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

Therapeutic hypothermia application vs standard support care in post resuscitated out-of-hospital cardiac arrest patients

INTRODUCTION

Survival after cardiac arrest remains poor, especially when it occurs outside of hospital. In recent years, therapeutic hypothermia has been used to improve outcomes in patients who have experienced cardiac arrest, however, application to out-of-hospital cardiac arrest (OHCA) patients remains controversial.

METHODS

A total of 175 OHCA patients underwent therapeutic hypothermia (TH), which was performed using large volume ice crystalloid fluid (LVICF) infusions after ICU admission. Ice packs and conventional cooling blankets were used to maintain a core body temperature of 33°C, according to standard protocol for 36 hours. Patients in the control group received standard supportive care without TH. Hospital survival and neurologic outcomes were compared.

RESULTS

There was no significant difference between the groups with regards to patient characteristics, underlying etiologies, and length of hospital stays. The duration of cardiac pulmonary resuscitation (CPR) was also similar. In the 51 patients that received TH, 14 were alive at hospital discharge. In the 124 patients belonging to the supportive care group, only 15 were alive at hospital discharge (27.5% vs. 12.1%, p = 0.013). Approximately 7.9% of patients in the TH group had good neurologic outcomes (4 of 51) compared with the 1.7% (2 of 124) of patients in the supportive group (p = 0.04). There were no specific treatment-related complications.

CONCLUSION

Therapeutic hypothermia can be safely applied to OHCA patients and can improve their outcome. Further large scale studies are needed to verify our results.

Association of neighborhood characteristics with bystander-initiated CPR

BACKGROUND

For persons who have an out-of-hospital cardiac arrest, the probability of receiving bystander-initiated cardiopulmonary resuscitation (CPR) may be influenced by neighborhood characteristics.

METHODS

We analyzed surveillance data prospectively submitted from 29 U.S. sites to the Cardiac Arrest Registry to Enhance Survival between October 1, 2005, and December 31, 2009. The neighborhood in which each cardiac arrest occurred was determined from census-tract data. We classified neighborhoods as high-income or low-income on the basis of a median household income threshold of $40,000 and as white or black if more than 80% of the census tract was predominantly of one race. Neighborhoods without a predominant racial composition were classified as integrated. We analyzed the relationship between the median income and racial composition of a neighborhood and the performance of bystander-initiated CPR.

RESULTS

Among 14,225 patients with cardiac arrest, bystander-initiated CPR was provided to 4068 (28.6%). As compared with patients who had a cardiac arrest in high-income white neighborhoods, those in low-income black neighborhoods were less likely to receive bystander-initiated CPR (odds ratio, 0.49; 95% confidence interval [CI], 0.41 to 0.58). The same was true of patients with cardiac arrest in neighborhoods characterized as low-income white (odds ratio, 0.65; 95% CI, 0.51 to 0.82), low-income integrated (odds ratio, 0.62; 95% CI, 0.56 to 0.70), and high-income black (odds ratio, 0.77; 95% CI, 0.68 to 0.86). The odds ratio for bystander-initiated CPR in high-income integrated neighborhoods (1.03; 95% CI, 0.64 to 1.65) was similar to that for high-income white neighborhoods.

CONCLUSIONS

In a large cohort study, we found that patients who had an out-of-hospital cardiac arrest in low-income black neighborhoods were less likely to receive bystander-initiated CPR than those in high-income white neighborhoods. (Funded by the Centers for Disease Control and Prevention and others.).

Hemodynamic and Metabolic Parameters During Prolonged Cardiac Arrest and Reperfusion by Extracorporeal Circulation

Extracorporeal membranous oxygenation (ECMO) is increasingly used in the management of refractory cardiac arrest. Our aim was to investigate early effects of ECMO after prolonged cardiac arrest. In fully anesthetized swine (48 kg, N=18) ventricular fibrillation (VF) was induced and untreated period (20 min) of cardiac arrest commenced, followed by 60 min extracorporeal reperfusion (ECMO flow 100 ml/kg.min). Hemodynamics, arterial blood gasses, plasma potassium, tissue oximetry (StO2) and cardiac (EGM) and cerebral (BIS) electrophysiological parameters were continuously recorded and analyzed. Within 3 minutes of VF hemodynamic and oximetry parameters fall abruptly while metabolic parameters destabilize gradually over 20 minutes peaking at pH 7.04±0.05, pCO2 89±14 mmHg, K+ 8.5±1.6 mmol/l. During reperfusion most parameters restore rapidly: within 3-5 minutes mean arterial pressure reaches >40 mmHg, StO2>50 %, paO2>100 mmHg, pCO2<50 mmHg, K+<5 mmol/l. EGMs mean amplitude peaks at 4.5±2.4 min. Cerebral activity (BIS>60) reappeared in 5 animals after 87±21 min. In 12/18 animals return of spontaneous circulation was achieved. In conclusions, ECMO provides rapid restitution of internal milieu even after prolonged arrest. However, despite normalization of global parameters full recovery was not guaranteed since cardiac and cerebral electrical activities were sufficiently restored only in some animals. More sensitive and organ specific indicators need to be identified in order to estimate adequacy of cardiac support devices.

Reduced in-hospital survival rates of out-of-hospital cardiac arrest victims with obstructive pulmonary disease

AIM

Out-of-hospital cardiac arrest (OHCA) due to sustained ventricular tachycardia/fibrillation (VT/VF) is common and often lethal. Patient's co-morbidities may determine survival after OHCA, and be instrumental in post-resuscitation care, but are poorly studied. We aimed to study whether patients with obstructive pulmonary disease (OPD) have a lower survival rate after OHCA than non-OPD patients.

METHODS

We performed a community-based cohort study of 1172 patients with non-traumatic OHCA with ECG-documented VT/VF between 2005 and 2008. We compared survival to emergency room (ER), to hospital admission, to hospital discharge, and at 30 days after OHCA, of OPD-patients and non-OPD patients, using logistic regression analysis. We also compared 30-day survival of patients who were admitted to hospital, using multivariate logistic regression analysis.

RESULTS

OPD patients (n=178) and non-OPD patients (n=994) had comparable survival to ER (75% vs. 78%, OR 0.9 [95% CI: 0.6-1.3]) and to hospital admission (56% vs. 57%, OR 1.0 [0.7-1.4]). However, survival to hospital discharge was significantly lower among OPD patients (21% vs. 33%, OR 0.6 [0.4-0.9]). Multivariate regression analysis among patients who were admitted to hospital (OPD: n=100, no OPD: n=561) revealed that OPD was an independent determinant of reduced 30-day survival rate (39% vs. 59%, adjusted OR 0.6 [0.4-1.0, p=0.035]).

CONCLUSION

OPD-patients had lower survival rates after OHCA than non-OPD patients. Survival to ER and to hospital admission was not different between both groups. However, among OHCA victims who survived to hospital admission, OPD was an independent determinant of reduced 30-day survival rate.

Use of automated external defibrillators in patients with traumatic out-of-hospital cardiac arrest

BACKGROUND

Because out-of-hospital cardiac arrests (OHCAs) due to a major trauma rarely present with shockable rhythms, the potential benefits of using automated external defibrillators (AEDs) at the scene of traumatic OHCAs have not been examined.

METHODS

We conducted an observational, retrospective cohort study using an Utstein-style analysis in Tainan city, Taiwan. The enrollees were adult patients with traumatic OHCAs accessed by emergency medical technicians (EMTs) from January 1, 2004 to December 31, 2010. The exposure was the use or non-use of AEDs at the scene, as determined by the clinical judgment of the EMTs. The primary outcome evaluated was a sustained (≥2h) return of spontaneous circulation (ROSC), and the secondary outcomes were prehospital ROSC, overall ROSC, survival to hospital admission, survival at one month and favorable neurologic status at one month.

RESULTS

A total of 424 patients (313 males) were enrolled, of whom 280 had AEDs applied, and 144 did not. Only 25 (5.9%) patients had received bystander cardiopulmonary resuscitation (CPR), and merely 21 (7.5%) patients in the AED group presented with shockable rhythms. Compared to the non-AED group, the primary and secondary outcomes of the AED group were not significantly different, except for a significantly lower prehospital ROSC rate (1.1% vs. 4.9%, p<0.05). Multivariate analysis showed no significant interactions between the use of AEDs and other key variables. Use of the AED was not associated with sustained ROSC (OR 1.33; 95% CI 0.75-2.38, p=0.33).

CONCLUSIONS

In a community with a low prevalence of shockable rhythms and administration of bystander CPR in patients with traumatic OHCA, we found no significant differences in the sustained ROSC between the AED and the non-AED groups. Considering scene safety and the possible interruption of CPR, we do not encourage the routine use of AEDs at the scene of traumatic OHCAs.

Use of cardiocerebral resuscitation or AHA/ERC 2005 Guidelines is associated with improved survival from out-of-hospital cardiac arrest: a systematic review and meta-analysis

OBJECTIVE

To determine whether the use of cardiocerebral resuscitation (CCR) or AHA/ERC 2005 Resuscitation Guidelines improved patient outcomes from out-of-hospital cardiac arrest (OHCA) compared to older guidelines.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, EMBASE, Web of Science and the Cochrane Library databases. We also hand-searched study references and consulted experts.

STUDY SELECTION

Design: randomised controlled trials and observational studies.

POPULATION

OHCA patients, age >17 years.

COMPARATORS

'Control' protocol versus 'Study' protocol. 'Control' protocol defined as AHA/ERC 2000 Guidelines for cardiopulmonary resuscitation (CPR). 'Study' protocol defined as AHA/ERC 2005 Guidelines for CPR, or a CCR protocol.

OUTCOME

Survival to hospital discharge.

QUALITY

High-quality or medium-quality studies, as measured by the Newcastle Ottawa Scale using predefined categories.

RESULTS

Twelve observational studies met inclusion criteria. All the three studies using CCR demonstrated significantly improved survival compared to use of AHA 2000 Guidelines, as did five of the nine studies using AHA/ERC 2005 Guidelines. Pooled data demonstrate that use of a CCR protocol has an unadjusted OR of 2.26 (95% CI 1.64 to 3.12) for survival to hospital discharge among all cardiac arrest patients. Among witnessed ventricular fibrillation/ventricular tachycardia (VF/VT) patients, CCR increased survival by an OR of 2.98 (95% CI 1.92 to 4.62). Studies using AHA/ERC 2005 Guidelines showed an overall trend towards increased survival, but significant heterogeneity existed among these studies.

CONCLUSIONS

We demonstrate an association with improved survival from OHCA when CCR protocols or AHA/ERC 2005 Guidelines are compared to use of older guidelines. In the subgroup of patients with witnessed VF/VT, there was a threefold increase in OHCA survival when CCR was used. CCR appears to be a promising resuscitation protocol for Emergency Medical Services providers in increasing survival from OHCA. Future research will need to be conducted to directly compare AHA/ERC 2010 Guidelines with the CCR approach.

Regionalization of post-cardiac arrest care: implementation of a cardiac resuscitation center

BACKGROUND

Guidelines recommend standardized treatment of post-cardiac arrest patients to improve outcomes. However, the infrastructure, resources, and personnel required to meet the complex needs of cardiac arrest victims remain a barrier to care. Given that regionalization of time-dependent high-acuity illness is an emerging paradigm, the aim of the present study was to develop and implement a regionalized approach to post-cardiac arrest care.

METHODS

We performed a prospective observational study on all patients treated in a regionalized clinical pathway from November 2007 through June 2011. All patients were enrolled after admission to an urban academic medical center. Clinical data including arrest and treatment variables, complications, and outcome were collected on consecutive patients with the use of a preformatted standard data collection tool using Utstein criteria.

RESULTS

A total of 220 patients were enrolled; 127 (58%) patients were local direct admissions from our community, and 93 (42%) were transferred from 1 of 24 outlying referral hospitals. One hundred six (48%, 95% CI 38%-53%) patients survived to hospital discharge. The primary outcome of hospital survival with good neurologic function was observed in 94 (43%, 95% CI 32%-48%). There was no difference in survival with good neurologic outcome among local and referred patients. Overall 1-year survival was 44% (95% CI 38%-51%). Among patients discharged from the hospital with good neurologic function, 93% (95% CI 85%-97%) remained alive at 1 year.

CONCLUSION

Development of a regionalized approach to post-cardiac arrest care using previously established referral relationships is feasible, and implementation of such an approach was clinically effective in our region.

Efficacy of metronome sound guidance via a phone speaker during dispatcher-assisted compression-only cardiopulmonary resuscitation by an untrained layperson: a randomised controlled simulation study using a manikin

AIM

Untrained laypersons should perform compression-only cardiopulmonary resuscitation (COCPR) under a dispatcher's guidance, but the quality of the chest compressions may be suboptimal. We hypothesised that providing metronome sounds via a phone speaker may improve the quality of chest compressions during dispatcher-assisted COCPR (DA-COCPR).

METHODS

Untrained laypersons were allocated to either the metronome sound-guided group (MG), who performed DA-COCPR with metronome sounds (110 ticks/min), or the control group (CG), who performed conventional DA-COCPR. The participants of each group performed DA-COCPR for 4 min using a manikin with Skill-Reporter, and the data regarding chest compression quality were collected.

RESULTS

The data from 33 cases of DA-COCPR in the MG and 34 cases in the CG were compared. The MG showed a faster compression rate than the CG (111.9 vs 96.7/min; p=0.018). A significantly higher proportion of subjects in the MG performed the DA-COCPR with an accurate chest compression rate (100-120/min) compared with the subjects in the CG (32/33 (97.0%) vs 5/34 (14.7%); p<0.0001). The mean compression depth was not different between the MG and the CG (45.9 vs 46.8 mm; p=0.692). However, a higher proportion of subjects in the MG performed shallow compressions (compression depth <38 mm) compared with subjects in the CG (median % was 69.2 vs 15.7; p=0.035).

CONCLUSIONS

Metronome sound guidance during DA-COCPR for the untrained bystanders improved the chest compression rates, but was associated more with shallow compressions than the conventional DA-COCPR in a manikin model.

The cardiocerebral resuscitation protocol for treatment of out-of-hospital primary cardiac arrest

Out-of-hospital cardiac arrest (OHCA) is a significant public health problem in most westernized industrialized nations. In spite of national and international guidelines for cardiopulmonary resuscitation and emergency cardiac care, the overall survival of patients with OHCA was essentially unchanged for 30 years--from 1978 to 2008 at 7.6%. Perhaps a better indicator of Emergency Medical System (EMS) effectiveness in treating patients with OHCA is to focus on the subgroup that has a reasonable chance of survival, e.g., patients found to be in ventricular fibrillation (VF). But even in this subgroup, the average survival rate was 17.7% in the United States, unchanged between 1980 and 2003, and 21% in Europe, unchanged between 1980 and 2004. Prior to 2003, the survival of patients with OHCA, in VF in Tucson, Arizona was less than 9% in spite of incorporating previous guideline recommendations. An alternative (non-guidelines) approach to the therapy of patients with OHCA and a shockable rhythm, called Cardiocerebral Resuscitation, based on our extensive physiologic laboratory studies, was introduced in Tucson in 2003, in rural Wisconsin in 2004, and in selected EMS areas in the metropolitan Phoenix area in 2005. Survival of patients with OHCA due to VF treated with Cardiocerebral Resuscitation in rural Wisconsin increased to 38% and in 60 EMS systems in Arizona to 39%. In 2004, we began a statewide program to advocate chest compression-only CPR for bystanders of witnessed primary OHCA. Over the next five years, we found that survival of patients with a shockable rhythm was 17.7% in those treated with standard bystander CPR (mouth-to-mouth ventilations plus chest compression) compared to 33.7% for those who received bystander chest-compression-only CPR. This article on Cardiocerebral Resuscitation, by invitation following a presentation at the 2011 Danish Society Emergency Medical Conference, summarizes the results of therapy of patients with primary OHCA treated with Cardiocerebral Resuscitation, with requested emphasis on the EMS protocol.

Dietary fat quality and risk of sudden cardiac death in women

BACKGROUND

Dietary n-3 PUFAs are inversely associated with risk of sudden cardiac death (SCD); however, little is known about other fats and SCD. Furthermore, concerns have been raised that high n-6 PUFA intake may attenuate the benefits of n-3 PUFAs.

OBJECTIVE

We examined associations and selected interactions between dietary fatty acids, expressed as a proportion of total fat and SCD.

DESIGN

We conducted a prospective cohort study among 91,981 women aged 34-59 y from the Nurses' Health Study in 1980. Over 30 y, we documented 385 SCDs.

RESULTS

In multivariable models, women in the highest compared with the lowest quintile of SFA intake had an RR of SCD of 1.44 (95% CI: 1.04, 1.98). Conversely, women in the highest compared with the lowest quintile of PUFA intake had an RR of SCD of 0.57 (95% CI: 0.41, 0.78). Intakes of n-6 and n-3 PUFAs were both significantly associated with a lower risk of SCD, and n-6 PUFAs did not modify the association between n-3 PUFAs and SCD. MUFAs and trans fats were not associated with SCD risk. After further adjustment for coronary heart disease (CHD) and CHD risk factors potentially in the causal pathway, the association between PUFAs and SCD remained significant, whereas the association for SFAs was no longer significant.

CONCLUSIONS

Intake of PUFAs as a proportion of fat was inversely associated with SCD risk, independent of traditional CHD risk factors. These results support dietary guidelines to improve dietary fat quality by replacing intake of SFAs with n-6 and n-3 PUFAs.

A pilot study examining the severity and outcome of the post-cardiac arrest syndrome: a comparative analysis of two geographically distinct hospitals

BACKGROUND

Cardiac arrest occurs in >400 000 patients in the United States per year, and mortality rates vary across the country. Whether variations in cardiac arrest outcome are the result of differences in hospital or patient characteristics remains understudied. We tested whether hospital-independent factors would account for the difference in outcome between 2 geographically distinct hospitals.

METHODS AND RESULTS

Consecutive adult (age >18 years) out-of-hospital cardiac arrests were considered for analysis. The primary outcome was in-hospital mortality. Predictor variables were classified according to whether they were hospital-independent or whether they could be related to the hospital's quality of care. Only hospital-independent variables were considered for the analysis. Sequential logistic modeling was used to assess outcome. A propensity score was derived and was used in subsequent multivariate logistic regression to predict hospital outcome. A total of 208 subjects were included. Overall mortality in the Detroit cohort was 87% in comparison with 61% in the Boston cohort (odds ratio: 4.4; 95% confidence interval: 2.2-8.8). After sequential adjustments for baseline covariates, out-of-hospital cardiac arrest score and propensity score, city was not significantly associated with mortality (odds ratio: 1.16; 95% confidence interval: 0.45-2.97). After propensity matching there was no significant difference in the odds ratio for death between the 2 cities (odds ratio: 1.15; 95% confidence interval: 0.51-2.61).

CONCLUSIONS

In this pilot study, we found that pre- and intra-arrest conditions contribute substantially to the severity of the postarrest syndrome and on outcomes. Postarrest quality-of-care evaluations should include inherent differences in the presenting syndrome rather than a crude mortality rate.

Comparison of the quality of basic life support provided by rescuers trained using the 2005 or 2010 ERC guidelines

INTRODUCTION

Effective delivery of cardiopulmonary resuscitation (CPR) and prompt defibrillation following sudden cardiac arrest (SCA) is vital. Updated guidelines for adult basic life support (BLS) were published in 2010 by the European Resuscitation Council (ERC) in an effort to improve survival following SCA. There has been little assessment of the ability of rescuers to meet the standards outlined within these new guidelines.

METHODS

We conducted a retrospective analysis of the performance of first year healthcare students trained and assessed using either the new 2010 ERC guidelines or their 2005 predecessor, within the University of Birmingham, United Kingdom. All students were trained as lay rescuers during a standardised eight hour ERC-accredited adult BLS course.

RESULTS

We analysed the examination records of 1091 students. Of these, 561 were trained and assessed using the old 2005 ERC guidelines and 530 using the new 2010 guidelines. A significantly greater proportion of candidates failed in the new guideline group (16.04% vs. 11.05%; p < 0.05), reflecting a significantly greater proportion of lay-rescuers performing chest compressions at too fast a rate when trained and assessed with the 2010 rather than 2005 guidelines (6.04% vs. 2.67%; p < 0.05). Error rates for other skills did not differ between guideline groups.

CONCLUSIONS

The new ERC guidelines lead to a greater proportion of lay rescuers performing chest compressions at an erroneously fast rate and may therefore worsen BLS efficacy. Additional study is required in order to define the clinical impact of compressions performed to a greater depth and at too fast a rate.

Regional variations in early and late survival after out-of-hospital cardiac arrest

BACKGROUND

While prior studies highlight regional variations in out-of-hospital cardiac arrest (OHCA) survival, the underlying reasons remain unknown. We sought to characterize regional variations early and later survival to hospital discharge after OHCA.

METHODS

We studied adult, non-traumatic OHCA treated by 10 regional sites of the Resuscitation Outcomes Consortium (ROC) during 12/01/2005-6/30/2007. We compared (1) early survival (up to one calendar day after arrest) and (2) later conditional survival to hospital discharge (early survivors progressing to eventual hospital discharge) between ROC regional sites.

RESULTS

Among 3763 VF/VT with complete covariates, site unadjusted early survival varied from 11.3 to 54.3%, and site unadjusted later survival varied from 33.3 to 70.5%. Compared with the largest site, adjusted VF/VT survival varied across sites: early survival OR 0.33 (95% CI: 0.17, 0.65) to 2.87 (2.20, 3.73), overall site variation p<0.001; later survival OR 0.29 (0.14, 0.59) to 1.21 (0.73, 2.00), p<0.001. Among 10,879 non-VF/VT with complete covariates, site unadjusted early survival varied from 6.6 to 14.3%, and site unadjusted later survival varied from 4.5 to 39.6%. Compared with the largest site, adjusted non-VF/VT survival varied across sites: early survival OR 1.02 (0.63, 1.64) to 2.43 (1.91, 3.12), p<0.001; later survival OR 0.11 (0.01, 0.82) to 1.56 (0.90, 2.70), p=0.02.

CONCLUSIONS

In this prospective multicenter North American series, there were regional disparities in early and later survival after OHCA, suggesting that there are underlying regional differences in out-of-hospital and post-arrest care beyond traditional Utstein predictors. Community efforts to improve OHCA survival must address both out-of-hospital and in-hospital care.

Effect of cardiopulmonary resuscitation on restoration of myocardial ATP in prolonged ventricular fibrillation

BACKGROUND

There has been controversy over whether a short period of cardiopulmonary resuscitation (CPR) prior to defibrillation improves survival in patients who experienced a sudden cardiac arrest. However, there have been no reports about whether CPR restores the myocardial energy source during prolonged ventricular fibrillation (VF). The aim of this study is to investigate the effect of CPR in restoring myocardial high energy phosphates during prolonged VF.

METHODS AND RESULTS

Seventy-two adult male Sprague-Dawley rats were used in this study. Baseline adenosine triphosphate (ATP) and adenosine diphosphate (ADP) prior to induction of VF were measured in nine rats, the No-VF group. Sixty-three rats were subjected to 4 min of untreated VF. Animals were then randomized into two groups: No-CPR (n=37) and CPR (n=26). In the No-CPR group, ATPs and ADPs were measured at 4 min (No-CPR4), 6 min (No-CPR6), 8 min (No-CPR8) or 10 min (No-CPR10) after the induction of VF. The CPR group received 2 min (CPR2), 4 min (CPR4) or 6 min (CPR6) of mechanical chest compressions before ATP was measured. Myocardial ATP (nmol/mg protein) was decreased as VF duration was prolonged (No-VF: 5.49±1.71, No-CPR4: 4.27±1.58, No-CPR6: 4.13±1.31, No-CPR8: 3.77±1.42, No-CPR10: 3.52±0.90, p<0.05 between each of No-CPRs vs. No-VF). Two minutes of CPR restored myocardial ATP to the level of No-VF group (5.27±1.67 nmol/mg protein in CPR2, p>0.05 vs. No-VF group). However, myocardial ATP (nmol/mg protein) decreased if the duration of CPR was longer than 2 min (CPR4: 3.77±1.05, CPR6: 3.49±1.08, p<0.05 between CPR4 and CPR6 vs. No-VF).

CONCLUSIONS

CPR for 2 min helps to maintain myocardial ATP after prolonged VF.

Cardiopulmonary resuscitation and management of cardiac arrest

The best chance of survival with a good neurological outcome after cardiac arrest is afforded by early recognition and high-quality cardiopulmonary resuscitation (CPR), early defibrillation of ventricular fibrillation (VF), and subsequent care in a specialist center. Compression-only CPR should be used by responders who are unable or unwilling to perform mouth-to-mouth ventilations. After the first defibrillator shock, further rhythm checks and defibrillation attempts should be performed after 2 min of CPR. The underlying cause of cardiac arrest can be identified and treated during CPR. Drugs have a limited effect on long-term outcomes after cardiac arrest, although epinephrine improves the success of resuscitation, and amiodarone increases the success of defibrillation for refractory VF. Supraglottic airway devices are an alternative to tracheal intubation, which should be attempted only by skilled rescuers. Care after cardiac arrest includes controlled reoxygenation, therapeutic hypothermia for comatose survivors, percutaneous coronary intervention, circulatory support, and control of blood-glucose levels and seizures. Prognostication in comatose survivors of cardiac arrest needs a careful, multimodal approach using clinical and electrophysiological assessments after at least 72 h.

A simple audio-visual prompt device can improve CPR performance

BACKGROUND

An adjunct to assist cardiopulmonary resuscitation (CPR) might improve the quality of CPR performance.

STUDY OBJECTIVES

This study was conducted to evaluate whether a simple audio-visual prompt device improves CPR performance by emergency medical technicians (EMTs).

METHODS

From June 2008 to October 2008, 55 EMTs (39 men, mean age 34.9±4.8 years) participated in this study. A simple audio-visual prompt device was developed. The device generates continuous metronomic sounds for chest compression at a rate of 100 beats/min with a distinct 30(th) sound followed by two respiration sounds, each for 1 second. All EMTs were asked to perform a 2-min CPR series on a manikin without the device, and one 2-min CPR series with the device.

RESULTS

The average rate of chest compressions was more accurate when the device was used than when the device was not used (101.4±12.7 vs. 109.0±17.4/min, respectively, p=0.012; 95% confidence interval [CI] 97.2-103.8 vs. 104.5-113.5/min, respectively), and hands-off time during CPR was shorter when the device was used than when the device was not used (5.4±0.9 vs. 9.2±3.9 s, respectively, p<0.001; 95% CI 5.2-5.7 vs. 8.3-10.3 s, respectively). The mean tidal volume during CPR with the device was lower than without the device, resulting in the prevention of hyperventilation (477.6±60.0 vs. 636.6±153.4 mL, respectively, p<0.001; 95% CI 463.5-496.2 vs. 607.3-688.9 mL, respectively).

CONCLUSION

A simple audio-visual prompt device can improve CPR performance by emergency medical technicians.

Basic life support and automated external defibrillator skills among ambulance personnel: a manikin study performed in a rural low-volume ambulance setting

BACKGROUND

Ambulance personnel play an essential role in the 'Chain of Survival'. The prognosis after out-of-hospital cardiac arrest was dismal on a rural Danish island and in this study we assessed the cardiopulmonary resuscitation performance of ambulance personnel on that island.

METHODS

The Basic Life Support (BLS) and Automated External Defibrillator (AED) skills of the ambulance personnel were tested in a simulated cardiac arrest. Points were given according to a scoring sheet. One sample t test was used to analyze the deviation from optimal care according to the 2005 guidelines. After each assessment, individual feedback was given.

RESULTS

On 3 consecutive days, we assessed the individual EMS teams responding to OHCA on the island. Overall, 70% of the maximal points were achieved. The hands-off ratio was 40%. Correct compression/ventilation ratio (30:2) was used by 80%. A mean compression depth of 40-50 mm was achieved by 55% and the mean compression depth was 42 mm (SD 7 mm). The mean compression rate was 123 per min (SD 15/min). The mean tidal volume was 746 ml (SD 221 ml). Only the mean tidal volume deviated significantly from the recommended (p = 0.01). During the rhythm analysis, 65% did not perform any visual or verbal safety check.

CONCLUSION

The EMS providers achieved 70% of the maximal points. Tidal volumes were larger than recommended when mask ventilation was applied. Chest compression depth was optimally performed by 55% of the staff. Defibrillation safety checks were not performed in 65% of EMS providers.

Engaging a whole community in resuscitation

BACKGROUND

Survival after out-of-hospital cardiac arrest (OHCA) is influenced by each link in the chain of survival. On the Danish island of Bornholm (population 42,000, area 588 km2) none survived an OHCA in 2001-2003. Therefore, we designed a multifaceted community-based approach aiming at strengthening each link in the chain of survival. The purpose of this study was to evaluate the effect of implementation of the intervention on bystander basic life support (BLS) rates and survival to hospital discharge after OHCA.

METHODS

Laypersons completed 24-min DVD-based-self-instruction BLS courses in schools and workplaces or 4-h BLS/automated external defibrillator (AED) courses. The local television station had broadcasts about resuscitation. The ambulance personnel were trained and the staff at the island hospital completed BLS courses or more advanced courses.

RESULTS

During 2 years 9226 people (22% of the population) completed the short course and 2453 (6% of the population) completed the 4-h course. The number of AEDs increased from 3 to 147. The bystander BLS rate for OHCAs with a presumed cardiac aetiology (N=96, incidence 114/100,000 person-years) was 47% [95% CI 30-50] and for witnessed OHCAs (N=35) it increased significantly from 22% (2004) to 74% [95% CI 58-86]. The AEDs were deployed in 9 cases. Survival to discharge for all-rhythms OHCA was 5.4% [95% CI 2-12], and for witnessed ventricular fibrillation (N=17) 18% [95% CI 5-42].

CONCLUSION

Strengthening all links in the chain of survival was associated with significant increases in bystander BLS rates and survival after OHCA on a rural island.

The hospital's role in improving survival of patients with out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest (OHCA) is a major public health problem. Unfortunately, in spite of recurring updated guidelines, survival of patients with OHCA had been unchanged for decades. Recently, new approaches to patients with OHCA during the community and prehospital phases of therapy for cardiac arrest have resulted in a dramatic improvement in survival. Further improvement in survival has resulted from hospitals designated as Cardiac Receiving Centers. These centers are committed to the treatment of post-cardiac arrest syndrome by providing 24/7 therapeutic mild hypothermia, urgent cardiac catheterization and percutaneous coronary intervention, evidence-based termination of resuscitation protocols that limit premature withdrawal of care, protocol to address organ donation, commitment of cardiocerebral resuscitation training in their community, and a commitment and proven ability of data collection to assure that instituted changes result in improved survival. This newer aspect of hospital practice is an aspect that needs to be embraced by either becoming a Cardiac Receiving Center or partnering with other hospitals that can provide this critically important service.

Continuous chest compression cardiopulmonary resuscitation training promotes rescuer self-confidence and increased secondary training: a hospital-based randomized controlled trial*

OBJECTIVE

Recent work suggests that delivery of continuous chest compression cardiopulmonary resuscitation is an acceptable layperson resuscitation strategy, although little is known about layperson preferences for training in continuous chest compression cardiopulmonary resuscitation. We hypothesized that continuous chest compression cardiopulmonary resuscitation education would lead to greater trainee confidence and would encourage wider dissemination of cardiopulmonary resuscitation skills compared to standard cardiopulmonary resuscitation training (30 compressions: two breaths).

DESIGN

Prospective, multicenter randomized study.

SETTING

Three academic medical center inpatient wards.

SUBJECTS

Adult family members or friends (≥ 18 yrs old) of inpatients admitted with cardiac-related diagnoses.

INTERVENTIONS

In a multicenter randomized trial, family members of hospitalized patients were trained via the educational method of video self-instruction. Subjects were randomized to continuous chest compression cardiopulmonary resuscitation or standard cardiopulmonary resuscitation educational modes.

MEASUREMENTS

Cardiopulmonary resuscitation performance data were collected using a cardiopulmonary resuscitation skill-reporting manikin. Trainee perspectives and secondary training rates were assessed through mixed qualitative and quantitative survey instruments.

MAIN RESULTS

Chest compression performance was similar in both groups. The trainees in the continuous chest compression cardiopulmonary resuscitation group were significantly more likely to express a desire to share their training kit with others (152 of 207 [73%] vs. 133 of 199 [67%], p = .03). Subjects were contacted 1 month after initial enrollment to assess actual sharing, or "secondary training." Kits were shared with 2.0 ± 3.4 additional family members in the continuous chest compression cardiopulmonary resuscitation group vs. 1.2 ± 2.2 in the standard cardiopulmonary resuscitation group (p = .03). As a secondary result, trainees in the continuous chest compression cardiopulmonary resuscitation group were more likely to rate themselves "very comfortable" with the idea of using cardiopulmonary resuscitation skills in actual events than the standard cardiopulmonary resuscitation trainees (71 of 207 [34%] vs. 57 of 199 [28%], p = .08).

CONCLUSIONS

Continuous chest compression cardiopulmonary resuscitation education resulted in a statistically significant increase in secondary training. This work suggests that implementation of video self-instruction training programs using continuous chest compression cardiopulmonary resuscitation may confer broader dissemination of life-saving skills and may promote rescuer comfort with newly acquired cardiopulmonary resuscitation knowledge.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov. Unique identifier: NCT01260441.

Optimizing outcome after cardiac arrest

PURPOSE OF REVIEW

To discuss recent data relating to survival rates after cardiac arrest and interventions that can be used to optimize outcome.

RECENT FINDINGS

A recent analysis of 70 studies indicates that following out-of-hospital cardiac arrest (OHCA), 7.6% of patients will survive to hospital discharge (95% confidence interval 6.7-8.4). Following in-hospital cardiac arrest, 18% of patients will survive to hospital discharge. Survival may be optimized by increasing the rate of bystander cardiopulmonary resuscitation (CPR), which can be achieved by improving recognition of cardiac arrest, simplifying CPR and training more of the community. Feedback systems improve the quality of CPR but this has yet to be translated into improved outcome. One study has shown improved survival following OHCA with active compression-decompression CPR combined with an impedance-threshold device. In those who have no obvious extracardiac cause of OHCA, 70% have at least one significant coronary lesion demonstrable by coronary angiography. Although generally reserved for those with ST-elevation myocardial infarction, primary percutaneous coronary intervention may also benefit OHCA survivors with ECG patterns other than ST elevation. The term 'mild therapeutic hypothermia' has been replaced by the term 'targeted temperature management'; its role in optimizing outcome after cardiac arrest continues to be defined.

SUMMARY

In several centres, survival rates following OHCA are increasing. All links in the chain of survival must be optimized if a good-quality neurological outcome is to be achieved.

The relevance of severity scores in predicting outcome after cardiac arrest

Cardiac arrest is a major health and economic problem, with a mortality rate remaining unacceptably high. Prediction of outcome in this setting, especially if determined in the early phase after hospital admission, would allow clinicians to prioritize rapid therapeutic interventions, to better stratify patients' severity of illness, to reconsider the intensity of care and to readdress resource utilization. This article focuses on the possibility of using a severity-of-illness score, combining the Sequential Organ Failure Assessment score and the Full Outline of Unresponsiveness score, to predict morbidity and mortality after cardiac arrest.