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

University of Chicago, Chicago, Illinois, United States
Resuscitation (Impact Factor: 4.17). 12/2006; 71(2):137-45. DOI: 10.1016/j.resuscitation.2006.04.008
Source: PubMed


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.

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Available from: Jo Kramer-Johansen
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    • "The depth of mattress compression averages approximately 1.5 cm [13]. An increase in CC depth is associated with shock success, and sufficient CC depth can achieve return of spontaneous circulation [1] [14]. Recently, various methods to compensate for or reduce mattress compression have been shown to be helpful in addressing this problem of CPR in the hospital [15] [16] [17]. "
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    ABSTRACT: Feedback devices are used to improve chest compression (CC) quality related to survival rates in cardiac arrest. However, several studies have shown that feedback devices are not sufficiently reliable to ensure adequate CC depth on soft surfaces. Here, we determined the proper target depth of feedback (TDF) using an accelerometer during cardiopulmonary resuscitation in hospital beds. In prospective randomized crossover study, 19 emergency physicians performed CCs for 2 minutes continuously on a manikin in 2 different beds with 3 TDFs (5, 6, and 7 cm). We measured CC depth, the proportion of accurate compression depths, CC rate, the proportion of incomplete chest decompressions, the velocity of CC (CC velocity), the proportion of time spent in CC relative to compression plus decompression (duty cycle), and the time spent in CC (CC time). Mean (SD) CC depths at TDF 5, 6, and 7 were 45.42 (5.79), 52.68 (4.18), and 58.47 (2.48) on one bed and 46.26 (4.49), 53.58 (3.15), and 58.74 (2.10) mm on the other bed (all P < .001), respectively. The proportions of accurate compression depths and CC velocity at TDF 5, 6, and 7 differed significantly according to TDF on both beds (all P < .001).The CC rate, CC time, and proportion of incomplete chest decompression did not differ on both beds (all P > .05). The duty cycle differed significantly on only B2. The target depth of the real-time feedback device should be at least 6 cm but should not exceed 7 cm for optimal CC on patients on hospital beds. Copyright © 2015. Published by Elsevier Inc.
    Full-text · Article · Jul 2015 · The American journal of emergency medicine
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    • "Whereas early studies suggested a benefit of CPR before defibrillation [23] [24] [25] [26] [27], recent studies do not support these findings [28] [29] [30] [31] [32] [33]. Thus, current CPR guidelines do not recommend a specific CPR interval before defibrillation but highlight the importance of efficient and continuous chest compressions with as short as possible hands-off time until successful defibrillation [25] [34] [35]. 3.2. "
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    ABSTRACT: Aim of the study Automated external defibrillation (AED) and public access defibrillation (PAD) have become cornerstones in the chain of survival in modern cardiopulmonary resuscitation. Most studies of AED and PAD have been performed in urban areas and evidence is scarce for sparsely populated rural areas. The aim of this review was to review the literature and discuss treatment strategies of out-of-hospital cardiac arrest in rural areas. Methods A Medline search was performed with the keywords “automated external defibrillation” (617 hits), “public access defibrillation” (256), “automated external defibrillator public” (542). Of these 1415 abstracts and additional articles found by manual searching references, 92 articles were included in this non-systematic review. Results Early defibrillation is crucial for survival with good neurological outcome after cardiac arrest. Rapid defibrillation can be a challenge in sparsely populated and remote areas, where the incidence of cardiac arrest is low and rescuer response times can be long. The few studies performed in rural areas showed that the introduction of AED programs based on a two-tier emergency medical system (EMS), consisting of a Basic Life Support (BLS) and Advanced Life Support (ALS) team, resulted in a decrease in collapse-to-defibrillation times and better survival of patients with out-of-hospital cardiac arrest. Conclusions In rural areas, introducing AED programs and a two-tier EMS may increase survival of out-of-hospital cardiac arrest patients. More studies on AED and PAD in rural areas are required.
    Full-text · Article · Aug 2014 · American Journal of Emergency Medicine
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    • "Christenson et al. reported that the chest compression fraction appears to be an important determinant of survival from cardiac arrest [13]. It was also reported that shallower chest compressions correlated significantly with a decrease in successful defibrillation [14,15]. Now, the rescuer should give chest compressions to a depth of at least 5 cm and at a rate of at least 100 times per minute, allow full chest recoil after each compression, and minimise interruptions in chest compression [5]. "
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    ABSTRACT: Background The 2010 Consensus on Science and Treatment Recommendations Statement recommended that short video/computer self-instruction courses, with minimal or no instructor coaching, combined with hands-on practice can be considered an effective alternative to instructor-led basic life support courses. The purpose of this study was to examine the effectiveness of a simplified cardiopulmonary resuscitation (CPR) training program for non-medical staff working at a university hospital. Methods Before and immediately after a 45-min CPR training program consisting of instruction on chest compression and automated external defibrillator (AED) use with a personal training manikin, CPR skills were automatically recorded and evaluated. Participants’ attitudes towards CPR were evaluated by a questionnaire survey. Results From September 2011 through March 2013, 161 participants attended the program. We evaluated chest compression technique in 109 of these participants. The number of chest compressions delivered after the program versus that before was significantly greater (110.8 ± 13.0/min vs 94.2 ± 27.4/min, p < 0.0001), interruption of chest compressions was significantly shorter (0.05 ± 0.34 sec/30 sec vs 0.89 ± 3.52 sec/30 sec, p < 0.05), mean depth of chest compressions was significantly greater (57.6 ± 6.8 mm vs 52.2 ± 9.4 mm, p < 0.0001), and the proportion of incomplete chest compressions of <5 cm among all chest compressions was significantly decreased (8.9 ± 23.2% vs 38.6 ± 42.9%, p < 0.0001). Of the 159 participants who responded to the questionnaire survey after the program, the proportion of participants who answered ‘I can check for a response,’ ‘I can perform chest compressions,’ and ‘I can absolutely or I think I can use an AED’ increased versus that before the program (81.8% vs 19.5%, 77.4% vs 10.1%, 84.3% vs 23.3%, respectively). Conclusions A 45-min simplified CPR training program on chest compression and AED use improved CPR quality and the attitude towards CPR and AED use of non-medical staff of a university hospital.
    Full-text · Article · May 2014 · Scandinavian Journal of Trauma Resuscitation and Emergency Medicine
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