Pulseless Rhythm Research Articles

Incidence and outcomes of in-hospital resuscitation for cardiac arrest among paediatric patients in Jordan: a retrospective observational study.

To investigate the incidence and survival rates of paediatric patients receiving resuscitation for in-hospital cardiac arrest (IHCA) in a teaching hospital in Northern Jordan, comparing initial pulseless rhythms and bradycardia rhythm with poor perfusion. Retrospective observational study SETTING: An university-affiliated tertiary hospital in Northern Jordan, covering January 2015 to December 2022. All hospitalised paediatric patients aged 1 month-18 years who received cardiopulmonary resuscitation (CPR) for cardiac arrest were included in the study. Resuscitation attempts were categorised into initial pulseless rhythm events and bradycardia with poor perfusion events. Incidence rate of paediatric CPR and the survival to hospital discharge rate. A total of 504 paediatric patients received CPR during the study period, with an incidence rate of 6.26 per 1000 paediatric admissions. The annual incidence rate was significantly reduced by an average of 5.5% for the total sample but increased by 25.0% for bradycardia events (n=110, 21.8%). The percentage of patients who sustained return of spontaneous circulation (ROSC) was 25.0%. Survival to hospital discharge was low at 4.8% while showing an increasing trend by an average of 24.0% per year. Bradycardia events had a significantly higher ROSC rate (34.6% vs 22.3%); but an insignificant higher survival rate (6.4 vs 4.3). Patients with neurological or cardiovascular medical conditions, those in non-intensive care unit departments, and those with respiratory causes had higher odds of survival to discharge. While the incidence rate of paediatric IHCA in Jordan is comparable to developed countries, the survival rate is much poorer. The study highlights the importance of strengthening healthcare infrastructure, establishing national legal and ethical frameworks around resuscitation policies and establishing robust data registries to monitor and optimise care practices.

Abstract 326: The Impact of a Critical Care Outreach Team on the Collection of In-Hospital Cardiac Arrest Resuscitation Quality Data

Introduction: Critical Care Outreach Teams (CCOTs) serve to recognize clinical deterioration and respond to rapid response activations prior to in-hospital cardiac arrest (IHCA) in non-intensive care unit (ICU) patient care areas. In some hospitals, the CCOT operates separately from the IHCA resuscitation team. However, limited data exist regarding the outcomes of CCOT and IHCA resuscitation team collaboration during IHCA. Research Question: The purpose of this pilot study was to determine if the addition of a CCOT member to an IHCA resuscitation team would improve the collection of quality metrics during adult IHCA resuscitations. Goals: The primary goal of this study was to increase the documentation of two quality metrics identified by the American Heart Association’s Get with the Guidelines®-Resuscitation (AHA GWT-R) program during adult IHCAs in non-ICU patient care areas: 1) documentation of initial pulseless rhythm and 2) documentation of time to first intervention (epinephrine or defibrillation). The secondary goal was to increase the percentage of completed IHCA records/code sheets integrated into the electronic medical record (EMR). Methods: All non-ICU IHCAs that occurred prior to the intervention during a year-long period (June 1 st , 2021, to May 31 st , 2022) were used to establish baseline resuscitation quality metrics. During the intervention period (June 1 st , 2022, to May 31, 2023), a member of the CCOT responded to inpatient IHCA activations to serve as the designated event recorder and assist with the resuscitation. At the end of the study period, all IHCA activations were reviewed. Results: There were 74 IHCAs in the pre-intervention group and 76 IHCAs in the post-intervention group. In the post-intervention group, integration of IHCA records/code sheets into the EMR increased in the post-intervention group from 56.8% (42/74) to 96% (73/76). In the post-intervention group, there was also an increase in the documentation of initial pulseless rhythm from 75.7% (56/74) to 96% (73/76) and documentation of the first intervention from 71.4% (n=40) to 98.6% (n=72). Conclusions: This pilot demonstrated that adding a CCOT member to non-ICU IHCA resuscitations improves the accuracy of IHCA documentation and AHA GWT-R quality metrics.

Abstract 136: Does End-Tidal Carbon Dioxide Measured at the Facial Mask Predict Return of Spontaneous Circulation in Out-of-Hospital Cardiac Arrest?

Introduction: High value of end-tidal carbon dioxide (EtCO2), measured at the end of a tracheal tube, is closely associated with return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest (OHCA) resuscitation. The aim of this study was to evaluate whether EtCO2 measured at the face mask (FM) before an intubation procedure, may also predict ROSC in OHCA. Material and Methods: This was a prospective non-interventional study. Between May 1 st 2022 and January 30 th 2023, all patients ≥ 18 years with an OHCA on EMS arrival and for whom a laryngoscopy for tracheal intubation was considered, were included. An EtCO2 sensor was directly placed between the valve of the bag-valve-mask and the FM while cardiopulmonary resuscitation was continued. Age, gender, initial rhythm, ROSC on scene and last EtCO2 at the FM (FM-EtCO2) value before laryngoscopy were collected. Patients were assigned to 3 groups: FM-EtCO2 < 10 mmHg ; 10 mmHg < FM-EtCO2 < 30 mmHg and FM-EtCO2 > 30 mmHg. Results: Twenty-three patients were included. Mean age was 64.9 ± 12.2 years and sex ratio was 3.6. Initial rhythm was asystole for 16 (69.6 %) patients, ventricular fibrillation for 5 (21.7 %) and pulseless rhythm for 2 (8.7%). Eight (34.8 %) patients had a ROSC on scene. Five (21,8 %) patients had a FM-EtCO2 < 10 mmHg ; 7 (30,4%) a 10 mmHg < FM-EtCO2 < 30 mmHg and 11 (47,8 %) a FM-EtCO2 > 30 mmHg. Among those with a ROSC, 2 had a FM-EtCO2 < 10 mmHg and 6 a FM-EtCO2 > 30 mmHg (p=0,038). Conclusion: A high value of EtCO2 measured at the face mask (above 30mmHg) was significantly associated with ROSC. This survey proposes a method that would facilitate the knowledge of an EtCO2 value, well known to predict ROSC in OHCA, earlier than with the reference method. Further studies are needed to validate these results.

Cardiopulmonary Resuscitation

Cardiopulmonary Resuscitation

Man With Cardiac Arrest

A 71-year-old man described abdominal pain prior to an out-of-hospital cardiac arrest with an initial pulseless rhythm. During emergency department (ED) resuscitation, a bedside ultrasound confirmed a large abdominal aortic aneurysm surrounded by a hematoma. We initiated blood transfusion and performed ultrasound-guided resuscitative endovascular balloon occlusion of the aorta (REBOA) within 30 minutes after ED arrival. During resuscitation, a transesophageal echocardiogram established the REBOA location (Video 1, Figure 1), revealing hyperechoic blood below the REBOA balloon.

Abstract 273: Epinephrine Dose Distribution And Impact On Survival After Extracorporeal Cardiopulmonary Resuscitation In Children

Background: Although AHA guidelines recommend a fixed epinephrine (epi) dosing frequency during cardiac arrest, it is unknown if a fixed dosing practice is both utilized and effective for EPCR events in children. We hypothesized that 1) epi dosing would not be uniformly distributed during ECPR events and 2) a strategy of limiting epi doses during ECPR would be associated with better survival to hospital discharge (SHD). Methods: This was a multicenter retrospective cohort study of ECPR after in-hospital cardiac arrest in children (< 18 years) between 2012 - 2019. Patient and arrest event details as well as epi dose and time-stamps were recorded. In patients with a CPR duration of ≥ 30 minutes, dosing strategies were categorized as either “frequent epi” (FE; average epi dosing interval of ≤ 5 mins/dose during the first 30 mins of CPR) or “limited epi” (LE; average dosing interval of ≤ 5 mins/dose for the first 10 mins followed by > 5 mins/dose through 30 mins). The primary outcome was SHD. Results: A total of 191 patients from 5 centers were included; overall SHD was 43% (82/191). Epi doses were not evenly distributed, with 66% (919/1385) of doses being given during the first half of CPR. Mean number of epi doses was similar between survivors and non-survivors in the first 10 mins (2.7 doses). After 10 mins, survivors received fewer doses than non-survivors per each 10 min interval (Figure). In the subset of patients that received ≥ 30 mins of CPR (n=147) the LE group had higher SHD [48% (14/52) vs. 27% (46/95), p=0.01] and improved odds of SHD after adjusting for age, sex, illness category, time of day, first pulseless rhythm and CPR duration [OR (95% CI) 4.2 (1.5-11.7); p =0.008]. Conclusion: In contrast to AHA guidelines, epi dosing was not evenly distributed during events in this multicenter study of pediatric in-hospital ECPR. For children with CPR duration ≥ 30 minutes a strategy of limiting epi doses was associated with improved SHD.

27 ECG monitoring during NRP: A false sense of security?

Abstract Primary Subject area Neonatal-Perinatal Medicine Background During neonatal resuscitation, use of an electrocardiogram (ECG) provides a more reliable measurement of heart rate than auscultation or pulse oximetry. Having an ECG monitor may, however, provide a false sense of security in the unlikely scenario of a newborn with pulseless rhythms. This could delay critical resuscitative steps during neonatal resuscitation. Objectives The aim of this study is to evaluate whether the presence of ECG monitoring has an impact on the resuscitative steps of neonatal resuscitation providers. Design/Methods We conducted a prospective crossover randomized controlled trial, which took place at Sainte-Justine University Health Center in Montreal, Quebec, Canada. Residents, fellows, attending physicians, transport nurses, and respiratory therapists were recruited in teams of three. They participated in two simulation scenarios (pulseless electrical activity [PEA] with and without ECG monitoring). Teams were randomized to one of the scenarios and then crossed over. A debriefing session followed the two scenarios. All sessions were video-recorded. The primary outcome was the time to pulse check once the simulated mannequin was programmed to become pulseless. Secondary outcomes were the number of pulse checks, time to intubation, time to start of chest compressions, and time to administration of epinephrine. Results Preliminary results (n=5 groups, 10 scenarios) showed that the time to check the pulse once the mannequin was pulseless was longer when ECG electrodes were used (98.0 vs 55.6 sec, p = 0.07). There was a statistically significant decreased number of pulse checks with the ECG compared to without (2.4 vs 5.6, p = 0.004). Time to start of positive pressure ventilation (31.3 vs 27 sec), intubation (182.4 vs 179.2 sec), chest compressions (235.2 vs 227.6 sec), and epinephrine administration (340.8 vs 241.5 sec), were all increased in the presence ECG monitoring, but the difference between groups was not statistically significant. Conclusion ECG monitoring may alter the behaviour of individuals and delay recognition of a pulseless state, but preliminary data suggest that clinical endpoints are not affected.

Factors associated with non-survival from in-hospital maternal cardiac arrest: An analysis of Get With The Guidelines® (GWTG) data

IntroductionMaternal mortality has risen in the United States during the 21st century. Factors influencing outcome of maternal cardiac arrest (MCA) remain largely unexplored. ObjectiveWe sought to further elucidate the factors affecting maternal death from in-hospital (IH) MCA. MethodsOur query of the American Heart Association’s GWTG®-Resuscitation voluntary registry from 2000–2017 revealed 561 index cases of IH MCA with complete outcome data. Logistic regression was performed using hospital death as the primary outcome and included variables with a p value = 0.1 or less based upon univariate analysis. Age, race, year of arrest, pre-existing conditions, first documented pulseless rhythm and location of arrest were used in the model. Sensitivity analyses and assessment of variable interaction were also performed to test model stability. Institutional review deemed this research exempt from ethical approval. ResultsAmong 561 cases of MCA, 57.2% (321/561) did not survive to hospital discharge. IH death was not associated with maternal age, race and year of event. In the final model, IH death was significantly associated with pre-arrest hypotension/hypoperfusion (OR = 1.80 (95% CI, 1.16–2.79); p = 0.009). The occurrence of MCA outside of the delivery suite (referent group) or operating room was associated with a significantly higher risk of death: ICU/Post-Anesthesia Care Unit (PACU) (OR = 3.32 (95% CI, 2.00–5.52); p < 0.001) and ER/other (OR = 1.89 (95% CI, 1.15–3.11); p = 0.012). While MCA cases with a shockable vs. non-shockable first documented pulseless rhythm had similar outcomes, those with an indeterminate rhythm were less likely to die, (OR = 0.41(95% CI, 0.20–0.84); p = 0.014). In a sensitivity analysis, removal of the indeterminate group did not alter outcomes regarding first documented pulseless rhythm or arrest location. Area under the curve for the final model was 0.715 (95% CI 0.673–0.757). ConclusionsOur study identified several novel factors associated with IH death of our MCA cohort. More research is required to further understand the pathophysiologic dynamics affecting outcomes of IH MCA in this unique population.

Racial disparities in survival outcomes following pediatric in-hospital cardiac arrest

BackgroundAmong adults with in-hospital cardiac arrest (IHCA), overall survival is lower in black patients compared to white patients. Data regarding racial differences in survival for pediatric IHCA are unknown. MethodsUsing 2000–2017 data from the American Heart Association Get With the Guidelines-Resuscitation® registry, we identified children >24 h and <18 years of age with IHCA due to an initial pulseless rhythm. We used generalized estimation equation to examine the association of black race with survival to hospital discharge, return of spontaneous circulation (ROSC), and favorable neurologic outcome at discharge. ResultsOverall, 2940 pediatric patients (898 black, 2042 white) at 224 hospitals with IHCA were included. The mean age was 3.0 years, 57% were male and 16% had an initial shockable rhythm. Age, sex, interventions in place at the time of arrest and cardiac arrest characteristics did not differ significantly by race. The overall survival to discharge was 36.9%, return of spontaneous circulation (ROSC) was 73%, and favorable neurologic survival was 20.8%. Although black race was associated with lower rates of ROSC compared to white patients (69.5% in blacks vs. 74.6% in whites; risk-adjusted OR 0.79, 95% CI 0.67−0.94, P = 0.016), black race was not associated with survival to discharge (34.7% in blacks vs. 37.8% in whites; risk-adjusted OR 0.96, 95% CI 0.80–1.15, P = 0.68) or favorable neurologic outcome (18.7% in blacks vs. 21.8% in whites, risk-adjusted OR 0.98, 95% CI 0.80–1.20, p = 0.85). ConclusionsIn contrast to adults, we did not find evidence for racial differences in survival outcomes following IHCA among children.

Abstract 116: Impella Device Success: Walking Home After Cardiogenic Shock From Ventricular Fibrillation

Ventricular fibrillation is a fatal arrhythmia due to its detrimental impact on cardiac output. Managing patients in V-Fib arrest is often challenging, but newer mechanical support devices such as Impella CP 5.0 (Abiomed, Danvers, MD) are proving to be an excellent adjunct to inotrope and vasopressor therapy. We present a 75-year-old female with a medical history of atrial fibrillation and obstructive sleep apnea that presented to the ER unresponsive. On arrival, the patient was pulseless and initial rhythm on telemetry revealed ventricular fibrillation. The patient demonstrated minimally reactive pupils to light, negative corneal reflex, and lower extremity clonus. ROSC was achieved with electric defibrillation and two rounds of CPR. Chest radiograph revealed mild bilateral pulmonary congestion. Head CT revealed no acute intracranial pathology. The patient was placed on targeted temperature management protocol for the next 48 hours. Emergent left heart catheterization revealed no signs of occlusive coronary disease. TTE revealed left ventricular ejection fraction 5-10%, likely from stunned myocardium. The patient continued to clinically decline and decision was made to place an Impella device for further hemodynamic support. Unlike ECMO, the Impella fully unloaded the LV and allowed diastolic coronary filling. The patient ultimately demonstrated significant improvement and repeat TTE revealed an improved EF of 45-50%. Prior to hospital discharge, an AICD was placed for primary SCD prevention. The patient maintained close outpatient follow-up with her cardiologist and PCP. This case illustrates the importance life-saving mechanical support devices such as Impella in the setting of cardiogenic shock, even from non-ischemic ventricular fibrillation.

Abstract 298: Predicting Pulse Status During Cardiopulmonary Resuscitation Using Dimensionality Reduction of Electrocardiogram Wavelet Transforms

Background: Current resuscitation protocols require pausing cardiopulmonary resuscitation (CPR) to check for a pulse. However, pausing CPR during a pulseless rhythm worsens patient outcome. We designed an ECG-based algorithm that predicts pulse status during uninterrupted CPR, and evaluated its performance both with and without CPR. Methods: We evaluated 383 patients who were treated for out-of-hospital cardiac arrest using defibrillators with real-time ECG, CPR, and audio recordings. We collected paired adjacent ECG segments with and without CPR during organized rhythms. Segments were collected during the 10-s CPR period just prior to pulse check, and 5-s segments without CPR during the pulse check. ECG segments with or without a pulse were identified by the audio annotation and recorded blood pressures. Patients were randomly divided into 60% (230/383) training and 40% (153/383) test groups. From training data, we developed an algorithm to predict clinical pulse status based on the wavelet transform of the bandpass-filtered ECG, applying principle component analysis (PCA). We then trained a linear discriminant model using 3 principle component modes as input features. Model performance was evaluated on test group segments with and without CPR using receiver operating curves overall and according to initial arrest rhythm. Results: There were 230 patients (540 pulse checks) in the training set and 153 patients (372 pulse checks) in the test set. In both of these sets, about 16% (37/230 and 25/153) of the patients presented with initial non-shockable rhythm . Overall 38% (351/912) of checks had a spontaneous pulse. The areas under the receiver operating characteristic curve (AUCs) for predicting pulse status with and without CPR on test data were 0.84 and 0.89, respectively. Conclusion: A novel ECG-based algorithm demonstrates potential to improve resuscitation by predicting presence of a spontaneous pulse without pausing CPR.

Abstract 286: Factors Associated with Non-survival From In-hospital Maternal Cardiac Arrest: An Analysis of Get with the Guidelines (gwtg) Data

Introduction: Maternal mortality has risen in the United States during the 21 st century. Factors influencing outcome of maternal cardiac arrest (MCA) remain largely unexplored. Hypothesis: We sought to further elucidate the factors affecting maternal death from in-hospital (IH) MCA. Methods: Our query of the American Heart Association’s GWTG ® -Resuscitation voluntary registry from 2000-2017 revealed 561 index cases of in IH MCA with complete outcome data. Logistic regression was performed using hospital death as the primary outcome and included variables with a p value = 0.1 or less based upon univariate analysis. Age, race, year of arrest, pre-existing conditions, first documented pulseless rhythm, and location of arrest were used in the model. Sensitivity analyses and assessment of variable interaction were also performed to test model stability. Results: Among 561 cases of MCA, 57.2% (321/561) did not survive to hospital discharge. In-hospital death was not associated with maternal age, race and year of event. In the final model (see table), IH death was significantly associated with prearrest hypotension/hypoperfusion (p=0.009). While MCA cases with a shockable vs non-shockable first documented pulseless rhythm had similar outcomes, those with an indeterminate rhythm were less likely to die, (p=0.014). The occurrence of MCA outside of the delivery suite (referent group) or operating room was associated with a significantly higher risk of death: ICU/Recovery Room (p=0.001) and ER/other (p= 0.012). In a sensitivity analysis, removal of the indeterminate group did not alter outcomes regarding first documented pulseless rhythm or arrest location. Area under the curve for the final model was 0.715 (95% CI 0.673-0.757). Conclusions: Our study identified several novel factors associated with IH death of our MCA cohort. More research is required to further understand the pathophysiologic dynamics affecting outcomes of IHCA in this unique population.

Life-threatening and major cardiac events during long-distance races: updates from the prospective RACE PARIS registry with a systematic review and meta-analysis.

Limited data exist regarding the incidence and aetiology of life-threatening events such as major cardiac events or exertional heat stroke during long-distance races. We aimed to provide an updated incidence, etiology and prognosis of life-threatening events during long-distance races. The prospective RACE PARIS registry recorded all life-threatening events/fatal events occurring during 46 marathons, half-marathons and other long-distance races in the Paris area between 2006 and 2016, comprising 1,073,722 runners. Event characteristics were determined by review of medical records and interviews with survivors. The incidence of life-threatening events, exertional heat stroke and major cardiac events was 3.35 per 100,000, 1.02 per 100,000 and 2.33 per 100,000, respectively, including 18 sudden cardiac arrests (1.67 per 100,000). The main aetiology of sudden cardiac arrest was myocardial ischaemia (11/18), due to acute coronary thrombosis (6/11), stable atherosclerotic coronary artery disease (2/11), coronary dissection (1/11), anomalous connection (1/11) or myocardial bridging (1/11). A third of participants with ischaemia-related major cardiac events presented with pre-race clinical symptoms. Major cardiac events were more frequent in the case of a high pollution index (6.78 per 100,000 vs. 2.07 per 100,000, odds ratio 3.27, 95% confidence interval 1.12-9.54). Case fatality was low (0.19 per 100,000). Similarly, we report in a meta-analysis of eight long-distance race registries comprising 16,223,866 runners a low incidence of long-distance race-related sudden cardiac arrest (0.82 per 100,000) and fatality (0.39 per 100,000). Death following sudden cardiac arrest was strongly associated with initial asystole or pulseless rhythm. Long-distance race-related life-threatening events remain rare although serious events. Better information for runners on the risk of pre-race clinical symptoms, outside air pollution and temperature may reduce their incidence.

Survival and Hemodynamics During Pediatric Cardiopulmonary Resuscitation for Bradycardia and Poor Perfusion Versus Pulseless Cardiac Arrest.

The objective of this study was to compare survival outcomes and intra-arrest arterial blood pressures between children receiving cardiopulmonary resuscitation for bradycardia and poor perfusion and those with pulseless cardiac arrests. Prospective, multicenter observational study. PICUs and cardiac ICUs of the Collaborative Pediatric Critical Care Research Network. Children (< 19 yr old) who received greater than or equal to 1 minute of cardiopulmonary resuscitation with invasive arterial blood pressure monitoring in place. None. Of 164 patients, 96 (59%) had bradycardia and poor perfusion as the initial cardiopulmonary resuscitation rhythm. Compared to those with initial pulseless rhythms, these children were younger (0.4 vs 1.4 yr; p = 0.005) and more likely to have a respiratory etiology of arrest (p < 0.001). Children with bradycardia and poor perfusion were more likely to survive to hospital discharge (adjusted odds ratio, 2.31; 95% CI, 1.10-4.83; p = 0.025) and survive with favorable neurologic outcome (adjusted odds ratio, 2.21; 95% CI, 1.04-4.67; p = 0.036). There were no differences in diastolic or systolic blood pressures or event survival (return of spontaneous circulation or return of circulation via extracorporeal cardiopulmonary resuscitation). Among patients with bradycardia and poor perfusion, 49 of 96 (51%) had subsequent pulselessness during the cardiopulmonary resuscitation event. During cardiopulmonary resuscitation, these patients had lower diastolic blood pressure (point estimate, -6.68 mm Hg [-10.92 to -2.44 mm Hg]; p = 0.003) and systolic blood pressure (point estimate, -12.36 mm Hg [-23.52 to -1.21 mm Hg]; p = 0.032) and lower rates of return of spontaneous circulation (26/49 vs 42/47; p < 0.001) than those who were never pulseless. Most children receiving cardiopulmonary resuscitation in ICUs had an initial rhythm of bradycardia and poor perfusion. They were more likely to survive to hospital discharge and survive with favorable neurologic outcomes than patients with pulseless arrests, although there were no differences in immediate event outcomes or intra-arrest hemodynamics. Patients who progressed to pulselessness after cardiopulmonary resuscitation initiation had lower intra-arrest hemodynamics and worse event outcomes than those who were never pulseless.

Synchronized Chest Compressions for Pseudo-PEA: Proof of Concept and a Synching Algorithm

Objective: The two objectives of this report are: first, to describe a comparison of chest compressions unsynchronized or synchronized to native cardiac activity in a porcine model of hypotension, and second, to develop an algorithm to provide synchronized chest compressions throughout a range of native heart rates likely to be encountered when treating PEA cardiac arrest. Methods: We adapted our previously developed signal-guided CPR system to provide compressions synchronized to native electrical activity in a porcine model of hypotension as a surrogate of PEA arrest. We describe the first comparison of unsynchronized to synchronized compressions in a single animal as a proof-of-concept. We developed an algorithm to provide optimal synchronized chest compressions regardless of intrinsic PEA heart rate while simultaneously maintaining the chest compression rate within a desired range. We tested the algorithm with computer simulations measuring the proportion of intrinsic and compression beats that were synchronized, and the compression rate and its standard deviation, as a function of intrinsic heart rate and heart rate jitter. Results: We demonstrate and compare unsynchronized versus synchronized chest compressions in a single porcine model with an intrinsic rhythm and hypotension. Synchronized, but not unsynchronized, chest compressions were associated with increased blood pressure and coronary perfusion pressure. Our synchronized chest compression algorithm is able to provide synchronized chest compressions to over 90% of intrinsic beats for most heart rates while maintaining an average compression rate between 90 and 140 compressions per minute with relatively low variability. Conclusions: Synchronized chest compression therapy for pulseless electrical rhythms is feasible. A high degree of synchronization can be maintained over a broad range of intrinsic heart rates while maintaining the compression rate within a satisfactory range. Further investigation to assess benefit for treatment of PEA is warranted.

Abstract 254: Synchronized Chest Compressions for Pseudo-PEA: Proof of Concept and Synching Algorithm

Introduction: Pulseless electrical activity (PEA) is a common rhythm in cardiac arrest with a persistently poor outcome. This report describes our successful development of a synchronized compression device and algorithm to treat PEA with or without intrinsic myocardial contractions. Methods: We adapted our previously developed signal-guided CPR system to provide synchronized compressions in a porcine model of cardiac arrest. We describe the first comparison of unsynchronized to synchronized compressions in a single animal as a proof-of-concept. We developed an algorithm to provide optimal synchronized chest compressions regardless of intrinsic heartrate while simultaneously maintaining the chest compression rate within a desired range. We tested the algorithm with computer simulations measuring the proportion of intrinsic and compression beats that were synchronized, and the compression rate and its standard deviation, as a function of intrinsic heartrate and heartrate jitter. Results: We demonstrate and compare unsynchronized versus synchronized chest compressions in a single porcine model with an intrinsic rhythm and hypotension. Synchronized, but not unsynchronized, chest compressions were associated with increased blood pressure and coronary perfusion pressure (Figure). Our synchronized chest compression algorithm is able to provide synchronized chest compressions to over 90% of intrinsic beats for most heartrates while maintaining an average compression rate between 95 and 135 BPM with relatively low variability. Conclusion: Synchronized chest compression therapy for pulseless electrical rhythms is feasible. A high degree of synchronization can be maintained over a broad range of intrinsic heart rates while maintaining the compression rate within a satisfactory range. Further investigation to assess benefit for treatment of PEA is warranted.

Abstract 188: Racial Disparities in Survival Outcomes Following Pediatric In-Hospital Cardiac Arrest

Introduction: Among adults with in-hospital cardiac arrest (IHCA), overall survival is lower in black patients compared to white patients. Data regarding racial differences in survival for pediatric IHCA remain unknown. Methods: Using data from the American Heart Association Get With the Guidelines-Resuscitation registry, we identified children &gt;24 hours and &lt; 18 years of age with IHCA due to an initial pulseless rhythm. We used generalized estimation equation to examine the association of black race with survival to hospital discharge and return of spontaneous circulation (ROSC). Results: Overall, 2940 pediatric patients (898 black, 2042 white) with IHCA were included. The mean age was 6 years, 57% were male and 16% had an initial shockable rhythm. Baseline demographics, cardiac arrest characteristics including initial rhythm did not differ significantly by race. Although black race was associated with lower rates of ROSC compared to white patients (69.5% in blacks vs. 74.6% in whites; adjusted OR 0.8012, 95% CI 0.6749 - 0.9512, P= 0.0113), it was not associated with survival to discharge (34.7% in blacks vs. 37.8% in whites; adjusted OR 0.9705, 95% CI 0.8086 – 1.1648, P=0.7476). A lower rate of ROSC in black patients was not explained by longer delays in epinephrine administration for patients with a non-shockable rhythm, or defibrillation in patients with a shockable rhythm. Conclusion: In contrast to adults, no statistically significant racial differences in survival were present in pediatric IHCA.

Capnography: A support tool for the detection of return of spontaneous circulation in out-of-hospital cardiac arrest

BackgroundAutomated detection of return of spontaneous circulation (ROSC) is still an unsolved problem during cardiac arrest. Current guidelines recommend the use of capnography, but most automatic methods are based on the analysis of the ECG and thoracic impedance (TI) signals. This study analysed the added value of EtCO2 for discriminating pulsed (PR) and pulseless (PEA) rhythms and its potential to detect ROSC. Materials and methodsA total of 426 out-of-hospital cardiac arrest cases, 117 with ROSC and 309 without ROSC, were analysed. First, EtCO2 values were compared for ROSC and no ROSC cases. Second, 5098 artefact free 3-s long segments were automatically extracted and labelled as PR (3639) or PEA (1459) using the instant of ROSC annotated by the clinician on scene as gold standard. Machine learning classifiers were designed using features obtained from the ECG, TI and the EtCO2 value. Third, the cases were retrospectively analysed using the classifier to discriminate cases with and without ROSC. ResultsEtCO2 values increased significantly from 41 mmHg 3-min before ROSC to 57 mmHg 1-min after ROSC, and EtCO2 was significantly larger for PR than for PEA, 46 mmHg/20 mmHg (p < 0.05). Adding EtCO2 to the machine learning models increased their area under the curve (AUC) by over 2 percentage points. The combination of ECG, TI and EtCO2 had an AUC for the detection of pulse of 0.92. Finally, the retrospective analysis showed a sensitivity and specificity of 96.6% and 94.5% for the detection of ROSC and no-ROSC cases, respectively. ConclusionAdding EtCO2 improves the performance of automatic algorithms for pulse detection based on ECG and TI. These algorithms can be used to identify pulse on site, and to retrospectively identify cases with ROSC.

Abstract 108: Pulselessness Despite Cardiopulmonary Resuscitation for Bradycardia in Hospitalized Children: Prevalence, Predictors of Survival, and Implications for Hospital Profiling

Background: Cardiopulmonary resuscitation (CPR) is initiated in hospitalized children with bradycardia and poor perfusion. However, it is unknown how often these children progress to pulseless in-hospital cardiac arrest (IHCA) despite CPR, and whether survival differs from primary pulseless IHCA. Methods: In Get With The Guidelines-Resuscitation (2000-2016), we identified all pediatric patients (age&gt;30 days, &lt;18 years) receiving CPR, and assessed the prevalence and predictors of survival among those progressing from bradycardia to pulselessness after initiation of CPR using multilevel Poisson regression that accounted for the pulseless rhythm. Results: Overall, 5592 pediatric patients were treated with CPR, of whom over half (2799) were for bradycardia with poor perfusion and the remaining 2793 were primary pulseless IHCAs. Among those with bradycardia, 869 (31%, or 16% of entire cohort) progressed to pulselessness after a median of 3 min of CPR (IQR 1- 9). Survival to discharge was 70% for bradycardia without pulselessness, 30% with bradycardia progressing to pulselessness, and 38% with primary pulseless IHCA (P&lt;.001). Children who became pulseless while receiving CPR for bradycardia had a 19% lower likelihood (RR 0.81 [0.70 - 0.93]) of surviving to hospital discharge than those initially pulseless. Among children who progressed to pulselessness while receiving CPR for bradycardia, longer time to pulselessness was an independent predictor of lower survival (ref: &lt;2 min, for 2-5 min: RR 0.54 [0.41 - 0.70]; for &gt;5 min: RR 0.41 [0.32 - 0.53], Figure ). Conclusions: Among non-neonatal pediatric patients in whom CPR is initiated, half have bradycardia with poor perfusion, and nearly one-third of these progress to IHCA despite CPR. Survival was lower for pediatric patients who subsequently became pulseless as compared to those who were initially pulseless. These findings have implications for care delivery and profiling hospital performance for pediatric IHCA.

Characteristics and outcomes of maternal cardiac arrest: A descriptive analysis of Get with the guidelines data

BackgroundMaternal mortality has risen in the United States in the twenty-first century, yet large cohort data of maternal cardiac arrest (MCA) are limited. ObjectiveWe sought to describe contemporary characteristics and outcomes of in-hospital MCA. MethodsWe queried the American Heart Association’s Get with the Guidelines Resuscitation voluntary registry from 2000 to 2016 to identify cases of maternal cardiac arrest. All index cardiac arrests occurring in women aged 18–50 with a patient illness category designated as obstetric or location of arrest occurring in a delivery suite were included. Institutional review deemed that this research was exempt from ethical approval. ResultsA total of 462 index events met criteria for MCA, with a mean age of 31 ± 7 years and a racial distribution of: 49.4% White, 35.3% Black and 15.3% Other/Unknown. While 32% had no pre-existing conditions or physiologic disorders, respiratory insufficiency (36.1%) and hypotension/hypoperfusion (33.3%) were the most common antecedent conditions. In most cases, the first documented pulseless rhythm was non-shockable; pulseless electrical activity (50.8%) or asystole (25.6%). Only 11.7% presented with a shockable rhythm; ventricular fibrillation (6.5%) or pulseless ventricular tachycardia (5.2%) while the initial pulseless rhythm was unknown in 11.9% of cases. Return of spontaneous circulation occurred in 73.6% but 68 (14.7%) had more than one arrest. The rate of survival to discharge was 40.7% overall; 37.3% with non-shockable rhythms, 33% with shockable rhythms and 64.3% with unknown presenting rhythms. ConclusionsMaternal survival at hospital discharge in this cohort was less than 50%, lower than rates reported in other epidemiological datasets. More research is required in maternal resuscitation science and translational medicine to continue to improve outcomes and understand maternal mortality.