EXPERIMENTAL PAPERA new device producing manual sternal compression with thoracic constraint for cardiopulmonary resuscitation☆,☆☆
Introduction
Only 2–5% of the 350,000 annual victims of sudden cardiac death (SCD) or out-of-hospital cardiac arrest due to sudden cardiac death survive to be discharged from the hospital.1 Of those that do survive, the vast majority suffer from the complications of anoxic encephalopathy, many are comatose or vegetative, and, of those who survive for more than a 6 months, few return to their pre-arrest normal daily activities.2, 3, 4 This poor outcome has been shown to be multi-factorial in origin. However, the two most important determinants of outcome are time to defibrillation (if ventricular fibrillation [VF] is the etiology of arrest) and the early administration of effective cardiopulmonary resuscitation (CPR).5 Early CPR is most commonly provided by trained citizens. Yet the public's reluctance to perform CPR and its declining effectiveness over time as currently practiced may limit its use and curtail dissemination of a potentially life saving intervention.6, 7, 8
A three-phase time-sensitive model for resuscitation after cardiac arrest has been described.9 The model emphasizes defibrillation in the first phase and artificial circulation, i.e., chest compressions, in the second phase. However, an increasing number of reports document the declining incidence of VF as the initially encountered cardiac arrest rhythm disturbance, even among instances of advanced rescuer witnessed cardiopulmonary collapse.10, 11, 12, 13 Patients with cardiac arrest not due to a ventricular arrhythmia now make the majority of victims of out-of-hospital cardiac arrest. The dismal outcome accompanying the appearance of post-countershock non-perfusing spontaneous cardiac rhythms (so-called pulseless electrical activity [PEA]) has been demonstrated and emphasized14, 15 and providing CPR and cardiac perfusion prior to electrical defibrillation has been shown to improve the outcome of VF arrest.16, 17 The latter two observations further emphasize the importance of effective CPR in life saving efforts. The use of effective CPR, the cornerstone of second phase, therefore assumes the role of the primary intervention in most victims.
The Post-resuscitative and initial Utility of Life Saving Efforts (PULSE) Conference, convened in 2000, represented a multi-agency initiative which defined five domains of resuscitation science, including translational studies and bioengineering.18 Mechanisms of generating greater blood flows during CPR and new mechanical devices and methods for securing maximal forward flow during cardiac arrest were included among high priority objectives.
A simple mechanical CPR device that can be applied rapidly and used easily by the lay person and advanced rescuers has obvious benefit in maximizing the likelihood of successful cardiac resuscitation. A simple device, manually operated and producing minimal user fatigue, may provide a means with which to overcome the lay public's demonstrated reluctance to perform CPR and improve the management of both ventricular fibrillation and other cardiac arrest rhythms.
Section snippets
The device
The LifeBelt™ CPR product is a simple mechanical device designed to provide a combination of circumferential thoracic and sternal compression force to generate blood flow during cardiac arrest (Figure 1). The device was designed primarily for use in the out-of-hospital environment by lay rescuers, emergency medical technicians, and paramedics. The initial specifications of the device include a three to one mechanical advantage for the operator, such that 40 lb of force will result in the
Angiographic studies
Contrast injections into the LV during VF produced opacity in the LV and left atrium, indicating mitral regurgitation (Figure 2a). During sternal depression (Figure 2b), the heart moved abruptly dorsally, the lower two-thirds of the LV cavity appeared to decrease in size on the lateral projection, and the aortic valve opened approximately 250 ms after maximal antero-posterior displacement of heart. Complete washout of the radiopaque medium was typically achieved after two or three sternal
Discussion
These preliminary studies demonstrated a primary mechanism for blood flow with the LifeBelt™ CPR device during cardiac arrest, defined optimal performance parameters for the device, and demonstrated efficacy for resuscitation from prolonged cardiac arrest and short-term survival.
Findings on ventriculography and aortography suggest that the LifeBelt™ functions largely as a “cardiac pump”. The circumferential thoracic strap incorporated into the device appears to function as a “thoracic
Acknowledgement
This study was supported, in part, by a grant from the National Institutes of Health, 1 R41 HL071378-01 A1.
References (25)
- et al.
Quality-of-life and formal functional testing of survivors of out-of-hospital cardiac arrest correlates poorly with traditional neurologic outcome scales
Ann Emerg Med
(1996) - et al.
Disagreeable physical characteristics affecting bystander CPR
Ann Emerg Med
(1989) - et al.
Basic CPR and AIDS. Are volunteer life-savers prepared for a storm?
Resuscitation
(1996) - et al.
Cardiac arrest witnessed by emergency medical services personnel: descriptive epidemiology, prodromal symptoms, and predictors of survival
Ann Emerg Med
(2000) - et al.
The incidence of out-of-hospital ventricular fibrillation in Helsinnki, Finland, from 1994–1999
Lancet
(2001) - et al.
Success changes the problem: why ventricular fibrillation is declining, why pulseless electrical activity is emerging, and what to do about it
Resuscitation
(2003) - et al.
Rhythm changes during resuscitation from ventricular fibrillation in relation to delay until defibrillation, number of shocks delivered and survival
Resuscitation
(1997) - et al.
Cardiopulmonary resuscitation with a novel chest compression device in a porcine model of cardiac arrest
J Am Coll Cardiol
(2004) - et al.
Improved hemodynamic performance with a novel chest compression device during treatment of in-hospital cardiac arrest
Resuscitation
(2004) - et al.
Decay in quality of closed-chest compressions over time
Ann Emerg Med
(1995)
The effect of rescuer fatigue on the quality of chest compressions
Resuscitation
Effect of rescuer fatigue on performance of continuous external chest compressions over 3 min
Resuscitation
Cited by (9)
Systematic review of the mechanisms driving effective blood flow during adult CPR
2014, ResuscitationCitation Excerpt :Specifically, a wide adjustable belt wraps around the patient's chest, allowing for downward compression of the sternum as well as lateral chest wall compression, thus spreading the force of compressions over a larger surface area of the chest. In an animal study 50, a significant increase in coronary perfusion pressure at 1- and 5-minute intervals and a greater level of end-tidal carbon dioxide at 1 min was reported with this device. However, in another study, the authors did not detect significant differences in neurologically intact survival between LifeBelt CPR and manual CPR 51.
Evolution and new perspective of chest compression mechanical devices
2008, American Journal of Emergency MedicineCitation Excerpt :Moreover, it was designed to lessen user fatigue [25,58]. Niemann et al [58], in an angiographic study of pigs (15 used LifeBelt and 14 S-CPR), reported that, with the use of the LifeBelt, there were significantly greater levels of CPP compared to S-CPR at 1 minute (15 ± 8 vs 10 ± 6 mm Hg, P < .05) and 5 minutes (17 ± 4 vs 13 ± 7 mm Hg, P < .02) of chest compression. Similarly, there were significantly greater levels of ETCO2 with LifeBelt compared to S-CPR (20 ± 7 vs 15 ± 75 mm Hg, respectively; P < .05) at 1 minute.
Cardiac arrest with continuous mechanical chest compression during percutaneous coronary intervention. A report on the use of the LUCAS device
2007, ResuscitationCitation Excerpt :Ballooning of the right ventricle is associated with compression of the interventricular septum during asystole and requires ongoing chest compression to empty the ventricle for effective defibrillation to occur.10 Diastolic aortic minus diastolic right atrial pressure is improved in experimental studies using mechanical devices such as the LifeBelt™.11 This may be explained by compression of the heart as demonstrated by angiography.
In this issue
2006, ResuscitationCatheterization laboratory activation during mechanical cardiopulmonary resuscitation: When should we say "no?"
2014, Catheterization and Cardiovascular Interventions
- ☆
Presented, in part, at the American Heart Association Resuscitation Science Symposium, November 5–6, 2004, New Orleans, LA.
- ☆☆
A Spanish translated version of the summary and keywords of this article appears as Appendix in the online version at 10.1016/j.resuscitation.2005.07.025.