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

Cardiac arrest management in general practice in Ireland: a 5-year cross-sectional study

OBJECTIVE

To document the involvement of general practitioners (GPs) in cardiac arrests with resuscitation attempts (CARAs) and to describe the outcomes.

DESIGN

A 5-year prospective cross-sectional study of GPs in Ireland equipped with automated external defibrillators (AEDs) and immediate care training by the MERIT Project, with data collection every 3 months over the 5-year period. Practices reported CARAs by quarterly survey with an 89% mean response rate (81-97% for the period).

SETTING

General practices throughout Ireland.

PARTICIPANTS

495 GP participated: 168 (33.9%) urban, 163 (32.9%) rural and 164 (33.1%) mixed.

INTERVENTIONS

All participating practices received a standard AED and basic life support kit. Training in immediate care was provided for at least one GP in the practice.

MAIN OUTCOME MEASURES

Incidence of CARA in participating practices. Return of spontaneous circulation (ROSC) and discharge alive from hospital.

RESULTS

36% of practices were involved in a CARA during the 5-year period and 13% were involved in more than one CARA. Of the 272 CARAs reported, ROSC occurred in 32% (87/272) and discharge from hospital in 18.7% (49/262). In 45% of cases, the first AED was brought by the GP and in 65%, the GP arrived before the ambulance service. More cases occurred in rural and mixed settings than urban ones, but the survival rates did not differ between areas. In 65% of cases, the GP was on duty at the time of the incident and 47% of cases occurred in the patient's home.

CONCLUSIONS

These outcomes are comparable with more highly structured components of the emergency response system and indicate that GPs have an important role to play in the care of patients in their own communities. GPs experience cardiac arrest cases during the course of their daily work and provide prompt care which results in successful outcomes in urban, mixed and rural settings.

A randomized trial of video self-instruction in cardiopulmonary resuscitation for lay persons

Background

Cardiopulmonary resuscitation (CPR) improves outcomes after cardiac arrest. Much of the lay public is untrained in CPR skills. We evaluated the effectiveness of a compression-only CPR video self-instruction (VSI) with a personal manikin in the lay public.

Methods

Adults without prior CPR training in the past year or responsibility to provide medical care were randomized into one of three groups: 1) Untrained before testing, 2) 10-minute VSI in compressions-only CPR (CPR Anytime, American Heart Association, Dallas, TX), or 3) 22-minute VSI in compressions and ventilations (CPR Anytime). CPR proficiency was assessed using a sensored manikin. The primary outcome was composite skill competence of 90% during five minutes of skill demonstration. Evaluated were alternative cut-points for skill competence and individual components of CPR. 488 subjects (143 in untrained group, 202 in compressions-only group and 143 in compressions and ventilation group) were required to detect 21% competency with compressions-only versus 7% with untrained and 34% with compressions and ventilations.

Results

Analyzable data were available for the untrained group (n = 135), compressions-only group (n = 185) and the compressions and ventilation group (n = 119). Four (3%) achieved competency in the untrained group (p-value = 0.57 versus compressions-only), nine (4.9%) in the compressions-only group, and 12 (10.1%) in the compressions and ventilations group (p-value 0.13 vs. compressions-only). The compressions-only group had a greater proportion of correct compressions (p-value = 0.028) and compressions with correct hand placement (p-value = 0.0004) compared to the untrained group.

Conclusions

VSI in compressions-only CPR did not achieve greater overall competency but did achieve some CPR skills better than without training.

A review of chest compression interruptions during out-of-hospital cardiac arrest and strategies for the future

BACKGROUND

It has been known for many years that interrupting chest compressions during cardiopulmonary resuscitation (CPR) from out-of-hospital cardiac arrest (OHCA) leads directly to negative outcomes. Interruptions in chest compressions occur for a variety of reasons, including provider fatigue and switching of compressors, performance of ventilations, placement of invasive airways, application of CPR devices, pulse and rhythm determinations, vascular access placement, and patient transfer to the ambulance. Despite significant resuscitation guideline changes in the last decade, several studies have shown that chest compressions are still frequently interrupted or poorly executed during OHCA resuscitations. Indeed, the American Heart Association has made great strides to improve outcomes by placing a greater emphasis on uninterrupted chest compressions. As highly trained health care providers, why do we still interrupt chest compressions? And are any of these interruptions truly necessary?

OBJECTIVES

This article aims to review the clinical effects of both high-quality chest compressions and the effects that interruptions during chest compressions have clinically on patient outcomes.

DISCUSSION

The causes of chest compression interruptions are explored from both provider and team perspectives. Current and future methods are introduced that may prompt the provider to reduce unnecessary interruptions during chest compressions.

CONCLUSIONS

New and future technologies may provide promising results, but the greatest benefit will always be a well-directed, organized, and proactive team of providers performing excellent-quality and continuous chest compressions during CPR.

Quantitative assessment of brain microvascular and tissue oxygenation during cardiac arrest and resuscitation in pigs

Cardiac arrest is associated with a very high rate of mortality, in part due to inadequate tissue perfusion during attempts at resuscitation. Parameters such as mean arterial pressure and end-tidal carbon dioxide may not accurately reflect adequacy of tissue perfusion during cardiac resuscitation. We hypothesised that quantitative measurements of tissue oxygen tension would more accurately reflect adequacy of tissue perfusion during experimental cardiac arrest. Using oxygen-dependent quenching of phosphorescence, we made measurements of oxygen in the microcirculation and in the interstitial space of the brain and muscle in a porcine model of ventricular fibrillation and cardiopulmonary resuscitation. Measurements were performed at baseline, during untreated ventricular fibrillation, during resuscitation and after return of spontaneous circulation. After achieving stable baseline brain tissue oxygen tension, as measured using an Oxyphor G4-based phosphorescent microsensor, ventricular fibrillation resulted in an immediate reduction in all measured parameters. During cardiopulmonary resuscitation, brain oxygen tension remained unchanged. After the return of spontaneous circulation, all measured parameters including brain oxygen tension recovered to baseline levels. Muscle tissue oxygen tension followed a similar trend as the brain, but with slower response times. We conclude that measurements of brain tissue oxygen tension, which more accurately reflect adequacy of tissue perfusion during cardiac arrest and resuscitation, may contribute to the development of new strategies to optimise perfusion during cardiac resuscitation and improve patient outcomes after cardiac arrest.

Traumatic cardiac arrest: should advanced life support be initiated?

BACKGROUND

Several studies recommend not initiating advanced life support in traumatic cardiac arrest (TCA), mainly owing to the poor prognosis in several series that have been published. This study aimed to analyze the survival of the TCA in our series and to determine which factors are more frequently associated with recovery of spontaneous circulation (ROSC) and complete neurologic recovery (CNR).

METHODS

This is a cohort study (2006-2009) of treatment benefits.

RESULTS

A total of 167 TCAs were analyzed. ROSC was obtained in 49.1%, and 6.6% achieved a CNR. Survival rate by age groups was 23.1% in children, 5.7% in adults, and 3.7% in the elderly (p < 0.05). There was no significant difference in ROSC according to which type of ambulance arrived first, but if the advanced ambulance first, 9.41% achieved a CNR, whereas only 3.7% if the basic ambulance first. We found significant differences between the response time and survival with a CNR (response time was 6.9 minutes for those who achieved a CNR and 9.2 minutes for those who died). Of the patients, 67.5% were in asystole, 25.9% in pulseless electrical activity (PEA), and 6.6% in VF. ROSC was achieved in 90.9% of VFs, 60.5% of PEAs, and 40.2% of those in asystole (p < 0.05), and CNR was achieved in 36.4% of VFs, 7% of PEAs, and 2.7% of those in asystole (p < 0.05). The mean (SD) quantity of fluid replacement was greater in ROSC (1,188.8 [786.7] mL of crystalloids and 487.7 [688.9] mL of colloids) than in those without ROSC (890.4 [622.4] mL of crystalloids and 184.2 [359.3] mL of colloids) (p < 0.05).

CONCLUSION

In our series, 6.6% of the patients survived with a CNR. Our data allow us to state beyond any doubt that advanced life support should be initiated in TCA patients regardless of the initial rhythm, especially in children and those with VF or PEA as the initial rhythm and that a rapid response time and aggressive fluid replacement are the keys to the survival of these patients.

LEVEL OF EVIDENCE

Therapeutic study, level IV; epidemiologic study, level III.

Quantifying the effect of cardiopulmonary resuscitation quality on cardiac arrest outcome: a systematic review and meta-analysis

Background- Evidence has accrued that cardiopulmonary resuscitation quality affects cardiac arrest outcome. However, the relative contributions of chest compression components (such as rate and depth) to successful resuscitation remain unclear. Methods and Results- We sought to measure the effect of cardiopulmonary resuscitation quality on cardiac arrest outcome through systematic review and meta-analysis. We searched for any clinical study assessing cardiopulmonary resuscitation performance on adult cardiac arrest patients in which survival was a reported outcome, either return of spontaneous circulation or survival to admission or discharge. Of 603 identified abstracts, 10 studies met inclusion criteria. Effect sizes were reported as mean differences. Missing data were resolved by author contact. Estimates were segregated by cardiopulmonary resuscitation metric (chest compression rate, depth, no-flow fraction, and ventilation rate), and a random-effects model was applied to estimate an overall pooled effect. Arrest survivors were significantly more likely to have received deeper chest compressions than nonsurvivors (mean difference, 2.44 mm; 95% confidence interval, 1.19-3.69 [P<0.001]; n=6 studies; I(2)=0.0%; P for heterogeneity=0.9). Likewise, survivors were significantly more likely to have received chest compression rates closer to 85 to 100 compressions per minute (cpm) than nonsurvivors (absolute mean difference from 85 cpm, -4.81 cpm; 95% confidence interval, -8.19 to -1.43 [P=0.005]; from 100 cpm, -5.04 cpm; 95% confidence interval, -8.44 to -1.65 [P=0.004]; n=6 studies; I(2)<49%; P for heterogeneity >0.2). No significant difference in no-flow fraction (n=7 studies) or ventilation rate (n=4 studies) was detected between survivors and nonsurvivors. Conclusions- Deeper chest compressions and rates closer to 85 to 100 cpm are significantly associated with improved survival from cardiac arrest.

Survival in out-of-hospital cardiac arrests with initial asystole or pulseless electrical activity and subsequent shockable rhythms

BACKGROUND

Non-shockable arrest rhythms (pulseless electrical activity and asystole) represent an increasing proportion of reported cases of out-of-hospital cardiac arrest (OHCA). The prognostic significance of conversion from non-shockable to shockable rhythms during the course of resuscitation remains unclear.

OBJECTIVE

To evaluate whether out-of-hospital cardiac arrest survival with initially non-shockable arrest rhythms is improved with subsequent conversion to shockable rhythms.

METHODS

Secondary analysis of data in Epistry - Cardiac Arrest, an epidemiologic registry maintained by the Resuscitation Outcomes Consortium (ROC). This analysis includes OHCA events from December 1, 2005 through May 31, 2007 contributed by six US and two Canadian sites. For all EMS-treated adult (18 and older) cardiac arrest patients who presented with non-shockable cardiac arrest, we compared survival to hospital discharge between patients who did develop a shockable rhythm and those who did not based on receipt of subsequent defibrillation. Missing data were handled using multiple imputation. Multivariable logistic regression was used to adjust for potentially confounding variables.

RESULTS

A total of 6556 EMS treated adult cardiac arrest cases presented in non-shockable rhythms. Survival to discharge in patients who converted to a shockable rhythm was 2.77% while survival in those who did not was 2.72% (p=0.92). After adjusting for confounders, conversion to a shockable rhythm was not associated with improved survival (OR 0.88, 95% CI: 0.60-1.30).

CONCLUSION

For OHCA patients presenting in PEA/asystole, survival to hospital discharge was not associated with conversion to a shockable rhythm during EMS resuscitation efforts.

Updates in the American Heart Association guidelines for cardiopulmonary resuscitation and potential applications to veterinary patients

OBJECTIVE

To review the updates in the American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) and identify potential applications to veterinary patients.

ETIOLOGY

Cardiopulmonary arrest is common in veterinary emergency and critical care, and consensus guidelines are lacking. Human resuscitation guidelines are continually evolving as new clinical and experimental studies support updated recommendations. Synthesis of human, experimental animal model, and veterinary literature support the potential for updates and advancement in veterinary CPR practices.

THERAPY

This review serves to highlight updates in the AHA guidelines for CPR and evaluate their application to small animal veterinary patients. Interventions identified will be evaluated for trans-species potential, raise questions regarding best resuscitation recommendations, and offer opportunities for further research to continue to advance veterinary CPR.

PROGNOSIS

The prognosis for any patient undergoing cardiopulmonary arrest remains guarded.

Therapeutic hypothermia after out-of-hospital cardiac arrest in Finnish intensive care units: the FINNRESUSCI study

PURPOSE

We aimed to evaluate post-resuscitation care, implementation of therapeutic hypothermia (TH) and outcomes of intensive care unit (ICU)-treated out-of-hospital cardiac arrest (OHCA) patients in Finland.

METHODS

We included all adult OHCA patients admitted to 21 ICUs in Finland from March 1, 2010 to February 28, 2011 in this prospective observational study. Patients were followed (mortality and neurological outcome evaluated by Cerebral Performance Categories, CPC) within 1 year after cardiac arrest.

RESULTS

This study included 548 patients treated after OHCA. Of those, 311 patients (56.8%) had a shockable initial rhythm (incidence of 7.4/100,000/year) and 237 patients (43.2%) had a non-shockable rhythm (incidence of 5.6/100,000/year). At ICU admission, 504 (92%) patients were unconscious. TH was given to 241/281 (85.8%) unconscious patients resuscitated from shockable rhythms, with unfavourable 1-year neurological outcome (CPC 3-4-5) in 42.0% with TH versus 77.5% without TH (p < 0.001). TH was given to 70/223 (31.4%) unconscious patients resuscitated from non-shockable rhythms, with 1-year CPC of 3-4-5 in 80.6% (54/70) with TH versus 84.0% (126/153) without TH (p = 0.56). This lack of difference remained after adjustment for propensity to receive TH in patients with non-shockable rhythms.

CONCLUSIONS

One-year unfavourable neurological outcome of patients with shockable rhythms after TH was lower than in previous randomized controlled trials. However, our results do not support use of TH in patients with non-shockable rhythms.

[Survival of out-hospital cardiac arrests attended by a mobile intensive care unit in Asturias (Spain) in 2010]

OBJECTIVE

To evaluate attendance timings, out- and in-hospital characteristics, and survival of cardiac arrests attended by an advanced life support unit in Asturias (Spain) in 2010. Factors related to survival upon admission and at discharge were also analyzed.

DESIGN

A retrospective, observational trial was carried out involving a cohort of out-hospital cardiac arrests (OHCA) occurring between 1 January 2010 and 31 December 2010, with one year of follow-up from OHCA.

SETTING

Health Care Area IV of the Principality of Asturias, with a population of 342,020 in 2010.

PATIENTS

All patients with OHCA and attended by an advanced life support unit were considered.

MAIN VARIABLES

Demographic data, the etiology of cardiac arrest, bystander cardiopulmonary resuscitation (CPR), attendance timings and survival upon admission, at discharge and after one year.

RESULTS

A total of 177 OHCA were included. Of these, 120 underwent CPR by the advanced life support team. Sixty-six of these cases (55%) were caused by presumed heart disease. A total of 63 patients (52.5%) recovered spontaneous circulation, and 51 (42.5%) maintained circulation upon admission to hospital. Thirteen patients (10.8%) were discharged alive. After one year, 11 patients were still alive (9.2%) - 9 of them (7.5%) with a Cerebral Performance Category (CPC) score of 1. Ventricular fibrillation and short attendance timings were related to increased survival.

CONCLUSIONS

The survival rate upon admission was better than in other series and similar at discharge. Initial rhythm and attendance timings were related. Public automated external defibrillators (AED) were not used, and bystander CPR was infrequent.

Extracorporeal membrane oxygenation to support cardiopulmonary resuscitation in a sheep model of refractory ischaemic cardiac arrest

BACKGROUND

Survival after out-of-hospital cardiac arrest remains limited. It is therefore imperative to develop new resuscitation techniques. We aimed to determine the potential role of extracorporeal membrane oxygenation assisted CPR (ECPR) in an animal model of refractory ischaemic cardiac arrest.

METHODS

Twelve sheep were assigned to either ECPR (n=6) or 'conventional' (n=6) resuscitation. All sheep had coronary occlusion, followed by induction of ventricular fibrillation (VF). CPR was than commenced for 10 min in both groups, followed by randomisation to ECPR or CPR for a further 10 min. At 23 min post induction of VF, advanced life support measures were commenced with direct cardioversion, adrenaline and amiodarone. Outcomes measures included rates of return of spontaneous circulation (ROSC), and analysis of VF wave form.

RESULTS

Baseline haemodynamics were similar between the two groups. CPR consistently produced coronary perfusion pressures (CPP) greater than 15 mmHg in both groups, with significantly increased CPP post commencement of ECMO in the ECPR group (17.84±2 mmHg vs 22.94±3 mmHg, p=0.04). Number of shocks, pH, lactate and oxygenation were also comparable. Significantly greater rates of ROSC were seen in the ECPR sheep, 3/6 (50%) vs 0/6 (0%) (p=0.032), which was also associated with significantly increased VF amplitude measures (0.51±0.08 mV vs 0.42±0.06 mV, p=0.04).

CONCLUSIONS

This study indicates that ECPR increases return of circulation and coronary perfusion pressure in a sheep model of ischaemic VF arrest. Our findings have supported the development of a pilot trial into the effectiveness and feasibility of ECPR in the clinical setting.

Chest Compression Alone Cardiopulmonary Resuscitation Is Associated With Better Long-Term Survival Compared with Standard Cardiopulmonary Resuscitation

Background—

Little is known about the long-term survival effects of type-specific bystander cardiopulmonary resuscitation (CPR) in the community. We hypothesized that dispatcher instruction consisting of chest compression alone would be associated with better overall long-term prognosis in comparison with chest compression plus rescue breathing.

Methods and Results—

The investigation was a retrospective cohort study that combined 2 randomized trials comparing the short-term survival effects of dispatcher CPR instruction consisting either of chest compression alone or chest compression plus rescue breathing. Long-term vital status was ascertained by using the respective National and State death records through July 31, 2011. We performed Kaplan-Meier method and Cox regression to evaluate survival according to the type of CPR instruction. Of the 2496 subjects included in the current investigation, 1243 (50%) were randomly assigned to chest compression alone and 1253 (50%) were randomly assigned to chest compression plus rescue breathing. Baseline characteristics were similar between the 2 CPR groups. During the 1153.2 person-years of follow-up, there were 2260 deaths and 236 long-term survivors. Randomization to chest compression alone in comparison with chest compression plus rescue breathing was associated with a lower risk of death after adjustment for potential confounders (adjusted hazard ratio, 0.91; 95% confidence interval, 0.83–0.99; P =0.02).

Conclusions—

The findings provide strong support for long-term mortality benefit of dispatcher CPR instruction strategy consisting of chest compression alone rather than chest compression plus rescue breathing among adult patients with cardiac arrest requiring dispatcher assistance.

Drowning related out-of-hospital cardiac arrests: characteristics and outcomes

AIM

There are few studies on drowning-related out-of-hospital cardiac arrest (OHCA) in which patients are followed from the scene through to hospital discharge. This study aims to describe this population and their outcomes in the state of Victoria (Australia).

METHODS

The Victorian Ambulance Cardiac Arrest Registry was searched for all cases of OHCA with a precipitating event of drowning attended by emergency medical services (EMS) between October 1999 and December 2011.

RESULTS

EMS attended 336 drowning-related OHCA during the study period. Cases frequently occurred in summer (45%) and the majority of patients were male (70%) and adult (77%). EMS resuscitation was attempted on 154 (46%) patients. Of these patients, 41 (27%) survived to hospital arrival and 12 (8%) survived to hospital discharge (5 adults [6%] and 7 [12%] children). Few patients were found in a shockable rhythm (6%), with the majority presenting in asystole (79%) or pulse-less electrical activity (13%). An initial shockable rhythm was found to positively predict survival (AOR 48.70, 95% CI: 3.80-624.86) while increased EMS response time (AOR 0.73, 95% CI: 0.54-0.98) and salt water drowning (AOR 0.69, 95% CI: 0.01-0.84) were found to negatively predict survival.

CONCLUSIONS

Rates of survival in OHCA caused by drowning are comparable to other OHCA causes. Patients were more likely to survive if they did not drown in salt water, had a quick EMS response and they were found in a shockable rhythm. Prevention efforts and reducing EMS response time are likely to improve survival of drowning patients.

Increasing arterial oxygen partial pressure during cardiopulmonary resuscitation is associated with improved rates of hospital admission

AIM

As recent clinical data suggest a harmful effect of arterial hyperoxia on patients after resuscitation from cardiac arrest (CA), we aimed to investigate this association during cardiopulmonary resuscitation (CPR), the earliest and one of the most crucial phases of recirculation.

METHODS

We analysed 1015 patients who from 2003 to 2010 underwent out-of-hospital CPR administered by emergency medical services serving 300,000 inhabitants. Inclusion criteria for further analysis were nontraumatic background of CA and patients >18 years of age. One hundred and forty-five arterial blood gas analyses including oxygen partial pressure (paO2) measurement were obtained during CPR.

RESULTS

We observed a highly significant increase in hospital admission rates associated with increases in paO2 in steps of 100 mmHg (13.3 kPa). Subsequently, data were clustered according to previously described cutoffs (≤ 60 mmHg [8 kPa]], 61-300 mmHg [8.1-40 kPa], >300 mmHg [>40 kPa]). Baseline variables (age, sex, initial rhythm, rate of bystander CPR and collapse-to-CPR time) of the three compared groups did not differ significantly. Rates of hospital admission after CA were 18.8%, 50.6% and 83.3%, respectively. In a multivariate analysis, logistic regression revealed significant prognostic value for paO2 and the duration of CPR.

CONCLUSION

This study presents novel human data on the arterial paO2 during CPR in conjunction with the rate of hospital admission. We describe a significantly increased rate of hospital admission associated with increasing paO2. We found that the previously described potentially harmful effects of hyperoxia after return of spontaneous circulation were not reproduced for paO2 measured during CPR.

CLINICAL TRIAL REGISTRATION

n/a.

Evaluation of Chest Compression Depth during Nine Minutes of Hands-Only Cardiopulmonary Resuscitation Performed by a Lone Rescuer and its Effect by Age Group: A Pilot Simulation Study Using a Manikin

Objective

There have been few studies on the use of long-standing hands-only cardiopulmonary resuscitation (CPR) by a lone rescuer. This study aimed to evaluate the long-standing (nine minutes) hands-only CPR by a lone rescuer, and the change of chest compression depth over time. The effect of age of rescuer on chest compression depth was also studied.

Methods

From a total of 404 adult lay-persons who participated in CPR training, 91 subjects were enrolled in the simulation trial of nine minutes of hands-only CPR using a manikin with a Skill-Reporter™. The quality of the chest compression over time and the effects of rescuer age were analysed.

Results

Of the 91 participants, 74 (81%) fully completed the nine minutes of CPR. No significant differences of incomplete CPR rate between each age group were observed. No significant differences in the degree of reduction in effective chest compressions were observed based on the time course among the different age groups. The total number of compressions decreased abruptly from the six-minute time point onwards (five minutes vs. six minutes, p=0.038).

Conclusions

Most trained lay-persons could complete the 9 minutes of hands-only CPR. The rate of chest compression shows a significant decrease after 6 minute. We do not find a significant difference in the decrease of adequate chest compressions over time among various age groups in this pilot simulation study.

Epinephrine in out-of-hospital cardiac arrest: A critical review

BACKGROUND

Epinephrine is recommended in advanced cardiac life support guidelines for use in adult cardiac arrest, and has been used in cardiopulmonary resuscitation since 1896. Yet, despite its long time use and incorporation into guidelines, epinephrine suffers from a paucity of evidence regarding its influence on survival. This critical review was conducted to address the knowledge deficit regarding epinephrine in out-of-hospital cardiac arrest and its effect on return of spontaneous circulation, survival to hospital discharge, and neurological performance.

METHODS

The EMBASE and MEDLINE (through the Pubmed interface) databases, and the Cochrane library were searched with the key words "epinephrine", "cardiac arrest" and variations of these terms. Original research studies concerning epinephrine use in adult, out-of-hospital cardiac arrest were selected for further review.

RESULTS

The search yielded nine eligible studies based on inclusion criteria. This includes five prospective cohort studies, one retrospective cohort study, one survival analysis, one case control study, and one RCT. The evidence clearly establishes an association between epinephrine and increased return of spontaneous circulation, the data were conflicting concerning survival to hospital discharge and neurological outcome.

CONCLUSIONS

The results of this review exhibit the paucity of evidence regarding the use of epinephrine in out of hospital cardiac arrest. There is currently insufficient evidence to support or reject its administration during resuscitation. Larger sample, placebo controlled, double blind, randomized control trials need to be performed to definitively establish the effect of epinephrine on both survival to hospital discharge and the neurological outcomes of treated patients.

Effects of terlipressin and naloxone compared with epinephrine in a rat model of asphyxia-induced cardiac arrest

OBJECTIVE

To evaluate the hemodynamic and metabolic effects of terlipressin and naloxone in cardiac arrest.

METHODS

Cardiac arrest in rats was induced by asphyxia and maintained for 3.5 minutes. Animals were then resuscitated and randomized into one of six groups: placebo (n = 7), epinephrine (0.02 mg/kg; n = 7), naloxone (1 mg/kg; n = 7) or terlipressin, of which three different doses were tested: 50 µg/kg (TP50; n = 7), 100 µg/kg (TP100; n = 7) and 150 µg/kg (TP150; n = 7). Hemodynamic variables were measured at baseline and at 10 (T10), 20 (T20), 30 (T30), 45 (T45) and 60 (T60) minutes after cardiac arrest. Arterial blood samples were collected at T10, T30 and T60.

RESULTS

The mean arterial pressure values in the TP50 group were higher than those in the epinephrine group at T10 (165 vs. 112 mmHg), T20 (160 vs. 82 mmHg), T30 (143 vs. 66 mmHg), T45 (119 vs. 67 mmHg) and T60 (96 vs. 66.8 mmHg). The blood lactate level was lower in the naloxone group than in the epinephrine group at T10 (5.15 vs. 10.5 mmol/L), T30 (2.57 vs. 5.24 mmol/L) and T60 (2.1 vs. 4.1 mmol/L).

CONCLUSIONS

In this rat model of asphyxia-induced cardiac arrest, terlipressin and naloxone were effective vasopressors in cardiopulmonary resuscitation and presented better metabolic profiles than epinephrine. Terlipressin provided better hemodynamic stability than epinephrine.

Regional variation and outcome of out-of-hospital cardiac arrest (ohca) in Finland - the Finnresusci study

Background

Despite the efforts of the modern Emergency Medical Service Systems (EMS), survival rates for sudden out-of-hospital cardiac arrest (OHCA) have been poor as approximately 10% of OHCA patients survive hospital discharge. Many aspects of OHCA have been studied, but few previous reports on OHCA have documented the variation between different sizes of study areas on a regional scale. The aim of this study was to report the incidence, outcomes and regional variation of OHCA in the Finnish population.

Methods

From March 1st to August 31st, 2010, data on all OHCA patients in the southern, central and eastern parts of Finland was collected. Data collection was initiated via dispatch centres whenever there was a suspected OHCA case or if a patient developed OHCA before arriving at the hospital. The study area includes 49% of the Finnish population; they are served by eight dispatch centres, two university hospitals and six central hospitals.

Results

The study period included 1042 cases of OHCA. Resuscitation was attempted on 671 patients (64.4%), an incidence of 51/100,000 inhabitants/year. The initial rhythm was shockable for 211 patients (31.4%). The survival rate at one-year post-OHCA was 13.4%. Of the witnessed OHCA events with a shockable rhythm of presumed cardiac origin (n=140), 64 patients (45.7%) were alive at hospital discharge and 47 (33.6%) were still living one year hence. Surviving until hospital admission was more likely if the OHCA occurred in an urban municipality (41.5%, p=0.001).

Conclusions

The results of this comprehensive regional study of OHCA in Finland seem comparable to those previously reported in other countries. The survival of witnessed OHCA events with shockable initial rhythms has improved in urban Finland in recent decades.

Impact of emergency coronary angiography on in-hospital outcome of unconscious survivors after out-of-hospital cardiac arrest

Acute coronary thrombotic occlusion is the most common trigger of cardiac arrest. The aim of the present study was to assess the impact of an invasive strategy characterized by emergency coronary angiography and subsequent percutaneous coronary intervention (PCI), if indicated, on in-hospital survival of resuscitated patients with out-of-hospital cardiac arrest (OHCA) and no obvious extracardiac cause who do not regain consciousness soon after recovery of spontaneous circulation. Ninety-three consecutive patients (67 ± 12 years old, 76% men) were included in the study. Clinical characteristics and coronary angiographic and in-hospital outcome data were retrospectively collected. Multivariate Cox proportional-hazards analysis was performed to identify independent determinants of in-hospital survival. Coronary angiography was performed in 66 patients (71%). Forty-eight patients underwent emergency coronary angiography; in the remaining 18 patients, mean time from OHCA to coronary angiography was 13 ± 10 days. In patients referred to emergency coronary angiography, successful emergency PCI of a culprit coronary lesion was performed in 25 patients (52%). In-hospital survival rate was 54%. At multivariate analysis, emergency coronary angiography (hazard ratio 2.32, 95% confidence interval 1.23 to 4.38, p = 0.009) and successful emergency PCI (hazard ratio 2.54, 95% confidence interval 1.35 to 4.8, p = 0.004) were independently related to in-hospital survival in the overall study population; delay in performing coronary angiography (hazard ratio 0.95, 95% confidence interval 0.92 to 0.99, p = 0.013) was independently related to in-hospital mortality in patients referred to coronary angiography. In conclusion, an invasive strategy characterized by emergency coronary angiography and subsequent PCI, if indicated, seems to improve in-hospital outcome of resuscitated but unconscious patients with OHCA without obvious extracardiac cause.

The significance of albumin corrected anion gap in patients with cardiopulmonary arrest

PURPOSE

The reliable parameter, which can be obtained easily and quickly, is necessary to predict the return of spontaneous circulation (ROSC) of patients with cardiopulmonary arrest (CPA) in the emergency situation. In this study, we evaluated the significance of albumin corrected anion gap (ACAG) for the prediction of ROSC in patients with CPA.

PATIENTS AND METHODS

In 166 patients with CPA between January 2009 and December 2010, 132 patients could be analyzed retrospectively. We compared acute physiology and chronic health evaluation (APACHE) II score, sequential organ failure assessment(SOFA) score, anion gap (AG) and ACAG levels between patients with/without ROSC and evaluated the significance of AG and ACAG to predict ROSC in patients with CPA.

RESULTS

Both AG and ACAG were significantly lower in patients with ROSC than in patients without ROSC. Both AG and ACAG had the relation with APACHE II and SOFA scores, however, coefficients of correlation with APACHE II and SOFA score were higher in ACAG (r = 0.506) than in AG (r = 0.482). The sensitivity, specificity, positive predictive value, and negative predictive value of ACAG for the prediction of ROSC in patients with CPA were better than those of AG.

CONCLUSION

Our study shows that both AG and ACAG have the relation with ROSC and ACAG is better to predict the ROSC following CPR in patients with CPA compared with AG. ACAG can be easily obtained in the emergency situation, and ACAG is a useful parameter to predict ROSC in patients with CPA.

Pediatric basic and advanced life support: an update on practice and education

This review aims to summarize the major changes in the 2010 Heart and Stroke foundation of Canada (HSFC) and the American Heart Association (AHA) Pediatric Basic and Advanced Life Support Guidelines. The Guidelines were based on the International Liaison Committee on Resuscitation's (ILCOR) comprehensive, evidence-based review of the resuscitation literature. The key recommendations from the Guidelines include: the removal of "look, listen and feel" and a de-emphasis on the use of the pulse check by healthcare providers to diagnose cardiac arrest; a change in the sequence of resuscitation for patients in cardiac arrest from the previously well-known "A-B-C" i.e. Airway, Breathing, and Chest Compressions to "C-A-B" i.e. Chest Compressions first; modification to the appropriate depth of compression (at least 1/3 of the anterior-posterior depth of the chest wall or about 4 cm in infants and 5 cm in children); end-tidal CO(2) monitoring (in intubated patients) to assess the quality of chest compressions and optimize cardiopulmonary resuscitation (CPR); and titrating Fi0O2 once "Return of Spontaneous Circulation" (ROSC) is achieved to maintain an oxygen saturation between 94-99%. Overall, pediatricians, family and community physicians who may care for acutely ill children should be aware of these updated guidelines in order to provide the best possible care to their patients.

Year in review 2011: Critical Care--Out-of-hospital cardiac arrest and trauma

In 2011, numerous studies were published in Critical Care focusing on out-of-hospital cardiac arrest, cardiopulmonary resuscitation, trauma, and some related airway, respiratory, and response time factors. In this review, we summarize several of these studies, including those that brought forth advances in therapies for the post-resuscitative period. These advances involved hypothesis-generating concepts in therapeutic hypothermia as well as the impact of early percutaneous coronary artery interventions and the potential utility of extracorporeal life support after cardiac arrest. There were also articles pertaining to the importance of timing in prehospital airway management, the outcome impact of hyperoxia, and the timing of end-tidal carbon dioxide measurements to predict futility in cardiac arrest resuscitation. In other articles, additional perspectives were provided on the classic correlations between emergency medical service response intervals and outcomes.

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.