Clinical outcomes following out-of-hospital cardiac arrest: The minute-by-minute impact of bystander cardiopulmonary resuscitation

Global Sex Disparities in Bystander Cardiopulmonary Resuscitation After Out-of-Hospital Cardiac Arrest: A Scoping Review

This scoping review collates evidence for sex biases in the receipt of bystander cardiopulmonary resuscitation (BCPR) among patients with out-of-hospital cardiac arrest patients globally. The MEDLINE, PsycINFO, CENTRAL, and Embase databases were screened for relevant literature, dated from inception to March 9, 2022. Studies evaluating the association between BCPR and sex/gender in patients with out-of-hospital cardiac arrest, except for pediatric populations and cardiac arrest cases with traumatic cause, were included. The review included 80 articles on BCPR in men and women globally; 58 of these studies evaluated sex differences in BCPR outcomes. Fifty-nine percent of the relevant studies (34/58) indicated that women are less likely recipients of BCPR, 36% (21/58) observed no significant sex differences, and 5% (3/58) reported that women are more likely to receive BCPR. In other studies, women were found to be less likely to receive BCPR in public but equally or more likely to receive BCPR in residential settings. The general reluctance to perform BCPR on women in the Western countries was attributed to perceived frailty of women, chest exposure, pregnancy, gender stereotypes, oversexualization of women's bodies, and belief that women are unlikely to experience a cardiac arrest. Most studies worldwide indicated that women were less likely to receive BCPR than men. Further research from non-Western countries is needed to understand the impact of cultural and socioeconomic settings on such biases and design customized interventions accordingly.

Racial and ethnic disparities in bystander resuscitation for out-of-hospital cardiac arrests

INTRODUCTION

Bystander-provided cardiopulmonary resuscitation (CRP) influences the survival rates of out-of-hospital cardiac arrests (OHCAs). Disparities on bystander resuscitation measures between Black, Hispanic, Asians and Non-Hispanic White OHCAs is unclear. Examining racial and ethnic differences in bystander resuscitations is essential to better target interventions.

METHODS

15,542 witnessed OHCAs were identified between April 1, 2011, and June 30, 2015 using the Resuscitation Outcomes Consortium Epidemiologic Registry 3, a multi-center, controlled trial about OHCAs in the United States and Canada. Multivariable logistic regression model was used to analyze the differences in bystander resuscitation (bystander CRP [B-CPR], CPR plus ventilation, automated external defibrillators/defibrillator application [B-AED/D], or delivery of shocks) and clinical outcomes (death at the scene or en route, return of spontaneous circulation upon first arrival at the emergency department [ROSC-ED], survival until ED discharge [S-ED], survival until hospital discharge [S-HOS], and favorable neurological outcome at discharge) between Black, Hispanic, or Asian victims and Non-Hispanic White victims.

RESULTS

Compared to OHCA victims in Non-Hispanic Whites, Black, Hispanic, and Asians were less likely to receive B-CPR (adjusted OR: 0.79; 95 % CI: 0.63-0.99), and B-AED/D (adjusted OR: 0.80; 95 % CI: 0.65-0.98) in public locations. And, Black, Hispanic, and Asian OHCAs were less likely to receive bystander resuscitation in street/highway locations and public buildings, and less likely to have better clinical outcomes, including ROSC-ED, S-ED and S-HOS.

CONCLUSION

Black, Hispanic and Asian victims with witnessed OHCAs are less likely to receive bystander resuscitation and more likely to get worse outcomes than Non-Hispanic White victims.

A quantitative evaluation of aerosol generation during cardiopulmonary resuscitation

It is unclear if cardiopulmonary resuscitation is an aerosol-generating procedure and whether this poses a risk of airborne disease transmission to healthcare workers and bystanders. Use of airborne transmission precautions during cardiopulmonary resuscitation may confer rescuer protection but risks patient harm due to delays in commencing treatment. To quantify the risk of respiratory aerosol generation during cardiopulmonary resuscitation in humans, we conducted an aerosol monitoring study during out-of-hospital cardiac arrests. Exhaled aerosol was recorded using an optical particle sizer spectrometer connected to the breathing system. Aerosol produced during resuscitation was compared with that produced by control participants under general anaesthesia ventilated with an equivalent respiratory pattern to cardiopulmonary resuscitation. A porcine cardiac arrest model was used to determine the independent contributions of ventilatory breaths, chest compressions and external cardiac defibrillation to aerosol generation. Time-series analysis of participants with cardiac arrest (n = 18) demonstrated a repeating waveform of respiratory aerosol that mapped to specific components of resuscitation. Very high peak aerosol concentrations were generated during ventilation of participants with cardiac arrest with median (IQR [range]) 17,926 (5546-59,209 [1523-242,648]) particles.l-1 , which were 24-fold greater than in control participants under general anaesthesia (744 (309-2106 [23-9099]) particles.l-1 , p < 0.001, n = 16). A substantial rise in aerosol also occurred with cardiac defibrillation and chest compressions. In a complimentary porcine model of cardiac arrest, aerosol recordings showed a strikingly similar profile to the human data. Time-averaged aerosol concentrations during ventilation were approximately 270-fold higher than before cardiac arrest (19,410 (2307-41,017 [104-136,025]) vs. 72 (41-136 [23-268]) particles.l-1 , p = 0.008). The porcine model also confirmed that both defibrillation and chest compressions generate high concentrations of aerosol independent of, but synergistic with, ventilation. In conclusion, multiple components of cardiopulmonary resuscitation generate high concentrations of respiratory aerosol. We recommend that airborne transmission precautions are warranted in the setting of high-risk pathogens, until the airway is secured with an airway device and breathing system with a filter.

Impact of "basic life support & defibrillation" training on quality of telephone-assisted cardiopulmonary resuscitation

While telephone-assisted cardiopulmonary resuscitation (T-CPR) is crucial for improving the chances of survival during cardiac arrest, there is limited information available on the effectiveness of T-CPR when administered by laypeople, especially those who are unfamiliar with these procedures. Therefore, we assessed the influence of basic life support and defibrillation (BLSD) training on the proficiency of T-CPR carried out by volunteer medical students participating in a BLSD course, using a simulated cardiac arrest scenario. The quality of T-CPR maneuvers was compared before and after the BLSD course. The results highlight the positive impact of BLSD training, significantly enhancing the quality of T-CPR and bringing it close to optimal levels.

Characteristics and Treatment Outcomes of Out-of-Hospital Cardiac Arrests Occurring in Public Places: A National Population-Based Observational Study

Sudden cardiac arrest, particularly out-of-hospital cardiac arrest (OHCA), is a global public health concern. However, limited research exists on the epidemiology of OHCAs occurring in public places, trends and impact of bystander intervention, and influence of extraordinary circumstances. This study investigated the epidemiological factors, bystander characteristics, and outcomes of OHCAs that occurred in public places in South Korea from 2016 to 2021 and analyzed the impact of the coronavirus disease 2019 (COVID-19) pandemic. A retrospective analysis was conducted using an Out-of-Hospital Cardiac Arrest Surveillance database, including 33,206 cases of OHCA that occurred in public places. Cases with do-not-resuscitate orders or insufficient data were excluded. A steady increase in bystander-performed cardiopulmonary resuscitation over the years and a constant decrease in bystander automated external defibrillator (AED) use were observed. Survival-to-discharge rates for OHCAs remained relatively steady until a marginal decrease was observed during the pandemic (pandemic, 13.1%; pre-pandemic, 14.4%). Factors affecting survival included the presence of a shockable rhythm, witnessed arrest, cardiac arrest due to disease, use of bystander AED, and period relative to the COVID-19 pandemic. These findings emphasize the critical role of bystanders in outcomes of OHCAs and inform public health strategies on better management of OHCAs in public places.