Article

Effects of compression depth and pre-shock pauses predict defibrillation failure during cardiac arrest

University of Chicago, Chicago, Illinois, United States
Resuscitation (Impact Factor: 3.96). 12/2006; 71(2):137-45. DOI: 10.1016/j.resuscitation.2006.04.008
Source: PubMed

ABSTRACT Cardiopulmonary resuscitation (CPR) and electrical defibrillation are the primary treatment options for ventricular fibrillation (VF). While recent studies have shown that providing CPR prior to defibrillation may improve outcomes, the effects of CPR quality remain unclear. Specifically, the clinical effects of compression depth and pauses in chest compression prior to defibrillation (pre-shock pauses) are unknown.
A prospective, multi-center, observational study of adult in-hospital and out-of-hospital cardiac resuscitations was conducted between March 2002 and December 2005. An investigational monitor/defibrillator equipped to measure compression characteristics during CPR was used.
Data were analyzed from 60 consecutive resuscitations in which a first shock was administered for VF. The primary outcome was first shock success defined as removal of VF for at least 5s following defibrillation. A logistic regression analysis demonstrated that successful defibrillation was associated with shorter pre-shock pauses (adjusted odds ratio 1.86 for every 5s decrease; 95% confidence interval 1.10-3.15) and higher mean compression depth during the 30s of CPR preceding the pre-shock pause (adjusted odds ratio 1.99 for every 5mm increase; 95% confidence interval 1.08-3.66).
The quality of CPR prior to defibrillation directly affects clinical outcomes. Specifically, longer pre-shock pauses and shallow chest compressions are associated with defibrillation failure. Strategies to correct these deficiencies should be developed and consideration should be made to replacing current-generation automated external defibrillators that require long pre-shock pauses for rhythm analysis.

0 Followers
 · 
192 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In CPR, sufficient compression depth is essential. The American Heart Association ("at least 5cm", AHA-R) and the European Resuscitation Council ("at least 5cm, but not to exceed 6cm", ERC-R) recommendations differ, and both are hardly achieved. This study aims to investigate the effects of differing target depth instructions on compression depth performances of professional and lay-rescuers. 110 professional-rescuers and 110 lay-rescuers were randomized (1:1, 4 groups) to estimate the AHA-R or ERC-R on a paper sheet (given horizontal axis) using a pencil and to perform chest compressions according to AHA-R or ERC-R on a manikin. Distance estimation and compression depth were the outcome variables. Professional-rescuers estimated the distance according to AHA-R in 19/55 (34.5%) and to ERC-R in 20/55 (36.4%) cases (p=0.84). Professional-rescuers achieved correct compression depth according to AHA-R in 39/55 (70.9%) and to ERC-R in 36/55 (65.4%) cases (p=0.97). Lay-rescuers estimated the distance correctly according to AHA-R in 18/55 (32.7%) and to ERC-R in 20/55 (36.4%) cases (p=0.59). Lay-rescuers yielded correct compression depth according to AHA-R in 39/55 (70.9%) and to ERC-R in 26/55 (47.3%) cases (p=0.02). Professional and lay-rescuers have severe difficulties in correctly estimating distance on a sheet of paper. Professional-rescuers are able to yield AHA-R and ERC-R targets likewise. In lay-rescuers AHA-R was associated with significantly higher success rates. The inability to estimate distance could explain the failure to appropriately perform chest compressions. For teaching lay-rescuers, the AHA-R with no upper limit of compression depth might be preferable. Copyright © 2015. Published by Elsevier Ireland Ltd.
    Resuscitation 02/2015; 89. DOI:10.1016/j.resuscitation.2015.01.031 · 3.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Chest compression (CC) is a significant emergency medical procedure for maintaining circulation during cardiac arrest. Although CC produces the necessary blood flow for patients with heart arrest, improperly deep CC will contribute significantly to the risk of chest injury. In this paper, an optimal CC closed-loop controller for a mechanical chest compressor (OCC-MCC) was developed to provide an effective trade-off between the benefit of improved blood perfusion and the risk of ribs fracture. The trade-off performance of the OCC-MCC during real automatic mechanical CCs was evaluated by comparing the OCC-MCC and the traditional mechanical CC method (TMCM) with a human circulation hardware model based on hardware simulations. A benefit factor (BF), risk factor (RF) and benefit versus risk index (BRI) were introduced in this paper for the comprehensive evaluation of risk and benefit. The OCC-MCC was developed using the LabVIEW control platform and the mechanical chest compressor (MCC) controller. PID control is also employed by MCC for effective compression depth regulation. In addition, the physiological parameters model for MCC was built based on a digital signal processor for hardware simulations. A comparison between the OCC-MCC and TMCM was then performed based on the simulation test platform which is composed of the MCC, LabVIEW control platform, physiological parameters model for MCC and the manikin. Compared with the TMCM, the OCC-MCC obtained a better trade-off and a higher BRI in seven out of a total of nine cases. With a higher mean value of cardiac output (1.35 L/min) and partial pressure of end-tidal CO2 (15.7 mmHg), the OCC-MCC obtained a larger blood flow and higher BF than TMCM (5.19 vs. 3.41) in six out of a total of nine cases. Although it is relatively difficult to maintain a stable CC depth when the chest is stiff, the OCC-MCC is still superior to the TMCM for performing safe and effective CC during CPR. The OCC-MCC is superior to the TMCM in performing safe and effective CC during CPR and can be incorporated into the current version of mechanical CC devices for high quality CPR, in both in-hospital and out-of-hospital CPR settings.
    Medical & Biological Engineering & Computing 03/2015; DOI:10.1007/s11517-015-1258-y · 1.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hintergrund Rasche Erste-Hilfe-Maßnahmen haben einen entscheidenden Effekt auf das Überleben eines Patienten mit einem Atem-Kreislauf-Stillstand. Ob eine Unterstützung mit akustischen Anweisungen die Qualität der Herz-Lungen-Wiederbelebung durch Ersthelfer steigert, ist nicht ausreichend untersucht. Material und Methoden 110 Probanden wurden mit der fiktiven Situation eines Atem-Kreislauf-Stillstandes konfrontiert. Die Probanden wurden in eine Testgruppe und eine Kontrollgruppe randomisiert. Die Probanden der Testgruppe erhielten zur Unterstützung einen Audioplayer mit Erste-Hilfe-Anweisungen für die kardiopulmonale Reanimation. Ergebnisse In beiden Gruppen lag die „hands-off time“ bei 59%. Die Bewusstseinskontrolle und das Freimachen der Atemwege erfolgte in der Testgruppe signifikant häufiger (93% vs. 33%, bzw. 44% vs. 15%), während der Hilferuf (53% vs. 55%), die Herzdruckmassage (100% vs. 100%) und die Beatmung (98% vs. 96%) in beiden Gruppen gleich häufig durchgeführt wurde. Der Beginn der ersten Herzdruckmassage erfolgte in der Kontrollgruppe signifikant früher (38 s vs. 67 s; p Schlussfolgerung Der Audioplayer führte zu keiner Verbesserung der Effektivität der Ersten-Hilfe-Maßnahmen bei einem Atem-Kreislauf-Stillstand.
    Notfall 06/2011; 15(5):405-409. DOI:10.1007/s10049-011-1490-4 · 0.32 Impact Factor

Full-text (2 Sources)

Download
54 Downloads
Available from
May 20, 2014