bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 332: Novel Peptide Administered During CPR Improves Long-Term Survival After Prolonged Cardiac Arrest
Authors: Li Jing , Zhu Xiangdong , Lee Chunpei , Tain Rong-Wen , Cai Kejia , Vanden Hoek Terry L
Published: June 2021

Introduction:
Cardiac arrest (CA) is a leading cause of death in the United State, affecting 600,000 people annually with overall survival rate of less than 10%. CPR and cooling are the few effective treatments that improve CA survival. No drugs are currently available to improve survival. Active cooling is more effective than targeted temperature management in improving survival, but can be difficult to implement clinically. We have developed a novel peptide (TAT-PHLPP) that inhibits PH domain and Leucine rich repeat Protein Phosphatases (PHLPP). When this peptide was administered intravenously (i.v.) during CPR, it expresses in both heart and brain within 5 min of intravenous injection and significantly improved 4 h survival in a 12 min mouse asystole arrest model.

Hypothesis:
We hypothesize that TAT-PHLPP improves neurologically intact long-term survival following SCA with improved early metabolic recovery.

Methods:
C57BL6 mice (n=20) were randomized to receive peptide treatment and appropriate blinding was ensured. A 12 min asystolic arrest was induced with KCl. CPR was started along with TAT-PHLPP (7.5 mg/kg) via i.v. Three day Survival was evaluated. Cerebral blood flow (CBF) and metabolic chemical exchange saturation transfer (CEST) contrast were measured with endogenous and dynamic arterial spin labeling (ASL) and CEST MRI respectively. Glucose utilization was assessed by pyruvate dehydrogenase (PDH) phosphorylation and ATP generation. Further, blood taurine and glutamate were measured.

Results:
Baseline characteristics including weight, temperature, heart rate, MAP were indistinguishable between the control (normal saline, NS) and peptide group. Compared to NS, TAT-PHLPP significantly improved 3-day survival with better neurological function. It progressively increased CBF and metabolic CEST contrast. It decreased p-PDH (increased activity) at 15 min post-ROSC and enhanced ATP generation in both heart and brain. It also reduced plasma taurine and glutamate concentrations as early as 5 min post-ROSC. Further, high levels of taurine and glutamate were detected in non-survivors.

Conclusions:
This novel therapy may have a high translational potential to reproduce critical outcomes of CPR cooling without physical cooling.
Abstract 336: A Machine Learning Algorithm for Detecting Pulse During Out-Of-Hospital Cardiac Arrest
Authors: Alonso Erik , Aramendi Elisabete , Irusta Unai , Daya Mohamud R
Published: June 2021

Introduction:
Pulse detection during out-of-hospital cardiac arrest (OHCA) is a challenge still not satisfactorily solved. An automated and accurate method for detecting pulse would reduce hands-off intervals and allow for more prompt post-cardiac arrest care. The aim of this study was to develop a method based on machine learning (ML) to detect pulse during OHCA.

Materials and methods:
Data were gathered from 187 OHCA patients treated by Tualatin Valley Fire & Rescue (Tigard, OR, USA) using the Philips HeartStart MRx monitor/defibrillator between 2010 and 2014. The dataset used in the study contained 1140 5-s epochs presenting organized rhythms, 792 pulse-generating rhythms (PRs) and 348 pulseless electrical activity (PEA), annotated by consensus between two clinicians and a biomedical engineer using the available clinical information and the capnography signal. The dataset was split patient-wise into training (60%) and test (40%) sets. Each epoch contained the ECG and the thoracic impedance that were first preprocessed and then used to adaptively extract the impedance circulation component (ICC). The ICC shows a small fluctuation with each effective heartbeat. A total of 7 well-known waveform features were computed from the ECG and ICC and fed as observations to a discrete observation density hidden Markov model that classified each observation as PR (pulse) or PEA (no-pulse). The training set was used to develop and optimize the method, while the test set was used to measure the performance in terms of sensitivity (PR detection) and specificity (PEA detection). This procedure was repeated 50 times to estimate the distributions of the performance metrics.

Results:
The method showed a mean (SD) sensitivity and specificity of 95.4%(2.2) and 91.6% (3.4), respectively. Results were slightly above those previously reported by other authors using different ML techniques.

Conclusions:
A method based on a discrete observation density hidden Markov model can accurately detect pulse during OHCA. Further studies with larger datasets are needed to confirm these findings.
Abstract 356: Dynamic Susceptibility Contrast Magnetic Resonance Imaging to Quantify Perfusion Changes in Early Ischemic Brain Insult Following Cardiac Arrest in a Swine Model
Authors: Peckham Miriam , DeHavenon Adam , Alexander Matthew D , Anderson Jeffrey , McNally Scott , McKellar Stephen H , Tonna Joseph , Wong Ka-ho , Steenblik Jacob , Youngquist Scott T
Published: June 2021

Introduction:
Derangement of the cerebrovascular unit (CVU) following ischemia-reperfusion from cardiac arrest contributes to overall brain injury. MRI can detect perfusion changes, but imaging timing and severity of injury vary in the clinical population.

Hypothesis:
We hypothesized that a large-animal model with fixed periods of global ischemia followed by standardized reperfusion and time to image acquisition would demonstrate a reliable gradient of perfusion changes. Such a model would allow neuroprotective strategies to be tested using early imaging biomarkers to quantify effects on cerebral perfusion.

Methods:
10 healthy swine were placed under isoflurane anesthesia and underwent control MRI with dynamic susceptibility contrast (DSC) perfusion. Following imaging, animals were randomized to sham, 10, 15, 20, and 30-minute arrest groups, after which extracorporeal membrane oxygenation (ECMO) catheters were placed in the distal aorta and right atrium. Ventricular fibrillation was then induced by a bipolar pacing catheter for the fixed period of ischemia, after which animals were reperfused at 2.8-3.5 L/min with unblended oxygenated blood. After 4 minutes they were defibrillated. Over the next 2 hours they were weaned from pump and decannulated with epinephrine and fluid boluses given for hemodynamic support. Animals were then re-imaged within 2 hours post-resuscitation using the same pre-arrest protocol. DSC post-processing was performed and regions of interest were drawn in the bilateral frontal lobes to quantify perfusion parameters.

Results:
Baseline hemodynamic parameters, including BP, Heart Rate, ETCO2, and SpO2 were similar between animals. When comparing pre- to post-arrest MRI, there was a linear correlation of increasing Cerebral Blood Volume (CBV) with ischemic duration (r=0.69, p=0.028), and downward trend of Cerebral Blood Flow (CBF) with duration (r=-0.48, p=0.164).

Conclusion:
MRI DSC perfusion abnormalities were observed early in the post arrest period following fixed periods of ischemia with CBV correlated with ischemia duration consistent with dysfunctional vasodilation and uncoupling of the CVU. CBF showed a downward trend with injury severity. The effect of vasopressors and fluids on these findings is unclear.
Abstract 357: Cerebral Arterial Endothelial Dysfunction in the Post-Cardiac Arrest Period
Authors: Hansen Frederik B , Esteves Goncalo , Secher Niels , Lofgren Bo , Simonsen Ulf , Granfeldt Asger
Published: June 2021

Introduction:
Cardiac arrest (CA) has a poor prognosis due to brain injury that progresses over time. Endothelial dysfunction may play an important role in the impairment of the cerebral circulation after CA.

Aims:
To investigate 1) whether endothelial dysfunction is present in cerebral arteries, and 2) if the altered endothelial function is caused by increased activity of calcium-activated potassium (K
ca
) channels.

Methods:
Male Sprague-Dawley rats (403g±24g) were anaesthetized, intubated and ventilated. Four groups were examined; two CA groups observed for either 2 hours (2h-CA, n=10) or 4 hours (4h-CA, n=10) and two corresponding sham groups (2h-sham, n=10; 4h-sham, n=10). Following 7 minutes of asphyxial CA, the rats were resuscitated using adrenaline, ventilation, and chest compressions. Middle cerebral arteries were isolated and examined in wire-myographs.

Results:
Cerebral vasodilation was significantly enhanced in response to bradykinin in arteries from 4h-CA rats when compared to 4h-sham rats (4h-sham: E
max
58% (5.57 of 9.69) ± 6% vs 4h-CA: E
max
84% (6.16 of 7.32) ± 4%, p=0.007). Likewise, vasodilation induced by NS309 (K
Ca
-channel activator) was increased in CA rats when compared to sham rats. In the presence of L-NAME (NO synthase inhibitor), bradykinin induced vasodilation was significantly augmented in 4h-CA rats when compared to 4h-sham rats, whereas SNP (NO donor) induced vasodilation was similar between groups. In the presence of L-NAME and K
Ca
-channel blockers (UCL1684 and ICA-17043), bradykinin induced vasodilation was abolished in cerebral arteries in all four groups.

Conclusion:
Our findings demonstrate an enhanced endothelial-dependent vasodilation in cerebral arteries in the post-cardiac arrest period. The increased vasodilatory response may be explained by increased endothelial K
Ca
-channel activity and bioavailability of NO, and may contribute to dysregulation of cerebral blood flow after CA.
Abstract 368: A Cardiac Arrest Simulation-Based Feasibility Cadaver Study Investigating Time for Semi Surgical Cut Down Procedure Followed by Insertion of a Novel REBOA Catheter
Authors: Duhem Helene , Lamhaut Lionel , Hutin Alice , Bellier Alexandre , Tanguy Stephane , Boucher Francois , Chaffanjon Philippe , Debaty Guillaume
Published: June 2021

Aim:
Non-traumatic cardiac arrest is a major public health problem that carries an extremely high mortality rate. The Resuscitative endovascular balloon occlusion of the aorta (REBOA) procedure is currently being discussed as a possible technique to be used during Advanced Life Support (ALS) in humans with Cardiac arrest (CA). The aim of this study was to assess the training of emergency physicians in the procedures related to insertion of a novel REBOA catheter.

Methods:
We developed a training program using a simulated CA model on human cadavers. CPR was performed using the LUCAS device (Stryker/Jolife AB, Lund, Sweden). All cadavers were hemodynamically monitored. The Neurescue REBOA catheter (Neurescue REBOA device, Neurescue ApS, Copenhagen, Denmark) was inserted using a semi-surgical cut-down and sheath placement technique. Time needed to perform the procedures was measured. The procedures were instructed by 2 experts using video, procedural simulation on manikin and full-scale training on cadavers.

Results:
Six human cadavers were enrolled and a total of 12 procedures were performed by 2 expert investigators and 10 novice investigators. Eight semi-surgical cut-down producers including placements of the introducer sheath were performed on the first attempt and 4 required a second attempt. The median time required for the semi-surgical cutdown procedure and sheath placement by the novice investigators was: 6 min 48 sec (Min: 3 min 45 sec and Max: 26 min 25 sec). The median time required for the insertion and occlusion of the REBOA catheter by the novice investigators was: 3 min 22 sec (Min: 1 min 22 sec and Max: 7 min 5 sec). The median time required for full insertion for the novice investigators was: 11 min 14 sec (Min: 6 min 49 sec and Max: 28 min 15 sec). The mean aortic pressure during compression was: 31.9 mmHg (±17.0).

Conclusions:
Semi surgical cut-down and introducer sheath placement were performed in 1 or two 2 attempts for all novice investigators with an insertion time compatible with ALS during refractory CA. Simulation training on cadavers brings clinical realism and could be an important addition to the use of manikin or animal training models.
Abstract 375: Utility of Routine Early Head Computed Tomography Following Non-Traumatic Out-Of Hospital Cardiac Arrest
Authors: Petek Bradley J , Hamilton David E , Panah Lindsay G , Dormish Philip E , Mendez Sean R , Stevenson Elizabeth K , Cardona Estrada David , Silverman Michael G
Published: June 2021

Introduction:
Head computed tomography (CT) is frequently performed in survivors of out-of-hospital cardiac arrest (OHCA). However, the clinical utility of routine, early head CT in these patients is not well understood. We sought to characterize the associations between findings on early head CT with presenting characteristics and outcomes in survivors of OHCA.

Hypothesis:
Presence of early intracranial swelling is associated with poor outcomes.

Methods:
This is a retrospective analysis from a multicenter cohort of 432 patients with non-traumatic OHCA between 2/1/17 through 4/1/19. Patients were included if they underwent head CT <24 hrs after return of spontaneous circulation. Head CT findings were based on reads performed by local radiologists. Intracranial swelling was defined as loss of gray-white matter differentiation, sulcal effacement, and/or cerebral edema. Underlying cause of OHCA was adjudicated by trained physicians. Baseline characteristics and outcomes were compared between those with and without intracranial swelling.

Result:
Early head CT (<24 hrs) was performed in 378 (87.5%) patients with OHCA. Intracranial swelling was present in 97 (25.7%) patients with early head CT, and 14 (3.7%) had evidence of intracranial hemorrhage (ICH, Table). Of the patients presenting with ICH, 3/14 (21.4%) had shockable rhythms, 7/14 (50%) had subarachnoid hemorrhage, and ICH was the adjudicated cause of arrest in 10/14 (71.4%) patients. Patients with intracranial swelling were younger, less likely to have presented with a shockable rhythm, cardiac etiology, and witnessed OHCA. They were more likely to have a suppressed EEG, anoxia on MRI, and were less likely to survive to hospital discharge.

Conclusions:
In survivors of non-traumatic OHCA, routine, early (<24 hrs) head CT identified ICH in 3.7% of patients, and ICH was the adjudicated cause of arrest in 2.6% of patients. Intracranial swelling was present in more than 1/4 of patients, and associated with poor outcomes.
Abstract 399: CPR in Chicago Public Schools; A Survey for Implementation of Sudden Cardiac Arrest Education in Schools
Authors: Vermeulen Alyssa , Del Rios Marina , Campbell Teri , Nguyen Hoang
Published: June 2021

Introduction:
There is variability on CPR and AED training requirements and mandates in schools; some states require teachers to be certified in CPR while others, such as Illinois, only require students to be taught CPR prior to graduation. However, even when required, implementation is not always successful. Most US schools do not establish protocols for sudden cardiac arrest. Identification of barriers to implementation of such protocols and school-wide CPR and AED training are needed for safety of students and staff.

Hypothesis:
To survey Chicago Public Schools (CPS) staff on knowledge and barriers to training in CPR, AED, and sudden cardiac arrest.

Methods:
A 20-question anonymous survey was distributed to adult Chicago Public School staff. Questions included on knowledge of CPR, AED, and sudden cardiac arrest, knowledge of the schools’ preparedness, barriers to CPR, AED training, and desire of staff to improve CPR, AED knowledge.

Results:
Of 95 respondents, 53% were teachers. 66% had previously participated in CPR training, but 60% had not taken it in the last 2 years and. 41% did not know how to operate an AED and 30% had learned but were not confident they would be able to use it. 90% said they would like more education on sudden cardiac arrest, but only 3.2% had CPR training available to them through the school. When asked about future training, 42% would sign up regardless of cost, 51% said they would sign up only if free of cost. 21% provided cost as the only barrier and 45% of respondents selected both cost and time as the main barriers.

Conclusions:
Our survey demonstrates a lack of knowledge in CPR, AED and sudden cardiac arrest. Despite strong interest, barriers such as availability, time, and cost stand in the way of increasing preparedness. Through community organizations and volunteers, free basic training programs for schools can be created addressing the issue of cost, time and comfort with CPR and AED use can be created; in teaching staff, we can increase safety and the availability of persons to train students.
Abstract 405: A Machine Learning-Based Prediction of Cardiac Arrest Outcome Using a Large Multi-Center Database
Authors: Kim Hanbiehn , Nguyen Hieu , Jin Qingchu , Tamby Sharmila , Gelaf Romer Tatiana , Sung Eric , Liu Ran , Greenstein Joseph , Winslow Raimund , Suarez Jose I , Storm Christian , Stevens Robert D
Published: June 2021

Background:
Cardiac arrest (CA) poses a significant risk of death and long-term neurological disability yet there remains a lack of accurate and reliable methods to prognosticate post-CA outcome, indicating a major unmet need. Additionally, no existing CA outcome prediction model utilizes physiological time series (PTS) data, which captures transitions in a patient’s health state at high temporal resolution.

Materials and Methods:
We screened the Philips eICU database, which includes over 200,000 patients in 200 hospitals, extracting data on CA patients within 24 hours of ICU admission. We first extracted PTS and Electronic Health Record (HER) features and selected our features using nested Random Forest. The outcome labels were neurological state or mortality at ICU discharge. We tested various individual and ensemble machine learning algorithms (GLM, Random Forest, Gradient Boosting, Support Vector Machine, Neural Networks) and optimization techniques (hyperparameter tuning, model stacking, and transfer learning) to maximize the accuracy of outcome prediction.

Results:
For prediction of neurological outcome, our model combining EHR and PTS features achieved a higher sensitivity (0.78), specificity (0.88), and AUC (0.87±0.01) compared to the APACHE baseline standard model (AUC: 0.74±0.01, sensitivity: 0.77, specificity: 0.63). Also, for prediction of mortality our model (AUC: 0.81±0.01, sensitivity: 0.78, specificity: 0.71) outperformed the APACHE clinical baseline (AUC: 0.75±0.01, sensitivity: 0.86, specificity: 0.56) by 7%. The integration of PTS with EHR data increased mean AUC by 4% for neurological outcome and 2% for mortality.

Conclusion:
Results demonstrate that for both neurological outcome and mortality prediction, our ensemble model was significantly more effective compared to the baseline APACHE model. Additionally, we find that PTS data adds to the discriminative power of clinical models. With appropriate validation in prospective cohorts, these findings could be used as point-of-care references to aid ICU physicians in clinical decision-making.
Abstract 406: Are Providers Overconfident in Predicting Outcome After Cardiac Arrest?
Authors: Steinberg Alexis , Callaway Clifton W , Dezfulian Cameron , Elmer Jonathan
Published: June 2021

Objective:
Prognostication after cardiac arrest is challenging. We tested if providers’ confidence in their neuroprognostic assessments correlates with accuracy.

Methods:
We presented physicians with clinical synopses using data from real-time, post-arrest patients being treated at a single academic medical center. We allowed providers to ask for any additional data available at the time the assessment was performed. We asked providers: (1) will the patient survive to hospital discharge?; (2) will the patient have favourable function at discharge?; and, (3) their confidence in each prediction (0-100%). We repeated assessments daily until death or post-arrest day 5.

Results:
We completed 414 assessments of 51 patients with 59 providers. Of patients, 79% died, 8% were discharged with unfavourable function and 12% had functionally favourable survival. Providers accurately predicted survival in 257/414 (62%) assessments. In most errors (136/141, 96%), providers predicted survival in a patient who died. Providers accurately predicted function in 282/414 (68%) assessments. In most errors (125/132, 95%), providers incorrectly predicted a favourable outcome. Providers were confident in their assessments (median confidence predicting survival 80 [IQR 60 - 90]; median confidence predicting function 80 [IQR 60 - 95]). Accuracy predicting survival and function were both positively correlated with confidence (both P<0.001), but confidence explained only 7% and 15% of observed variance in accuracy, respectively. When providers reported 100% confidence predicting survival, they were correct in 31/42 (74%) cases. Accuracy did not vary over time. Attending physicians were not more accurate than trainees predicting survival (65% vs 60% accurate) and were less accurate prediciting functional outcome (62% vs 84% accurate, P< 0.001). Confidence did not differ between attendings and trainees.

Conclusions:
Providers were overly optimistic predicting outcomes at discharge. Self-reported confidence explained only a small percentage of variance in accuracy. Even when extremely confident, providers were often wrong. Our future work will explore patient and provider factors that contribute to error.
Abstract 408: Predictors of Survival to Hospital Discharge, a Machine Learning Modelfor Out-Of-Hospital Cardiac Arrest in the Young
Authors: Vermeulen Alyssa , Nguyen Hoang , Nguyen Hai , Campbell Teri , Del Rios Marina
Published: June 2021

Background:
Many efforts in the area of Out of Hospital Cardiac Arrest (OHCA) have been made to enhance diagnosis, interventions, and increase survival; there is little data on OHCA in the young (1-35 years old). Machine learning (ML) enhances medical diagnosis and decision making with recent models allowing clinicians better control and interpretation of their features.

Objective:
To develop a machine learning model to predict a young patient with OHCA survival to hospital discharge. The ML model will be used to identify important factors contributing to this predictive model.

Methods:
Utilizing the CARES database in Chicago, IL, from 2013 to 2017, all OHCA in ages 1-35 years were analyzed; the primary outcome of interest is survival to hospital discharge. Eight machine learning techniques were applied to classify survival to hospital discharge. XGBoost was used with decision trees. Synthetic Minority Over-sampling Technique was used to over-sample the under-represented population. All statistics were performed using Python.

Results:
744 events were analyzed from 2013 to 2017. Median age was 24.6 years, of these 19.2% were 18 years and younger. The sample was 46% black, 31% caucasian and 19% Hispanic and 68% were male. Presumed cardiac etiology was identified in 61%; 13% had a shockable rhythm; 59% of events were unwitnessed. The model was able to classify survival and death with an accuracy of 90% and AUC of 0.98. Strongest positive correlation of survival to discharge was seen with sustained ROSC, first rhythm type being a shockable rhythm, and use of hypothermia. There was correlation with the year arrest occurred, with positive trend of survival over the study period time. There was a positive trend toward survival with advanced airway and epinephrine use. There was a negative trend toward survival with unwitnessed arrest and location outside of home or healthcare facility.

Conclusions:
The XGBoost model showed excellent classification of those who survive to discharge and die with OHCA in those 1-35 years old. Most rhythms in this population were not shockable rhythms despite over half of arrests being presumed cardiac in nature. Standard machine learning models can help identify and determine relevant interventions to improve OHCA in the young.
Abstract 410: Early Imaging Incompletely Predicts Subsequent Cerebral Physiological Derangements After Cardiac Arrest
Authors: Gomez Francisco , Abella Benjamin , Balu Ramani
Published: June 2021

Introduction:
Decreased grey-white matter ratio (GWR) on early head CT scans correlates with poor outcome after cardiac arrest. However, it is unknown if early imaging features fully predict of subsequent derangments in cerebral physiology that cause secondary brain injury.

Hypothesis:
GWR on early head CT correlates with average intracranial pressure (ICP), brain tissue oxygen (PbtO2), and pressure reactivity (a proxy for cerebral autoregulation) after cardiac arrest.

Methods:
A total of 30 post-arrest patients were identified over a 3-year period who underwent head CT within 1 day of arrest as well as intracranial monitoring (IM) during hospitalization. 5 patients were excluded either due to unavailable IM recordings (n=1) or motion degraded head CTs (n=4). ICP, P
bt
O
2
, and mean arterial pressure (MAP) were recorded continuously using a bedside recording unit (CNS Monitor, Moberg Research Inc). Pressure reactivity index (PRx), was calculated as the Pearson correlation coefficient between ICP and MAP over 5 minute intervals, updated every minute. GWR was measured for the basal ganglia from Hounsfield unit measurements made from initial head CT. Relationships between average ICP, PRx, P
bt
O
2
and GWR was calculated using linear regression.

Results:
Average GWR for the cohort was 1.2154. Average ICP was weakly correlated with initial GWR (R
2
=0.257, p=0.01). A trend towards higher PRx values was seen with lower initial GWR; however, this did not reach statistical significance (R
2
=0.15, p=0.07). There was no relation between average P
bt
O
2
and GWR (R
2
=0.02, p=0.56).

Conclusions:
Lower initial GWR is associated with higher average ICP, and may also be associated with disorderd cerebral autoregulation. However, no relationship could be identified between initial imaging findings and average brain oxygen levels. These data imply that physiological stressors such as brain hypoxia are not predicted by initial imaging findings and suggests a role for invasive neuromonitoring to identify and treat processes that promote secondary brain injury.
Abstract 412: Chance of Survival Decreases Within 10 Minutes of Transport in Trauma Patients Receiving Preospital Cardiopulmonary Resuscitation
Authors: Naito Hiromichi , Yumoto Tetsuya , Yorifuji Takashi , Nojima Tsuyoshi , Nakao Atsunori
Published: June 2021

Introduction:
Patients with traumatic cardiac arrest (TCA) are known to have poor prognoses. The joint committee of the National Association of EMS Physicians and the American College of Surgeons Committee on Trauma proposes stopping cardiopulmonary resuscitation (CPR) more than 15 minutes after TCA. However, with advances in resuscitation strategies, recent published data show improved outcomes. Data supporting TCA’s critical time limit is lacking.

Hypothesis:
We studied whether longer transport time is associated with poor outcomes in TCA.

Methods:
Retrospective review from the Japan Trauma Data Bank (2004-2017). Inclusion criteria were patients age ≥ 16 with at least one Abbreviated Injury Scale score (AIS) ≥ 3 trauma and CPR performed during the transport. Exclusion criteria were patients with burns, AIS score = 6 in any region, and missing survival data. Primary outcome was the association between transport time and survival in patients with no vital signs at arrival. For secondary outcomes, survival between penetrating injury/blunt injury and no vital signs (Revised Trauma Score [RTS] = 0)/any vital sign (RTS > 0) were compared. For the primary outcome, probability of survival was drawn with risk ratio (reference 15 min) according to transport time. Fisher’s exact test was used to compare secondary outcomes.

Results:
5,334 patients were included. Patient characteristics were age (53 ± 21 years), sex (67% male), Injury Severity Score (31 ± 13), blunt trauma (95%), and transportation time (16 ± 15 min). Overall survival rate was 4.5%, survival rate in patients without vital sign at arrival was 1.2%. Survival rate decreased within 10 min (
Figure
). Penetrating trauma increased the chance of survival compared with blunt trauma (7.7% vs. 4.1%, OR 1.9,
p
= 0.006). Chance of survival increased when the patient had any vital sign at arrival (28% vs. 1.2%, OR 33,
p
< 0.001).

Conclusions:
Longer transport time was associated with worse outcome, supporting the current guideline.
Abstract 429: First-Line Vasopressor Agent for Cardiogenic Shock Due to Acute Myocardial Infarction: Results From Tokyo CCU Network Registry
Authors: Ashida Tadashi , Yagi Tsukasa , Nagao Ken , Kuroki Norihiro , Takayama Tadateru , Hosokawa Yusuke , Nakata Jun , Kuwabara Masanari , Yamamoto Takeshi , Takayama Morimasa
Published: June 2021

Background:
In the guidelines for cardiogenic shock, norepinephrine, as compared with dopamine, was associated with fewer cases of arrhythmia and may be a better first-line vasopressor agent. However, few clinical studies have investigated the effects of optimal first-line vasopressor agents for patients with poor renal function.

Methods:
From a multicenter, prospective, cohort registry of emergency cardiovascular patients in Tokyo between 2013 and 2016, we identified adult patients with cardiogenic shock due to acute myocardial infarction (AMI) who received either norepinephrine, dopamine or both as a vasopressor agent without mechanical circulatory supports. Study patients were divided into 4 groups according to estimated glomerular filtration rate (eGFR). The primary endpoint was all-cause mortality at 30 days after admission.

Results:
Of the 4,034 patients with cardiogenic shock due to AMI, 665 were eligible for this study; 419 received norepinephrine (N group), 154 dopamine (D group), and 92 both agents (B group). There was a significant difference in the all-cause mortality rate between the three groups in the whole cohort (16.0% in the N group, 9.7% in the D group and 40.2% in the B group, P<0.001). In addition, there was a significant difference in the all-cause mortality rate between the three groups in the subgroups of patients with eGFR stage 3a and 3b. (Figure). After adjustment of independent factors for mortality, the odds ratio of the D group (reference, the N group) was 0.51 (95%CI 0.26-0.99, p=0.049).

Conclusion:
Compared with norepinephrine, dopamine was associated with a lower all-cause mortality rate for patients with cardiogenic shock due to AMI, especially patients with poor renal function.
Abstract 434: A Randomized Blinded Trial of Three Chest Compression Strategies in a Porcine Model of Pediatric Cardiac Arrest
Authors: Menegazzi James J , Salcido David D , Koller Allison C , Genbrugge Cornelia , Fink Ericka L , Berg Robert A , Patterson Charity G
Published: June 2021

Background:
Current guidelines recommend that chest compressions for children be done at either 1.5 inches depth and 100 per minute, or one-third the chest A-P diameter depth and 100 per minute. Neither of these recommendations is based on scientific evidence.

Objective:
As part of an ongoing efficacy trial, we sought to compare the safety of three different chest compression strategies in a porcine model of pediatric cardiac arrest.

Methods:
Following anesthesia, instrumentation, and induction of asphyxial cardiac arrest, we randomly assigned 48 domestic swine to one of three groups (n=16 per group). The mean mass of 25.7 kg approximates the 50
th
percentile for a 7 year old. Group 1 had fixed chest compression depth of 1.5 inches/rate 100; group 2 had fixed proportional depth of one-third the A-P diameter/rate 100; group 3 used an adaptive algorithm that incrementally increased chest compression rate and/or depth from baseline 1.5in (max: 2.13in) and 100/min (max; 130/min) every 25s while coronary perfusion pressure was below 25mmHg. Necropsies were independently performed by a veterinarian and veterinary technologist who were blinded to group assignment. The primary safety outcome was unrecoverable injury (i.e. toxicity), which we defined as either a total lung injury score ≥16 (score can range from 0 to 20) plus presence of hemothorax, or disruption of either the aorta or vena cava. Data were analyzed with the Bayesian Beta Binomial to determine if within-group toxicity exceeded an unacceptable level (30%) with a pre-selected posterior predictive threshold of 0.75(ptox). Lung injury scores between groups were compared with Kruskal-Wallis tests.

Results:
Median total lung injury scores were: 12 for group 1; 18 for group 2; 14 for group 3. Group 2 was significantly different from both groups 1 and 3 (p<0.001). Groups 1 and 3 did not differ (p=0.24). Toxicity occurred in zero animals in group 1 (ptox=0.0001); 7 animals in group 2 (ptox=0.8180); and 1 animal in group 3 (ptox=0.0076). The posterior probability threshold was exceeded in group 2 which warranted termination of the treatment arm for safety.

Conclusions:
Chest compressions performed at a depth of one-third the A-P diameter are unsafe. The safety of this approach in children should be carefully evaluated.
Abstract 437: The Relation Between Cerebral Oxygenation and Blood Flow During CPR in Swine
Authors: Gould Jeffrey R , Lick Michael , Lampe Joshua W , Berger Paul S , Metzger Anja
Published: June 2021

Introduction:
The physiology underlying cerebral oxygenation and blood flow during resuscitation from cardiac arrest (CA) is poorly understood. This study examined the relation between cerebral oxygenation and blood flow during standard CPR (SCPR) and CPR with active decompression and lift (ACD) plus an impedance threshold device (ITD).

Methods:
Ventricular fibrillation (VF) was electrically induced in 15 domestic swine. Following 6 minutes of untreated VF, chest compressions were initiated at 100 cpm and 10% anterior-posterior distance. Depth increased to 20% anterior-posterior distance over a 2-min period, and was then maintained for 6 minutes (SCPR). ACD+ITD was performed for an additional 6 minutes at the same rate and depth as SCPR, but with 20% anterior-posterior distance of active lift. Microspheres were injected 2 minutes after the start of SCPR and ACD+ITD to measure blood flow. Cerebral oxygenation was measured using NIRS, and 8-sec averages collected 2 minutes following microsphere injection were used for comparison. Changes in oxygenation and blood flow that occurred in response to ACD+ITD relative to SCPR were analyzed using linear regression to predict oxygenation based on blood flow.

Results:
ACD+ITD increased blood flow in 13 animals and oxygenation in 12 animals relative to SCPR. Changes in cerebral oxygenation were directly proportional to changes in blood flow for 12 of 15 animals in response to ACD+ITD following SCPR. Cerebral blood flow explained 34% of the variance in cerebral oxygenation (

R
2

= 0.34,
F
(1, 13) = 6.7,
P
= 0.02).

Conclusions:
Changes in cerebral oxygenation during CA are associated with measured changes in cerebral blood flow, however 66% of the variance in cerebral oxygenation remains unexplained. Other physiological parameters should be considered to further understand how NIRS may provide clinically useful information during resuscitation.
Abstract 449: Cost Analysis of a Contextualized Cardiopulmonary Resuscitation Training for Orderlies Participating in In-Hospital Cardiac Arrests
Authors: Vincelette Christian , Sokoloff Catalina , Carrier François-Martin , Desaulniers Pierre , Nadon Nathalie
Published: June 2021

Introduction:
Basic life support (BLS) training poses challenges for healthcare organizations. It requires numerous resources, complicates scheduling and is expensive. Orderlies typically provide chest compressions during in-hospital cardiac arrests, and are therefore recertified in cardiopulmonary resuscitation (CPR) every 2 years. However, such time lapse between CPR certifications induces skills decay.

Hypothesis:
Based on the American Heart Association statement on resuscitation education science published in 2018, we aimed to train all orderlies (n= 900) in less than 1 year, in order to reach proficiency in chest compressions, at a fraction of the cost.

Method:
A shortened (20 minutes), and adapted version of CPR training was created. This training specifically addressed high quality chest compressions, the cornerstone skill relevant to the scope of practice of orderlies in CPR. It was delivered in situ during working hours, as a mass training program that spanned over a period of 1 week. The training was provided through Mastery Learning and Deliberate Practice with direct feedback and live coaching. The cost analysis aimed to compare the costs of the new approach as compared to BLS training.

Results:
With this innovative approach, 30 trainers were able to train 600 employees in only 5 days. Preliminary results suggest most were able to perform high quality compressions after training. The total cost of the activity was 2 347.21 $CAD which represents 3% (2 347 of 76 200) of what it would take to train 600 people in BLS (76 200$CAD), and 13% (2 347 of 18 000) of the budget planned per year for orderlies’ BLS training at our institution (~18 000$CAD). The individual cost of our initiative was 4.13$CAD per employee. This method allowed to train employees around the clock, to cover all working shifts, thereafter preventing the removal of employees from the rolling schedule. Also, this solution allows us to repeat the experience another time this year, to train all orderlies.

Conclusions:
Although further research is needed to assess if skills are sustained over time and comparable based on performance outcomes, our inquiry is an innovative, sustainable and cost-effective way to train specific CPR skills to large groups.
Abstract 462: Medical Emergency Team Replaces Code Blue Activations at Pediatric Hospital
Authors: Masse Elizabeth , Roberts Joan S
Published: June 2021

Introduction:
In free-standing pediatric hospitals, the Code Blue team may be activated for events in adults to provide triage, resuscitation, medical screening exams, EMTALA documentation and disposition decisions. However, activation of the Code Blue team can require significant time and critical care resources and may delay patient care if the activation is external to the building.

Hypothesis:
Development of a small triage team focused on specific adult triage algorithms will provide a safe, effective and efficient alternative to Code Blue team response.

Methods:
407 bed tertiary pediatric hospital, within metropolitan area. Collaborative multi-disciplinary QI process to design and simulate the roles, workflow and documentation of the Medical Emergency Team (MET). Education and communication to hospital-wide staff on MET, as well as MET responders completion of Advanced Cardiac Life Support course. Collaboration with local EMS leadership to coordinate transfer of patient was also undertaken.

Results:
MET roles were developed and two configurations of the MET team were implemented July 2018: one inside the footprint of the building and anther outside the footprint of the building, including the hospital grounds. The teams consisted of a mid-level provider, charge nurse, two security officers and a shift administrator: inside team relied on ICU provider and charge nurse, while outside team led by Emergency Medicine provider and charge nurse. Each team had a backpack with supplies, and transport gurney. Since inception, 199 activations occurred, 191 inside and 8 outside the facility. The activations included 45 staff or volunteers, 84 adult visitors, 75 pediatric visitors. Outcome for the activations: 57 transported to the hospital ED, 47 transported to another facility, 21 refused treatment and 68 had resolution of concerns. EMTALA documentation was complete in 112/137 (82%).

Conclusions:
Pediatric hospitals have substantial adult populations, where medical emergencies that arise rely on Code Blue in medical emergencies for simplicity. Development of a response team for nonpatients allows specific training, triage, and processes to improve care and reduce drain on ICU resources.
Abstract 465: PERC: A 23 Years Experience of Disseminating BLS Techniques in Underserved Areas
Authors: Lima Neiberg A , Lima Swelen , Pessoa Gabriel , Costa Priscila , Costa Thomaz , Vasconcelos Emanuel , Praxedes Wesla , Silva Larissa , Silva Thais , Barbosa Thais
Published: June 2021

Background:
Ischemic heart disease is the main cause of mortality in Brazil. Sudden cardiac death is often the initial presentation of a myocardial infarction, however Basic Life Support (BLS) undertraining is real not only for lay rescuers but for health care providers in Brazil. A group of medical students from the Universidade Federal do Ceara (UFC) founded in 1996 the Cardiorespiratory Resuscitation Education Program (PERC) with a goal of disseminating BLS techniques.

Objective:
Emphasize the importance of creating social projects to propagate BLS techniques in underserved populations.

Methods:
An experience of over 23 years of BLS training with a non profit medical student group in the northeast of Brazil will be reported.

Results/Discussion:
The group is formed by students from the first to the last year of the UFC medical school. They are trained by cardiology faculties and senior members on the most recent ILCOR guidelines for BLS. A member usually stays in the program for two or three years and during this time is responsible to facilitate free classes in schools, public hospitals, health centers and medical schools. These courses are based on one lecture followed by a hands on training on CPR manikins. Pre and post testing are applied to evaluate satisfaction and learning. With 23 years of experience, a total of 11,841 people were directly trained by our program: 4.626 lay rescuers, 3.124 medical/nursing students and 4.091 health providers. A satisfaction rate is above 95%. The impact of this program in our community is immeasurable.

Conclusion:
Even though these courses don’t replace the official AHA-BLS training, nonprofit organizations as PERC can play an important role in communities with limited resources, helping to disseminate BLS techniques and maybe decreasing the mortality and morbidity associated with the sudden cardiac death in those areas.
Abstract 015: Importance of Balanced Follow-up Time and Other Study Design Considerations When Evaluating Adherence Using Two Novel Oral Anticoagulants
Authors: Coleman Craig , Yuan Zhong , Schein Jeffrey , Crivera Concetta , Ashton Veronica , Laliberté François , Lefebvre Patrick , Peterson Eric
Published: June 2021

Background:
Medication adherence rates decline over time, especially after the first dispensing. Comparing adherence rates for medications that have been on the market for differing period of time may distort real differences in medication adherence. Other analysis factors such as minimum number of dispensing criteria and Pharmacy Quality Alliance (PQA) adherence measures can also affect adherence measurement.

Objectives:
To use one real world example (rivaroxaban vs apixaban) in non-valvular atrial fibrillation (NVAF) patients to quantify the impact of adjusting for imbalances in follow-up periods, minimum number of dispensing, and use of the PQA adherence measure.

Methods:
Using IMS Health Real-World Data Adjudicated Claims and Truven MarketScan claims databases, we included adult patients with ≥1 rivaroxaban or apixaban dispensing (index date), ≥1 year of pre-index eligibility, ≥1 AF diagnosis pre-index, newly initiated on oral anticoagulant therapy, and no valvular involvement. Adherence was evaluated using proportion of days covered (PDC) ≥0.8 for cohorts with (1) unbalanced follow-up (2) balanced follow-up (by matching on month and year of follow-up since fill-date) (3) ≥2 rivaroxaban or apixaban dispensings and a balanced follow-up, and using (4) the PQA adherence measure.

Results:
Rivaroxaban users had significantly longer mean (SD) follow-up than apixaban (408 [300] versus 254 [196] days, respectively). While apixaban users appeared to be more adherent in unadjusted analyses, this finding was reversed after 1) adjusting for unbalanced follow-up 2) excluding single-time users; and 3) applying the PQA-endorsed adherence measure (Figure). Similar results were found using the Truven databases.

Conclusion:
Comparisons of the adherence rates among medications need to account for the period of time each have been on the market, number of dispensing and PQA measures. Retrospective analyses of adherence that do not adjust for such differences could produce spurious findings.
Abstract 025: Factors Influencing Blood Pressure Control and Adherence in a Middle income Country That Provides Universal Free Access to a Comprehensive Hypertension Program
Authors: Sandoval Huenchual Daniela , Nazzal Carolina , Romero Tomás
Published: June 2021

Background:
Limited information exists on the association of clinical, socio-economic, psychosocial factors and free access to national health programs with blood pressure control (BPC) and adherence to therapy (Rx) in developing middle income countries.

Methods:
Cross-sectional study in randomly selected 992 hypertensive patients (30 to 64 years of age) served in the Chilean national Cardiovascular Health Program (CVHP) that provides free medical care and life style modification counseling to approximately 75% of the population. Association of education, income, diabetes, obesity, physical activity, psychosocial characteristics, smoking, abnormal alcohol use with BPC and adherence to Rx was evaluated in patients with at least 1 year in the CVHP. Adherence to Rx and psychosocial characteristics were assessed using validated questionnaires. Odds ratios (OR) with 95% of confidence intervals for uncontrolled BP (≥140/90 mm/Hg) and no adherence to Rx were obtained through multivariable logistic regression analysis adjusted for all variables included in the study (see Table).

Results:
A larger number of women (65.2%) were part of the study. BPC was achieved in 53.5% of patients and 38.7% were adherent to Rx. Uncontrolled BP was significantly associated with non adherence (OR: 1.34 [95% CI 1.09 - 1.65]); other associations are shown in table.

Discussion and Conclusions:
In hypertensive patients followed in the CVHP, BPC was achieved in 53.5%. It is of note that a 2010 Chilean National Health Survey reported BPC in 16.7% of the population and in 45.3% of subjects that stated to be under Rx. Uncontrolled BP and low Rx adherence were significantly associated to male gender, also underrepresented in the study population (34.8%) and low Rx adherence to high score of emotional stress and depression, underlining need of measures addressing those issues. Low adherence was associated to low income notwithstanding free access to care and therapy.