lucasWhen talking about Out of Hospital Cardiac Arrest (OHCA) there are really only three things that make a true difference on outcomes (i.e. survival and neurologic function):

  • High quality, non-interrupted CPR
  • Early defibrillation
  • Therapeutic hypothermia

The quality of CPR is often under appreciated and performed incorrectly (too slow and/or not hard enough).  With mechanical CPR, chest compressions are delivered uninterrupted and at a predefined depth and rate. In my own practice I have seen these devices being used more and more, but my questions is do these devices impact outcomes?

How good are we at maintaining an optimal rate of 100/min during manual CPR? 1

  • 97 arrests
  • 36.9% had a compression rate of <80/minute
  • 21.7% had a compression rate of < 70/minute
  • Higher compression rates correlated with ROSC
  • Conclusion:  Manual compression rates are often suboptimal and correlate with poor likelihood of ROSC

So what is the evidence for mechanical vs manual CPR?

1. Cochrane Review (January 2011) 2

  • 4 trials (868 patients)
  • Conclusion: Insufficient evidence from human RCTs to conclude that mechanical chest compressions are associated with benefit or harm

2. Mannequin Study (February 2013) 2

  • Mechanical CPR using Lund University Cardiac Assist System (LUCAS) versus manual CPR by 25 paramedics on manikins
  • Correct chest compressions: LUCAS (99%) vs manual (59%)
  • Correct depth of chest compressions: LUCAS (99%) vs manual (79%)
  • Hands off time: LUCAS (46 sec) vs manual (130 sec)
  • Time to defibrillation: LUCAS (112 sec) vs manual (49 sec)
  • Conclusion:  Mechanical CPR improves quality of CPR and hands on time, but prolongs the time to first defibrillation

3. Largest Meta-Analysis (July 2013) 3

Screen Shot 2013-10-20 at 12.45.28 AMScreen Shot 2013-10-20 at 12.45.36 AM

  • 12 studies with 6,538 patients
  • Primary Outcome: OR of ROSC
  • OR of Piston Driven-CPR (PD-CPR) and Load Distributing Band-CPR (LDB-CPR) vs manual-CPR (M-CPR)
  • Conclusion: Load distributing band (LDB) mechanical compression devices significantly improved the likelihood of ROSC when compared with manual chest compression devices, but still need to be tested in larger RCTs

Final Thoughts

Currently, there are two randomized control studies underway: CIRC Autopulse Clinical Trial and LINC study trying to answer the ultimate question… Does mechanical CPR in OHCA improve survival to discharge and neurologic status?

Abella B, Sandbo N, Vassilatos P, et al. Chest compression rates during cardiopulmonary resuscitation are suboptimal: a prospective study during in-hospital cardiac arrest. Circulation. 2005;111(4):428-434. [PubMed]
Putzer G, Braun P, Zimmermann A, et al. LUCAS compared to manual cardiopulmonary resuscitation is more effective during helicopter rescue-a prospective, randomized, cross-over manikin study. Am J Emerg Med. 2013;31(2):384-389. [PubMed]
Westfall M, Krantz S, Mullin C, Kaufman C. Mechanical versus manual chest compressions in out-of-hospital cardiac arrest: a meta-analysis. Crit Care Med. 2013;41(7):1782-1789. [PubMed]
Salim Rezaie, MD

Salim Rezaie, MD

ALiEM Associate Editor Clinical Assistant Professor of EM and IM University of Texas Health Science Center at San Antonio Founder, Editor, Author of R.E.B.E.L. EM and REBEL Reviews