy tube was offered as was surgical fixation; however, the patient's family decided to pursue comfort measures. DISCUSSION: Lung herniation is an extremely rare entity first described in association with CPR in 1986. Since then, there have been only seven cases of lung herniation after CPR reported in the literature. Furthermore, an occurrence with chondrosternal disruption is even more uncommon, such as our patient with flail chest. When providing high-quality chest compressions, traumatic injuries to the sternum and ribs is often unavoidable and rate of injury does not vary based on medical training of compressor nor patient factors such as age and gender. However, certain comorbidities place patients at increased risk for traumatic lung herniation including COPD and obesity. Chest tube drainage of associated hemothorax may result in spontaneous reduction of the herniated lung. Otherwise, early surgical fixation should be pursued as it is associated with low morbidity and excellent prognosis. There is no consensus on management with concurrent flail chest. Clinicians should include lung herniation in the differential of a patient with recent chest trauma from CPR, when confronted with worsening respiratory symptoms or worsening ventilatory mechanics, as intervention is necessary. CONCLUSIONS: Lung herniation is a rare phenomenon that may be the result of high-quality CPR, especially in patients with the aforementioned risk factors. We believe the incidence of this thoracic pathology will increase as the at-risk population continues to rise thus emphasizing the importance of clinician recognition of this condition as early surgical fixation may provide a definitive treatment. REFERENCE #1: Batra AK. Lung herniation after CPR. Crit Care Med. 1986;14(6):595-6. doi: 10.1097/00003246-198606000-00022. PMID: 3709206. REFERENCE #2: Deliliga, A., Chatzinikolaou, F., Koutsoukis, D. et al. Cardiopulmonary resuscitation (CPR) complications encountered in forensic autopsy cases. BMC Emerg Med 19, 23 (2019). https://doi.org/10.1186/s12873-019-0234-5 REFERENCE #3: Allen GS, Fischer RP. Traumatic lung herniation. Annal Thoracic Surg. 1997;63(5):1455–6. doi: 10.1016/s0003-4975(97)00109-4. DISCLOSURES: No relevant relationships by Andrew Deitchman, source=Web Response No relevant relationships by Jesse Liou, source=Web Response No relevant relationships by John Nawrocki, source=Web Response

This Month in Anesthesiology

This Month in Anesthesiology

Advanced reperfusion strategies for patients with out-of-hospital cardiac arrest and refractory ventricular fibrillation (ARREST): a phase 2, single centre, open-label, randomised controlled trial

Among patients with out-of-hospital cardiac arrest (OHCA) and ventricular fibrillation, more than half present with refractory ventricular fibrillation unresponsive to initial standard advanced cardiac life support (ACLS) treatment. We did the first randomised clinical trial in the USA of extracorporeal membrane oxygenation (ECMO)-facilitated resuscitation versus standard ACLS treatment in patients with OHCA and refractory ventricular fibrillation. For this phase 2, single centre, open-label, adaptive, safety and efficacy randomised clinical trial, we included adults aged 18-75 years presenting to the University of Minnesota Medical Center (MN, USA) with OHCA and refractory ventricular fibrillation, no return of spontaneous circulation after three shocks, automated cardiopulmonary resuscitation with a Lund University Cardiac Arrest System, and estimated transfer time shorter than 30 min. Patients were randomly assigned to early ECMO-facilitated resuscitation or standard ACLS treatment on hospital arrival by use of a secure schedule generated with permuted blocks of randomly varying block sizes. Allocation concealment was achieved by use of a randomisation schedule that required scratching off an opaque layer to reveal assignment. The primary outcome was survival to hospital discharge. Secondary outcomes were safety, survival, and functional assessment at hospital discharge and at 3 months and 6 months after discharge. All analyses were done on an intention-to-treat basis. The study qualified for exception from informed consent (21 Code of Federal Regulations 50.24). The ARREST trial is registered with ClinicalTrials.gov, NCT03880565. Between Aug 8, 2019, and June 14, 2020, 36 patients were assessed for inclusion. After exclusion of six patients, 30 were randomly assigned to standard ACLS treatment (n=15) or to early ECMO-facilitated resuscitation (n=15). One patient in the ECMO-facilitated resuscitation group withdrew from the study before discharge. The mean age was 59 years (range 36-73), and 25 (83%) of 30 patients were men. Survival to hospital discharge was observed in one (7%) of 15 patients (95% credible interval 1·6-30·2) in the standard ACLS treatment group versus six (43%) of 14 patients (21·3-67·7) in the early ECMO-facilitated resuscitation group (risk difference 36·2%, 3·7-59·2; posterior probability of ECMO superiority 0·9861). The study was terminated at the first preplanned interim analysis by the National Heart, Lung, and Blood Institute after unanimous recommendation from the Data Safety Monitoring Board after enrolling 30 patients because the posterior probability of ECMO superiority exceeded the prespecified monitoring boundary. Cumulative 6-month survival was significantly better in the early ECMO group than in the standard ACLS group. No unanticipated serious adverse events were observed. Early ECMO-facilitated resuscitation for patients with OHCA and refractory ventricular fibrillation significantly improved survival to hospital discharge compared with standard ACLS treatment. National Heart, Lung, and Blood Institute.

Extracorporeal Membrane Oxygenation (ECMO) for Refractory Cardiac Arrest.

Extracorporeal Membrane Oxygenation (ECMO) for Refractory Cardiac Arrest.

Rationale and methods of the Advanced R2Eperfusion STrategies for Refractory Cardiac Arrest (ARREST) trial

Venoarterial extracorporeal membrane oxygenation has emerged as a prominent therapy for patients with refractory cardiac arrest. However, the optimal time of initiation remains unknown. The aim was to assess the rate of survival to hospital discharge in adult patients with refractory ventricular fibrillation/pulseless ventricular tachycardia out-of-hospital cardiac arrest treated with 1 of 2 local standards of care: (1) early venoarterial extracorporeal membrane oxygenation-facilitated resuscitation for circulatory support and percutaneous coronary intervention, when needed, or (2) standard advanced cardiac life support resuscitation. Phase II, single-center, partially blinded, prospective, intention-to-treat, safety and efficacy clinical trial. Adults (aged 18-75), initial out-of-hospital cardiac arrest rhythm of ventricular fibrillation/pulseless ventricular tachycardia, no ROSC following 3 shocks, body morphology to accommodate a Lund University Cardiac Arrest System automated cardiopulmonary resuscitation device, and transfer time of <30 minutes. Hospital-based. Primary: survival to hospital discharge. Secondary: safety, survival, and functional assessment at hospital discharge and 3 and 6 months, and cost. Assuming success rates of 12% versus 37% in the 2 arms and 90% power, a type 1 error rate of .05, and a 15% rate of withdrawal prior to hospital discharge, the required sample size is N = 174 evaluated patients. The ARREST trial will generate safety/effectiveness data and comparative costs associated with extracorporeal cardiopulmonary resuscitation, informing broader implementation and a definitive Phase III clinical trial.

Triple-sequential defibrillation for refractory ventricular fibrillation in a 24-year-old male out of hospital cardiac arrest.

SUMMARYRefractory ventricular fibrillation encountered during cardiac arrest has a mortality rate of 97%.1 As per the advanced cardiac life support (ACLS) guidelines, the management algorithm of ventricular fibrillation consists of chest compressions, epinephrine, defibrillation, and anti-arrhythmics.2 There have been reports describing the use of the fast-acting selective β-blocker, esmolol, and dual-sequential defibrillation in the management of ventricular fibrillation that is refractory to standard ACLS. We present a case of a 24-year-old male who had an out-of-hospital cardiac arrest, with refractory ventricular fibrillation despite high-quality cardiopulmonary resuscitation (CPR) and ACLS management. Along with standard ACLS, triple-sequential defibrillation was used to achieve return of spontaneous circulation (ROSC) after 82 minutes of downtime. An electrocardiogram (ECG) after ROSC showed an ST-elevation myocardial infarction (MI), and the patient underwent angiography showing a 100% occlusion of his left anterior descending artery. Following management of his coronary artery disease, he was discharged from the hospital 16 days later and was neurologically intact.

Abstract 205: Blood Flow Backward into the Vein During Chest Compression; The Correlation Between the Vessel Pressure and Return of Circulation in Out-of-Hospital Cardiac Arrest

Introduction: Little is known about the hemodynamic flow during chest compression (CC) for patients with cardiac arrests; some previous studies reported blood may flow backward into vein and oxygenated blood may not forward into artery during CC. We set out to describe the pattern of the hemodynamic flow during CC and identify the relationship between the pattern and their outcome. Method: We prospectively enrolled out-of-hospital cardiac arrest (OHCA) patients admitted to our emergency department (ED) and for whom femoral arterial and venous pressure were successfully measured from May 2017 to April 2018. The exclusion criteria was those with traumatic OHCA, who received extracorporeal membrane oxygenation or who aged &lt;15 years. We inserted a 4Fr catheter both in femoral artery and vein. The standard advanced cardiac life support was provided with manual or mechanical CC. We defined the case that the artery pressure was higher than the venous pressure as the A group, and the opposite case as the V group. The proportion of ROSC in both groups was statistically evaluated by chi-square test. Results: Total 70 patients were transported to our ED during the study period. Of the 25 patients for whom femoral arterial and venous pressure were tried to measure, 22 patients (90%) were successful and included in our final analysis. Each group had 11 patients. In A group, seven out of 11 patients achieved ROSC, whereas no patients did in V group (p=0.006). Conclusion: In this study, half of the patients predominantly showed the backward flow during CC and no patients could achieve ROSC in this group. This suggests that blood flowing backward into venous may be associated with the lower quality of CC during CPR.

Quantitative pupillometry and neuron-specific enolase independently predict return of spontaneous circulation following cardiogenic out-of-hospital cardiac arrest: a prospective pilot study

This study aimed to identify neurological and pathophysiological factors that predicted return of spontaneous circulation (ROSC) among patients with out-of-hospital cardiac arrest (OHCA). This prospective 1-year observational study evaluated patients with cardiogenic OHCA who were admitted to a tertiary medical center, Nippon Medical School Hospital. Physiological and neurological examinations were performed at admission for quantitative infrared pupillometry (measured with NPi-200, NeurOptics, CA, USA), arterial blood gas, and blood chemistry. Simultaneous blood samples were also collected to determine levels of neuron-specific enolase (NSE), S-100b, phosphorylated neurofilament heavy subunit, and interleukin-6. In-hospital standard advanced cardiac life support was performed for 30 minutes.The ROSC (n = 26) and non-ROSC (n = 26) groups were compared, which a revealed significantly higher pupillary light reflex ratio, which was defined as the percent change between maximum pupil diameter before light stimuli and minimum pupil diameter after light stimuli, in the ROSC group (median: 1.3% [interquartile range (IQR): 0.0–2.0%] vs. non-ROSC: (median: 0%), (Cut-off: 0.63%). Furthermore, NSE provided the great sensitivity and specificity for predicting ROSC, with an area under the receiver operating characteristic curve of 0.86, which was created by plotting sensitivity and 1-specificity. Multivariable logistic regression analyses revealed that the independent predictors of ROSC were maximum pupillary diameter (odds ratio: 0.25, 95% confidence interval: 0.07–0.94, P = 0.04) and NSE at admission (odds ratio: 0.96, 95% confidence interval: 0.93–0.99, P = 0.04). Pupillary diameter was also significantly correlated with NSE concentrations (r = 0.31, P = 0.027). Conclusively, the strongest predictors of ROSC among patients with OHCA were accurate pupillary diameter and a neuronal biomarker, NSE. Quantitative pupillometry may help guide the decision to terminate resuscitation in emergency departments using a neuropathological rationale. Further large-scale studies are needed.

P029: A descriptive analysis of defibrillation vector change for prehospital refractory ventricular fibrillation

Introduction: Patients in ventricular fibrillation (VF) who do not respond to standard Advanced Cardiac Life Support treatments are deemed to be in refractory VF (rVF). The ideal prehospital treatment for patients with rVF remains unknown. Double sequential external defibrillation (DSED) has been proposed as a viable option for patients in rVF. Although the mechanism by which DSED terminates rVF remains unknown, one theory is that the change in defibrillation vector that occurs may contribute. The objective of this study was to describe clinical outcomes for patients presenting in rVF during out-of-hospital cardiac arrest (OOHCA) for those who underwent vector change defibrillation, compared to those who received standard treatment. Methods: This was a retrospective chart review of adult (18 years) patients presenting in rVF during OOHCA over 15 months beginning in March 2016. Patients who underwent vector change defibrillation had a change in pad position (anterior-anterior to anterior-posterior) after 3 or more consecutive shocks. Termination of rVF was defined as the absence of VF after a vector change or standard shock during the next rhythm analysis. Results: There were 372 OOHCA, with 25 (6.7%) patients meeting our definition of rVF. Of these, 16 (64.0%) patients (median age 62 years, 81.3% male) had vector change after a median (IQR) of 3 (3.0-4.0) paramedic defibrillation attempts. Median (IQR) time to vector change defibrillation was 8.8 (7.1-11.1) minutes. Eight (50%) patients had termination of rVF after the first vector change shock, 6 (37.5%) had prehospital return of spontaneous circulation (ROSC) and 5 (31.3%) patients survived to hospital discharge. Of the 9 rVF patients who did not have vector change, median age was 63 years and 88.9% were male. The median (IQR) number of defibrillations within this group was 5 (4.5-7.0). No patients converted after the 4th defibrillation. Prehospital ROSC was achieved in 3 (33.3%) patients and 5 (55.5%) patients were transported while in rVF . Three patients (33.3%) survived to hospital discharge. Conclusion: This is preliminary evidence that vector change defibrillation in patients with rVF may result in VF termination. A randomized controlled trial is warranted to test whether or not vector change has a role in the termination of rVF.

Incorporating Nonphysician Stroke Specialists Into the Stroke Team.

Stroke care is team-based care, but trainees in neurology programs may have little experience in working directly with stroke specialists from other disciplines. Outside of an intensive care unit, nurses and physicians rarely round as a team, and stroke neurologists often have few interactions with prehospital care providers besides a quick handoff in the emergency room. However, nonphysician stroke specialists bring a broad base of expertise which overlaps with and complements the stroke neurologist’s knowledge. Increasingly, integrated stroke care is being provided by multidisciplinary teams. Team structures may vary from hospital to hospital and country to country, but often include integration of emergency medical services (EMS; particularly where mobile stroke treatment units are used); specialized nurses and nurse practitioners (NPs); and specialized therapy teams including speech and language pathologists, occupational therapists, and physical therapists with particular expertise in poststroke care. The stroke chain of survival begins with the 911 call, yet even high-level paramedics receive little formal stroke training outside of standard Advanced Cardiac Life Support protocols. EMS providers are often the first point of contact for the stroke patient and have the opportunity to collect vital information about timing of symptoms and medication use. First responders to stroke 911 calls may be Basic Life Support or Advanced Cardiac Life Support level. EMS providers should be familiar with validated prehospital stroke scales such as the Cincinnati Prehospital Stroke Scale.1 EMS providers who have more experience with stroke, such as paramedics who staff mobile stroke treatment units, find stroke to be an exciting field because of the time-critical nature of the treatment. Therefore, it is imperative that stroke neurologists reach out to EMS providers to offer additional training in stroke care. A basic understanding of stroke syndromes is both fascinating and extremely useful to EMS providers, who are often eager …

A retrospective study of pulseless electrical activity, bedside ultrasound identifies interventions during resuscitation associated with improved survival to hospital admission. A REASON Study

ObjectiveOur objective was to determine whether organized or disorganized cardiac activity is associated with increased survival in patients who present in pulseless electrical activity (PEA) treated with either 1) standard advanced cardiac life support (ACLS) medications or 2) other interventions. MethodsThis was a secondary analysis of a prospective, multi-center observational study utilizing ultrasound in out-of-hospital or inemergency department PEA arrest. Bedside ultrasound was performed as ACLS protocol started and during pulse checks. Only cases with visible cardiac activity on ultrasound were included in the present analysis. Cardiac activity was categorized as disorganized (agonal twitching) or organized (contractions with changes in ventricular dimensions). Patients were categorized as receiving either standard bolus ACLS medications or alternative medications during the resuscitation (continuous adrenergic agents, thrombolytics, others). The primary outcome was survival to hospital admission. The secondary outcome was return of spontaneous circulation (ROSC). Multivariate modeling was performed to assess association between survival to hospital admission in patients with intravenous adrenergic agents and cardiac activity. ResultsIn our cohort of 225 patients in PEA cardiac arrest with cardiac activity on ultrasound, the overall survival rate was higher in patients with organized cardiac activity than with disorganized cardiac activity. PEA cardiac arrest patients with organized cardiac activity treated with standard ACLS interventions demonstrated improved survival to hospital admission compared to those with disorganized activity (37.7% (95%CI 24.8–50.2%) versus 17.9% (95%CI 10.9–28%). PEA cardiac arrest patients with organized cardiac activity who received continuous adrenergic agents during the resuscitation and prior to ROSC demonstrated higher survival to hospital admission 45.5% (95%CI 26.9–65.4%) and ROSC 90.9% (95%CI 71.0–98.7%) compared to those with disorganized cardiac activity who received continuous adrenergic agents during the resuscitation 0% (95%CI 0–23.0%) and 47.1% (95%CI 26–69%). Regression analysis demonstrates an association between increased survival in patients receiving intravenous adrenergic agents and organized cardiac activity. ConclusionSurvival in patients following PEA arrest is higher in patients with organized cardiac activity. The initiation of continuous adrenergic agents during PEA was associated with improved survival to hospital admission in patients with organized cardiac activity on bedside ultrasound, but this improvement was not seen in patients in PEA with disorganized cardiac activity. Bedside ultrasound may identify a subset of patients that respond differently to ACLS interventions.

LO68: Extracorporeal membrane oxygenation in the emergency department for resuscitation of out-of-hospital cardiac arrest patients: a systematic review

Introduction: With one person in Canada suffering an out-of-hospital cardiac arrest (OHCA) every 12 minutes and an estimated survival to hospital discharge with good neurologic function ranging from 3 to 16%, OHCA represents a major source of morbidity and mortality. An evolving adjunct for resuscitation of OHCA patients is the use of extracorporeal membrane oxygenation-assisted CPR (ECPR). The purpose of this systematic review is to investigate the survival to hospital discharge with good neurologic recovery in patients suffering from OHCA treated with ECPR compared to those who received standard advanced cardiac life support with conventional CPR (CCPR) alone. Methods: A systematic database search of both MEDLINE &amp;amp; EMBASE was performed up until September 2016 to identify studies with ≥5 patients reporting ECPR use in adults (age ≥16 years) with OHCA. Only studies reporting survival to hospital discharge were included. All identified studies were assessed independently using pre-determined inclusion criteria by two reviewers. Study quality and risk of bias were evaluated using the Newcastle Ottawa regulations assessment scale. Results: Of the 1065 records identified, 54 studies met all inclusion criteria. Inter-rater reliability was high with a kappa statistic of 0.85. The majority of studies were comprised of case series (n=45) of ECPR with 5 to 83 patients/study. Out of the 45 case series, 37 presented neurologic data at hospital discharge and demonstrated a broad range of patients surviving with good neurologic outcome (0 to 71.4%). Only 9 cohort studies with relevant control group (CCPR) were identified (38 to 21750 patients/study). Preliminary analysis demonstrated that 6 cohort studies were sufficient quality to compare ECPR to CCPR. All 6 studies showed significantly increased survival to hospital discharge with good neurologic recovery (ECPR 10.6 to 41.6% vs CCPR 1.5 to 7.7%, respectively). Conclusion: Given the paucity of studies using appropriate comparators to evaluate the impact of ECMO, our confidence in a clinically relevant difference in outcomes compared to current standards of care for OHCA remains weak. Interestingly, a limited number of studies with suitable controls demonstrated a potential benefit associated with ECPR in the management of OHCA in selected patients. In this state of equipoise, high quality RCT data is urgently needed.

Sodium nitroprusside enhanced cardiopulmonary resuscitation improves short term survival in a porcine model of ischemic refractory ventricular fibrillation

IntroductionSodium nitroprusside (SNP) enhanced CPR (SNPeCPR) demonstrates increased vital organ blood flow and survival in multiple porcine models. We developed a new, coronary occlusion/ischemia model of prolonged resuscitation, mimicking the majority of out-of-hospital cardiac arrests presenting with shockable rhythms. HypothesisSNPeCPR will increase short term (4-h) survival compared to standard 2015 Advanced Cardiac Life Support (ACLS) guidelines in an ischemic refractory ventricular fibrillation (VF), prolonged CPR model. MethodsSixteen anesthetized pigs had the ostial left anterior descending artery occluded leading to ischemic VF arrest. VF was untreated for 5min. Basic life support was performed for 10min. At minute 10 (EMS arrival), animals received either SNPeCPR (n=8) or standard ACLS (n=8). Defibrillation (200J) occurred every 3min. CPR continued for a total of 45min, then the balloon was deflated simulating revascularization. CPR continued until return of spontaneous circulation (ROSC) or a total of 60min, if unsuccessful. SNPeCPR animals received 2mg of SNP at minute 10 followed by 1mg every 5min until ROSC. Standard ACLS animals received 0.5mg epinephrine every 5min until ROSC. Primary endpoints were ROSC and 4-h survival. ResultsAll SNPeCPR animals (8/8) achieved sustained ROSC versus 2/8 standard ACLS animals within one hour of resuscitation (p=0.04). The 4-h survival was significantly improved with SNPeCPR compared to standard ACLS, 7/8 versus 1/8 respectively, p=0.0019. ConclusionSNPeCPR significantly improved ROSC and 4-h survival compared with standard ACLS CPR in a porcine model of prolonged ischemic, refractory VF cardiac arrest.