Hands-only (compression-only) cardiopulmonary resuscitation: a call to action for bystander response to adults who experience out-of-hospital sudden cardiac arrest: a science advisory for the public from the American Heart Association Emergency Cardiovascular Care Committee

CPR with chest compression alone or with rescue breathing

BACKGROUND

The role of rescue breathing in cardiopulmonary resuscitation (CPR) performed by a layperson is uncertain. We hypothesized that the dispatcher instructions to bystanders to provide chest compression alone would result in improved survival as compared with instructions to provide chest compression plus rescue breathing.

METHODS

We conducted a multicenter, randomized trial of dispatcher instructions to bystanders for performing CPR. The patients were persons 18 years of age or older with out-of-hospital cardiac arrest for whom dispatchers initiated CPR instruction to bystanders. Patients were randomly assigned to receive chest compression alone or chest compression plus rescue breathing. The primary outcome was survival to hospital discharge. Secondary outcomes included a favorable neurologic outcome at discharge.

RESULTS

Of the 1941 patients who met the inclusion criteria, 981 were randomly assigned to receive chest compression alone and 960 to receive chest compression plus rescue breathing. We observed no significant difference between the two groups in the proportion of patients who survived to hospital discharge (12.5% with chest compression alone and 11.0% with chest compression plus rescue breathing, P=0.31) or in the proportion who survived with a favorable neurologic outcome in the two sites that assessed this secondary outcome (14.4% and 11.5%, respectively; P=0.13). Prespecified subgroup analyses showed a trend toward a higher proportion of patients surviving to hospital discharge with chest compression alone as compared with chest compression plus rescue breathing for patients with a cardiac cause of arrest (15.5% vs. 12.3%, P=0.09) and for those with shockable rhythms (31.9% vs. 25.7%, P=0.09).

CONCLUSIONS

Dispatcher instruction consisting of chest compression alone did not increase the survival rate overall, although there was a trend toward better outcomes in key clinical subgroups. The results support a strategy for CPR performed by laypersons that emphasizes chest compression and minimizes the role of rescue breathing. (Funded in part by the Laerdal Foundation for Acute Medicine and the Medic One Foundation; ClinicalTrials.gov number, NCT00219687.)

Bystander-initiated rescue breathing for out-of-hospital cardiac arrests of noncardiac origin

BACKGROUND

Although chest compression-only cardiopulmonary resuscitation (CPR) is effective for adult out-of-hospital cardiac arrest (OHCA) of cardiac origin, it remains uncertain whether bystander-initiated rescue breathing has an incremental benefit for OHCA of noncardiac origin.

METHODS AND RESULTS

A nationwide, prospective, population-based, observational study covering the whole population of Japan and involving consecutive OHCA patients with emergency responder resuscitation attempts was conducted from January 2005 through December 2007. The primary outcome was neurologically intact 1-month survival. Multiple logistic regression analysis was used to assess the contribution of bystander-initiated CPR to better neurological outcomes. Among a total of 43 246 bystander-witnessed OHCAs of noncardiac origin, 8878 (20.5%) received chest compression-only CPR, and 7474 (17.3%) received conventional CPR with rescue breathing. The conventional CPR group (1.8%) had a higher rate of better neurological outcome than both the no CPR group (1.4%; odds ratio, 1.58; 95% confidence interval, 1.28 to 1.96) and the compression-only CPR group (1.5%; odds ratio, 1.32; 95% confidence interval, 1.03 to 1.69). However, the compression-only CPR group did not produce better neurological outcome than the no CPR group (odds ratio, 1.19; 95% confidence interval, 0.96 to 1.47). The number of OHCAs needed to treat with conventional CPR versus compression-only CPR to save a life with favorable neurological outcome after OHCA was 290.

CONCLUSIONS

This nationwide observational study indicates that rescue breathing has an incremental benefit for OHCAs of noncardiac origin, but the impact on the overall survival after OHCA was small.

Air medical transport personnel experiences with and opinions about research

INTRODUCTION

This study examined air medical transport (AMT) personnel's experiences with and opinions about prehospital and AMT research.

METHODS

A Web-based questionnaire was sent to eight randomly selected AMT programs from each of six Association of Air Medical Services (AAMS) regions. Responders were defined by university association (UA) and AMT professional role.

RESULTS

Forty-eight of 54 (89%) contacted programs and 536 of 1,282 (42%) individuals responded. Non-UA responders (74%) had significantly more work experience in emergency medical services (EMS) (13.5 +/- 8.5 vs. 10.8 +/- 8.3 years, P = .002) and AMT (8.3 +/- 6.3 vs. 6.8 +/- 5.7 years, P = .008), whereas UA responders (26%) had more research training (51% vs. 37%, P = .006), experience (79% vs. 59%, P < .001), and grants (7% vs. 2%, P = .006). By AMT role, administrators had the most work experience, and physicians had the most research experience. Research productivity of responders was low, with only 9% having presented and 10% having published research; and UA made no difference in productivity. A majority of responders advocated research: EMS (66%) and AMT (68%), program (53%). Willingness to participate in research was high for both EMS research (87%) and AMT research (92%).

CONCLUSIONS

Although AMT personnel were strong advocates of and willing to participate in research, few had research knowledge. For AMT personnel, disparity exists between advocating for and producing research.

Diagnostic performance of a new multifunctional electrocardiograph during uninterrupted chest compressions in cardiac arrest patients

BACKGROUND

External chest compression is considered to play a significant role in cardiopulmonary resuscitation (CPR), but during a rhythm check, chest compressions must be discontinued to avoid artifacts. A new multifunctional electrocardiograph (ECG; Radarcirc) has been developed for use in clinical settings.

METHODS AND RESULTS

The performance of the Radarcirc and conventional ECG (CoECG) during CPR was compared in a single-center, non-randomized, sequential self-controlled study. CPR was performed on 41 out-of-hospital cardiac arrest patients. Cardiac rhythm with and without chest compressions during a rhythm check was measured using leads I and II. When the rhythm changed during CPR, it was measured as another waveform. Fifty ECG recordings were obtained, of which 27 were asystole, 18 pulseless electrical activity, and 5 ventricular fibrillation (VF). The area under the receiver-operating characteristic curve (AUC) for VF was 0.448 (95% confidence interval (CI) 0.274-0.622) for lead II of the CoECG, and 0.797 (95%CI 0.684-0.910) for lead II of the Radarcirc. The AUC for VF was 0.422 (95%CI 0.219-0.626) for lead I of the CoECG, and 0.987 (95%CI 0.975-1.00) for lead I of the Radarcirc.

CONCLUSIONS

Diagnoses based on the data from Radarcirc were more accurate in predicting rhythm during chest compressions than those based on data from the CoECG.

Conventional and chest-compression-only cardiopulmonary resuscitation by bystanders for children who have out-of-hospital cardiac arrests: a prospective, nationwide, population-based cohort study

BACKGROUND

The American Heart Association recommends cardiopulmonary resuscitation (CPR) by bystanders with chest compression only for adults who have cardiac arrests, but not for children. We assessed the effect of CPR (conventional with rescue breathing or chest compression only) by bystanders on outcomes after out-of-hospital cardiac arrests in children.

METHODS

In a nationwide, prospective, population-based, observational study, we enrolled 5170 children aged 17 years and younger who had an out-of-hospital cardiac arrest from Jan 1, 2005, to Dec 31, 2007. Data collected included age, cause, and presence and type of CPR by bystander. The primary endpoint was favourable neurological outcome 1 month after an out-of-hospital cardiac arrest, defined as Glasgow-Pittsburgh cerebral performance category 1 or 2.

FINDINGS

3675 (71%) children had arrests of non-cardiac causes and 1495 (29%) cardiac causes. 1551 (30%) received conventional CPR and 888 (17%) compression-only CPR. Data for type of CPR by bystander were not available for 12 children. Children who were given CPR by a bystander had a significantly higher rate of favourable neurological outcome than did those not given CPR (4.5% [110/2439] vs 1.9% [53/2719]; adjusted odds ratio [OR] 2.59, 95% CI 1.81-3.71). In children aged 1-17 years who had arrests of non-cardiac causes, favourable neurological outcome was more common after bystander CPR than no CPR (5.1% [51/1004] vs 1.5% [20/1293]; OR 4.17, 2.37-7.32). However, conventional CPR produced more favourable neurological outcome than did compression-only CPR (7.2% [45/624] vs 1.6% [six of 380]; OR 5.54, 2.52-16.99). In children aged 1-17 years who had arrests of cardiac causes, favourable neurological outcome was more common after bystander CPR than no CPR (9.5% [42/440] vs 4.1% [14/339]; OR 2.21, 1.08-4.54), and did not differ between conventional and compression-only CPR (9.9% [28/282] vs 8.9% [14/158]; OR 1.20, 0.55-2.66). In infants (aged <1 year), outcomes were uniformly poor (1.7% [36/2082] with favourable neurological outcome).

INTERPRETATION

For children who have out-of-hospital cardiac arrests from non-cardiac causes, conventional CPR (with rescue breathing) by bystander is the preferable approach to resuscitation. For arrests of cardiac causes, either conventional or compression-only CPR is similarly effective.

FUNDING

Fire and Disaster Management Agency and the Ministry of Education, Culture, Sports, Science and Technology (Japan).

Improved out-of-hospital cardiac arrest survival after the sequential implementation of 2005 AHA guidelines for compressions, ventilations, and induced hypothermia: the Wake County experience

STUDY OBJECTIVE

We assess survival from out-of-hospital cardiac arrest after community-wide implementation of 2005 American Heart Association guidelines.

METHODS

This was an observational multiphase before-after cohort in an urban/suburban community (population 840,000) with existing advanced life support. Included were all adults treated for cardiac arrest by emergency responders. Excluded were patients younger than 16 years and trauma patients. Intervention phases in months were baseline 16; phase 1, new cardiopulmonary resuscitation 12; phase 2, impedance threshold device 6; and phase 3, full implementation including out-of-hospital-induced hypothermia 12. Primary outcome was survival to discharge. Other survival and neurologic outcomes were compared between study phases, and adjusted odds ratios with 95% confidence intervals (CIs) for survival by phase were determined by multivariate regression.

RESULTS

One thousand three hundred sixty-five cardiac arrest patients were eligible for inclusion: baseline n=425, phase 1 n=369, phase 2 n=161, phase 3 n=410. Across phases, patients had similar demographic, clinical, and emergency medical services characteristics. Overall and witnessed ventricular fibrillation and ventricular tachycardia survival improved throughout the study phases: respectively, baseline 4.2% and 13.8%, phase 1 7.3% and 23.9%, phase 2 8.1% and 34.6%, and phase 3 11.5% and 40.8%. The absolute increase for overall survival from baseline to full implementation was 7.3% (95% CI 3.7% to 10.9%); witnessed ventricular fibrillation/ventricular tachycardia survival was 27.0% (95% CI 13.6% to 40.4%), representing an additional 25 lives saved annually in this community.

CONCLUSION

In the context of a community-wide focus on resuscitation, the sequential implementation of 2005 American Heart Association guidelines for compressions, ventilations, and induced hypothermia significantly improved survival after cardiac arrest. Further study is required to clarify the relative contribution of each intervention to improved survival outcomes.

The effect of basic life support education on laypersons' willingness in performing bystander hands only cardiopulmonary resuscitation

BACKGROUND

Recently, hands only CPR (cardiopulmonary resuscitation) has been proposed as an alternative to standard CPR for bystanders. The present study was performed to identify the effect of basic life support (BLS) training on laypersons' willingness in performing standard CPR and hands only CPR.

METHODS

The participants for this study were non-medical personnel who applied for BLS training program that took place in 7 university hospitals in and around Korea for 6 months. Before and after BLS training, all the participants were given questionnaires for bystander CPR, and 890 respondents were included in the final analyses.

RESULTS

Self-assessed confidence score for bystander CPR, using a visual analogue scale from 0 to 100, increased from 51.5+/-30.0 before BLS training to 87.0+/-13.7 after the training with statistical significance (p 0.001). Before the training, 19% of respondents reported willingness to perform standard CPR on a stranger, and 30.1% to perform hands only CPR. After the training, this increased to 56.7% of respondents reporting willingness to perform standard CPR, and 71.9%, hands only CPR, on strangers. Before and after BLS training, the odds ratio of willingness to perform hands only CPR versus standard CPR were 1.8 (95% CI 1.5-2.3) and 2.0 (95% CI 1.7-2.6) for a stranger, respectively. Most of the respondents, who reported they would decline to perform standard CPR, stated that fear of liability and fear of disease transmission were deciding factors after the BLS training.

CONCLUSIONS

The BLS training increases laypersons' confidence and willingness to perform bystander CPR on a stranger. However, laypersons are more willing to perform hands only CPR rather than to perform standard CPR on a stranger regardless of the BLS training.

Nationwide public-access defibrillation in Japan

BACKGROUND

It is unclear whether dissemination of automated external defibrillators (AEDs) in public places can improve the rate of survival among patients who have had an out-of-hospital cardiac arrest.

METHODS

From January 1, 2005, through December 31, 2007, we conducted a prospective, population-based, observational study involving consecutive patients across Japan who had an out-of-hospital cardiac arrest and in whom resuscitation was attempted by emergency responders. We evaluated the effect of nationwide dissemination of public-access AEDs on the rate of survival after an out-of-hospital cardiac arrest. The primary outcome measure was the 1-month rate of survival with minimal neurologic impairment. A multivariate logistic-regression analysis was performed to assess factors associated with a good neurologic outcome.

RESULTS

A total of 312,319 adults who had an out-of-hospital cardiac arrest were included in the study; 12,631 of these patients had ventricular fibrillation and had an arrest that was of cardiac origin and that was witnessed by bystanders. In 462 of these patients (3.7%), shocks were administered by laypersons with the use of public-access AEDs, and the proportion increased, from 1.2% to 6.2%, as the number of public-access AEDs increased (P<0.001 for trend). Among all patients who had a bystander-witnessed arrest of cardiac origin and who had ventricular fibrillation, 14.4% were alive at 1 month with minimal neurologic impairment; among patients who received shocks from public-access AEDs, 31.6% were alive at 1 month with minimal neurologic impairment. Early defibrillation, regardless of the type of provider (bystander or emergency-medical-services personnel), was associated with a good neurologic outcome after a cardiac arrest with ventricular fibrillation (adjusted odds ratio per 1-minute increase in the time to administration of shock, 0.91; 95% confidence interval, 0.89 to 0.92; P<0.001). The mean time to shock was reduced from 3.7 to 2.2 minutes, and the annual number of patients per 10 million population who survived with minimal neurologic impairment increased from 2.4 to 8.9 as the number of public-access AEDs increased from fewer than 1 per square kilometer of inhabited area to 4 or more.

CONCLUSIONS

Nationwide dissemination of public-access AEDs in Japan resulted in earlier administration of shocks by laypersons and in an increase in the 1-month rate of survival with minimal neurologic impairment after an out-of-hospital cardiac arrest.

Cardiopulmonary resuscitation training for family members

Out-of-hospital sudden cardiac arrest survival rate is significantly higher when the patient receives cardiopulmonary resuscitation (CPR) before the arrival of emergency providers although published data suggest a significantly lower prevalence of CPR training among cardiac patients' family members and bystanders in the United States. This article presents information including attitudes of patients, family members, and the general population toward CPR; the barriers for CPR training among the public; and the most effective method of CPR training for bystanders, so that CPR training for family members can be promoted to improve out-of-hospital sudden cardiac arrest survival rate.

Optimizing survival from out-of-hospital cardiac arrest

Cardiac arrest is an important public health problem and often occurs in the out-of-hospital setting in patients without a prior history of heart disease. Very few communities or emergency medical service (EMS) systems report survival rates for out-of-hospital cardiac arrest. Among those who do, survival rates vary substantially between cities, due in large part to community differences in the chain of survival. To improve survival in cardiac arrest, care must be optimized at each point along the cardiac arrest continuum, including a rapid emergency response, provision of cardiopulmonary resuscitation (CPR) by bystanders, delivery of high-quality chest compressions with minimal interruptions by first responders, rapid defibrillation, and optimization of postresuscitation care, including therapeutic hypothermia. Important current initiatives to improve cardiac arrest survival include hands-only CPR delivered by laypersons prior to the arrival of EMS, dispatcher-assisted CPR, and implementation of hospital-based therapeutic hypothermia protocols to improve postresuscitation care. Optimizing cardiac arrest survival requires a team effort between EMS directors, emergency physicians, cardiologists, hospital leadership, and the public.

Shock advisory system for heart rhythm analysis during cardiopulmonary resuscitation using a single ECG input of automated external defibrillators

Minimum "hands-off" intervals during cardiopulmonary resuscitation (CPR) are required to improve the success rate of defibrillation. In support of such life-saving practice, a shock advisory system (SAS) for automatic analysis of the electrocardiogram (ECG) contaminated by chest compression (CC) artefacts is presented. Ease of use for the automated external defibrillators (AEDs) is aimed and therefore only processing of ECG from usual defibrillation pads is required. The proposed SAS relies on assessment of outstanding components of ECG rhythms and CC artefacts in the time and frequency domain. For this purpose, three criteria are introduced to derive quantitative measures of band-pass filtered CC-contaminated ECGs, combined with three more criteria for frequency-band evaluation of reconstructed ECGs (rECG). The rECGs are derived by specific techniques for CC waves similarity assessment and are reproducing to some extent the underlying ECG rhythms. The rhythm classifier embedded in SAS takes a probabilistic decision designed by statistics on the training dataset. Both training and testing are fully performed on real CC-contaminated strips of 10 s extracted from human ECGs of out-of-hospital cardiac arrest interventions. The testing is done on 172 shockable strips (ventricular fibrillations VF), 371 non-shockable strips (NR) and 330 asystoles (ASYS). The achieved sensitivity of 90.1% meets the AHA performance goal for noise-free VF (>90%). The specificity of 88.5% for NR and 83.3% for ASYS are comparable or even better than accuracy reported in literature. It is important to note that, the aim of this SAS is not to recommend shock delivery but to advice the rescuers to "Continue CPR" or to "Stop CPR and Prepare for Shock" thus minimizing "hands-off" intervals.

Performance of chest compressions by laypersons during the Public Access Defibrillation Trial

BACKGROUND

Increasing evidence indicates that health professionals often may not achieve guideline standards for cardiopulmonary resuscitation (CPR). Little is known about layperson CPR performance.

METHODS

The investigation was a retrospective cohort study of cardiac arrest patients treated by layperson CPR and one model of automated external defibrillator (AED) as part of the Public Access Defibrillation Trial (n=26). CPR was measured using software that integrates the event log, ECG signal, and thoracic impedance signal. We assessed chest compression fraction (proportion of attempted resuscitation spent performing chest compressions), prompted compression fraction (proportion of attempted resuscitation spent performing compressions during AED-prompted periods), compression rate, and compressions per minute.

RESULTS

Of the 26 cases, 13 presented with ventricular fibrillation and 13 with nonshockable rhythms. Overall, during the period when patients did not have spontaneous circulation, the median chest compression fraction was 34% (IQR 17-48%), median prompted chest compression fraction was 49% (IQR 30-66%), and the median chest compression rate was 96/min (IQR 90-110/min). Taken together, the median chest compression delivered per minute among all arrests was 29 (IQR 20-42). CPR characteristics differed according to initial rhythm: median chest compression per minute was 20 (IQR 13-29) among ventricular fibrillation and 42 (IQR 28-47) among nonshockable rhythms (p=0.003).

CONCLUSIONS

In this study of trained laypersons, CPR varied substantially and often did not achieve guideline parameters. The findings suggest a need to improve CPR training, consider changes to CPR protocols, and/or improve the AED-rescuer interface.

Dispatcher-assisted cardiopulmonary resuscitation: risks for patients not in cardiac arrest

BACKGROUND

Dispatcher-assisted cardiopulmonary resuscitation (CPR) instructions can increase bystander CPR and thereby increase the rate of survival from cardiac arrest. The risk of bystander CPR for patients not in arrest is uncertain and has implications for how assertive dispatch is in instructing CPR. We determined the frequency of dispatcher-assisted CPR for patients not in arrest and the frequency and severity of injury related to chest compressions.

METHODS AND RESULTS

The investigation was a prospective cohort study of adult patients not in cardiac arrest for whom dispatchers provided CPR instructions in King County, Washington, between June 1, 2004, and January 31, 2007. The study focused on those who received chest compressions. Information was collected through review of the audio and written dispatch report, written emergency medical services report, hospital record, and telephone survey. Of the 1700 patients for whom dispatcher CPR instructions were initiated, 55% (938 of 1700) were in arrest, 45% (762 of 1700) were not in arrest, and 18% (313 of 1700) were not in arrest and received bystander chest compressions. Of the 247 not in arrest who received chest compressions and had complete outcome ascertainment, 12% (29 of 247) experienced discomfort, and 2% (6 of 247) sustained injuries likely or possibly caused by bystander CPR. Only 2% (5 of 247) suffered a fracture, and no patients suffered visceral organ injury.

CONCLUSIONS

In this prospective study, the frequency of serious injury related to dispatcher-assisted bystander CPR among nonarrest patients was low. When coupled with the established benefits of bystander CPR among those with arrest, these results support an assertive program of dispatcher-assisted CPR.

Effect of listening to Nellie the Elephant during CPR training on performance of chest compressions by lay people: randomised crossover trial

OBJECTIVES

To determine whether listening to music during cardiopulmonary resuscitation (CPR) training increases the proportion of lay people delivering chest compressions of 100 per minute.

DESIGN

Prospective randomised crossover trial.

SETTING

Large UK university.

PARTICIPANTS

130 volunteers (81 men) recruited on an opportunistic basis. Exclusion criteria included age under 18, trained health professionals, and cardiopulmonary resuscitation (CPR) training within the past three months.

INTERVENTIONS

Volunteers performed three sequences of one minute of continuous chest compressions on a skill meter resuscitation manikin accompanied by no music, repeated choruses of Nellie the Elephant (Nellie), and That's the Way (I like it) (TTW) according to a pre-randomised order.

MAIN OUTCOME MEASURES

Rate of chest compressions delivered (primary outcome), depth of compressions, proportion of incorrect compressions, and type of error.

RESULTS

Median (interquartile range) compression rates were 110 (93-119) with no music, 105 (98-107) with Nellie, and 109 (103-110) with TTW. There were significant differences within groups between Nellie v no music and Nellie v TTW (P<0.001) but not no music v TTW (P=0.055). A compression rate of between 95 and 105 was achieved with no music, Nellie, and TTW for 15/130 (12%), 42/130 (32%), and 12/130 (9%) attempts, respectively. Differences in proportions were significant for Nellie v no music and Nellie v TTW (P<0.001) but not for no music v TTW (P=0.55). Relative risk for a compression rate between 95 and 105 was 2.8 (95% confidence interval 1.66 to 4.80) for Nellie v no music, 0.8 (0.40 to 1.62) for TTW v no music, and 3.5 (1.97 to 6.33) for Nellie v TTW. The number needed to treat for listening to Nellie v no music was 5 (4 to 10)-that is, the number of cardiac arrests required during which lay responders listen to Nellie to facilitate one patient receiving compressions at the correct rate (v no music) would be between four and 10. A greater proportion of compressions were too shallow when participants listened to Nellie v no music (56% v 47%, P=0.022).

CONCLUSIONS

Listening to Nellie the Elephant significantly increased the proportion of lay people delivering compression rates at close to 100 per minute. Unfortunately it also increased the proportion of compressions delivered at an inadequate depth. As current resuscitation guidelines give equal emphasis to correct rate and depth, listening to Nellie the Elephant as a learning aid during CPR training should be discontinued. Further research is required to identify music that, when played during CPR training, increases the proportion of lay responders providing chest compressions at both the correct rate and depth.

The resuscitation blanket: a useful tool for "hands-on" defibrillation

AIM OF STUDY

We investigated the safety, feasibility and efficacy of a resuscitation blanket designed with the intent to protecting the rescuer from the risk of receiving electrical current during defibrillation which, would allow for uninterrupted chest compressions.

METHODS

Fifteen pigs weighing between 22 and 40 kg were investigated with an established model of cardiac arrest and CPR. CPR was performed with the interposition of the blanket between the rescuer's hands and the chest of the animal. Defibrillation voltage and current over the blanket were measured. Hemodynamics, including coronary perfusion pressure (CPP), end-tidal CO(2) (EtCO(2)) and 50% successful defibrillation threshold (DFT50) were measured and compared during CPR with and without the blanket.

RESULTS

Leakage through the blanket was nominal. Voltages of 42.0, 56.6 and 105 V and mean leakage currents of 1.1, 1.4 and 3.3 microA were measured above the blanket for 150, 200 and 360 J defibrillation shocks. CPP and EtCO(2) in the animals during chest compression with the resuscitation blanket were not significantly different compared to those measured without the blanket. However, when the blanket was not utilized, CPP decreased (P<0.05) during the 15-s hands-off interruption prior to defibrillation. Defibrillation threshold was significantly lower when the blanket was used.

CONCLUSION

The resuscitation blanket is a safe and useful tool which protects the rescuer from hands-on defibrillation shocks, allowing for uninterrupted chest compressions, and therefore improving defibrillation success.

Optimizing Community Resources to Address Sudden Cardiac Death

The "chain of survival" (early access, early cardiopulmonary resuscitation, early defibrillation, and early advanced care) defines the proven interventions necessary for successful resuscitation and survival of patients with cardiac arrest. Low survival rates from cardiac arrest are not due to lack of understanding of effective interventions, but instead are due to weak links in the chain of survival and the inability of communities to make sure these links function in an efficient, timely, and coordinated fashion. This article reviews how quality is defined for each link, how communities can strengthen each link, and how communities can forge a strong relationship between each link. By optimizing local leadership and stakeholder collaboration, communities have the potential to vastly improve outcomes from this devastating disease.

Advances in Cardiopulmonary Resuscitation

This article focuses on important advances in the science of cardiopulmonary resuscitation (CPR) in the last decade that have led to a significant improvement in understanding the complex physiology of cardiac arrest and critical interventions for the initial management of cardiac arrest and postresuscitation treatment. Special emphasis is given to the basic simple ways to improve circulation, vital organ perfusion pressures, and the grave prognosis of sudden cardiac death.

Predictors of survival from out-of-hospital cardiac arrest: a systematic review and meta-analysis

BACKGROUND

Prior studies have identified key predictors of out-of-hospital cardiac arrest (OHCA), but differences exist in the magnitude of these findings. In this meta-analysis, we evaluated the strength of associations between OHCA and key factors (event witnessed by a bystander or emergency medical services [EMS], provision of bystander cardiopulmonary resuscitation [CPR], initial cardiac rhythm, or the return of spontaneous circulation). We also examined trends in OHCA survival over time.

METHODS AND RESULTS

An electronic search of PubMed, EMBASE, Web of Science, CINAHL, Cochrane DSR, DARE, ACP Journal Club, and CCTR was conducted (January 1, 1950 to August 21, 2008) for studies reporting OHCA of presumed cardiac etiology in adults. Data were extracted from 79 studies involving 142 740 patients. The pooled survival rate to hospital admission was 23.8% (95% CI, 21.1 to 26.6) and to hospital discharge was 7.6% (95% CI, 6.7 to 8.4). Stratified by baseline rates, survival to hospital discharge was more likely among those: witnessed by a bystander (6.4% to 13.5%), witnessed by EMS (4.9% to 18.2%), who received bystander CPR (3.9% to 16.1%), were found in ventricular fibrillation/ventricular tachycardia (14.8% to 23.0%), or achieved return of spontaneous circulation (15.5% to 33.6%). Although 53% (95% CI, 45.0% to 59.9%) of events were witnessed by a bystander, only 32% (95% CI, 26.7% to 37.8%) received bystander CPR. The number needed to treat to save 1 life ranged from 16 to 23 for EMS-witnessed arrests, 17 to 71 for bystander-witnessed, and 24 to 36 for those receiving bystander CPR, depending on baseline survival rates. The aggregate survival rate of OHCA (7.6%) has not significantly changed in almost 3 decades.

CONCLUSIONS

Overall survival from OHCA has been stable for almost 30 years, as have the strong associations between key predictors and survival. Because most OHCA events are witnessed, efforts to improve survival should focus on prompt delivery of interventions of known effectiveness by those who witness the event.

Rescuer fatigue during actual in-hospital cardiopulmonary resuscitation with audiovisual feedback: a prospective multicenter study

BACKGROUND

Rescuer fatigue during cardiopulmonary resuscitation (CPR) is a likely contributor to variable CPR quality during clinical resuscitation efforts, yet investigations into fatigue and CPR quality degradation have only been performed in simulated environments, with widely conflicting results.

OBJECTIVE

We sought to characterize CPR quality decay during actual in-hospital cardiac arrest, with regard to both chest compression (CC) rate and depth during the delivery of CCs by individual rescuers over time.

METHODS

Using CPR recording technology to objectively quantify CCs and provide audiovisual feedback, we prospectively collected CPR performance data from arrest events in two hospitals. We identified continuous CPR "blocks" from individual rescuers, assessing CC rate and depth over time.

RESULTS

135 blocks of continuous CPR were identified from 42 cardiac arrests at the two institutions. Median duration of continuous CPR blocks was 112s (IQR 101-122). CC rate did not change significantly over single rescuer performance, with an initial mean rate of 105+/-11/min, and a mean rate after 3 min of 106+/-9/min (p=NS). However, CC depth decayed significantly between 90s and 2 min, falling from a mean of 48.3+/-9.6mm to 46.0+/-9.0mm (p=0.0006) and to 43.7+/-7.4mm by 3 min (p=0.002).

CONCLUSIONS

During actual in-hospital CPR with audiovisual feedback, CC depth decay became evident after 90s of CPR, but CC rate did not change. These data provide clinical evidence for rescuer fatigue during actual resuscitations and support current guideline recommendations to rotate rescuers during CC delivery.

Chest compression-only cardiocerebral resuscitation

PURPOSE OF REVIEW

Conventional cardiopulmonary resuscitation (CPR) by bystanders with chest compressions and mouth-to-mouth ventilation has been documented to save life. Nevertheless, despite four decades of promulgation, it is a serious problem that the majority of bystanders are unwilling or unable to perform conventional CPR. I review the efficacy of chest compression-only cardiocerebral resuscitation (CCR) for all adult patients with out-of-hospital cardiac arrest.

RECENT FINDINGS

Recent observational studies showed that chest compression-only CCR by bystanders was equivalent or superior to conventional CPR in adult patients with out-of-hospital cardiac arrest in terms of neurological benefits. In 2008, the American Heart Association Emergency Cardiovascular Care committee recommended that bystanders who witness a sudden collapse in an adult should give chest compressions without ventilations (chest compression-only CCR; hands-only CPR). Furthermore, an observational study showed that chest compression-only CCR by emergency medical services personnel was a preferable approach to advanced cardiovascular life support for adult patients with out-of-hospital cardiac arrest.

SUMMARY

To save more lives, I hope that compression-only CCR by citizen is generally, known, recommended, and taught to the public, because chest compression-only CCR by citizen is the preferable approach to basic life support for adult victims with out-of-hospital cardiac arrest.

Cardiopulmonary resuscitation in children

PURPOSE OF REVIEW

To summarize recent advances in pediatric cardiopulmonary arrest prevention, resuscitation and postresuscitation management.

RECENT FINDINGS

Pediatric cardiac arrest has traditionally been considered a futile medical condition with dismal outcomes. Data in the 21st century indicate that more than 25% of children treated for in-hospital cardiac arrests survive to hospital discharge and more than 10% of children older than 1 year treated for out-of-hospital cardiac arrests survive to hospital discharge. These data establish that children are more likely to survive to hospital discharge than adults after both in-hospital and out-of-hospital cardiac arrests. Before arrest, exciting new studies demonstrate that the implementation of in-hospital pediatric medical emergency teams is associated with significant decreases in cardiac arrest incidence and overall pediatric hospital mortality. During arrest, ventricular fibrillation or ventricular tachycardia, once thought to be rare in children, occurs during 25% of inhospital pediatric cardiac arrests and at least 7% of out-of-hospital pediatric cardiac arrests. Survival to hospital discharge is much more likely after arrests with a first documented rhythm of ventricular fibrillation or ventricular tachycardia than after pulseless electric activity and asystole. However, ventricular fibrillation or ventricular tachycardia is not always a favorable rhythm, as survival to discharge is much less likely when ventricular fibrillation or ventricular tachycardia occurs during resuscitation from an arrest with the first documented rhythm of pulseless electric activity or asystole. Further, extracorporeal membrane oxygenation cardiopulmonary resuscitation appears promising under special resuscitation circumstances to improve outcome from highly selected in-hospital pediatric cardiac arrest victims. Further, postresuscitation interventions such as goal-directed therapies and therapeutic hypothermia have been demonstrated in adults and infants to improve outcome for selected cardiac arrest victims and are promising candidate targets for study in children.

SUMMARY

Pediatric cardiac arrest is not a futile condition; many children are successfully resuscitated each year. The implementation of new prearrest, intraarrest and postresuscitative therapies has the potential to further improve survival rates following pediatric cardiac arrest.

Out-of-hospital cardiac arrest: first documented experience in a Mexican urban setting

OBJECTIVE

Out-of-hospital cardiac arrest is one of the leading causes of death in Mexico, but many survival and prognostic factors are unknown. The aim of this study was to assess out-of-hospital cardiac arrest in a Mexican city.

METHODS

This was a prospective, cohort study that evaluated the records of the major ambulance services in the city of Queretaro, Mexico. Means, standard deviation, and percentages for the categorical variables were obtained. Logistic regression was performed to determine the effects between interventions, times, and return of spontaneous circulation (ROSC).

RESULTS

For an 11-month period, 148 out-of-hospital cardiac arrest cases were recorded. The mean age of the victims was 54 +/- 22.6 years and 90 (65.3%) were males. Forty-nine cases were related to cardiac disease, 46 to other disease, 27 to trauma, 18 to terminal illnesses, and three to drowning. Twelve (8.6%) patients had a pulse upon hospital arrival, but none survived to discharge. No victims were defibrillated prior to ambulance arrival. The collapse-assessment interval was 22.5 +/- 19:1 minutes, the mean value for the ambulance response times was 13:6 +/-10:4 minutes. Basic emergency medical technicians applied chest compressions to 40 victims (27.2%), controlled the airway in 32 (21.8%), and defibrillated seven (4.8%). Chest compressions and airway control showed an OR of 8 and 12 respectively for ROSC.

CONCLUSIONS

The poor survival rate in this study emphasizes the need to improve efforts in provider training and public education. Authorities must promote actions to enhance prehospital emergency services capabilities, shorten response times, and provide community education to increase the chances of survival for out-of-hospital cardiac arrest victims in Mexico.

Cardiopulmonary resuscitation: from the beginning to the present day

Cardiac arrest represents a dramatic event that can occur suddenly and often without premonitory signs, characterized by sudden loss of consciousness and breathing after cardiac output ceases and both coronary and cerebral blood flows stop. Restarting of the blood flow by cardiopulmonary resuscitation potentially re-establishes some cardiac output and organ blood flows. This article summarizes the major events that encompass the history of cardiopulmonary resuscitation, beginning with ancient history and evolving into the current American Heart Association's commitment to save hearts.

Basic life support with four different compression/ventilation ratios in a pig model: the need for ventilation

BACKGROUND

During cardiac arrest the paramount goal of basic life support (BLS) is the oxygenation of vital organs. Current recommendations are to combine chest compressions with ventilation in a fixed ratio of 30:2; however the optimum compression/ventilation ratio is still debatable. In our study we compared four different compression/ventilation ratios and documented their effects on the return of spontaneous circulation (ROSC), gas exchange, cerebral tissue oxygenation and haemodynamics in a pig model.

METHODS

Study was performed on 32 pigs under general anaesthesia with endotracheal intubation. Arterial and central venous lines were inserted. For continuous cerebral tissue oxygenation a Licox PtiO(2) probe was implanted. After 3 min of cardiac arrest (ventricular fibrillation) animals were randomized to a compression/ventilation-ratio 30:2, 100:5, 100:2 or compressions-only. Subsequently 10 min BLS, Advanced Life Support (ALS) was performed (100%O(2), 3 defibrillations, 1mg adrenaline i.v.). Data were analyzed with 2-factorial ANOVA.

RESULTS

ROSC was achieved in 4/8 (30:2), 5/8 (100:5), 2/8 (100:2) and 0/8 (compr-only) pigs. During BLS, PaCO(2) increased to 55 mm Hg (30:2), 68 mm Hg (100:5; p=0.0001), 66 mm Hg (100:2; p=0.002) and 72 mm Hg (compr-only; p<0.0001). PaO(2) decreased to 58 mmg (30:2), 40 mm Hg (100:5; p=0.15), 43 mm Hg (100:2; p=0.04) and 26 mm Hg (compr-only; p<0.0001). PtiO(2) baseline values were 12.7, 12.0, 11.1 and 10.0 mm Hg and decreased to 8.1 mm Hg (30:2), 4.1 mm Hg (100:5; p=0.08), 4.3 mm Hg (100:2; p=0.04), and 4.5 mm Hg (compr-only; p=0.69).

CONCLUSIONS

During BLS, a compression/ventilation-ratio of 100:5 seems to be equivalent to 30:2, while ratios of 100:2 or compressions-only detoriate peripheral arterial oxygenation and reduce the chance for ROSC.

A randomized cross-over study of the quality of cardiopulmonary resuscitation among females performing 30:2 and hands-only cardiopulmonary resuscitation

Background

Hands-Only cardiopulmonary resuscitation (CPR) is recommended for use on adult victims of witnessed out-of-hospital (OOH) sudden cardiac arrest or in instances where rescuers cannot perform ventilations while maintaining minimally interrupted quality compressions. Promotion of Hands-Only CPR should improve the incidence of bystander CPR and, subsequently, survival from OOH cardiac arrest; but, little is known about a rescuer's ability to deliver continuous chest compressions of adequate rate and depth for periods typical of emergency services response time. This study evaluated chest compression rate and depth as subjects performed Hands-Only CPR for 10 minutes. For comparison purposes, each also performed chest compressions with ventilations (30:2) CPR. It also evaluated fatigue and changes in body biomechanics associated with each type of CPR.

Methods

Twenty healthy female volunteers certified in basic life support performed Hands-Only CPR and 30:2 CPR on a manikin. A mixed model repeated measures cross-over design evaluated chest compression rate and depth, changes in fatigue (chest compression force, perceived exertion, and blood lactate level), and changes in electromyography and joint kinetics and kinematics.

Results

All subjects completed 10 minutes of 30:2 CPR; but, only 17 completed 10 minutes of Hands-Only CPR. Rate, average depth, percentage at least 38 millimeters deep, and force of compressions were significantly lower in Hands-Only CPR than in 30:2 CPR. Rates were maintained; but, compression depth and force declined significantly from beginning to end CPR with most decrement occurring in the first two minutes. Perceived effort and joint torque changes were significantly greater in Hands-Only CPR. Performance was not influenced by age.

Conclusion

Hands-Only CPR required greater effort and was harder to sustain than 30:2 CPR. It is not known whether the observed greater decrement in chest compression depth associated with Hands-Only CPR would offset the potential physiological benefit of having fewer interruptions in compressions during an actual resuscitation. The dramatic decrease in compression depth in the first two minutes reinforces current recommendations that rescuers take turns performing compressions, switching every two minutes or less. Further study is recommended to determine the impact of real-time feedback and dispatcher coaching on rescuer performance.

A qualitative study to identify barriers to local implementation of prehospital termination of resuscitation protocols

BACKGROUND

Despite the existence of national American Heart Association guidelines and 2 termination-of-resuscitation (TOR) rules for ceasing efforts in refractory out-of-hospital cardiac arrest, many emergency medical services agencies in the United States have adopted their own local protocols. Public policies and local perceptions may serve as barriers or facilitators to implementing national TOR guidelines at the local level.

METHODS AND RESULTS

Three focus groups, lasting 90 to 120 minutes, were conducted at the National Association of Emergency Medical Services Physicians meeting in January 2008. Snowball sampling was used to recruit participants. Two reviewers analyzed the data in an iterative process to identify recurrent and unifying themes. We identified 3 distinct groups whose current policies or perceptions may impede efforts to adopt national TOR guidelines: payers who incentivize transport; legislators who create state mandates for transport and allow only narrow use of do-not-resuscitate orders; and communities where cultural norms are perceived to impede termination of resuscitation. Our participants suggested that national organizations, such as the American Heart Association and American College of Emergency Physicians, may serve as potential facilitators in addressing these barriers by taking the lead in asking payers to change reimbursement structures; encouraging legislators to revise laws to reflect the best available medical evidence; and educating the public that rapid transport to the hospital cannot substitute for optimal provision of prehospital care.

CONCLUSIONS

We have identified 3 influential groups who will need to work with national organizations to overcome current policies or prevailing perceptions that may impede implementing national TOR guidelines.

Continuous Improvements in “Chain of Survival” Increased Survival After Out-of-Hospital Cardiac Arrests

Background— The impact of ongoing efforts to improve the “chain of survival” for out-of-hospital cardiac arrest (OHCA) is unclear. The objective of this study was to evaluate the incremental effect of changes in prehospital emergency care on survival after OHCA.

Methods and Results— This prospective, population-based observational study involved consecutive patients with OHCA from May 1998 through December 2006. The primary outcome measure was 1-month survival with favorable neurological outcome. Multiple logistic regression analysis was used to assess factors that were potentially associated with better neurological outcome. Among 42 873 resuscitation-attempted adult OHCAs, 8782 bystander-witnessed arrests of presumed cardiac origin were analyzed. The median time interval from collapse to call for medical help, first cardiopulmonary resuscitation, and first shock shortened from 4 (interquartile range [IQR] 2 to 11) to 2 (IQR 1 to 5) minutes, from 9 (IQR 5 to 13) to 7 (IQR 3 to 11) minutes, and from 19 (IQR 13 to 22) to 9 (IQR 7 to 12) minutes, respectively. Neurologically intact 1-month survival after witnessed ventricular fibrillation increased from 6% (6/96) to 16% (49/297; P <0.001). Among all witnessed OHCAs, earlier cardiopulmonary resuscitation (odds ratio per minute 0.89, 95% confidence interval 0.85 to 0.93) and earlier intubation (odds ratio per minute 0.96, 95% confidence interval 0.94 to 0.99) were associated with better neurological outcome. For ventricular fibrillation, only earlier shock was associated with better outcome (odds ratio 0.84, 95% confidence interval 0.80 to 0.88).

Conclusions— Data from a large, population-based cohort demonstrate a continuous increase in OHCA survival with improvement in the chain of survival. The incremental benefit of early advanced care on OHCA survival is also suggested.

[Chest compression without ventilation during basic life support? Confirmation of the validity of the European Resuscitation Council (ERC) guidelines 2005]

Basic life support (BLS) refers to maintaining airway patency and supporting breathing and the circulation, without the use of equipment other than infection protection measures. The scientific advisory committee of the American Heart Association (AHA) published recommendations (online-first) on March 31 2008, which promote a call to action for bystanders who are not or not sufficiently trained in cardiopulmonary resuscitation (CPR) and witness an adult out-of-hospital sudden collapse probably of cardiac origin. These bystanders should provide chest compression without ventilation (so-called compression-only CPR). If bystanders were previously trained and thus confident with CPR, they should decide between conventional CPR (chest compression plus ventilation at a ratio of 30:2) and chest compression alone. However, considering current evidence-based medicine and latest scientific data both the European Resuscitation Council (ERC) and the German Resuscitation Council (GRC) do not at present intend to change or supplement the current resuscitation guidelines "Basic life support for adults". Both organisations do not see any need for change or amendments in central European practice and continue to recommend that only those lay rescuers that are not willing or unable to give mouth-to-mouth ventilation should provide CPR solely by uninterrupted chest compressions until professional help arrives. It is also stressed that the training of young people especially teenagers as lay rescuers should be promoted and the establishment of training programs through emergency medical organizations and in schools should be encouraged.