AutoPulse

The AutoPulse is an automated cardiopulmonary resuscitation machine created by Revivant and subsequently purchased by ZOLL. It is a circumferential chest compression device composed of a constricting band and half backboard that is intended to be used as an adjunct to CPR during advanced cardiac life support by paramedics. The 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation give load-distributing band CPR (LDB-CPR) a Class IIb recommendation. [2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care - [http://circ.ahajournals.org/cgi/content/full/112/24_suppl/IV-47 Part 6: CPR Techniques and Devices] "Circulation" 2005;112:IV-47 – IV-50. Accessed February 13, 2007.]

Device operation

The patient's head, shoulders and upper back lay upon the base unit, with the controls for the AutoPulse beside the patient's left ear. It can be augmented for cervical spinal support. The unit contains the control computer, the rechargeable battery, and the motors that operate the LifeBand. The LifeBand is an adjustable strap that covers the entire rib cage. When the patient (who must be disrobed) is strapped in and the start button is pressed, the LifeBand pulls tight around the chest and proceeds to rhythmically constrict the entire rib cage, compressing and pumping the heart at a rate of 80 beats per minute equivalent. The LifeBand can be placed over AED pads but must be taken off to use standard paddle defibrillators. The LifeBand is disposable, and designed to be used on a single patient for sanitary reasons.

tudies and clinical trials

The gold standard for resuscitation research is "survival to hospital discharge". Although common sense suggests that short-term and intermediate outcomes like "return of spontaneous circulation (ROSC)" or "survival to hospital admission" are promising, experienced scientists know that anything less than a neurologically intact survivor walking out of the hospital is ultimately irrelevant."ACLS: Principles and Practice". p. 62. Dallas: American Heart Association, 2003. ISBN 0-87493-341-2.]

Several animal studies have shown that automated CPR machines are more effective at providing circulatory support than manual CPR. One study showed that use of the AutoPulse produced blood flow to the heart and brain that was comparable to pre-arrest levels.Halperin HR, Paradis N, Ornato JP, et al. "Cardiopulmonary resuscitation with a novel chest compression device in a porcine model of cardiac arrest: improved hemodynamics and mechanisms." "J Am Coll Cardiol" 2004; 44(11): 2214-20. PMID 15582320] In another study, an adapted AutoPulse was shown to be highly effective in support of cardiac arrest in animals, whereas manual CPR was tenuous in its effectiveness. Pigs were used in the study, and were left in cardiac arrest for eight minutes to simulate average ambulance response time. 73% of the pigs that were put into the AutoPulse were revived, and 88% of the surviving pigs showed no neurological damage. None of the pigs that received manual CPR survived. [Ikeno F, Lyons J, Kaneda H, Hongo Y, Emami S, Chiistine N, Rezaee M. Improved survival with a novel chest compression device in a porcine model of cardiac arrest. Circulation. 2003; 108: IV–381. Abstract.]

The device has shown less promise with human research. Although some studies showed improved coronary perfusion pressureTimmerman S, Cardoso LF, Ramires JA, et al. "Improved hemodynamic performance with a novel chest compression device during treatment of in-hospital cardiac arrest." "Resuscitation" 2004; 61(3): 273-80. PMID 15172705] and more spontaneous return of circulationOrnato JP et al. " Improvement in field return of spontaneous circulation using circumferential chest compression cardiopulmonary resuscitation." "Prehosp Emerg Care" 2005; 9(1): 104.] Casner M, Andersen D, and Isaacs SM. "The impact of a new CPR assist device on rate of return of spontaneous circulation in out-of-hospital cardiac arrest." "Prehosp Emerg Care" 2005; 9(1): 61-7. PMID 16036830] with the AutoPulse, one large, multi-centered, randomized clinical trialHallstrom A, Rea TD, Sayre MR et al. "Manual chest compression vs use of an automated chest compression device during resuscitation following out-of-hospital cardiac arrest: a randomized trial." "JAMA" 2006; 295: 2620-2628. PMID 16772625] was canceled early by the Institutional Review Board (IRB) when it was determined that patients who received manual CPR were more likely to walk out of the hospital, suggesting that enthusiasm for the device "is premature, given that the effectiveness of the device likely depends on still-to-be-defined factors independent of the mechanical capabilities of the device."Lewis RJ and Niemann JT. "Manual vs Device-Assisted CPR: Reconciling Apparently Contradictory Results." "JAMA" 2006; 295: 2661-2664. PMID 16772632]

AutoPulse in the news

ABC World News Tonight on May 19, 2005, did a story on automated CPR machines, and profiled the story of Caralee Welch, who survived thirty minutes of cardiac arrest during which the AutoPulse was used. She had a heart attack in front of a theatre, but even after a half-hour of no heartbeat, with AutoPulse's help she ultimately recovered with no apparent brain damage.

References

External links

* [http://www.zoll.com/product.aspx?id=84 AutoPulse] Official Website
* [http://abcnews.go.com/WNT/Health/story?id=953534&page=1 CPR Machine Proves More Effective Than Paramedics] from ABCNews.com (It does not mention AutoPulse by name, but her story is also profiled on the AutoPulse website.)
* [http://www.lucas-cpr.com/ LUCAS] An alternative method for providing mechanical chest compressions.