bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 215: New Mannequin Made by Recyclable Plastic Bottles for Training Thoracic Compressions at Schools
Authors: Piscopo Agnaldo , Piscopo Isabella C , AVEZUM Alvaro , Pinto Ibrain M , Saraiva Francisco K
Published: July 2021

Introduction:
The teaching of Cardiopulmonary Resuscitation (CPR) in schools is already established by the "Kids Save Lives".A low-cost mannequin with the possibility of using recycled material may be a new means of training for children and young people in low-income areas.

Objectives:
To develop a low-cost mannequin derived from recycled material and evaluate its ability to demonstrate simulations of chest compressions for children and young people.

Methods:
Development of the model of a low fidelity mannequin made by children in a standard platform based on a plastic bottle (PET) inserted in a T-shirt with other recycled materials such as paper and Styrofoam. The compression simulation test was conducted by a randomized, single-blind study with the inclusion of volunteers at a high school. The children, without previous training in CPR, were randomized to one of the training arms of Laerdal’s Litle Anne mannequin (L) or plastic bottle mannequin (PB). The compression test was performed on a multi-sport court, during 60 minutes, through a video demonstration of CPR with emphasis on chest compressions. The two groups were balanced in age and gender. After the training, all students underwent a test on the Anne Quality Laedal mannequin with two minutes of chest compressions supervised by an instructor (blind to the previous training), that evaluate the frequency of the compressions, correct position of the hands, mean time without compression, total number of compressions and mean depth of compressions.

Results:
A total of 88 children and young people with a mean age of 14 years of both genders were included. Forty children trained with the L mannequin and 48 with the PB. The variable depth of compression showed differences between the trained groups, where the PB model was 4.1 points higher than the L model (p=0.012) without being able to affirm that there was an effect on the item depth sufficient (p=0.077). Others variables did not present differences between groups.

Conclusion:
The PB mannequins have very low cost and can be a new model for CPR training in schools. On the compressions ability, only the depth variable was superior in the PB model, perhaps due to the greater similarity of the mannequin to human chest strength.
Abstract 221: Mean Arterial Pressure and Impact on Organ Function and Survival During Targeted Temperature Management After Out-of-Hospital Cardiac Arrest
Authors: Grand Johannes , Hassager Christian , Winther-Jensen Matilde , Wiberg Sebastian , Thomsen Jakob H , Frydland Martin , Kjaergaard Jesper
Published: July 2021

Introduction:
Hemodynamic instability is common after resuscitated out-of-hospital cardiac arrest (OHCA). However, data on hemodynamic treatment-goals are sparse. This study investigates mean arterial pressure (MAP) in patients surviving 48 hours after OHCA in relation to organ injury and survival as a post hoc analysis of a large multicenter trial cohort.

Hypothesis:
We hypothesized that low MAP during TTM was associated with more organ injury.

Methods:
Post-hoc analysis of the prospective randomized TTM-trial including 851 comatose OHCA patients surviving more than 48 hours with available blood pressure data. Neuron-specific enolase (NSE) (brain injury) was the primary endpoint and estimated glomerular filtration rate (eGFR) (renal function) was the secondary endpoint.

Measurements and Main Results:
Patients were stratified by mean MAP during TTM in the following groups; <70 mmHg (22%), 70-80 mmHg (43%), and >80 mmHg (35%). NSE at 24, 48 and 72 hours was inversely related to mean MAP: 28 ng/ml [95% confidence interval (CI) 24-33], 26 [23-29], 21 [19-24] ng/mL; p
group
=0.002 for low, intermediate and high MAP groups. After adjusting for potential confounders, this association remained significant (p
group_adjusted
=0.006). A similar result was seen for eGFR (p
group_adjusted
=0.003). Mean MAP was not associated with mortality after 180 days, however higher mean MAP was independently associated with lower odds of renal replacement therapy (odds ratio
adjusted
= 0.75 [95% CI, 0.63-0.88] per 5 mmHg increase; p < 0.001]) (figure 1).

Conclusions:
Lower mean MAP during TTM was independently associated with increased biomarkers of brain injury and initiation of renal replacement therapy in a large cohort of comatose OHCA patients. Increasing blood pressure above the guideline-recommended threshold of 65 mmHg during TTM could potentially mitigate organ injury and be renal-protective. This hypothesis should be investigated in prospective trials.
Abstract 224: Socioeconomic Disparities in Layperson CPR Training Within a Large U.S. City
Authors: Abdulhay Nabil M , Totolos Konstantinos , Buckler David G , Hewitt Nicole , Leary Marion , Abella Benjamin S
Published: July 2021

Aim of the Study:
Prompt bystander CPR is a crucial intervention to improve cardiac arrest survival. However, recent work suggests that the prevalence of layperson CPR training remains low. We sought to understand how individual factors and neighborhood characteristics influence an individual’s likelihood of being trained in CPR within a large U.S. city. We hypothesized that higher socioeconomic status (educational attainment, and median household income (MHI)) would be associated with a higher likelihood of having previously received CPR training.

Methods:
Through The Mobile CPR Project, a program providing hands-only CPR and AED education to underserved communities in the greater Philadelphia region, we surveyed participants regarding prior CPR training. Survey questions pertained to race, gender, education, prior CPR training, Automated External Defibrillator (AED) awareness, and nearest street intersection to their residence. MHI was extrapolated via census tract data.

Results:
From 7/2016 to 4/2018, 1665 subjects completed surveys prior to CPR training. Of these, 70% were female, 70% were non-white, median age was 41 [IQR 25-59] yrs, and MHI was $39,318 [IQR $27,708-$60,795]. Subjects residing in tracts with MHI below the cohort median were significantly less likely to have ever received CPR training (first quartile: OR 0.646, CI 0.491 -0.850, p=0.002; second quartile: OR 0.576, CI 0.437 - 0.759, p<0.001). Gender was not significantly related to likelihood of being trained. Individuals who did not complete high school were less likely to ever receive training (Less than high school: OR 0.175, CI 0.089 - 0.344, p<0.001; Some high school: OR 0.452 0.303 - 0.675, p<0.001). In multiple logistic regression controlling for age, race, gender, MHI, and education, increasing educational attainment was associated with higher likelihoods of ever receiving trained (OR 7.96 Master’s or Doctoral compared to less than high school, CI 5.24 - 12.11, p < 0.001).

Conclusions:
Among laypersons attending a free CPR training session, there is a strong association between socioeconomic factors (MHI, educational attainment) and likelihood of prior CPR training.
Abstract 230: Differential Effects of Prehospital Hypotension and Injury Severity in Isolated vs. Multisystem Major Traumatic Brain Injury
Authors: Spaite Daniel W , Hu Chengcheng , Bobrow Bentley J , Barnhart Bruce J , Chikani Vatsal , Gaither Joshua B , Denninghoff Kurt R , Rice Amber D , Keim Samuel M
Published: July 2021

Background:
In hospital-based studies, hypotension (HT, SBP <90) is more likely to occur in multisystem traumatic brain injury (MTBI) than isolated (ITBI). However, there are few EMS studies on this issue.

Hypothesis:
Prehospital
HT is associated with differential effects in MTBI and ITBI and these effects are influenced by the severity of primary brain injury.

Methods:
Inclusion: TBI cases in the EPIC Study (NIH 1R01NS071049) before TBI guideline implementation (1/07-3/14). ITBI: Major TBI cases (CDC Barell Matrix Type 1) that had no injury with ICD9-based Regional Severity Score [RSS (AIS equivalent)] ≥3 in any other body region. MTBI: Type 1 TBI plus at least one non-head region injury with RSS ≥3.

Results:
Included were 13,435 cases [Excl: age <10 (5.9%), missing data (6.2%)]. 10,374 (77.2%) were ITBI, 3061 (22.8%) MTBI. Mortality: ITBI: 7.7% (797/10,374), MTBI: 19.2% (587/3061, p<0.0001). Prehospital HT occurred 3.5 times more often in MTBI (14.8%, 453/3061 vs 4.2%, 437/10,374; p<0.0001). Among HT cases, 40.8% (185/453) with MTBI died vs 30.9% with ITBI (135/437; p<0.0001). In the hypotensive moderate/severe TBI cohort (RSS-Head 3/4), MTBI mortality was 2.4 times higher (17.2%, 40/232) than ITBI (7.1%, 17/240, p = 0.001). However, in the hypotensive very/extremely severe TBI group (RSS-Head 5/6), mortality was almost identical in MTBI (73.4%, 141/192) and ITBI (72.1%, 116/161, p = 0.864).

Conclusion:
Among major TBI patients with
prehospital
HT, those with MTBI were much more likely to die than those with ITBI. However, this association varied dramatically with TBI severity. In mod/severe TBI cases with HT, MTBI mortality was 2.4 times higher than in ITBI. In contrast, in very/extremely severe TBI with HT, there was no identifiable mortality difference. Thus, in cases with substantial potential to survive the primary brain injury (mod/severe), outcome is markedly worse in patients with multisystem injuries. However, in very/extremely severe TBI, non-head region injuries have no apparent association with mortality. This may be because the TBI is the primary factor leading to death in these cases. The main EPIC study is evaluating whether this severity-based difference in “effect” has implications for TBI guideline treatment effectiveness.
Abstract 231: Difference of the Trauma-Induced Coagulopathy Between Penetrating and Blunt Trauma
Authors: Kanehata Keita , Ogura Takayuki
Published: July 2021

Introduction:
The trauma-induced coagulopathy is well-known pathophysiology of severely injured trauma patients. However, the difference due to the injury type is not well researched. The aim of this study is to investigate the difference of coagulopathy between the blunt and penetrating trauma. PATIENTS and

Methods:
Single-center retrospective study was conducted. The electrical record of patients admitted from April 2008 to March 2017 were reviewed and penetrating trauma patients with injury severity score (ISS) 9 or more were enrolled. The case-control matching with blunt trauma patients was performed, adjusting for ISS, Shock-Index, the need for transfusion, and lactate level at the hospital arrival. After the matching, 5 points of hemoglobin, fibrinogen, platelet, prothrombin-time percentage (PT%), fibrin/fibrinogen degradation products (FDP), and D-dimer in their clinical course were statistically compared.

Results:
8 patients were matched. FDP at hospital arrival was significantly higher in the blunt group compared to the penetrating group (Median 7.85 vs 92.8; p<0.01). Although there is no statistical significance, in the blunt group, D-dimer of the acute phase was much higher and PT% of the early phase was much lower than that of the penetrating group (refer the figures).

Conclusion:
In the acute and early phase of severe traumatic injury, the hyperfibrinolysis of blunt trauma can be significantly more severe than that of penetrating trauma.
Abstract 233: Prehospital End-Tidal CO2 Measurement in Non-Intubated Traumatic Brain Injury Patients: Concordance Between EMS Provider Documentation and Non-Invasive Monitor Data Tracking
Authors: Perez Octavio , Spaite Daniel W , Helfenbein Eric , Babaeizadeh Saeed , Jorgenson Dawn B , Hu Chengcheng , Gaither Joshua B , Rice Amber , Keim Samuel M , Barnhart Bruce J
Published: July 2021

Background:
End-Tidal CO2 (ETCO2) monitoring is valuable in the management of traumatic brain injury (TBI). In intubated patients it helps prevent hyper/over-ventilation. In non-intubated patients, placing a sensor in the nares allows accurate monitoring of respiratory rate and has other promising uses (e.g. monitoring ETCO2 trends in worsening TBI, COPD, etc).

Study Objective:
To identify how accurately EMS providers document ETCO2, we compared the values recorded in EMS patient care records (PCR) to monitor data in non-intubated TBI patients.

Methods:
Cases from 6 EMS agencies reporting continuous monitor data (Philips MRx) in the EPIC Study (NIH 1R01NS071049) were evaluated (4/13-3/17). All ETCO2 data available for this post-hoc review were displayed and accessible to the EMS providers during care. Concordance was defined in two ways (for both highest and lowest ETCO2): ≤5 and ≤3 mmHg difference between the monitor data and PCR-documented values.

Results:
106 cases were included [median age: 47 (range: 9-91), 66% male]. The figure shows concordance between PCR documentation and monitor data for both the lowest and highest recorded ETCO2 values.

Conclusion:
The
highest
PCR-recorded vs monitor ETCO2 values had excellent concordance for a difference ≤5 mmHg (85.9%) and it was good (76.4%) even when defined at the limits of instrument precision (≤3 for ETCO2 compared to actual pCO2). However, for
lowest
ETCO2, concordance was very poor (only 42.5% for ≤5). The failure to accurately document low ETCO2 in a “passive-ventilation” setting may also have significant implications for improving ventilatory care among intubated patients because identifying and correcting hypocapnia/hyperventilation in actively-ventilated cases is extraordinarily important. The low concordance rates may be due to the emphasis on discreet, intermittent vital sign documentation rather than ongoing identification and documentation of significant ETCO2 variation.
Abstract 237: Less is More When Using Gauze to Stop Bleeding
Authors: Charlton Nathan P , Solberg Robert , Rizer Justin , Singletary Eunice , Woods William
Published: July 2021

Introduction:
In first aid gauze is often used over the wound to absorb blood while applying pressure. Several sources recommend that if the gauze becomes saturated with blood, add more gauze and apply more pressure but offer no supporting data. However, adding more gauze will theoretically dissipate the force applied to the wound, thereby decreasing the pressure on the required area.

Hypothesis:
The purpose of this study is to evaluate the pressure generated when adding increasing layers of gauze to a simulated wound.

Methods:
In this IRB approved study subjects were recruited as a convenience sample of medical providers during a weekly medical conference. A standardized bleeding simulator (Z-Medica) and a flat (<0.5 mm) force sensitive resistor were used to measure force. Subjects were randomized to order of gauze application and were instructed to apply pressure to the simulated wound with three different layers of gauze (10, 20 & 30 4x4 inch cotton gauze, respectively) with the finger pads of 3 digits of the dominant hand as they would to stop bleeding. Subjects were asked to hold pressure for ten seconds and then release. All subjects completed application with each of the three stacks. Researchers were not blinded during data collection, but researchers analyzing data were blinded to the groups.

Results:
Thirty-three subjects were enrolled and all had data available for analysis. Twenty-two were residents, 11 attending physicians, 22 were male, and the average age of the subjects was 34.2 years (range 26-63). A steady decline in pressure with increasing amounts of gauze occurred. A stack of 10 4x4 inch gauze pads generated a constant of 3.20 (SD 1.11) lbs of force, 20 gauze pads 2.25 (SD 0.77) lbs of force, 30 gauze pads generated an average constant of only 1.5 (SD 0.54) lbs of force (p <0.001).

Conclusions:
In this simulated model of bleeding, medical personnel generated the most force on a wound when a stack of 10 4x4 inch gauze was used to apply pressure over the wound. From this study, it is apparent that increasing the amount of gauze will decrease the amount of pressure generated on the wound. As pressure on the bleeding vessel is important in stopping bleeding, this is likely detrimental to hemorrhage control.
Abstract 243: Variation in Both Layperson Cardiopulmonary Resuscitation Delivery and Subsequent Survival From Sudden Cardiac Arrest Based on Neighborhood-Level Ethnic Characteristics
Authors: Blewer Audrey L , McGovern Shaun , Schmicker Robert , May Susanne , Morrison Laurie , Aufderheide Tom , Daya Mohamud , Idris Ahamed , Callaway Clifton , Kudenchuk Peter , Vilke Gary , Abella Benjamin
Published: July 2021

Background:
Bystander cardiopulmonary resuscitation (B-CPR) delivery and survival from sudden cardiac arrest (SCA) varies at the neighborhood-level with poorer outcomes seen in predominantly black neighborhoods. Despite Latinos being the fastest growing minority population in the US, few studies have assessed whether the proportion of Latinos in a neighborhood is associated with B-CPR delivery and survival from SCA.

Objective:
We sought to assess whether there is variation in B-CPR rates and survival by neighborhood-level ethnicity. We hypothesized that neighborhoods with a higher proportion of Latinos are associated with lower B-CPR rates and lower survival.

Methods:
We conducted a retrospective cohort study, using data from the Resuscitation Outcomes Consortium (ROC) Epistry Registry US sites. Neighborhoods were classified by census tract, based on percentage of Latino residents: < 25%, 25%-50%, 51%-75%, or > 75%. We independently modelled the likelihood of receipt of layperson B-CPR and survival by neighborhood-level ethnicity controlling for site and patient-level confounding characteristics.

Results:
From 2011-2015, ROC collected 27,481 US arrest events; after excluding pediatric arrests, those witnessed by EMS, or occurred in a healthcare or institutional facility, 18,544 were included. B-CPR was administered in 37% events. Among neighborhoods with <25% Latino residents, B-CPR was administered in 39% of events, while it was administered in 27% of events among neighborhoods with >75% Latino residents. B-CPR delivery varied by patient ethnicity with Latinos being less likely to receive B-CPR compared to Whites (OR: 0.73 (CI: 0.62-0.88), p<0.01). Compared with <25% Latino neighborhoods, those in predominantly Latino neighborhoods had lower B-CPR rates (50%-75% Latino: OR: 0.79 (CI:0.69-90), p<0.01, >75% Latino: OR: 0.75 (CI: 0.62-0.90), p<0.01) and lower rates of survival (50%-75% Latino: OR: 0.81 (CI: 0.67-0.97), p=0.02, >75% Latino: OR: 0.62 (CI: 0.47-0.81), p<0.01).

Conclusion:
Individuals in predominantly Latino neighborhoods were less likely to receive B-CPR and had lower likelihood of survival. These findings could inform future messaging around B-CPR educational initiatives targeting largely Latino neighborhoods.
Abstract 244: Racial Disparities In Cardiopulmonary Training Status in the United States
Authors: McGovern Shaun K , Murray Andrew , Abella Benjamin S , Leary Marion , Blewer Audrey L
Published: July 2021

Background:
Survival from out-of-hospital cardiac arrest varies by race, possibly due to poor penetration of CPR training in minority communities. Targeted trainings and campaigns to increase access to CPR education have sought to address these gaps, yet it is unknown if these initiatives have equalized training rates.

Objectives:
We sought to examine racial variation of CPR training status on the individual-level by assessing current CPR training and ever CPR trained status. We hypothesized that whites would be more likely to hold current CPR training and be ever trained in CPR compared to minorities.

Methods:
As a secondary analysis to a previous random digit dial survey of a nationally-representative adult sample, we defined CPR training status of individuals as currently trained (only ≤2 years) and ever trained. Chi-squared test and multivariate logistic regression were used to determine variation by race.

Results:
From 09/2015-11/2015, 9,022 individuals completed the national survey. Of those, 65% had been CPR trained at some point in time, while 18% reported being currently trained. Minorities were significantly less likely to ever be trained in CPR compared to whites (54.9% vs 70.8%, p<0.01). However, minorities and whites were equally as likely to be currently CPR trained (18.2% vs. 18.2%, p=0.99); no significant difference was found when adjusting for age, sex, and education (p=ns). Probability of training status by age displayed variation between groups (Figure 1).

Conclusions:
Significant disparities by race were observed in those ever trained in CPR, however no significant difference exists in attainment of current CPR training. Increased access to CPR education and targeted training campaigns may have closed the gap in current CPR training status disparities. Continued surveillance of CPR training rates is needed to monitor these findings over time.
Abstract 249: The Effect of Response Time on Out-Of-Hospital Cardiac Arrest Survival Varies by Patient Subpopulation
Authors: Stoesser Clara , Boutilier Justin , Sun Christopher L , Dainty Katie N , Lin Steve , Ko Dennis , Brooks Steven C , Morrison Laurie J , Scales Damon C , Feldman Michael , Cheskes Sheldon , Chan Timothy C
Published: July 2021

Itroduction:
Previous research has quantified the impact of EMS response time on the probability of survival from OHCA, but the impact on different subpopulations is currently unknown.

Aim:
To investigate how response time affects OHCA survival for different patient subpopulations.

Methods:
We conducted a logistic regression analysis on non-EMS witnessed OHCAs of presumed cardiac etiology from the Toronto Regional RescuNet between January 1, 2007 and December 31, 2016. We predicted survival using age, sex, public location, presenting rhythm, bystander witnessed, bystander resuscitation, and response time, defined as the time interval from 911 call to EMS arrival at the patient. We conducted subgroup analyses to quantify the effect of response time on survival for eight different subpopulations: public, private, bystander resuscitation, no bystander resuscitation, patients ≥65, patients <65, witnessed, and unwitnessed OHCA. We also quantified the effect of response time on survival for pairwise intersections of the subpopulations. We compared our results to Valenzuela et al. (1997), which suggests survival odds decrease by 10% for each minute delay in response time.

Results:
We identified 22,988 OHCAs. Overall, a one-minute delay in EMS response time was associated with a 13.2% reduction in the odds of survival. The reduction varied by subpopulation, ranging from a 7.2% reduction in survival odds for unwitnessed arrests to a 16.4% reduction in survival odds for arrests with bystander resuscitation. Response time had the largest impact on survival for the subpopulation of OHCAs that were both witnessed and received bystander resuscitation (17.4% reduction in survival odds).

Conclusion:
The effect of a one-minute delay in EMS response on the odds of survival from OHCA can be as low as a 7.2% reduction and as high as a 17.4% reduction. This variability contrasts with the currently accepted 10% rule that is assumed across the entire population.
Abstract 250: Pre-Hospital Factors and Survival After Out-of-Hospital Cardiac Arrest According to Patient Income and Education; a Danish Nationwide Study
Authors: Møller Sidsel , Folke Fredrik , Hansen Carolina Malta Hansen , Hansen Steen Møller , Lippert Freddy , Køber Lars , Rajan Shahzleen , Kragholm Kristian , Karlsson Lena , Gislason Gunnar , Thorp-Pedersen Christian , Wissenberg Mads
Published: July 2021

Introduction:
Little is known about how patient socioeconomic status (income and education), relates to chance of bystander cardiopulmonary resuscitation (CPR) and survival after out-of-hospital cardiac arrest (OHCA). We assessed the association between patient socioeconomic status and bystander CPR as well as 30-day survival.

Methods:
OHCA patients ≥30 years of age and of presumed cardiac cause were identified through the nationwide Danish Cardiac Arrest Register, 2001-2014, and divided into high, medium and low subgroups according to 1) tertiles of household income from the year prior to OHCA and 2) highest degree of education according to the International Standard Classification of Education (ISCED) (<10 years, 10-12 years and >12 years of education). Associations of income and education with bystander CPR and 30-day survival were estimated using logistic multivariable logistic regression analysis adjusted for age, gender and calendar year.

Results:
In total, 25,233 OHCAs were included. Comparing patients in the highest group with patients in the lowest group of income and education, patients in the highest groups were younger, less often female and had less comorbidities. Patients in the highest groups were more likely to have: public arrests (income: 31.6% vs. 22.5%, education: 30.9% vs. 24.3%), witnessed arrests (income: 55.3% vs. 50.2%, education: 56.6% vs. 50.4%), bystander CPR (income: 52.4% vs. 34.7%, education: 51.6% vs. 40.9%) and an initial shockable heart rhythm (income: 37.6% vs. 22.1%, education: 35.7% vs. 24.1%), all p<0.001. High income and education compared to low were also associated with higher survival upon hospital arrival (income: 23.4% vs. 13.1%, education: 23.8% vs. 15.0%) and 30-day survival (income: 15.8% vs. 4.5%, education: 15.4% vs. 6.3%), p<0.001. Differences persisted in adjusted analyses: bystander CPR (high vs. low, income OR 1.43 95%CI 1.32-1.54, education OR 1.27 95%CI 1.17-1.39) and for 30-day survival (high vs. low, income OR 2.01 95%CI 1.74-2.31, education OR 2.08 95%CI 1.83-2.36).

Conclusions:
In this nationwide study of OHCA patients, higher socioeconomics status (income and education) was associated with higher rates of bystander CPR and 30-day survival, compared with those with lower socioeconomic status.
Abstract 251: Comparison of Ischemia-Reperfusion Injury in Langendorff-Prepared Hearts From Zucker Diabetic Fatty and Lean Rats
Authors: Cleveland William J , Balzer Claudius , Salzman Michele M , Riess Matthias L
Published: July 2021

Introduction:
The Zucker Diabetic Fatty (ZDF) rat is a relevant model for assessing ischemia-reperfusion (IR) injury, due to it having comorbidities associated with a higher risk for cardiac arrest and poorer outcomes following cardiopulmonary resuscitation in humans.

Hypothesis:
Based on previous studies in the literature, we hypothesize that ZDF rats would have similar outcomes to lean rats subjected to IR when accounting for perfusion buffer osmolarity.

Methods:
ZDF (n=4) and lean control (n=6) rats were anesthetized with pentobarbital, intubated, and mechanically ventilated and monitored for 3-hours, with blood glucose (BG) readings taken before and after ventilation. They were then decapitated and a thoracotomy performed to isolate the Langendorff-prepared hearts. Krebs buffer with the osmolarity adjusted to each rat’s BG level using glucose was used to perfuse the hearts. Following a 20-minute stabilization period, the hearts were subjected to a 30-minute period of global no-flow ischemia followed by 120-minutes of reperfusion. Spontaneous heart rate, isovolumetric left ventricular pressure (LVP), and mitochondrial redox state were measured continuously. Data are mean ± SD. Statistics: two-tailed t-test, p<0.05

Results:
There was no significant difference in average body weight between the two groups; however, ZDF rats showed significantly higher BG levels (504±52 vs 174±14 mg/dl) than their lean littermates. ZDF rats had a greater percent change from baseline systolic LVP upon reperfusion than lean rats (133±33.3 vs 84.9±16.5 %), with the lean rats never returning to baseline. Diastolic contracture occurred more in lean rats during ischemia, but trended towards a lower contracture during reperfusion. No significant difference was seen in developed LVP, rate pressure products, or mitochondrial redox states, although lean rats trended towards better diastolic contractility and relaxation.

Conclusion:
Lean rats showed marginally better outcomes in heart function than their ZDF littermates. Future studies will focus on potential mechanisms of Type 2 diabetes that may exacerbate IR injuries.
Abstract 253: Increased Blood Brain Barrier Permeability After Successful Resuscitation in a Rat Model of Cardiac Arrest
Authors: Guo Qinyue , Yang Jin , Hu Zhangle , Xiao Yan , Wu Xiaobo , Bradley Jennifer , Peberdy Mary Ann , Ornato Joseph , Mangino Martin , Tang Wanchun
Published: July 2021

Introduction:
We have previously demonstrated that administration of PEG-20k during cardiopulmonary resuscitation (CPR) improves post-resuscitation neurologic function and survival. Since PEG-20k does not cross the blood brain barrier (BBB) during normal circulation due to its size, the mechanism of improved neurologic function remains unclear. The potential mechanism may be related to an increased permeability of the BBB after cardiac arrest and CPR which allows large molecules like PEG-20k to cross.

Hypothesis:
The BBB is damaged with increased permeability after successful resuscitation from cardiac arrest.

Methods:
Ten rats were randomized into two groups, 1) CPR+ Evan’s Blue (EB, molecular weight 68kDa) group; 2) NO CPR+EB group. Ventricular fibrillation was induced and untreated for 8 min for all CPR groups. S-100β, NSE and EB concentrations were analyzed for blood brain barrier (BBB) permeability damage.

Results:
All animals were resuscitated successfully. Brain permeability was increased in the CPR+EB group after 6h of CPR (p<0.01) (Fig 1). Serum S-100β and NSE levels were significantly higher in the CPR group compared to NO CPR+EB group (p < 0.01) (Fig 1).

Conclusions:
The function of BBB is impaired after successful resuscitation from cardiac arrest with increased permeability.
Abstract 254: Ultrasound Improves the Outcomes After Cardiopulmonary Resuscitation by Stimulating the Cholinergic Anti-Inflammatory Pathway
Authors: Sun Peng , Zhang Yuhan , Shu Tingting , Liang Licai , Shao Weijing , Guo Lang , Xu Li
Published: July 2021

Introduction:
Recently it was shown that the ultrasound (US) treatment prevented renal ischemia- reperfusion injury (IRI) in mice. In the present study, we investigated the effects of the US treatment against IRI after CPR .

Hypothesis:
US would improve the outcomes after resuscitation in a rat model of CPR, and the protective effect of US would be dependent on the cholinergic anti-inflammatory pathway (CAP) via α7nAChR.

Methods:
The animals were randomized into 5 groups (n=8 each): (1) CPR group: the rats underwent 6 mins of untreated ventricular fibrillation (VF) followed by CPR and defibrillation; (2) US group: the treatment was identical to the CPR group except that rats were exposed to US treatment 24h before CPR; (3) MLA group: the treatment was identical to the US group except thatα7nAChR antagonist MLA (4mg/kg) was administered 30 mins prior to US treatment and VF respectively; (4) GTS group: the treatment was identical to the CPR group except that α7nAChR agonist GTS-21(4mg/kg) was injected 30 mins before VF. (5) SHAM group: the rats were exposed to surgical preparation without CPR and US application. One day before CPR, the US treatment was delivered to the left kidney by US pulses (contrast general mode with 9 MHz) with a bursting mechanical index of 0.72. US pulses were 1 second in duration and were applied once every 6 seconds for 2 mins. After the treatment of the left kidney, the right kidney was exposed to US treatment for another 2 mins.

Results:
Significantly longer duration of survival was observed in US-treated animals. And US treatment also suppressed the TNF-α and IL-6 following resuscitation, and improved neurological function. The expression of α7nAChR were promoted in hippocampal neurons in US group. Moreover, the protective effect of US treatment could be abolished by MLA and imitated by GTS-21.

Conclusions:
US treatment before IRI improves the outcomes after CPR, and CAP via α7nAChR plays an important role during CPR.
Abstract 255: Dendrimer-Based N-Acetyl-l-Cysteine Therapy Improves 7 Days Outcomes After Cardiac Arrest in a Rat Model
Authors: Modi Hiren R , Wang Qihong , Bertrand Sarah J , Kannan Rangaramanujam , Kannan Sujatha , Geocadin Romergryko G , Thakor Nitish V
Published: July 2021

Cardiac arrest (CA) entails significant risks of coma resulting in poor neurological and behavioral outcomes after resuscitation. Morbidity and mortality in post-CA patients are due largely to the cerebral dysfunction that accompanies prolonged whole-body ischemia called as post-CA syndrome (PCAS). PCAS involves strong inflammatory responses including neuroinflammation. Currently, there are no proven neuroprotective therapies to improve post-CA outcomes apart from therapeutic hypothermia. Furthermore, there are no acceptable approaches which can target neuroinflammation and lead to good neurological outcome post-CA. Moreover, delivering drugs across the blood-brain barrier to the target injured cells for treating diffuse brain injury is a major challenge. We hypothesize that dendrimer-based N-acetyl-L-cysteine (D-NAC) therapy ameliorates Neuroinflammation by specifically targeting activated glial cells and leads to a marked improvement in post-CA neurological outcome. we used an asphyxial CA rat model to determine the effects of D-NAC treatment. D-NAC was administered 30-minute post return of spontaneous circulation after cardiopulmonary resuscitation (ROSC). The behavioral neurologic deficit score (NDS score) was evaluated at 4, 24 and 48 hrs post-CA. CA resulted in a 50% decrease in survival and a dramatic decrease in NDS score acutely. D-NAC improved survival to 75% and led to a more rapid improvement in NDS scores when compared to the saline group in the short term while free NAC was not effective. We also tested long term (7 days) behavioral outcomes (novel object and fear conditioning) post-CA. Administration of D-NAC significantly improved novel object recognition and decreases freezing behavior in a novel context suggesting an improvement in cognitive deficits following CA in this model. In summary, acute administration of D-NAC following CA results in physiological and behavioral improvements both acutely and long term.
Abstract 257: Unselective Pulmonary Vasodilation is an Important Factor in Sodium Nitroprusside Enhanced Cardiopulmonary Resuscitation Improved Blood Flow
Authors: Ripeckyj Adrian , Shekar Kadambari Chandra , Voicu Sebastian , Rees Jennifer , Matsuura Timothy , Bartos Jason A , Yannopoulos Demetris
Published: July 2021

Introduction:
Sodium nitroprusside enhanced CPR (SNPeCPR) is a novel CPR method that includes a potent vasodilator, active compression-decompression CPR, an inspiratory impedance threshold device and abdominal binding. SNPeCPR has been shown to improve vital organ flow and functional survival outcomes compared to standard CPR methods in animals. We hypothesize that one of the main effects of SNPeCPR mediated increase in cardiac output during prolonged resuscitation is profound pulmonary artery vasodilation.

Methods:
After electrically induced VF was left untreated for 3 min, 20 (44-48Kg) pigs were randomized to receive SNPeCPR (10) or standard CPR (10) for a total of 30 min; the first 10 minutes were BLS CPR followed by twenty minutes of ACLS. During ACLS, animals were given IV SNP (1mg bolus) or standard epinephrine (0.5mg) q5 min until ROSC or 45 min total CPR. Shocks were delivered after 30 minutes of CPR at 300J. If ROSC was achieved, animal was monitored until 4-hour endpoint. Ventilations were provided with 10ml/kg at 10/min with a mechanical ventilator. Initially during CPR, room air was used and FiO2 was adjusted q5 minutes to maintain O
2
%saturation > 92% based on ABG. Lactic acid was also measured. Aortic, right atrial, and coronary artery pressures and carotid blood flow were recorded continuously. A-a oxygen gradient was measured with standard technique.

Results:
SNPeCPR animals documented a significantly higher mean CPP, lower lactic acid and 3x higher carotid blood flow over 30 minutes compared to standard CPR as previously documented. A-a oxygen gradient was dramatically increased in the SNPeCPR and coincided with a decreased lactate level (see Figure 1).

Discussion:
SNPeCPR causes profound pulmonary vasodilation and increases flow through non-ventilated lung areas. Despite that, the overall increase in forward flow leads to higher minute O
2
delivery and improved tissue perfusion. SNPeCPR should be used with 100% oxygen in the first human clinical trial.
Abstract 261: Assessment of Area Duty Cycle in Manual Chest Compressions During Out-of-Hospital Cardiopulmonary Resuscitation
Authors: Ruiz de Gauna Sofía , Ruiz Jesus M , González-Otero Digna M , Leturiondo Mikel , Gutiérrez Jose J , Arana Iker , Russell James K , Daya Mohamud
Published: July 2021

Introduction:
To be compliant with resuscitation guidelines, chest compressions (CCs) should be provided at a rate between 100 and 120 min
-1
and a depth between 50 and 60mm during cardiopulmonary resuscitation (CPR). However, two manual CCs coincident in rate (the inverse of duration) and depth can show very different compression waveforms (left figure: the narrower CC depicted in blue suggests a higher impulse compression/decompression pattern). We hypothesized that area duty cycle (ADC) could characterize the narrowness of manual CCs.

Objective:
To assess the ADC of manual CCs during out-of-hospital CPR and its relationship with rate and depth.

Methods:
We collected electronic recordings containing compression signals from Philips HeartStart MRx monitor-defibrillators used in 30 patients during out-of-hospital CPR. ADC was defined as the ratio between the area under the compression curve (dashed area in the right figure) and the total area of the compression cycle with maximum depth (area of the red box). For each CC, we annotated the compression duration T
c
, the area under the depth curve A, and the maximum compression depth D. ADC was computed as 100·A/T
c
·D (%). The linear relationship of ADC with compression rate and depth was assessed.

Results:
A total of 66,971 CCs were annotated. Medians (5
th
-95
th
percentiles) for compression rate, depth and ADC were 109.9 min
-1
(93.8, 133), 46.5 mm (30.1, 61.7), and 41.9% (32.1, 49.5), respectively. ADC showed a very low correlation with rate and depth, favoring ADC’s independence. For every 10 min
-1
increase in rate, ADC increased 0.16%. For every 10 mm increase in depth, ADC decreased 0.5%.

Conclusions:
ADC metric could be used for characterizing the narrowness of manual CCs, independently of depth and rate. This finding could contribute to improve understanding of manual CPR dynamics and their influence on patient’s outcome.
Abstract 264: Use of an Acronym to Reduce Medical Emergency Call Time and Improve Survival
Authors: Graves Karen M , Siegmund Lee Anne
Published: July 2021

Introduction:
An average of 1500 medical emergencies are called to the operators each month for the main campus Cleveland Clinic. Acronyms can help the employee to remember necessary information to quickly and accurately activate the right medical emergency team in a short time. We developed the acronym LEAN (L-Location, E-Event Type; code or rapid response, A-Adult or Child, N-Call back number). We reduced the length of the call which led to the prompt activation of the medical emergency team.

Hypothesis:
We hypothesized that this quality improvement initiative, using the LEAN acronym would: 1. Reduce length of call time to the operator and 2. Lead to increased event survival of event for patients who have had a life-threatening medical emergency.

Methods:
The LEAN acronym was implemented in 2016 by sharing this acronym at staff meetings, and daily huddles. We developed an operator scorecard which tracked the average call time to the 111 (code) and 122 (rapid response) operator lines before and after LEAN implementation. We used our AHA Get With The Guidelines-Resuscitation® data to determine cardiopulmonary arrest (CPA) event survival.

Results:
Since August of 2016 we have reduced our 122 rapid response calls by 30 seconds and our 111 code calls by 12 seconds. CPA survival rates were 73% (437 of 599) in 2015 and 78.9% (548 of 703) in 2017, for an 8.1% increase (
Figure 1
). While there is not a statistically significant (
p
= 0.511) difference between time periods when we look at percentage of lives saved, the number of lives saved increased. This is a clinically important difference because more people survived. We plan to continue to disseminate LEAN and work to improve response time.

Conclusion:
Since we introduced LEAN there has been a reduction in the time to activation of our medical emergency teams and an 8% increase in our GWTG-R® Cardiopulmonary Arrest event survival. Lives were saved and LEAN may have played a role in this clinically important difference.
Abstract 267: Photoplethysmography-Based Algorithm Uninterruptedly Supports Pulse Detection in Porcine Automatic 30:2 Cardiopulmonary Resuscitation Data by Handling Transitions Between Compressions and Pauses
Authors: Wijshoff Ralph , Van de Laar Jakob , Muehlsteff Jens , Noordergraaf Gerrit Jan
Published: July 2021

Introduction:
Pulse checks by manual palpation during CPR are challenging, time-consuming and interrupt chest compressions. To support pulse checks during 30:2 CPR, we developed an algorithm to uninterruptedly detect pulse in a photoplethysmography (PPG) signal by handling transitions between compressions and ventilation pauses. We retrospectively evaluated the algorithm on porcine automated-CPR (ACPR) data.

Methods:
In 10 anesthetised pigs, VF was induced, followed by 20 min of 30:2 ACPR with 2.5 s ventilation pauses (Phase 1). Next, up to four defibrillation attempts were made, each shock followed by 2 min of 30:2 ACPR (Phase 2). Infrared nasal PPG and thoracic impedance (TI) signals were measured, with aortic blood pressure (ABP) as reference. The developed algorithm detected pulse rate (PR) in the PPG signal, by estimating the main frequencies present in the signal and ignoring compression frequencies, where the compression rate (CR) was determined from the TI waveform. The PPG signal was analysed by sliding a 5 s window by 1 s shifts. When analysing a signal with an abrupt change due to the start/end of a compression series, frequency estimates will be compromised. Therefore, the algorithm identified the start/end of compressions in the TI signal and analysed in the 5 s window (1) a compression-free interval of at least 2 s or (2) a compression interval of at least 2.8 s. The window was ignored if no such interval was found. Pulse detection performance was quantified by comparison to pulse presence annotations determined from the protocol and visual inspection of ABP and PPG signals.

Results:
Table I gives sensitivity for pulse presence (SNV), specificity for arrest (SPC) and positive and negative predictive values (PPV/NPV).

Conclusions:
Overall, SPC, PPV and NPV are high. In Phase 2, SNV is reasonable in pauses, but compromised during compressions when PR and CR are close. In 30:2 CPR the algorithm can provide frequent detections from 2 s pauses.
Table I:
detection results.
Abstract 268: A Convolutional Neural Network for Real-Time Discrimination of Shock-Indicated Rhythms During CPR
Authors: Hatanaka Tetsuo , Kaneko Hiroshi , Nagase Aki , Marukawa Seishiro
Published: July 2021

Introduction:
An interruption of chest compressions during CPR adversely affects patient outcome. Currently, however, periodical interruptions are unavoidable to assess the ECG rhythms and to give shocks for defibrillation if indicated. Evidence suggests a 5-second interruption immediately before shocks may translate into ~15% reduction of the chance of survival. The objective of this study was to build, train and validate a convolutional neural network (artificial intelligence) for detecting shock-indicated rhythms out of ECG signals corrupted with chest compression artifacts during CPR.

Methods:
Our convolutional neural network consisted of 7 convolutional layers, 3 pooling layers and 3 fully-connected layers for binary classification (shock-indicated vs non-shock-indicated). The input data set was a spectrogram consisting of 56 frequency-bins by 80 time-segments transformed from a 12.16-seconds ECG signal. From AEDs used for 236 patients with out-of-hospital cardiac arrest, 1,223 annotated ECG strips were extracted. Ventricular fibrillation and wide-QRS ventricular tachycardia with HR>180 beats/min were annotated as shock-indicated, and the others as non-shock-indicated. The total length of the strips was 8:49:57 (hr:min:sec) and 8:02:07 respectively for shock-indicated and non-shock-indicated rhythms. Those strips were converted into 465,102 spectrograms allowing partial overlaps and were fed into the neural network for training. The validation data set was obtained from a separate group of 225 patients, from which annotated ECG strips (total duration of 62:11:28) were extracted, yielding 43,800 spectrograms.

Results:
After the training, both the sensitivity and specificity of detecting shock-indicated rhythms over the training data set were 99.7% - 100% (varying with training instances). The sensitivity and specificity over the validation data set were 99.3% - 99.7% and 99.3% - 99.5%, respectively.

Conclusions:
The convolutional neural network has accurately and continuously evaluated the ECG rhythms during CPR, potentially obviating the need for rhythm checks for defibrillation during CPR.
Abstract 269: Bedside Monitoring of Peripheral Blood Perfusion Using Pulse Oximetry Sensor and its Reliability and Clinical Usefulness Compared With Traditional Capillary Refill Measurement
Authors: Shinozaki Koichiro , Saeki Kota , Jacobson Lee , Falotico Julianne , Li Timmy , Becker Lance B
Published: July 2021

Objective:
The traditional capillary refill time (CRT) assessment is a manual measurement that is commonly used by clinicians to identify a shock status. Given that the measurement is manual only, it is a relatively subjective measurement. Our study tested an investigational CRT device, comprised of existing pulse oximeter technology paired with a novel measuring algorithm, at an emergency department (ED) setting to determine its reliability and clinical usefulness compared with the traditional, manual CRT assessment.

Methods:
Three healthcare providers (registered nurses or physician assistants) were selected to perform manual CRT assessments at the bedside to classify patients into either a normal (≤2 seconds) or abnormal (>2 seconds) CRT groups. An attending ED physician, blinded from the healthcare providers’ classifications, quantitatively measured CRT using a chronograph (visual CRT). The pulse oximeter sensor was attached to the same hand used for visual CRT assessments but on a different fingertip. Visual and device CRTs were measured alternately and were repeated three times for each method. Device CRT data from 30 healthy volunteers in a previous study was used as a reference.

Results:
Thirty ED patients were recruited. Mean device CRT of ED patients (3.9±2.7 sec) was significantly longer than those of healthy volunteers (2.0±1.0 sec, p<0.01). Mean visual CRT of ED patients was 1.9±0.8 seconds and was significantly correlated with device CRT (r=0.723, p<0.001). Area under the receiver operator characteristic curve (AUC) to predict whether or not visual CRT was greater than or less than 2.0 seconds was 0.84 (95% CI 0.70-0.98). The ED physician identified 10 patients with abnormal CRT, while only two patients were classified to the abnormal CRT group by healthcare providers. Intra-rater reliability of the device CRT was 0.88 (95% CI 0.79-0.94) and that of the visual CRT was 0.92 (0.85-0.96). 12 patients were admitted to the hospital. AUC to predict patient admission was 0.67 (95% CI 0.46-0.87) by device CRT and 0.76 (0.58-0.94) by visual CRT.

Conclusions:
CRT assessments by healthcare providers were variable compared with those of the ED physician. Device CRT was as reliable and useful as the CRT measured quantitatively by the ED physician.