Clinical paperOut-of-hospital cardiopulmonary resuscitation with the AutoPulse™ system: A prospective observational study with a new load-distributing band chest compression device☆
Introduction
During cardiopulmonary resuscitation (CPR), adequate perfusion of the heart and the brain is needed to reestablish spontaneous circulation and to achieve survival with a good neurological outcome. If manual chest compressions are performed during CPR, the blood flow to the “vital organs” is generally impaired. Even if trained health personnel provides manual CPR, the blood flow in the brain is reduced to approximately 30–40% of the normal blood supply and in the heart to 10–20%.1 Vital organ blood flow may be even more reduced if the quality of the manual chest compressions is inadequate, because of incorrect compression rate or depth, or frequent interruptions. Suboptimal chest compressions correlate with a poor return of spontaneous circulation,2, 3 and interruptions to chest compression-generated blood flow are detrimental.4, 5 Improved survival of patients with out-of-hospital cardiac arrest was recently reported by Kellum et al. using a CPR protocol minimising the rate of interruptions of chest compressions.6 A potential solution to overcome the difficulties of suboptimal chest compressions and CPR interruptions may be the use of automated mechanical CPR devices.
The first mechanical CPR device introduced to clinical and preclinical application, the “Thumper” (Michigan Instruments, USA), was a mechanical chest compressor using a piston driven by pressurised air and it has been used since the late 1970s.7 Since then, various devices have been developed. In the present study, the AutoPulse™ system (Zoll Circulation, Chelmsford, MA, USA), a recently introduced device, has been assessed in a prospective observational trial in an urban emergency system. The AutoPulse™ is a fully automated CPR device that uses a load-distributing, broad compression band that is applied across the entire anterior chest. Previous animal and human studies demonstrated an improvement of haemodynamics and short term outcome using the AutoPulse™ technique compared to standard CPR performed by manual chest compressions or using the Thumper.8, 9, 10, 11 In the present observational study, resuscitation success rate was determined by achievement of the return of spontaneous circulation (ROSC), subsequent haemodynamics during AutoPulse™-CPR and long term outcome of the patients. Since invasive monitoring of patients with out-of-hospital cardiac arrest is not feasible, we used end-tidal carbon-dioxide (etCO2) as an indirect measurement of cardiac output.12 The patients admitted to an intensive care unit were visited daily for the first 3 days after admittance, and the hospital was regularly called until discharge or death. At discharge, the neurological state was evaluated by the attending physician using the Glasgow–Pittsburgh cerebral performance category (CPC), and 6 months after discharge, the patients or the relatives were called again for information about their further recovery.
Section snippets
Study design
The study was approved by the ethical committee of the University of Bonn. We conducted a prospective observational study with the new chest compression device AutoPulse™ on out-of-hospital cardiac arrest patients in the EMS system of Bonn city. Inclusion criteria for the study were aged 18–85 years, and cardiac arrest of non-traumatic origin. Pregnant patients were excluded. The decision to apply the AutoPulse™ system was made individually by the emergency doctors at the scene. Patients
Patients, cardiac arrest, and CPR characteristics
The study was performed in the EMS system of Bonn from September 2004 until May 2005. During this period, the AutoPulse™ was applied in 46 patients during CPR. The patients demographic data such as mean age, sex, and mean weight are given in Table 1. In patients resuscitated with the AutoPulse™, 63.0% of the cases cardiac arrest was witnessed, and in 30.4% bystander CPR was performed (Table 1). The initial ECG-rhythm was asystole in 52.2%, ventricular fibrillation or ventricular tachycardia in
Discussion
We performed a prospective observational preclinical study with the new load-distributing band chest compression device AutoPulse™ (Revivant Corporation, Sunnyvale, CA, USA) in the EMS system of Bonn city. Primary goals of the study were to verify the effectiveness, safety, and practicability of the automated mechanical resuscitation device in out-of-hospital cardiac arrest. The effectiveness was shown by the number of patients with ROSC and by the measurement of end-tidal CO2 during CPR. The
Conclusions
In conclusion, we presented operating experience and resuscitation success and survival rates after out-of-hospital cardiac arrest cardiopulmonary resuscitation with the new load-distributing band chest compression device AutoPulse™. In our observational preclinical study, the AutoPulse™ system proved to be an effective and safe mechanical CPR device for use in out-of-hospital cardiac arrest CPR. Automated CPR devices may play an increasingly important role in CPR in the future because they
Conflict of interest
The authors confirm that they have no financial interest in Zoll Circulation or other conflict of interest in performing the presented study.
Acknowledgements
We would like to thank the emergency doctors of the University Clinics of Bonn and the staff of the emergency medical system of Bonn for cooperation in our study.
References (25)
Coronary perfusion pressure during cardiopulmonary resuscitation
Baillieres Clin Anesth
(2000)- et al.
Cardiocerebral resuscitation improves survival of patients with out-of-hospital cardiac arrest
Am J Med
(2006) - et al.
Improved hemodynamic performance with a novel chest compression device during treatment of in-hospital cardiac arrest
Resuscitation
(2004) - et al.
Cardiopulmonary resuscitation with a novel chest compression in a porcine model of cardiac arrest: improved hemodynamics and mechanisms
J Am Coll Cardiol
(2004) - et al.
Augmentation of tissue perfusion by a novel compression device increases neurologically intact survival in a porcine model of prolonged cardiac arrest
Resuscitation
(2006) - et al.
The relationship between airway carbon dioxide excretion and cardia output during cardiopulmonary resuscitation
Resuscitation
(1997) - et al.
Influence of early defibrillation on the survival rate and the quality of life after CPR in prehospital emergency medical service in a German metropolitan area
Resuscitation
(2002) - et al.
Evaluation of LUCAS, a new device for automatic mechanical compression and active decompression resuscitation
Resuscitation
(2002) - et al.
Chest compression rates during cardiopulmonary resuscitation are suboptimal. A prospective study during in-hospital cardiac arrest
Circulation
(2005) - et al.
Quality of cardiopulmonary resuscitation during in-hospital cardiac arrest
JAMA
(2005)
Interruptions of chest compressions during emergency medical system resuscitation
Circulation
Importance of continuous chest compressions during cardiopulmonary resuscitation. Improved outcome during a simulated single lay-rescuer scenario
Circulation
Cited by (67)
Intact survival from a blunt trauma cardiac arrest using intraoperative automated CPR
2023, Trauma Case ReportsLoad distributing band device for mechanical chest compressions: An Utstein-categories based analysis of survival to hospital discharge
2019, International Journal of CardiologyCitation Excerpt :The first demonstrated a non-significant trend towards negative results while the second reached similar hospital discharge between LDB and high-quality manual CPR. In addition, there are four observational studies [8–10,12] with different end-points (ROSC for the first one and survival to discharge for the others) and different methodology: comparison with an historical control group [9], comparison with case-matched control group [8,12] or without a control group [10]. Concerning meta-analysis [16–19], only two [18,19] assessed separately the role of piston driven device and of LDB device in term of ROSC and survival to hospital discharge showing conflicting results: a neutral effect in the former and a negative result for LDB in the latter in term of survival with good neurological outcome.
A Review of Carbon Dioxide Monitoring During Adult Cardiopulmonary Resuscitation
2015, Heart Lung and CirculationSystematic review of the mechanisms driving effective blood flow during adult CPR
2014, ResuscitationCitation Excerpt :Other advantages include the consistent chest compression rate and depth, the decreased interruptions in CPR, and the elimination of rescuer fatigue. However, research so far has given inconsistent results regarding the clinical value of this device 53,54, although this device is currently being used clinically in the United States. Although ventilation is required to maintain gas exchange during CPR, particularly in prolonged resuscitation efforts, increased evidence suggest that it may be harmful when excessive or when chest compressions are interrupted both prior and after the onset of CPR.
- ☆
A Spanish translated version of the summary of this article appears as Appendix in the final online version at 10.1016/j.resuscitation.2006.08.027.