AutoPulse
The AutoPulse is an automated, portable, battery-powered cardiopulmonary resuscitation device created by Revivant and subsequently purchased and currently manufactured by ZOLL Medical Corporation. It is a 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 professional health care providers. The AutoPulse uses a distributing band to deliver the chest compressions. In literature it is also known as LDB-CPR (Load Distributing Band-CPR).
The AutoPulse measures chest size and resistance before it delivers the unique combination of thoracic and cardiac chest compressions. The compression depth and force varies per patient. The chest displacement equals a 20% reduction in the anterior-posterior chest depth. The physiological duty cycle is 50%, and it runs in a 30:2 or continuous compression mode, which is user-selectable.
Contents |
[edit] 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, determines the patient's chest size and resistance, and proceeds to rhythmically constrict the entire rib cage, pumping the heart at a rate of 80 compressions per minute. The LifeBand can be placed over defibrillation pads but must be temporarily loosened to use standard paddle defibrillators and repositioned after the shock has been delivered. The LifeBand is disposable, and designed to be used on a single patient for sanitary reasons.
[edit] Mechanism of CPR blood flow
The load-distributing band system, employing thoracic compressions, produces higher blood flow compared to CPR consisting of sternal compressions only. The potential to produce blood flow for a sudden cardiac arrest victim is in large part determined by the peak power of the compression. Factors determining the power of the compression are the force of the compression, the depth of the compression, and the duration that the compression is held at maximum depth.
|
|
|
[edit] Studies 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.[1]
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.[2] 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.[3]
The device has shown less promise with human research. Although some studies showed improved coronary perfusion pressure[4] and more spontaneous return of circulation[5][6] with the AutoPulse, one large, multi-centered, randomized clinical trial[7] 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."[8]
The 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation give load-distributing band CPR (LDB-CPR) a Class IIb recommendation.[9]
| Class I | Definitely recommended. Supported by excellent evidence. |
| Class IIa | Acceptable and useful. Good to very good evidence provides support. |
| Class IIb | Acceptable and useful. Fair to good evidence provides support. |
| Class III | Unacceptable, no documented benefit, may be harmful. |
[edit] In the news
Mirror, a U.K. news website, on January 14, 2011, reports on Arun Bhasin, who 'came back from the dead' after 3 and a half hours. He was found unconscious and brought into Croydon University Hospital. He suffered a cardiac arrest and was placed on the AutoPulse, which performed almost 20,000 compressions, keeping his heart and lungs functioning while a medical team worked on him. After almost 3 and a half hours, his pulse returned.
CNN's Anderson Cooper 360° featured a story on April 6, 2010, about the Firehouse Subs Public Safety Foundation, in which Firehouse Subs founders Chris and Robin Sorensen met with Francisco Tuttle, a father who was saved by the Mt. Pleasant, SC, Fire Department using a ZOLL AutoPulse, which the Foundation donated to the department last year.
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.
[edit] Miscellaneous
On March 8, 2010 a Fire Department Captain put himself in the AutoPulse device and the device was turned on while he was giving an introduction of the device to a group of children. After providing two complete compressions, the device was turned off and the Fire Captain was released. A medical evaluation is pending.
[edit] References
- ^ ACLS: Principles and Practice. p. 62. Dallas: American Heart Association, 2003. ISBN 0-87493-341-2.
- ^ 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
- ^ 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.
- ^ Timmerman 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
- ^ Ornato 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. doi:10.1080/10903120590891714 PMID 16036830
- ^ Hallstrom 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
- ^ Lewis RJ and Niemann JT. "Manual vs Device-Assisted CPR: Reconciling Apparently Contradictory Results." JAMA 2006; 295: 2661-2664. PMID 16772632
- ^ 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care - Part 6: CPR Techniques and Devices Circulation 2005;112:IV-47 – IV-50. Accessed February 13, 2007.
[edit] External links
- AutoPulse Official Website
- 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.)
- LUCAS An alternative method for providing mechanical chest compressions.
