Mechanical versus manual chest compressions in the treatment of in-hospital cardiac arrest patients in a non-shockable rhythm: a randomised controlled feasibility trial (COMPRESS-RCT)

Systematic analysis of approaches used in cardiac arrest trials to inform relatives about trial enrolment of non-surviving patients

BACKGROUND

The recruitment of patients to emergency research studies without the requirement for prior informed consent has furthered the conduct of randomised studies in cardiac arrest. Frameworks enabling this vary around the world depending on local legal or ethical requirements. When an enrolled patient does not survive, researchers may take one of three approaches to inform relatives of their enrolment: a direct (active) approach, providing information indirectly (passively) and inviting relatives to seek further information if they choose, or providing no information about the trial (no attempt). Previous studies have described experiences of US researchers' active approach but there is little known about approaches elsewhere.We aimed to conduct a structured investigation of methods used in cardiac arrest trials to provide information about trial enrolment to relatives of non-surviving patients.

METHODS

We systematically searched trial registries to identify randomised clinical trials that recruited cardiac arrest patients. Trials were eligible for inclusion if they recruited adults during cardiac arrest (or within 1 hour of return of spontaneous circulation) between 2010 and 2022 (in the decade prior to study conception). We extracted data from trial registries and, where relevant, published papers and protocols. Investigators were contacted and asked to describe the style, rationale and timing of approach to relatives of non-surviving patients. We present descriptive statistics.

RESULTS

Our trial registry search identified 710 unique trials, of which 108 were eligible for inclusion. We obtained information from investigators for 64 (62%) trials. Approximately equal numbers of trials attempted to actively inform relatives of non-survivors (n=28 (44% (95% CI; 31% to 57%))), or made no attempt (n=25 (39% (95% CI; 27% to 52%))). The remaining studies provided general information about the trial to relatives but did not actively inform them (n=11 (17% (95% CI; 8% to 29%))).

CONCLUSIONS

There is wide variability in the approach taken to informing relatives of non-surviving patients enrolled in cardiac arrest randomised clinical trials.

Mechanical versus manual chest compressions in the treatment of in-hospital cardiac arrest patients in a non-shockable rhythm: A multi-centre feasibility randomised controlled trial (COMPRESS-RCT)

BACKGROUND

Mechanical chest compression devices deliver high-quality chest compressions. Early data suggests that mechanical devices may be superior to manual chest compressions in adults following an in-hospital cardiac arrest patients. To determine the feasibility of undertaking an effectiveness trial in this population, we undertook a feasibility randomised controlled trial.

METHODS

We undertook a multi-centre parallel group feasibility randomised controlled trial (COMPRESS-RCT). Adult in-hospital cardiac arrest patients that were in a non-shockable rhythm were randomised in a 3:1 ratio to receive mechanical CPR (Jolfe AB/Stryker, Lund, Sweden) or ongoing manual CPR. Recruitment was led by the clinical cardiac arrest team. The primary study outcome was the proportion of eligible participants randomised in the study during site operational recruitment hours. Patients were enrolled under a model of deferred consent. We report data using descriptive statistics, point estimates and 95% confidence intervals.

RESULTS

Over a two-year period, we recruited 127 patients across five UK hospitals. We recruited 55.2% (95% CI 48.5%-61.8%) of eligible study participants in site operational recruitment hours. Most participants were male (n = 76, 59.8%) with a mean age of 72 (95% CI: 69.9-74.9) years. Median arrest duration was 18 (IQR 13-29) minutes. In patients randomised to mech-CPR, median time from CPR start to device deployment was 11 (IQR 7-15) minutes. ROSC was achieved in 27.6% (n = 35) participants and 4.7% (n = 6) were alive at 30-days.

CONCLUSION

COMPRESS-RCT identified important factors that preclude progression to an effectiveness trial of mechanical CPR in the hospital setting in the UK. Findings will inform the design of future in-hospital intra-arrest intervention trials. ISRCTN38139840, date of registration 9th January 2017.

Comparison of in-hospital use of mechanical chest compression devices for out-of-hospital cardiac arrest patients: AUTOPULSE vs LUCAS

This study aimed to investigate the prognostic difference between AUTOPULSE and LUCAS for out-of-hospital cardiac arrest (OHCA) adult patients.A retrospective observational study was performed nationwide. Adult OHCA patients after receiving in-hospital mechanical chest compression from 2012 to 2016 were included. The primary outcomes were sustained return of spontaneous circulation (ROSC) of more than 20 minutes and survival to discharge.Among 142,906 OHCA patients, 820 patients were finally included. In multivariate analysis, female (OR, 0.57; 95% CI, 0.33-0.99), witnessed arrest (OR, 2.10; 95% CI, 1.20-3.69), and arrest cause of non-cardiac origin (OR, 0.25; 95% CI, 0.10-0.62) were significantly associated with the increase in ROSC. LUCAS showed a lower survival than AUTOPULSE (OR, 0.23; 95% CI, 0.06-0.84), although it showed no significant association with ROSC. Percutaneous coronary intervention (OR, 6.30; 95% CI, 1.53-25.95) and target temperature management (TTM; OR, 7.30; 95% CI, 2.27-23.49) were the independent factors for survival. We categorized mechanical CPR recipients by witness to compare prognostic effectiveness of AUTOPULSE and LUCAS. In the witnessed subgroup, female (OR, 0.46; 95% CI, 0.24-0.89) was a prognostic factor for ROSC and shockable rhythm (OR, 5.04; 95% CI, 1.00-25.30), percutaneous coronary intervention (OR, 12.42; 95% CI, 2.04-75.53), and TTM (OR, 9.03; 95% CI, 1.86-43.78) for survival. In the unwitnessed subgroup, no prognostic factors were found for ROSC, and TTM (OR, 99.00; 95% CI, 8.9-1100.62) was found to be an independent factor for survival. LUCAS showed no significant increase in ROSC or survival in comparison with AUTOPULSE in both subgroups.The in-hospital use of LUCAS may have a deleterious effect for survival compared with AUTOPULSE.