Relationship between duration of prehospital resuscitation and favorable prognosis in ventricular fibrillation

Alterations in Respiratory Mechanics and Neural Respiratory Drive After Restoration of Spontaneous Circulation in a Porcine Model Subjected to Different Downtimes of Cardiac Arrest

Background

The potential alterations of respiratory pathophysiology after cardiopulmonary resuscitation (CPR) are relatively undefined. While untreated arrest is known to affect post–cardiopulmonary resuscitation circulation, whether it affects respiratory pathophysiology remains unclear. We aimed to investigate the post–cardiopulmonary resuscitation changes in respiratory mechanics and neural respiratory drive with varying delays (5 or 10 minutes) in the treatment of ventricular fibrillation (VF).

Methods and Results

Twenty‐six male Yorkshire pigs were used. Anesthetized pigs weighing 38±5 kg were randomized into 3 groups (n=10 each in the VF5 and VF10 groups, with VF kept untreated for 5 and 10 minutes, respectively, and n=6 in the sham group without VF). Defibrillation was attempted after 6 minutes of cardiopulmonary resuscitation. Pulse‐induced contour cardiac output, respiratory mechanics, diaphragmatic electromyogram, blood gas, lung imaging, and histopathology were evaluated for 12 hours. Significantly elevated mean root mean square of diaphragmatic electromyogram, transdiaphragmatic pressure, and minute ventilation were observed, but reduced minute ventilation/mean root mean square, dynamic pulmonary compliance, and Pao₂ were noted in both VF groups. Despite recovery of spontaneous breathing, the abnormalities in respiratory mechanics and neural respiratory drive, Pao₂, and extravascular lung water continued to last for >12 hours. The changes in imaging (P=0.027) and histopathology (P=0.012) were more severe in the VF10 group compared with the VF5 group.

Conclusions

There is an uncoupling between the respiratory center and ventilation after restoration of spontaneous circulation. Prolonged untreated arrest from cardiac arrest contributes to more serious alterations in lung pathophysiology.

Association between cardiopulmonary resuscitation duration and one-month neurological outcomes for out-of-hospital cardiac arrest: a prospective cohort study

Background

The duration of cardiopulmonary resuscitation (CPR) is an important factor associated with the outcomes for an out-of-hospital cardiac arrest. However, the appropriate CPR duration remains unclear considering pre- and in-hospital settings. The present study aimed to evaluate the relationship between the CPR duration (including both the pre- and in-hospital duration) and neurologically favorable outcomes 1-month after cardiac arrest.

Methods

Data were utilized from a prospective multi-center cohort study of out-of-hospital cardiac arrest patients transported to 67 emergency hospitals between January 2012 and March 2013 in the Kanto area of Japan. A total of 3,353 patients with out-of-hospital cardiac arrest (age ≥18 years) who underwent CPR by emergency medical service personnel and achieved the return of spontaneous circulation in a pre- or in-hospital setting were analyzed. The primary outcome was a 1-month favorable neurological outcome. Logistic regression analysis was performed to estimate the influence of cardiopulmonary resuscitation duration. The CPR duration that achieved a cumulative proportion >99% of cases with a 1-month neurologically favorable outcome was determined.

Results

Of the 3,353 eligible cases, pre-hospital return of spontaneous circulation was obtained in 1,692 cases (50.5%). A total of 279 (8.3%) cases had a 1-month neurologically favorable outcome. The CPR duration was significantly and inversely associated with 1-month neurologically favorable outcomes with adjustment for pre- and in-hospital confounders (adjusted odds ratio: 0.911, per minute, 95% CI: 0.892–0.929, p < 0.001). After 30 min of CPR, the probability of a 1-month neurologically favorable outcome decreased from 8.3 to 0.7%. At 45 min of CPR, the cumulative proportion for a 1-month neurologically favorable outcome reached >99%.

Conclusions

The CPR duration was independently and inversely associated with 1-month neurologically favorable outcomes after out-of-hospital cardiac arrest. The CPR duration required to achieve return of spontaneous circulation in >99% of out-of-hospital cardiac arrest patients with a 1-month favorable neurological outcome was 45 min, considering both pre- and in-hospital settings.

Impact of cardiopulmonary resuscitation duration on neurologically favourable outcome after out-of-hospital cardiac arrest: A population-based study in Japan

BACKGROUND

The optimal cardiopulmonary resuscitation (CPR) duration for patients with out-of-hospital cardiac arrest (OHCA) remains unclear. We aimed to assess the association between CPR duration and outcome after OHCA.

METHODS

This prospective, population-based observational study conducted in Osaka, Japan enrolled 6981 adult patients with non-traumatic witnessed OHCA who achieved return of spontaneous circulation (ROSC) from January 2005 through December 2012. CPR duration was defined as the time of CPR initiation by emergency medical service personnel to the ROSC in pre-hospital settings or after hospital admission. The primary outcome was one-month survival with neurologically favourable outcome (cerebral performance category scale 1 or 2).

RESULTS

Overall, median CPR duration was 25min (interquartile range: 15-34) and the proportion of neurologically favourable outcome was 12.5% (875/6,981). The proportion of neurologically favourable outcome among the CPR duration ≥31min group was significantly lower compared with that among the 0-5min group (55.1% [320/581] versus 2.2% [54/2424], adjusted odds ratio [AOR] 0.04; 95% confidence interval [CI] 0.03-0.05 in all patients, 78.4% [240/306] versus 11.4% [30/264], AOR 0.04; 95% CI 0.02-0.06 in the shockable group, 29.1% [80/275] versus 1.1% [24/2160], and AOR 0.03; 95% CI 0.02-0.05 in the non-shockable group). The cumulative proportion for neurologically favourable outcome reached 99% after 44, 41, and 43min of CPR in all patients, the shockable group, and the non-shockable group, respectively.

CONCLUSION

The proportion of patients with neurologically favourable outcome declined with increasing CPR duration, but some OHCA patients could benefit from prolonged CPR duration >30min.

Extracorporeal Life Support and New Therapeutic Strategies for Cardiac Arrest Caused by Acute Myocardial Infarction - a Critical Approach for a Critical Condition

This review summarizes the most recent developments in providing advanced supportive measures for cardiopulmonary resuscitation, and the results obtained using these new therapies in patients with cardiac arrest caused by acute myocardial infarction (AMI). Also detailed are new approaches such as extracorporeal cardiopulmonary resuscitation (ECPR), intra-arrest percutaneous coronary intervention, or the regional models for systems of care aiming to reduce the critical times from cardiac arrest to initiation of ECPR and coronary revascularization.

Duration of Prehospital Cardiopulmonary Resuscitation and Favorable Neurological Outcomes for Pediatric Out-of-Hospital Cardiac Arrests: A Nationwide, Population-Based Cohort Study

BACKGROUND

The appropriate duration of cardiopulmonary resuscitation (CPR) for pediatric out-of-hospital cardiac arrests (OHCAs) remains unclear and may differ based on initial rhythm. We aimed to determine the relationship between the duration of prehospital CPR by emergency medical services (EMS) personnel and post-OHCA outcomes.

METHODS

We analyzed the records of 12 877 pediatric patients who experienced OHCAs (<18 years of age). Data were recorded in a nationwide Japanese database between 2005 and 2012. Study end points were 30-day survival and 30-day survival with favorable neurological outcomes (Cerebral Performance Category [CPC] scale 1-2). Prehospital EMS-initiated CPR duration was defined as the time from CPR initiation by EMS personnel to prehospital return of spontaneous circulation (ROSC) or to hospital arrival when prehospital ROSC was not achieved during prehospital CPR efforts.

RESULTS

The rates of 30-day survival and 30-day CPC 1 to 2 were 9.1% (n=1167) and 2.5% (n=325), respectively. Prehospital EMS-initiated CPR duration was significantly and inversely associated with 30-day outcomes (adjusted odds ratio for 1-minute increments: 0.94, 95% confidence interval: 0.93-0.95 for survival; adjusted odds ratio: 0.90, 95% confidence interval: 0.88-0.92 for CPC 1-2). The duration of prehospital EMS-initiated CPR, beyond which the chance for favorable outcomes diminished to <1%, was 42 minutes for each key outcome, 30-day survival, and 30-day survival with CPC 1 to 2. When categorized by initial rhythm, the prehospital EMS-initiated CPR durations beyond which the chance for 30-day survival with CPC 1 to 2 diminished to <1% were 39 minutes for shockable rhythms, 42 minutes for pulseless electric activity, and 46 minutes for asystole, respectively. In patients with bystander-initiated CPR, the prehospital CPR duration, beyond which the chance for favorable outcome diminished to <1%, was 46 minutes from call receipt.

CONCLUSIONS

Prehospital EMS-initiated CPR duration for pediatric OHCAs was independently and inversely associated with 30-day favorable outcomes. The duration of prehospital EMS-initiated CPR, beyond which the chance for 30-day favorable outcomes diminished to <1%, was 42 minutes. However, the CPR duration to achieve this proportion of outcomes differed based on initial rhythm. Further research is required to elucidate appropriate CPR duration for pediatric OHCAs, including in-hospital CPR time.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifier: NCT02432196.

Relationship Between the Duration of Cardiopulmonary Resuscitation and Favorable Neurological Outcomes After Out-of-Hospital Cardiac Arrest: A Prospective, Nationwide, Population-Based Cohort Study

BACKGROUND

The determination of appropriate duration of in-the-field cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) patients is one of the biggest challenges for emergency medical service providers and clinicians. The appropriate CPR duration before termination of resuscitation remains unclear and may differ based on initial rhythm. We aimed to determine the relationship between CPR duration and post-OHCA outcomes.

METHODS AND RESULTS

We analyzed the records of 17 238 OHCA patients (age ≥18 years) who achieved prehospital return of spontaneous circulation. Data were prospectively recorded in a nationwide, Japanese database between 2011 and 2012. The time from CPR initiation to prehospital return of spontaneous circulation (CPR duration) was calculated. The primary end point was 1-month survival with favorable neurological outcomes (Cerebral Performance Category [CPC] scale; CPC 1-2). The 1-month CPC 1-2 rate was 21.8% (n=3771). CPR duration was inversely associated with 1-month CPC 1-2 (adjusted unit odds ratio: 0.95, 95% CI: 0.94-0.95). Among all patients, a cumulative proportion of >99% of 1-month CPC 1-2 was achieved with a CPR duration of 35 minutes. When sorted by the initial rhythm, the CPR duration producing more than 99% of survivors with CPC 1-2 was 35 minutes for shockable rhythms and pulseless electrical activity, and 42 minutes for asystole.

CONCLUSIONS

CPR duration was independently and inversely associated with favorable 1-month neurological outcomes. The critical prehospital CPR duration for OHCA was 35 minutes in patients with initial shockable rhythms and pulseless electrical activity, and 42 minutes in those with initial asystole.