bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 266: The Effect of Different Kinds of Chest Compression Waveforms on the Heart Ischemia-Reperfusion Injury After Cardiac Arrest
Authors: Songling Tang , He Yarong , Yao Peng , Cao Yu
Published: June 2021

Purpose:
This study was aimed to compare the effect of different kinds of chest compression waveforms on the heart ischemia-reperfusion injury after cardiac arrest (CA) in a rat model.

Materials and methods:
After the CA model was successfully established with continuous electrical stimulation of ventricular fibrillation, rats were divided into four different chest compression groups randomly, including manual group, triangular wave group, sine wave group and trapezoidal wave group. The success rates of return of spontaneous circulation (ROSC) of those four groups were calculated, and all ROSC rats were executed 30 minutes after ROSC. Further comparisons were made among those four groups, including pathological changes, superoxide dismutase (SOD) activities, malondialdehyde (MDA) and superoxide (O
2
-
) content.

Results:
The success ROSC rates for those four groups (manual group, triangular wave group, sine wave group and trapezoidal wave group) were 30%, 40%, 40% and 90% respectively. There were inflammatory cell infiltration and edema in the heart tissue of those four groups. The activities of SOD in trapezoidal wave group were 85.91±1.91 U/mg, much higher than those of the other three groups (P <0.05). On the other hand, the MDA and O
2
-
levels of trapezoidal wave group were much lower than those of the other three groups (p<0.05).

Conclusion:
Our study demonstrated that trapezoidal wave chest compression may be beneficial in improving the success rate of ROSC and alleviate heart injury. Its possible mechanism might lie in its anti-oxidative stress capability during the chest compression.
Abstract 273: Noninvasive Mitochondrial Modulation: Neuroprotection in a Translational Model of Cardiac Arrest and Resuscitation
Authors: Wider Joseph M , Gruley Erin , Mathieu Jennifer , Murphy Emma , Mount Rachel , Oneil Brian J , Przyklenk Karin , Neumar Robert W , Huttemann Maik , Sanderson Thomas H
Published: June 2021

Background:
Mitochondrial dysfunction contributes to cardiac arrest induced brain injury and has been a target for neuroprotective therapies. An emerging concept suggests that hyperactivation of neuronal mitochondria following resuscitation results in hyperpolarization of the mitochondrial membrane during reperfusion, which drives generation of excess reactive oxygen species. Previous studies from our group demonstrated that limiting mitochondrial hyperactivity by non-invasively modulating mitochondrial function with specific near infrared light (NIR) wavelengths can reduce brain injury in small animal models of global and focal ischemia.

Hypothesis:
Inhibitory wavelengths of NIR will reduce neuronal injury and improve neurocognitive outcome in a clinically relevant swine model of cardiac arrest.

Methods:
Twenty-eight male and female adult swine were enrolled (3 groups: Sham, CA/CPR, and CA/CPR + NIR). Cardiac arrest (8 minutes) was induced with a ventricular pacing wire and followed by manual CPR with defibrillation and epinephrine every 30 seconds until return of spontaneous circulation (ROSC), 2 of the 20 swine that underwent CA did not achieve ROSC and were not enrolled. Treatment groups were randomized prior to arrest and blinded to the CPR team. Treatment was applied at onset of ROSC by irradiating the scalp with 750 nm and 950 nm LEDs (5W) for 2 hours.

Results:
Sham-operated animals all survived (8/8), whereas 22% of untreated animals subjected to cardiac arrest died within 45 min of ROSC (CA/CPR, n= 7/9). All swine treated with NIR survived the duration of the study (CA/CPR + NIR, n=9/9). Four days following cardiac arrest, neurological deficit score was improved in the NIR treatment group (50 ± 21 CA/CPR vs. 0.8 ± 0.8 CA/CPR + NIR, p < 0.05). Additionally, neuronal death in the CA1/CA3 regions of the hippocampus, assessed by counting surviving neurons with stereology, was attenuated by treatment with NIR (17917 ± 5534 neurons/mm
3
CA/CPR vs. 44655 ± 5637 neurons/mm
3
CA/CPR + NIR, p < 0.05). All data is reported as mean ± SEM.

Conclusions:
These data provide evidence that noninvasive modulation of mitochondria, achieved by transcranial irradiation of the brain with NIR, mitigates post-cardiac arrest brain injury.
Abstract 274: Identifying the Optimal Cerebral Perfusion Pressure Following Hypoxic-Ischemic Brain Injury
Authors: Rasheed Izad-Yar D , Abella Benjamin S , Kofke W. Andrew , Balu Ramani
Published: June 2021

Introduction:
The optimal cerebral perfusion pressure (CPP) following hypoxic-ischemic brain injury (HIBI) is currently unknown. We retrospectively analyzed intracranial monitoring data from a cohort of patients with HIBI to identify a threshold level for CPP that optimizes cerebrovascular pressure reactivity (a surrogate for CA) while limiting the risk of intracranial hypertension and brain tissue hypoxia.

Hypothesis:
We hypothesized that higher CPP values would be associated with improved cerebrovascular pressure reactivity.

Methods:
ICP, brain tissue oxygen (P
bt
O
2
), MAP, and CPP (defined as MAP - ICP) were recorded continuously and time synchronized for all patients using a bedside monitor (CNS Monitor, Moberg Research). Pressure Reactivity Index (PRx) was calculated as the time varying correlation between MAP and ICP over 5 min intervals updated every minute. The degree of CA impairment (defined as % time PRx > 0.2) was plotted against MAP and CPP, respectively. The relationships between ICP and P
bt
O
2
versus CPP, as well as ICP and P
bt
O
2
versus % time PRx > 0.2, were similarly calculated.

Results:
We analyzed 37 patients (33 cardiac arrest, 4 prolonged hypoxia) with HIBI who underwent intracranial neuromonitoring over a 3 year period. Lower CPP values were associated with higher degrees of CA impairment. The cumulative burden of elevated PRx was significantly lower for CPP values above a cutoff of 85 mmHg compared to lower CPP values (p < 0.001, Wilcoxon rank sum test). A similar cutoff for MAP could not be identified, although lower MAP values were also associated with greater CA impairment. Intracranial hypertension (ICP > 20 mmHg) and brain hypoxia (P
bt
O2 < 20 mmHg) were both associated with CA impairment (p < 0.001 and p < 0.001, respectively, Wilcoxon rank sum test).

Conclusions:
Higher CPP and MAP values appear to be associated with improved CA after HIBI. Given that CA impairment is associated with both intracranial hypertension and brain hypoxia, our work reaffirms the notion that higher blood pressure targets may improve outcome after HIBI. The identification of a distinct CPP cutoff for CA optimization suggests that targeting CPP instead of MAP may be advantageous, although further work is required to clarify this issue.
Abstract 276: TAT-PTEN9c Targets Heart Directly to Improve Survival From Cardiac Arrest
Authors: Zhu Xiangdong , Gasior Filip , Li Jing , Wang Huashan , Zhu Zhiyi , Odonnell J M , Vanden Hoek Terry L
Published: June 2021

Introduction:
It is well established that hypothermia enhances cardiac arrest (CA) survival due, in part, to a mechanism of enhanced Akt activation. In this study we investigate whether the biosynthetic PTEN inhibitor (TAT-PTEN9c) provides therapeutic protection on survival due to direct effects on heart.

Hypothesis:
We hypothesized that TAT-PTEN9c interferes with endogenous PTEN binding at its cell membrane adaptor and leads to enhanced Akt activation, mouse survival and cardiac functional recovery. The improved CA survival is due in part to the improved contractile functional recovery of heart by TAT-PTEN9c. We also tested if the treatment targets the heart directly to enhanced recovery in isolated perfused rat heart after a period of global arrest.

Methods:
TAT-PTEN9c (7.5 mg/kg) was given intravenously (IV) after CA in mouse to determine protective effects of the treatment on survival and heart function. Western blot was used to determine the efficacy of TAT-PTEN9c for Akt activation. In the isolated rat heart, direct effect of treatment (1-10 μm) on cardiac function (HR, LVDP, RPP) were measured for 20 min following 20 min global ischemia.

Results:
In the mouse model of cardiac arrest, survival was significantly increased in the TAT-PTEN9c treated group compared to saline controls at 4 h (10/15, 67% vs. 6/15, 40%,
P
< 0.05) after CPR. TAT-PTEN9c improved MAP at both R30 min and R2h. The treated mice had increased Akt phosphorylation at R15 min in both heart and brain tissues with significantly decreased sorbitol content and reduced release of taurine and glutamate into blood, suggesting improved metabolic recovery and glucose utilization. For the isolated heart model, RPP was reduced by 25% for both TAT vehicle and non-treatment groups following arrest. With TAT-PTEN9c treatment, cardiac contractile function was completely recovered (pre-arrest RPP 29.1k+/- 4.8; post-arrest 28.0K +/- 5.0).

Conclusion:
TAT-PTEN9c enhances Akt activation and decrease glucose shunting to the polyol pathway in critical organs, preventing osmotic injury and early cardiovascular collapse and death. The improved survival by this treatment is in part due to its direct effect on heart functional recovery.
Abstract 28: Feasibility and Safety of Pre-Hospital Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in Non-Traumatic Out-Of-Hospital Cardiac Arrest
Authors: Brede Jostein R , Lafrenz Thomas , Klepstad Pål , Skjærseth Eivinn A , Nordseth Trond , Søvik Edmund , Kruger Andreas J
Published: June 2021

Introduction:
The proportion of patients surviving to hospital discharge after out of hospital cardiac arrest (OHCA) is low and any measure that may improve circulation to vital organs during cardiopulmonary resuscitation (CPR) is beneficial. The use of resuscitative endovascular balloon occlusion of the aorta (REBOA) will redistribute cardiac output to the organs proximal to the occlusion. Animal studies supports that aortic occlusion during CPR might benefit patients suffering from OHCA, but human data are scarce.

Methods:
We performed an observational study at the helicopter emergency medical service in Trondheim (Norway) to assess the feasibility and safety of establishing REBOA in OHCA patients. The femoral artery was identified by ultrasound and a REBOA catheter was placed in the thoracic aorta. All patients received advanced cardiac life support (ACLS) during the procedure. REBOA eligibility, procedural success and time intervals were registered. A safety monitoring program was conducted to ensure that the procedure did not interfere with the quality of ACLS.

Results:
REBOA was initiated in ten of 98 OHCA patients. The mean age was 63 years (55-71) and 7 were male. The REBOA procedure was successful in all cases (100%), with 80% success rate on first cannulation attempt. Mean REBOA procedural time was 11,7 minutes (8-16, SD 3,2). End-tidal CO2 (EtCO2) increased by a mean of 1.9 kPa at 60 seconds after inflation compared to baseline (p < 0.001). Six of 10 patients (60%) achieved return of spontaneous circulation, 3 (30%) was admitted to hospital. 30-day survival was 10%. The mean width of the femoral artery and vein during CPR was 5,9 mm (3,6 - 7,4, SD 1,2) and 9,4 mm (5,0 - 12,9, SD 2,9), respectively. The safety monitoring group identified no negative influence on the ACLS quality.

Conclusions:
This is the first study to assess the pre-hospital use of REBOA in patients with non-traumatic cardiac arrest. The REBOA procedure does not interfere with the quality of the ACLS. REBOA is a feasible adjunct treatment in OHCA. The significant increase in EtCO2 after occlusion suggests improved organ circulation during CPR.
Abstract 280: Evaluation of Cerebral Blood Oxygenation by NIRS During Asphyxia Cardiac Arrest and Resuscitation in Rats
Authors: Yagi Tsukasa , Shinozaki Koichiro , Okuma Yu , Yin Tai , Nishikimi Mitsuaki , Kiguchi Takeyuki , Iwami Taku , Becker Lance B
Published: June 2021

Background:
Clinical investigators have focused on the real-time evaluation of cerebral blood oxygenation (CBO) by near-infrared spectroscopy (NIRS) during cardiopulmonary resuscitation (CPR). A previous study showed that an abrupt increase of Oxy-hemoglobin (Hb) concentration and tissue oxygenation index (TOI) was associated with the timing of return of spontaneous circulation (ROSC). However, it is not clear how TOI decreases in cardiac arrest (CA) and increases by resuscitation. Therefore, this study aimed to assess CBO with asphyxia CA and its association with CPR to ROSC in rats

Method:
Male Sprague-Dawley rats were used. We attached NIRS (NIRO-200NX, Hamamatsu Photonics, Japan) from nasion to upper cervical spine in rats. 10-minute asphyxia was given to induce CA. After CA, mechanical ventilation was restarted, and manual CPR was performed. We examined the mean arterial pressure (MAP), end-tidal carbon dioxide (ETCO2), and Oxy/Deoxy-Hb and TOI.

Results:
Out of 12 rats, 9 obtained sustained ROSC. After the induction of asphyxia, TOI rapidly dropped, and as subsequent CPR was undergoing, Oxy-Hb, Deoxy-Hb, and TOI increased in synchrony with chest compressions. And then, an abrupt increase in MAP, ETCO2, and TOI observed at the time of ROSC.

Conclusion:
Recent CPR guidelines suggest a use of ETCO2 during CPR since its abrupt increase is a reasonable indicator of ROSC. TOI can be an alternative of ETCO2, and in addition, it has the potential to serve as monitoring CBO during CPR and subsequently in post-ROSC care.
Abstract 284: Cerebral Oximetry During Resuscitation: Course and Outcome
Authors: Shin Jenny , Blackwood Jennifer E , Walker Rob G , Chapman Fred W , Crackel Joe , Rea Thomas
Published: June 2021

Background:
Anoxic brain injury is a common cause of death following out-of-hospital cardiac arrest (OHCA). Cerebral oximetry provides a real-time tool to brain ischemia. Little is known about the course of cerebral oximetry and its relationship to outcome following OHCA.

Methods:
We conducted a pilot cohort study during OHCA to evaluate the course and prognosis related to cerebral oximetry in a single US EMS agency. Cerebral oximetry was applied by first responders at the outset of EMS resuscitation using the Nonin SenSmart Model X-100 Universal Oximetry System. EMS providers were blinded to oximeter information. The oximeter recording was linked to the defibrillator recording and the OHCA clinical registry, which includes the outcomes of return of spontaneous circulation (ROSC) and survival to hospital discharge with good function as determined by Cerebral Performance Category (CPC) of 1 or 2. We evaluated the variability of cerebral oximetry over time and the relationship between oximetry and outcome according to ROSC and survival status.

Results:
Of the 100 eligible OHCA events, 81 had complete oximeter and defibrillator information. Average age was 62, 43% were female, 14% presented with ventricular fibrillation, 49% (n=40) achieved ROSC, and 16% (n=13) survived (all with CPC of 1 or 2). Average initial cerebral oxygen saturation was 46% (SD 15) among all cases and among those requiring resuscitation >10 minutes. Among those with ongoing resuscitation, mean oximetry was 49% at 5 minutes and 51% at 10 minutes. The average change in oximetry
during
resuscitation
was 8% with 59% demonstrating an increase in oximetry, 32% a decrease, and 9% no change. Brain oximetry increased 10% following ROSC. Initial cerebral oximetry was 53% (SD 18) among survivors versus 44% (SD 15) among non-survivors (p=0.1). When stratified by groups defined by ROSC and survival, initial brain oximetry was 43% among those without ROSC, 46% among those who achieved ROSC but did not survive, and 53% among those who survived (p=0.1 test for trend).

Conclusion:
Cerebral oximetry can be deployed by first responders in OHCA. Cerebral oximetry exhibits some variability during the course of resuscitation and increases with ROSC. Whether cerebral oximetry can be used to guide care is uncertain.
Abstract 29: Comparison of Amiodarone versus Lidocaine for Treatment of In-Hospital Cardiac Arrest
Authors: Wagner Deborah S , Nawer Humaira , Kronick Steven L , Cranford James A , Bradley Steven M , Neumar Robert W
Published: June 2021

Introduction:
Over 200,000 patients are treated annually in the United States for in-hospital cardiac arrest (IHCA). Patients with an initial rhythm of ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT) have a survival rate of less than 50%. The current American Heart Association (AHA) Advanced Cardiovascular Life Support guidelines suggest amiodarone or lidocaine as first-line agents for shock-refractory VF/pVT based on randomized clinical trials in adults with out-of-hospital cardiac arrest. Based on these results, we hypothesized that amiodarone and lidocaine have equivalent efficacy in treating hospitalized patients with VF/pVT.

Methods:
This is a retrospective risk-adjusted cohort study using the AHA Get with the Guidelines-Resuscitation® (GWTG-R) registry. The study included adult patients between January 1, 2000 to December 31, 2014 with IHCA due to VF/pVT that received either amiodarone or lidocaine. The primary outcome was return of spontaneous circulation (ROSC). Secondary outcomes were 24-hour survival, survival to hospital discharge, and survival with favorable neurologic outcome based on Cerebral Performance Category (CPC) 1 or 2.

Results:
A total of 14,630 events were included in the analysis. Among patients who met inclusion criteria, 68.7% (n=10,058) were treated with amiodarone and 31.3% (n=4,572) were treated with lidocaine. Results from multivariable logistic regression analysis showed that, controlling for 19 covariates, ROSC rates were not statistically different with lidocaine treatment vs. amiodarone (AOR = 1.02, 95% CI 0.94, 1.11). However, lidocaine treatment was associated with higher odds of a) 24-hour survival, AOR = 1.14, 95% CI 1.06, 1.23; b) survival to discharge, AOR = 1.15, 95% CI 1.06, 1.24; and c) favorable neurologic outcome at hospital discharge, AOR = 1.21, 95% CI 1.11, 1.31.

Conclusion:
In adult IHCA patients with VF/pVT, treatment with lidocaine compared to amiodarone was not associated with higher ROSC rates, but was associated with higher rates of survival and favorable neurological outcomes. Additional research is needed to determine the optimal antiarrhythmic therapy for VF/pVT in IHCA.
Abstract 291: Cardiopulmonary Resuscitation Prior to Arrival of Emergency Medical Services in Arizona Extended Care Facilities
Authors: Maher Steven A , Rice Amber D , Gaither Joshua B , Hu Chengcheng , Mullins Margaret , Spaite Daniel W , Bobrow Bentley J
Published: June 2021

Background:
Extended care facilities (ECFs) house unique patient populations with increased risk of out of hospital cardiac arrest (OHCA) and with unique, generally medically trained first responders initiating care prior to arrival of emergency medical services (EMS). However, little is known about bystander cardiopulmonary resuscitation (CPR) and resuscitation outcomes in this population. Our aim is to assess rate of CPR delivery prior to EMS arrival in cases of OHCA among residents ECFs across the state of Arizona.

Methods:
Cases of OHCA between 2016-2018, cared for by participating Arizona EMS agencies, were included if OHCA occurred at an ECF, age 18+, and was of presumed cardiac etiology. Association between survival status at discharge and bystander CPR was examined first by Chi-squared test then by logistic regression, which adjusted for important risk factors and potential confounders including: age, gender, witnessed arrest, shockable initial rhythm, and return of spontaneous circulation (ROSC) in EMS care.

Results:
There were 1,046 cases included in this study after excluding 32 cases with DNR and 11 with unknown bystander CPR status. Median patient age was 74 (interquartile range 64, 83). The overall rate of CPR prior to EMS arrival was 78.4% (95% CI, 75.8%, 80.9%). Survival to hospital discharge and survival with favorable neurologic outcome were not different between nursing home patients who received CPR prior to EMS arrival and those who did not [6.2% vs. 4.4% (p = 0.34) and 3.1% vs. 1.8% (p = 0.29)]. There was no statistically significant difference in the adjusted analysis.

Conclusions:
In this study population CPR was commonly delivered prior to EMS arrival. However, delivery of CPR prior to EMS arrival was not associated with survival to hospital discharge or favorable neurologic outcome. The lack of positive association between CPR prior to arrival and survival to hospital discharge may be related to comorbid factors present in ECF patients or differences in the time between collapse and initiation of CPR. Further study is needed to identify factors that might improve survival in this unique population.
Abstract 292: Accuracy of a Dispatch-Directed Breathing Verification Diagnostic Tool as Assessed by Data From Electronic Patient Care Records and Emergency Dispatch Systems
Authors: Youngquist Scott T , Poulson Jonathan , Ashwood Daniel , Sangaraju Srilakshmi , Stoecklein Hill , Scott Greg , Clawson Jeff , Olola Christopher H
Published: June 2021

Introduction:
Identification of sudden out-of-hospital cardiac arrest (OHCA) and delivery of bystander emergency medical dispatcher (EMD)-directed pre-arrival instructions are key elements in the chain of survival. In order to provide instructions, dispatchers must formulate a clinical impression (rather than a definitive diagnosis) after an abbreviated history and dispatcher-directed examination of the scene. Thus, fast and accurate identification tools are imperative in the treatment of OHCA.

Hypothesis:
A dispatch-directed breathing verification diagnostic tool (BVDxT) accurately identifies inadequate breathing from OHCA.

Methods:
A retrospective design using EMD data matched to electronic patient care records (ePCRs) from the Salt Lake City Fire Department. The BVDxT, an embedded interface within the dispatch system, allows dispatchers to count breaths as reported by callers and record the rate of 4 consecutive patient breaths. OHCA was defined as non-trauma cases that had paramedic primary impression of cardiac arrest, respiratory arrest, or overdose or a Glasgow Coma Score of 3.

Results:
A total of 45,007 emergency dispatch cases were matched with the paramedic impressions of 38,258 ePCRs. Of the matched cases, 2660 cases included some use of the BVDxT, 1,365 (51.3%) had used the BVDxT to completion (i.e. breathing rate was recorded during the call) and, of those, 1,248 (91.4%) had complete on-scene paramedic primary or secondary impressions to match to the BVDxT outcomes. Median time using the tool was 28 seconds (IQR: 21-39). Overall, BVDxT identified 68.6% (n = 856/1,248) callers with disordered breathing and paramedics recorded 16.4% (205/1,248) cases of OHCA. BVDxT demonstrated a 70.7% (145/205) sensitivity, and 31.8% specificity for OHCA.

Conclusions:
Preliminary evidence suggest the BVDxT does well in predicting abdominal breathing condition. Although, by design, emergency dispatch tools tend to have high sensitivity, the low specificity of the tool may over-triage the number of abnormal breathing issues in the field - which may result in a substantial proportion of possible false positives. Changes in patient condition between call receipt and EMS arrival may also impact these findings.
Abstract 295: Improving Response to Out-Of-Hospital Cardiac Arrest: Verified Responder Pilot Program
Authors: Blackwood Jennifer , Jorgenson Dawn B , Gao Mengqi , Price Richard , Mancera Michael , Bavery Scott , Carbon Christopher , Luther Jeffrey , Charbonneau Julie , Robertson Jeremy , Helm Jeff , Nania James M , Schaeffer Brian , Collins Bryan , Daya Mohamud R , VanKeulen Brent , Rea Thomas
Published: June 2021

Background:
Survival following out-of-hospital cardiac arrest (OHCA) decreases as the interval from collapse to CPR and defibrillation increases. Most OHCA events occur in private locations. Innovative approaches are needed to reduce response interval, especially into private locations.

Methods:
We undertook the Verified Responder Program in 5 United States communities during calendar year 2018, whereby off-duty EMS professionals volunteered and were equipped with Philips automated external defibrillators (AEDs). Volunteers were alerted using a geospatial smartphone application (PulsePoint) integrated with 9-1-1 dispatch to respond to nearby private and public suspected OHCA. The prospective study evaluated the frequency of verified responder alert, response, scene arrival, and initial care for OHCA occurring prior to EMS arrival. The investigation surveyed responder experience using a 5 point Likert scale. OHCA surveillance was assessed using the CARES registry.

Results:
The Verified Responder Program involved 593 volunteers equipped with 550 AEDs drawn from 5 EMS agencies covering a population of 1.3 million persons (Table 1). Of the 660 eligible OHCA events (483 private, 177 public), verified responders were alerted in 9.4% (n=62) of events. Among the 483 in a private location, responders were alerted in 10.4% (n=50), responded in 2.1% (n=10), arrived on scene in 1.7% (n=8), and provided initial care in 1.5% (n=7). Among the 177 in a public location, responders were alerted in 6.8% (n=12), responded in 3.4% (n=6), arrived on scene in 2.8% (n=5), and provided initial care in 1.1% (n=2). Overall, responders reported a highly favorable experience (4.5/5). None reported an adverse event.

Conclusions:
In this initial US-based experience of smartphone alert program for suspected OHCA in private or public locations, volunteer experiences were uniformly favorable. Volunteers were alerted, responded, and involved in a small fraction of OHCA.
Abstract 300: End-Tidal CO
2
-Guided Chest Compression Delivery Improves Survival in a Pediatric Model of Respiratory Failure and Cardiac Arrest
Authors: O’Brien Caitlin E , Santos Polan T , Reyes Michael , Adams Shawn , Hopkins C. Danielle , Kulikowicz Ewa , Lee Jennifer K , Hunt Elizabeth A , Koehler Raymond C , Shaffner Donald H
Published: June 2021

Introduction:
The American Heart Association (AHA) recommends the use of end-tidal CO
2
(ETCO
2
) to evaluate the quality of chest compression delivery during CPR. In a pediatric model of asphyxial cardiac arrest, ETCO
2
-guided chest compression delivery improved survival over standard CPR. Since the most common cause of pediatric cardiac arrest is respiratory failure, we investigated whether this observed survival benefit persisted in a model of respiratory failure preceding cardiac arrest.

Methods:
Prior to a 17-min asphyxial cardiac arrest, peak inspiratory pressures were adjusted to a goal PaCO
2
of 80 torr to mimic pre-arrest respiratory failure. Male swine (3-4 kg) were randomized to receive either ETCO
2
-guided or standard CPR for 10 min of BLS followed by 10 min of ALS. In the ETCO
2
-guided group, chest compression rate and depth were adjusted to obtain a maximal ETCO
2
level. In the standard group, chest compressions were delivered per AHA guidelines. Hemodynamic parameters were recorded every 30 seconds, and resuscitation was continued for 20 min or until ROSC.

Results:
Twenty swine underwent asphyxial cardiac arrest. After adjustment of ventilation prior to asphyxia, pH and PaCO
2
were 7.15 and 79 torr in the ETCO
2
-guided group and 7.14 and 78 torr in the standard group. Survival was greater in the ETCO
2
-guided group than in the standard group (7/10 versus 1/10; p=0.02). During resuscitation, mean ETCO
2
and chest compression rate were higher in the ETCO
2
-guided group (38.6 ± 1.2 versus 22.9 ± 1.2, p=0.01; 154.4 ± 1.2 versus 100.5 ± 0.1, p<0.001, respectively). During resuscitation, diastolic blood pressure, myocardial perfusion pressure, systemic perfusion pressure, and cerebral perfusion pressure were higher in the ETCO
2
-guided group (
Figure 1
)

Conclusions:
ETCO
2
-guided chest compression delivery improves survival and resuscitation hemodynamics over standard CPR in a pediatric model of respiratory failure and cardiac arrest.
Abstract 302: Pediatric CPR Performance During One Year of RQI in a Pediatric Emergency Department
Authors: Donoghue Aaron , Abbadessa Mary Kate , Gaines Shannon , Watanabe Ichiro , Hanna Richard , Heard Debra , Myers Sage , Niles Dana E , Nadkarni Vinay M , Griffin Russell E
Published: June 2021

The Resuscitation Quality Improvement Program is a low-dose high-frequency training method for CPR skills. Evidence linking high-frequency training to improved performance during actual CPR is lacking. We have previously reported on the simultaneous use of video review and chest compression (CC) monitoring devices to describe CC quality at the level of individual providers. We sought to evaluate CC quality in pediatric CPR over a one year period following RQI implementation.

Methods:
Observational study in a pediatric ED where codes are videorecorded and where all providers were enrolled in RQI in October 2017. Video review is used to identify CPR providers and measure the duration of CC segments they perform. A monitor device is used to record CC depth and rate, allowing summarization of CC parameters for those individual time segments (i.e. CC performance by individual providers). CCs were analyzed by ‘compressor segment’, defined as the period of time where a single provider performed chest compressions until replaced by another. Data was summarized by quarter; change over time was analyzed by mixed effect logistic regression modeling adjusting for quarter and segment duration as fixed effects.

Results:
159 providers enrolled in RQI. Data for 18 events totaling 206 CC segments were analyzed. 52 providers performed CC at some point during the study period. CC segments are graphed per quarter in Figure 1. There were no significant differences in proportion of CC segments meeting guidelines during the study period.

Conclusions:
CPR events in our ED are infrequent and a minority of providers perform CPR in routine clinical practice. Over a 15 month period following the implementation of RQI in a pediatric ED, CC quality during CPR events in children did not improve with time, although our analysis was limited by sample size constraints. Future research should expand this method to examine the impact of varied retraining intervals and varied participant groups on CC quality.
Abstract 312: Evaluating Novel Methods of Post Cardiac Arrest Outcome Assessment
Authors: Krampe Noah , Rittenberger Jon C , Callaway Clifton W , Elmer Jonathan
Published: June 2021

Introduction:
Recovery of cardiac arrest patients is dynamic over the first year. Loss to follow up is common and validated tools to assess long-term survival and function useful for observational research are lacking. We tested novel methods of long-term follow-up after resuscitation from cardiac arrest.

Hypothesis:
We hypothesized that post-acute encounters in our electronic health record (EHR) and internet-based searches would each allow determination of long-term vital status and function.

Methods:
We performed a retrospective study including consecutive patients treated after cardiac arrest at a single academic medical center from 2010 to 2018 who survived to hospital discharge. We used a structured data collection tool and three methods to assess post-discharge vital status and function (modified Rankin Scale score (mRS)): 1) a search of our health system’s EHR for post-discharge encounters; 2) an web-based search of local newspapers, ancestry sites, and other sources; and 3) a search of public social media postings attributed to the patient on Facebook, Twitter, and Instagram.

Results:
Overall, 900 patients met inclusion criteria. Of these, 544 (60%) were male and 643 (71%) arrested out-of-hospital. A minority, 257 patients, (29%) had good function (mRS 0-2) at hospital discharge. Overall, 862 patients (96%) had EHR data after their index hospitalization. Of these, 307 (36%) had a date of death confirmed in the EHR a median of 196 days [interquartile range (IQR) 59-703] days post-arrest. The remaining 555 patients were alive at their last known follow-up after a median of 830 [IQR 246 - 1661] days. Of these, 357 (64%) had documentation of function consistent with an mRS of 0-2. By contrast, we found 602 (67%) patients using web-based sources: 333 (37%) in local newspapers, 239 (27%) in ancestry sites, 319 (35%) on Facebook, 65 (7%) on Twitter, and 55 (6%) on Instagram. Web-based sources confirmed 25 additional deaths not identified in the EHR.

Conclusions:
This work supports use of novel methods of outcome assessment of patients’ vital and functional status after cardiac arrest. Further work will test these methods against reference standards.
Abstract 313: Visualizing Out-Of-Hospital Cardiac Arrest in the Young: A Network Analysis of the Cardiac Arrest Registry for Enhanced Survival in Chicago
Authors: Vermeulen Alyssa , Del Rios Marina , Campbell Teri L , Nguyen Hai , Nguyen Hoang H
Published: June 2021

Introduction:
The interactions of various variables on out-of-hospital cardiac arrest (OHCA) in the young (1-35 years old) outcomes are complex. Network models have emerged as a way to abstract complex systems and gain insights into relational patterns among observed variables.

Hypothesis:
Network analysis helps provide qualitative and quantitative insights into how various variables interact with each other and affect outcomes in OHCA in the young.

Methods:
A mixed graphical network analysis was performed using variables collected by CARES. The network allows the visualization and quantification of each unique interaction between two variables that cannot be explained away by other variables in the data set. The strength of the underlying interaction is proportional to the thickness of the connections (edges) between the variables (nodes). We used the mgm package in R.

Results:
Figure 1 shows the network of the OHCA in the young cases in Chicago from 2013 to 2017. There are apparent clusters. Sustained return of spontaneous circulation and hypothermia are strongly correlated with survival and neurological outcomes. This cluster is in turn connected to the rest of the network by survival to emergency room. The interaction between any two variables can also be quantified. For example, American Indians cases occur more often in disadvantaged locations when compared to Whites (OR 4.5). The network also predicts how much one node can be explained by adjacent nodes. Only 20% of survival to emergency room is explained by its adjacent nodes. The remaining 80% is attributed to variables not represented in this network. This suggests that interventions to improve this node is difficult unless further data is available.

Conclusion:
Network analysis provides both a qualitative and quantitative evaluation of the complex system governing OHCA in the young. The networks predictive capability could help in identifying the most effective interventions to improve outcomes.
Abstract 315: Community Characteristics Associated With Out of Hospital Cardiac Arrest Mortality: The Intersection of Urbanicity, Poverty, and Race
Authors: Barbe John , Gaieski David F , Zebrowski Alexis M , Buckler David G , Lang Marissa N , Abella Benjamin S , Carr Brendan G
Published: June 2021

Introduction:
Variation in survival for out-of-hospital cardiac arrest (OHCA) has been described, but the intersection of urbanicity, race, and poverty and the impact on OHCA outcomes remains unclear. We sought to test whether rurality was associated with increased in-hospital mortality compared to urban and suburban communities when accounting for differences in poverty and race.

Methods:
We performed a retrospective analysis using 2013-2014 Medicare claims for inpatient stays originating in the emergency department. OHCA Patients (≥65 years) were identified by ICD-9-CM diagnosis code. Urbanicity was assigned based on county of residence using Rural-Urban Continuum Codes. Census data were used for county poverty and racial composition measures. Multivariate logistic regression was used to estimate the association of in-hospital mortality with urbanicity, percent of resident population in poverty, and percent black residency. Also included were individual, hospital, and community characteristics.

Results:
A total of 246,736 OHCA cases were identified of which 53% were male, 23% non-white, and 36% >75 years. Survival to discharge was 22%. Over 95% of OHCA patients resided in urban (85%) or suburban (11%) areas. Predicted probabilities of death (Figure) were lowest in suburban communities with moderate poverty and small black populations (0.76, CI 0.75-0.76) and highest in urban areas with moderate poverty and larger black populations (0.80, CI 0.80-0.81). All areas with high poverty and larger black populations had similar predicted probabilities (0.77-0.78), regardless of urbanicity.

Conclusions:
Suburban residence was associated with lower odds of mortality, even in communities with high levels of poverty. Communities with moderate poverty showed the greatest spread of outcomes in all 3 urbanicity categories. Further work should explore access to care, social determinants of health, and hospital factors that lead to the observed disparities.
Abstract 322: Prehospital Care From Emergency Life-Saving Technicians Promotes the Survival of Trauma Patients
Authors: Nojima Tsuyoshi , Naito Hiromichi , Yumoto Tetsuya , Nakao Atsunori
Published: June 2021

Introduction:
Optimal trauma care strategies remain a matter of debate. Prehospital trauma care protocols for paramedics range from no intervention to full field stabilizations. In Japan, emergency life-saving technicians (ELSTs) are certified specialists trained to provide advanced techniques and knowledge for prehospital emergency care. They can give fluid resuscitation and inform the receiving hospital for definitive surgery. However, the effectiveness of ELSTs over basic emergency medical technicians (BEMTs) regarding trauma transport remains unclear.

Hypothesis:
We tested whether the presence of an ELST improves the outcomes of trauma patients.

Methods:
We retrospectively studied 2004- 2017 data from the Japan Trauma Data Bank (JTDB). Inclusion criteria were patients age ≥ 16 with at least one Abbreviated Injury Scale (AIS) score ≥ 3 trauma. Exclusion criteria were patients with burns, AIS score = 6 in any region, and missing data. We compared two trauma patient groups. ELST group: patients transported by EMS including at least one ELST. BEMT group: patients transported only by basic EMS personnel. The primary outcome measure was survival at discharge. A multivariable logistic regression model was used to adjust for patient baseline characteristics.

Results:
Included were 124,563 patients, with 119,352 patients in the ELST group and 5,211 patients in the BEMT group. Patients’ ages (ELST vs. BEMT [Mean ± SD]: 57 ± 22 vs. 59 ± 22 years,
p
< 0.01) were lower and transportation time (15 ± 12 vs. 17 ± 14 min,
p
< 0.01) was shorter in the ELST group. Gender (male: 64 vs. 64 %,
p
= 0.66), proportion of blunt trauma (96 vs. 96 %,
p
= 0.10), proportion of blood transfusion (15 vs. 14 %,
p
= 0.11) and Injury Severity Score (16 ± 11 vs. 16 ± 11,
p
= 0.28) were similar between groups. Revised Trauma Score (7.0 ± 1.9 vs. 7.1± 1.7,
p
< 0.01) was lower in the ELST group and proportion of emergency surgery (12 vs. 11 %,
p
< 0.01) was higher in the ELST group, indicating that ELSTs treat more severe cases. In the multivariable logistic regression, the ELST group had higher odds for survival (adjusted OR: 1.18, 95% CI: 1.01-1.37).

Conclusions:
ELSTs encountered more severe cases than BEMTs. After adjustment, transport by the ELST group was associated with improved survival of trauma patients.
Abstract 331: Novel Electrocardiogram Features and Dichotomous Variables to Predict Resuscitation Outcomes During Chest Compressions
Authors: Coult Jason , Blackwood Jennifer E , Rea Thomas , Kudenchuk Peter , Kwok Heemun
Published: June 2021

Objective:
Analysis of the ventricular fibrillation (VF) ECG to predict patient outcomes can potentially improve defibrillation timing and monitor prognosis during resuscitation. However, accurate ECG analysis requires pausing CPR. We evaluated strategies to predict patient outcomes during CPR using novel ECG features, adaptive filtering, and dichotomous variables.

Methods:
We collected a 5-s VF ECG segment during chest compressions prior to 2137 shocks in 942 out-of-hospital VF arrests. Using training segments from 376 patients (40%), we designed ten features of the VF ECG to characterize amplitude, time-frequency energy, and complexity. Features were calculated with and without adaptive filtering. We used support vector machine and logistic models to combine ECG features with dichotomous variables presumed available during treatment: age<60, sex, and prior shock success. Using segments from 566 patients (60%) for validation, we evaluated performance of individual variables and the combined model. For comparison, we also computed the amplitude spectrum area (AMSA) ECG metric. Performance was characterized by area under the receiver operating characteristic curve (AUC) to predict return of organized rhythm after shock and survival with Cerebral Performance Category of 1-2.

Results:
Of individual ECG variables, filtering improved amplitude features, and the best performance was observed using high-frequency energy features above CPR artifact frequencies (Table 1). Of dichotomous variables, age<60 predicted survival but not return of rhythm, and prior shock success was more indicative of return of rhythm than survival. The combined model had improved performance versus AMSA for predicting return of rhythm (AUC=0.74 vs. 0.66, p<0.001) and survival (AUC=0.75 vs. 0.70, p<0.001).

Conclusion:
Combining ECG characteristics, adaptive filtering, and dichotomous variables may improve prediction of defibrillation outcomes during uninterrupted CPR.
Abstract 333: End-Tidal Carbon Dioxide, CPR Quality and ROSC During Pediatric Cardiac Arrests in a Large Academic Children’s Hospital, 2013-2018
Authors: Sorcher Jill L , Hunt Elizabeth A , Shaffner Donald H , Jeffers Justin , Newton Heather , Jones Sara I , Badaki-Makun Oluwakemi , Duval-arnould Jordan M
Published: June 2021

Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Little evidence exists to guide end-tidal carbon dioxide (ETCO
2
) use during cardiac arrest events in pediatric populations. Despite this, integrating physiologic feedback, including ETCO
2
, into resuscitation optimization is recognized as an important component to precision resuscitation. This was a prospective observational study of ETCO
2
, CPR quality and ROSC. The study population included any pediatric patient who received chest compressions from January 1, 2013 through July 10, 2018 in the Johns Hopkins Children’s Center. During this time, 457 arrest events of any length requiring chest compressions occurred. Of these events, 274 utilized ETCO
2
in some capacity and 198 recorded ETCO
2
on a Zoll R Series® defibrillator. Data files from 145 of these events that contained both chest compression and ETCO
2
data were successfully obtained. These 145 events contained 2200 minutes of ETCO
2
data and 2156 minutes of both chest compression and ETCO
2
data; values are reported as median [IQR]. The average ETCO
2
for all events was 21 mmHg [15-32]. ETCO
2
by age category was (0-1: 12 [0-29]; 1-8: 20 [2-35]; 8+: 10.15 [0-21]). When comparing patients who achieved ROSC > 20 minutes to those who did not, we observed a significant difference in ETCO
2
between those who survived and those who did not (ROSC: 25 [15-30] vs. NO ROSC: 15 [9-22]; p<0.001). Analysis to assess associations between ROSC and chest compression depth, rate, and fraction are underway. In this analysis of the largest set of pediatric ETCO
2
and resuscitation data, our findings suggest that a difference may exist in survival associated with an ETCO
2
difference between 15 and 20 mmHg.
Abstract 334: Point-Of-Care Ultrasound in the Assessment of Optic Nerve Sheath Diameter After Out-Of-Hospital Cardiac Arrest
Authors: Kotini-Shah Pavitra , Kim Sarah E , Gordon Richard , Karfunkle Benjamin , Doshi Pratik B , Granado Misha , Wang Henry E , Vanden Hoek Terry L
Published: June 2021

Introduction:
Hypoxic-ischemic injury from cardiac arrest may cause cerebral edema, leading to increased intracranial pressure (ICP) and brain tissue damage. Optic nerve sheath diameter (ONSD) is associated with elevated ICP. Limited clinical studies have reported ONSD changes in the early post-resuscitation time frame. We sought to evaluate the utility of bedside ocular ultrasound measurements in the assessment of post-cardiac arrest brain injury.

Methods:
We studied adult out-of-hospital cardiac arrests treated at an urban academic ED and achieving return of spontaneous circulation (ROSC) between May 2018 to May 2019. We included witnessed and unwitnessed arrest as well as shockable and non-shockable rhythms. After ROSC, trained emergency physicians performed bedside ultrasonographic assessment of bilateral ONSD at 1, 6, 24, 48, and 72 hours using an ocular preset on a 15MHz linear probe. ONSD measurements at these time frames were compared between groups stratified by rhythm type and neurological outcome. Cerebral performance category (CPC) was measured at 72 hours and at discharge.

Results:
Out of 48 eligible patients, 15 were excluded from the study due to lack of consent or available ultrasound images. We included 33 patients, of which 11 were female and 22 were male, with a median age of 57 (IQR 20). There were 19 with an initial rhythm of asystole or pulseless electrical activity (PEA), 9 with ventricular fibrillation arrests, and 5 with an unclear rhythm. At 1 hour, patients with CPC 1-2 had smaller ONSD compared to patients with CPC 3-5 (5.5mm vs 6.1mm, p=0.03). At 72 hour, patients with CPC score of 1-2 had an average reduction in ONSD of 1.6mm verses 0.29mm increase in patients with CPC 3-5. Despite small sample size, a trend towards higher ONSD were seen in patients with non-shockable vs shockable rhythm. Females were also consistently found to have smaller ONSD measurements in all time periods compared to males.

Conclusions:
This is the first study in the USA to perform analysis using ONSD measurements in cardiac arrest patients. Preliminary analysis of this on-going pilot revealed a greater improvement in ONSD diameters in patients with a favorable neurological outcome. OSND may have utility in prognostication of the post-arrest state.