Elsevier

Resuscitation

Volume 85, Issue 6, June 2014, Pages 741-748
Resuscitation

Clinical Paper
Manual vs. integrated automatic load-distributing band CPR with equal survival after out of hospital cardiac arrest. The randomized CIRC trial,☆☆

https://doi.org/10.1016/j.resuscitation.2014.03.005Get rights and content

Abstract

Objective

To compare integrated automated load distributing band CPR (iA-CPR) with high-quality manual CPR (M-CPR) to determine equivalence, superiority, or inferiority in survival to hospital discharge.

Methods

Between March 5, 2009 and January 11, 2011 a randomized, unblinded, controlled group sequential trial of adult out-of-hospital cardiac arrests of presumed cardiac origin was conducted at three US and two European sites. After EMS providers initiated manual compressions patients were randomized to receive either iA-CPR or M-CPR. Patient follow-up was until all patients were discharged alive or died. The primary outcome, survival to hospital discharge, was analyzed adjusting for covariates, (age, witnessed arrest, initial cardiac rhythm, enrollment site) and interim analyses. CPR quality and protocol adherence were monitored (CPR fraction) electronically throughout the trial.

Results

Of 4753 randomized patients, 522 (11.0%) met post enrollment exclusion criteria. Therefore, 2099 (49.6%) received iA-CPR and 2132 (50.4%) M-CPR. Sustained ROSC (emergency department admittance), 24 h survival and hospital discharge (unknown for 12 cases) for iA-CPR compared to M-CPR were 600 (28.6%) vs. 689 (32.3%), 456 (21.8%) vs. 532 (25.0%), 196 (9.4%) vs. 233 (11.0%) patients, respectively. The adjusted odds ratio of survival to hospital discharge for iA-CPR compared to M-CPR, was 1.06 (95% CI 0.83–1.37), meeting the criteria for equivalence. The 20 min CPR fraction was 80.4% for iA-CPR and 80.2% for M-CPR.

Conclusion

Compared to high-quality M-CPR, iA-CPR resulted in statistically equivalent survival to hospital discharge.

Introduction

High-quality chest compressions (i.e., correct depth, rate, full release and high chest compression fraction) are emphasized by The International Liaison Committee on Resuscitation (ILCOR).1 Mechanical chest compression devices were developed to assist rescuers in giving consistent high-quality compressions.2, 3, 4 A mechanical chest compression device that uses a load distributing band (LDB) has been shown in animal and human studies to improve hemodynamic parameters over manual CPR (M-CPR).5, 6, 7, 8 Studies comparing LDB devices with M-CPR in the setting of out-of-hospital cardiac arrests (OHCA) have produced conflicting results.9, 10, 11, 12 Retrospective studies found improved outcomes,10, 11, 12 but one randomized controlled trial showed worse cerebral performance at hospital discharge in the LDB arm, and consequently the trial was terminated early.9

It is important to determine the role of mechanical CPR in prehospital resuscitation, as it could be a powerful adjunct in treating OHCA. It is unlikely that a CPR device will ever fully replace the need for manual compressions. However, if device compressions can be shown to be as safe and effective as manual compressions, then it could be used to assist providers when performing CPR. Therefore, there was a need for another randomized clinical trial comparing manual and integrated mechanical CPR, where a patient receives manual compressions while the mechanical device is deployed.

The randomized Circulation Improving Resuscitation Care (CIRC) Trial objective was to compare automated LDB-CPR integrated with manual CPR (iA-CPR) to high quality manual CPR (M-CPR), to determine equivalence, superiority, or inferiority in survival to hospital discharge after OHCA.

Section snippets

Methods

The CIRC methods and design including the statistical analysis plan have been previously published.13 CIRC was a randomized, controlled group sequential trial of adult OHCA of presumed cardiac origin conducted under exception from informed consent for emergency research and approved by the Institutional Review Boards (three US sites: Fox Valley Region, WI; Hillsborough County, FL; Houston, TX) or Ethics committee (two European sites: Vienna, Austria; Nijmegen, The Netherlands).13 Sites

Results

During the run-in phase data was collected for 621 patients. The first site began enrollment into the statistical inclusion phase on March 5, 2009. The equivalence stopping boundary was crossed at the 8th interim analysis and the last patient was enrolled on January 11, 2011. During the statistical inclusion phase, 9068 cardiac arrests occurred in the study communities, but 3987 did not meet the study inclusion criteria and 328 patients were missed for enrollment (Fig. 1). Post enrollment, 522

Discussion

The CIRC study demonstrated that iA-CPR is equivalent to high-quality M-CPR for survival to hospital discharge from OHCA of presumed cardiac origin. Neurologic outcome did not differ between strategies. There were slight differences between the unadjusted and adjusted OR for survival to hospital discharge. Adjustment for the interim analyses changed the OR from a small negative effect to a small positive effect. The reason for this is that the study was stopped when the iA-CPR arm had just

Authors’ contribution

LW oversaw development of the protocol and was responsible for the overall conduct of the trial. All authors contributed to protocol development. FS, RM, MB, PG, ML, DT, MW, DP, and CS oversaw data collection at each of the trial sites. JO oversaw the analysis of all electronic ECG files. AW, an academic statistician at Lancaster University, was responsible for the group sequential design and for conducting the primary and secondary statistical analyses. LW drafted the manuscript and all

Conflict of interest statement

UH is an employee of ZOLL which manufactures and sells the LDB device (AutoPulse). All other authors’ institutions received funding from ZOLL for their participation in the trial. The authors have no other relevant financial conflicts of interest to report.

Funding

This trial was funded by ZOLL Medical (the manufacturer of the study device), and all authors’ institutions received funding from ZOLL for their participation in the trial. ZOLL developed the CIRC trial protocol in consultation with the principal investigator, study investigators, staff at the data coordinating center, and the statistician (AW). Norwegian Center for Prehospital Emergency Care (NAKOS), Oslo University Hospital funded the PI during and after the study.

Acknowledgements

The authors would like to acknowledge the EMS providers who contributed to this study as well as other individuals who made this study possible. We would specifically like to thank the following people for their contributions to the project: CIRC management and operation: Trial manager Jeff Jensen, Trial coordinators Marcia Hefner, Colin Thomas; Central Data management: Brian Baker, Wave Engineering; Ronald Pirrallo MD, MHSA and Guy Gleisberg, BS, NR-EMT Medical College of Wisconsin. Fox Valley

References (35)

  • R.S. Hoke et al.

    Skeletal chest injuries secondary to cardiopulmonary resuscitation

    Resuscitation

    (2004)
  • F.S. Stecher et al.

    Transthoracic impedance used to evaluate performance of cardiopulmonary resuscitation during out of hospital cardiac arrest

    Resuscitation

    (2008)
  • G. Nichol et al.

    Consent in resuscitation trials: Benefit or harm for patients and society?

    Resuscitation

    (2006)
  • M. van Wely et al.

    AutoPulse facilitated resuscitation in out-of-hospital cardiac arrest as a bridge to coronary intervention

    Resuscitation

    (2011)
  • K. Omori et al.

    The analysis of efficacy for AutoPulse™ system in flying helicopter

    Resuscitation

    (2013)
  • D.A. Agarwal et al.

    Ventricular fibrillation in Rochester, Minnesota: experience over 18 years

    Resuscitation

    (2009)
  • M.R. Sayre et al.

    Adult basic life support chapter collaborators: Part 5. Adult basic life support: 2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

    Circulation

    (2010)
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    A Spanish translated version of the summary of this article appears as Appendix in the final online version at http://dx.doi.org/10.1016/j.resuscitation.2014.03.005.

    ☆☆

    Registration Name and Number: ClinicalTrials.gov Identifier: Circulation Improving Resuscitation Care (CIRC) NCT00597207.

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