Analysis of prehospital care for cardiac arrest in an urban setting in Japan

Evidence-Based Guideline for Prehospital Airway Management

Airway management is a cornerstone of emergency medical care. This project aimed to create evidence-based guidelines based on the systematic review recently conducted by the Agency for Healthcare Research and Quality (AHRQ). A technical expert panel was assembled to review the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. The panel made specific recommendations on the different PICO (population, intervention, comparison, outcome) questions reviewed in the AHRQ review and created good practice statements that summarize and operationalize these recommendations. The recommendations address the use of ventilation with bag-valve mask ventilation alone vs. supraglottic airways vs. endotracheal intubation for adults and children with cardiac arrest, medical emergencies, and trauma. Additional recommendations address the use of video laryngoscopy and drug-assisted airway management. These recommendations, and the associated good practice statements, offer EMS agencies and clinicians an opportunity to review the available evidence and incorporate it into their airway management strategies.

Prehospital Airway Management: A Systematic Review

Objective: To assess comparative benefits and harms across three airway management approaches (bag valve mask [BVM], supraglottic airway [SGA], and endotracheal intubation [ETI]) used by prehospital emergency medical services (EMS) to treat patients with trauma, cardiac arrest, or medical emergencies, and how they differ based on techniques and devices, EMS personnel and patient characteristics. Data sources: We searched electronic citation databases (Ovid® MEDLINE®, CINAHL®, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, and Scopus®) from 1990 to September 2020. Review methods: We followed Agency for Healthcare Research and Quality Effective Health Care Program Methods guidance. Outcomes included mortality, neurological function, return of spontaneous circulation (ROSC), and successful advanced airway insertion. Meta-analyses using profile-likelihood random effects models were conducted, with analyses stratified by study design, emergency type, and age. Results: We included 99 studies involving 630,397 patients. We found few differences in primary outcomes across airway management approaches. For survival, there was no difference for BVM versus ETI or SGA in adult and pediatric patients with cardiac arrest or trauma. For neurological function, there was no difference for BVM versus ETI and SGA versus ETI in pediatric patients with cardiac arrest. There was no difference in BVM versus ETI in adults with cardiac arrest, but improved neurological function with BVM or ETI versus SGA. There was no difference in ROSC for patients with cardiac arrest for BVM versus ETI or SGA in adults and pediatrics, or SGA versus ETI in pediatrics. There was higher frequency of ROSC in adults with SGA versus ETI. For successful advanced airway insertion, there was higher first-pass success with SGA versus ETI for all patients except adult medical patients (no difference), and no difference in overall success using SGA versus ETI in adults. Conclusions: The currently available evidence does not indicate benefits of more invasive airway approaches based on survival, neurological function, ROSC, or successful airway insertion. Strength of evidence was low or moderate; most included studies were observational. This supports the need for high-quality randomized controlled trials to advance clinical practice and EMS education and policy, and improve patient-centered outcomes.

A review of ventilation in adult out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest continues to be a devastating condition despite advances in resuscitation care. Ensuring effective gas exchange must be weighed against the negative impact hyperventilation can have on cardiac physiology and survival. The goals of this narrative review are to evaluate the available evidence regarding the role of ventilation in out-of-hospital cardiac arrest resuscitation and to provide recommendations for future directions. Ensuring successful airway patency is fundamental for effective ventilation. The airway management approach should be based on professional skill level and the situation faced by rescuers. Evidence has explored the influence of different ventilation rates, tidal volumes, and strategies during out-of-hospital cardiac arrest; however, other modifiable factors affecting out-of-hospital cardiac arrest ventilation have limited supporting data. Researchers have begun to explore the impact of ventilation in adult out-of-hospital cardiac arrest outcomes, further stressing its importance in cardiac arrest resuscitation management. Capnography and thoracic impedance signals are used to measure ventilation rate, although these strategies have limitations. Existing technology fails to reliably measure real-time clinical ventilation data, thereby limiting the ability to investigate optimal ventilation management. An essential step in advancing cardiac arrest care will be to develop techniques to accurately and reliably measure ventilation parameters. These devices should allow for immediate feedback for out-of-hospital practitioners, in a similar way to chest compression feedback. Once developed, new strategies can be established to guide out-of-hospital personnel on optimal ventilation practices.

Meta-Analysis Comparing Cardiac Arrest Outcomes Before and After Resuscitation Guideline Updates

Updates of resuscitation guidelines have limited high-level supporting evidence. Moreover, the overall effect of such bundled practice changes depends not only on the impact of the individual interventions but also on their interplay and swift functioning of the entire chain of survival. Therefore, real-world data monitoring is essential. We performed a meta-analysis of comparative studies on outcomes before and after successive guideline updates. On January 16, 2019, we searched for comparative studies (PubMed, Web-of-Science, Embase, and the Cochrane Libraries) reporting outcomes before and after resuscitation guidelines 2005, 2010, and 2015. We followed PRISMA, Cochrane, and Moose-recommendations. Studies on outcomes during the 2005 versus 2000 guideline period (n = 23; 40,859 patients) reported significantly higher ROSC (odds ratio [OR] 1.21 [1.04 to 1.42], p = 0.014), survival to admission (OR 1.34 [1.09 to 1.65], p = 0.005), survival to discharge (OR 1.46 [1.25 to 1.70], p <0.001), and favorable neurologic outcome (OR 1.35 [1.01 to 1.81], p = 0.040). Studies on outcomes during the 2010 versus 2005 guideline period (n = 11; 1,048,112 patients) indicated no difference in ROSC (OR 1.25 [95% confidence interval 0.95 to 1.63], p = 0.11), whereas survival to discharge improved significantly (OR 1.30 [1.17 to 1.45], p <0.001). Only 2 studies reported on neurologic outcomes, both showing improved outcome after the 2010 guideline update. No data on the 2015 guidelines were available. This meta-analysis on real-world data of >1 million patients demonstrates improved outcomes after the 2005 and 2010 resuscitation guideline updates, and a lack of data on the 2015 guideline. In conclusion, although limited in terms of causality, this study suggests that the sum of all efforts to improve outcomes, including updated CPR guidelines, contributed to increased survival after cardiac arrest.

The Effect of Prehospital Epinephrine in Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis

INTRODUCTION

Epinephrine has been recommended for out-of-hospital cardiac arrest (OHCA) resuscitation for nearly one century, but its efficacy and safety remain unclear in the literature. The primary aim of this review was to determine whether epinephrine increases the return of spontaneous circulation in OHCA patients.

METHODS

A systematic review and meta-analysis were conducted using the following databases: MEDLINE, EMBASE, and CENTRAL, from their inception until October 2018. All the randomized controlled trials (RCTs) were included. Observational studies, case reports, case series, and non-systematic reviews were excluded.

RESULTS

Two trials including 8,548 patients were eligible for inclusion in the data synthesis. In patients who received epinephrine during OHCA, the incidence of return of spontaneous circulation was increased, with an odds ratio (95%CI) of 4.25 (3.79-4.75), P <.001, high-quality of evidence. The number of patients transported to hospital was increased in patients who had prehospital epinephrine, with an odds ratio (95%CI) of 2.31 (2.11-2.53), P <.001, high-quality of evidence. The prehospital use of epinephrine was associated with an increased survival to hospital discharge, the odds ratio (95%CI) being 1.43 (1.10-1.87), P = .008, moderate-quality of evidence. No significant effect was noted on the favorable neurologic state of patient at hospital discharge, with an odds ratio (95%CI) of 1.21 (0.90-1.64), P = .21, moderate-quality of evidence.

CONCLUSIONS

This meta-analysis suggests that the prehospital use of epinephrine increases return of spontaneous circulation, transport of patients to hospital, and survival to hospital discharge for OHCA. However, no significant effects on favorable neurologic function at hospital discharge were demonstrated. The general quality of evidence ranged from moderate to high.

Advanced airway management during adult cardiac arrest: A systematic review

AIM

To systematically review the literature on advanced airway management during adult cardiac arrest in order to inform the International Liaison Committee of Resuscitation (ILCOR) consensus on science and treatment recommendations.

METHODS

The review was performed according to PRISMA guidelines and registered on PROSPERO (CRD42018115556). We searched Medline, Embase, and Evidence-Based Medicine Reviews for controlled trials and observational studies published before October 30, 2018. The population included adult patients with cardiac arrest. Two investigators reviewed studies for relevance, extracted data, and assessed the risk of bias of individual studies.

RESULTS

We included 78 observational studies and 11 controlled trials. Most of the observational studies and all of the controlled trials only included patients with out-of-hospital cardiac arrest. The risk of bias for individual observational studies was overall assessed as critical or serious, with confounding and selection bias being the primary sources of bias. Three of the controlled trials, all published in 2018, were powered for clinical outcomes with two comparing a supraglottic airway to tracheal intubation and one comparing bag-mask ventilation to tracheal intubation. All three trials had some concerns regarding risk of bias primarily due to lack of blinding and variable adherence to the protocol. Clinical and methodological heterogeneity across studies, for both the observational studies and the controlled trials, precluded any meaningful meta-analyses.

CONCLUSIONS

We identified a large number of studies related to advanced airway management in adult cardiac arrest. Three recently published, large randomized trials in out-of-hospital cardiac arrest will help to inform future guidelines. Trials of advanced airway management during in-hospital cardiac arrest are lacking.

Outcomes following cardiopulmonary resuscitation in an emergency department of a low- and middle-income country

BACKGROUND

Cardiopulmonary resuscitation (CPR) is a key component of emergency care following cardiac arrest. A better understanding of factors that influence CPR outcomes and their prognostic implications would help guide care. A retrospective analysis of 800 adult patients that sustained an in- or out-of-hospital cardiac arrest and underwent CPR in the emergency department of a tertiary care facility in Karachi, Pakistan, between 2008 and 15 was conducted.

METHODS

Patient demographics, clinical history, and CPR characteristics data were collected. Logistic regression model was applied to assess predictors of return of spontaneous circulation and survival to discharge. Analysis was conducted using SPSS v.21.0.

RESULTS

Four hundred sixty-eight patients met the study's inclusion criteria, and overall return of spontaneous circulation and survival to discharge were achieved in 128 (27.4%) and 35 (7.5%) patients respectively. Mean age of patients sustaining return of spontaneous circulation was 52 years and that of survival to discharge was 49 years. The independent predictors of return of spontaneous circulation included age ≤ 49 years, witnessed arrest, ≤ 30 min interval between collapse-to-start, and 1-4 shocks given during CPR (aOR (95% CI) 2.2 (1.3-3.6), 1.9 (1.0-3.7), 14.6 (4.9-43.4), and 3.0 (1.4-6.4) respectively), whereas, age ≤ 52 years, bystander resuscitation, and initial rhythm documented (pulseless electrical activity and ventricular fibrillation) were independent predictors of survival to discharge (aOR (95% CI) 2.5 (0.9-6.5), 1.4 (0.5-3.8), 5.3 (1.5-18.4), and 3.1 (1.0-10.2) respectively).

CONCLUSION

Our study notes that while the majority of arrests occur out of the hospital, only a small proportion of those arrests receive on-site CPR, which is a key contributor to unfavorable outcomes in this group. It is recommended that effective pre-hospital emergency care systems be established in developing countries which could potentially improve post-arrest outcomes. Younger patients, CPR initiation soon after arrest, presenting rhythm of pulseless ventricular tachycardia and ventricular fibrillation, and those requiring up to four shocks to revive are more likely to achieve favorable outcomes.

Advanced airway management in out of hospital cardiac arrest: A systematic review and meta-analysis

OBJECTIVES

To assess the difference in survival and neurological outcomes between endotracheal tube (ETT) intubation and supraglottic airway (SGA) devices used during out-of-hospital cardiac arrest (OHCA).

METHODS

A systematic search of five databases was performed by two independent reviewers until September 2018. Included studies reported on (1) OHCA or cardiopulmonary resuscitation, and (2) endotracheal intubation versus supraglottic airway device intubation. Exclusion criteria (1) stimulation studies, (2) selectively included/excluded patients, (3) in-hospital cardiac arrest. Odds Ratios (OR) with random effect modelling was used. Primary outcomes: (1) return of spontaneous circulation (ROSC), (2) survival to hospital admission, (3) survival to hospital discharge, (4) discharge with a neurologically intact state.

RESULTS

Twenty-nine studies (n = 539,146) showed that overall, ETT use resulted in a heterogeneous, but significant increase in ROSC (OR = 1.44; 95%CI = 1.27 to 1.63; I² = 91%; p < 0.00001) and survival to admission (OR = 1.36; 95%CI = 1.12 to 1.66; I² = 91%; p = 0.002). There was no significant difference in survival to discharge or neurological outcome (p > 0.0125). On sensitivity analysis of RCTs, there was no significant difference in ROSC, survival to admission, survival to discharge or neurological outcome (p > 0.0125). On analysis of automated chest compression, without heterogeneity, ETT provided a significant increase in ROSC (OR = 1.55; 95%CI = 1.20 to 2.00; I² = 0%; p = 0.0009) and survival to admission (OR = 2.16; 95%CI = 1.54 to 3.02; I² = 0%; p < 0.00001).

CONCLUSIONS

The overall heterogeneous benefit in survival with ETT was not replicated in the low risk RCTs, with no significant difference in survival or neurological outcome. In the presence of automated chest compressions, ETT intubation may result in survival benefits.

A comparison between evacuation from the scene and interhospital transportation using a helicopter for subarachnoid hemorrhage

PURPOSE

We investigated the changes in the vital signs and the final outcomes subarachnoid hemorrhage (SAH) patients who were evacuated from the scene using the doctor-helicopter (Dr. Heli) service and those who only underwent interhospital transportation using the doctor-helicopter Dr. Heli service to investigate safety of this system.

METHODS

We retrospectively investigated all of the patients with non-traumatic SAH who were transported by a Dr. Heli between January 2010 and March 2016. The subjects were divided into two groups: the Scene group included subjects who were evacuated from the scene by a Dr. Heli, while the Interhospital group included subjects who were transported by a ground ambulance to a nearby medical facility and then transported by a Dr. Heli to a single tertiary center.

RESULTS

The systolic blood pressure, ratio of cardiac arrest, and Fisher classification values of the patients in the Scene group were significantly greater than those in the Interhospital group. The Glasgow Coma Scale in the Scene group was significantly lower than that in the Interhospital group. After excluding the patients with cardiac arrest, the Glasgow Coma Scale scores of the patients in the two groups did not differ to a statistically significant extent during, before or after transportation. There were no significant differences in Glasgow Outcome Scores or the survival ratio of the two groups, even when cardiac arrest patients were included.

CONCLUSION

The present study indirectly suggests the safety of using a Dr. Heli to evacuate SAH patients from the scene.

Epinephrine in cardiac arrest: systematic review and meta-analysis

Objective

evaluate the effectiveness of epinephrine used during cardiac arrest and its effect on the survival rates and neurological condition.

Method

systematic review of scientific literature with meta-analysis, using a random effects model. The following databases were used to research clinical trials and observational studies: Medline, Embase and Cochrane, from 2005 to 2015.

Results

when the Return of Spontaneous Circulation (ROSC) with administration of epinephrine was compared with ROSC without administration, increased rates were found with administration (OR 2.02. 95% CI 1.49 to 2.75; I2 = 95%). Meta-analysis showed an increase in survival to discharge or 30 days after administration of epinephrine (OR 1.23; 95% IC 1.05-1.44; I2=83%). Stratification by shockable and non-shockable rhythms showed an increase in survival for non-shockable rhythm (OR 1.52; 95% IC 1.29-1.78; I2=42%). When compared with delayed administration, the administration of epinephrine within 10 minutes showed an increased survival rate (OR 2.03; 95% IC 1.77-2.32; I2=0%).

Conclusion

administration of epinephrine appears to increase the rate of ROSC, but when compared with other therapies, no positive effect was found on survival rates of patients with favorable neurological status.

The role of prehospital advanced airway management on outcomes for out-of-hospital cardiac arrest patients: a meta-analysis

OBJECTIVE

The objective of this meta-analysis was to compare the benefits of prehospital advanced airway management (AAM) and basic airway management (BAM) for out-of-hospital cardiac arrest (OHCA) patients.

METHODS

Two investigators performed a systematic review of PubMed, EMBASE, and the Cochrane Database to identify all peer-reviewed articles relevant to this meta-analysis. We included all articles describing emergency medical system-treated nontraumatic OHCAs; specifically, all articles that described intervention of the prehospital AAM type were considered. The primary outcome was survival to discharge, whereas the secondary outcome was neurologic recovery after an OHCA event. For subgroup analysis, we compared the clinical outcome of endotracheal intubation (ETI), a specific type of AAM, vs BAM.

RESULTS

We reviewed 1452 studies, 10 of which satisfied all the inclusion criteria and involved 17 380 patients subjected to AAM and 67 525 subjected to BAM. Based on the full random effects model, patients who received AAM had lower odds of survival (odds ratio [OR], 0.51; 95% confidence interval [CI], 0.29-0.90) compared with BAM. Subgroup analysis for ETI vs BAM showed no significant association with respect to survival (OR, 0.44; 95% CI, 0.16-1.23). There were no significant differences in the odds of neurologic recovery between AAM and BAM (OR, 0.64; 95% CI, 0.03-1.37).

CONCLUSIONS

Our results reveal decreased survival odds for OHCA patients treated with AAM by emergency medical service personnel compared with BAM. However, the role of prehospital AAM, especially ETI, on achieving neurologic recovery remains unclear.

Difficult intubation and outcome after out-of-hospital cardiac arrest: a registry-based analysis

Background

Airway management during resuscitation attempts is pivotal for treating hypoxia, and endotracheal intubation is the standard procedure. This German Resuscitation Registry analysis investigates the influence of airway management on primary outcomes after out-of-hospital cardiac arrest, in a physician-based emergency system.

Methods

A total of 8512 patients recorded in the German Resuscitation Registry (2007–2011) were analyzed. The Return of Spontaneous Circulation After Cardiac Arrest (RACA) score was used to compare observed return of spontaneous circulation (ROSC) rates with the ROSC predicted by the score and to analyze factors influencing the primary outcome. Patients were classified into three groups: difficult intubation, impossible intubation, and a control group with normal airways.

Results

The observed ROSC matched the predicted ROSC in the group with difficult airways. The impossible intubation group had lower ROSC rates (31.3 % vs. 40.5 %; P < 0.05). Impossible intubation was more frequent in men (OR 2.28; 95 % CI, 1.43–3.63; P = 0.001), young patients (OR 2.18; 95 % CI, 1.26–3.76; P = 0.005) and those with trauma (OR 2.22; 95 % CI, 1.01–4.85; P = 0.046). Fewer impossible intubations were reported when the emergency physicians were anesthesiologists (OR 0.65; 95 % CI, 0.44–0.96; P = 0.028). If a supraglottic airway device was not used in the impossible intubation group, the observed ROSC (18.0 %; 95 % CI, 7.4–28.6 %) was poorer than predicted (38.2 %) (P < 0.05).

Conclusions

Outcomes after resuscitation attempts are poorer when endotracheal intubation is not possible. Predictive factors for impossible intubation are male gender, younger age, and trauma. Supraglottic airway devices should be used at an early stage whenever these negative factors are present.

Electronic supplementary material

The online version of this article (doi:10.1186/s13049-015-0124-0) contains supplementary material, which is available to authorized users.

Analysis of patients with decompression illness transported via physician-staffed emergency helicopters

CONTEXT

There have been few reports investigating the effects of air transportation on patients with decompression illness (DCI).

AIMS

To investigate the influence of air transportation on patients with DCI transported via physician-staffed emergency helicopters (HEMS: Emergency medical system of physician-staffed emergency helicopters).

SETTINGS AND DESIGN

A retrospective medical chart review in a single hospital.

MATERIALS AND METHODS

A medical chart review was retrospectively performed in all patients with DCI transported via HEMS between July 2009 and June 2013. The exclusion criteria included cardiopulmonary arrest on surfacing.

STATISTICAL ANALYSIS USED

The paired Student's t-test.

RESULTS

A total of 28 patients were treated as subjects. Male and middle-aged subjects were predominant. The number of patients who suddenly surfaced was 15/28. All patients underwent oxygen therapy during flight, and all but one patient received the administration of lactate Ringer fluid. The subjective symptoms of eight of 28 subjects improved after the flight. The range of all flights under 300 m above sea level. There were no significant differences between the values obtained before and after the flight for Glasgow coma scale, blood pressure, and heart rate. Concerning the SpO2, statistically significant improvements were noted after the flight (96.2 ± 0.9% versus 97.3 ± 0.7%). There were no relationships between an improvement in subjective symptoms and the SpO2.

CONCLUSION

Improvements in the subjective symptoms and/or SpO2 of patients with DCI may be observed when the patient is transported via HEMS under flights less than 300 m in height with the administration of oxygen and fluids.

Does pre-hospital endotracheal intubation improve survival in adults with non-traumatic out-of-hospital cardiac arrest? A systematic review

INTRODUCTION

Endotracheal intubation (ETI) is currently considered superior to supraglottic airway devices (SGA) for survival and other outcomes among adults with non-traumatic out-of-hospital cardiac arrest (OHCA). We aimed to determine if the research supports this conclusion by conducting a systematic review.

METHODS

We searched the MEDLINE, Scopus and CINAHL databases for studies published between January 1, 1980, and 30 April 30, 2013, which compared pre-hospital use of ETI with SGA for outcomes of return of spontaneous circulation (ROSC); survival to hospital admission; survival to hospital discharge; and favorable neurological or functional status. We selected studies using pre-specified criteria. Included studies were independently screened for quality using the Newcastle-Ottawa scale. We did not pool results because of study variability. Study outcomes were extracted and results presented as summed odds ratios with 95% CI.

RESULTS

We identified five eligible studies: one quasi-randomized controlled trial and four cohort studies, involving 303,348 patients in total. Only three of the five studies reported a higher proportion of ROSC with ETI versus SGA with no difference reported in the remaining two. None found significant differences between ETI and SGA for survival to hospital admission or discharge. One study reported better functional status at discharge for ETI versus SGA. Two studies reported no significant difference for favorable neurological status between ETI and SGA.

CONCLUSION

Current evidence does not conclusively support the superiority of ETI over SGA for multiple outcomes among adults with OHCA.

Effects of prehospital adrenaline administration on out-of-hospital cardiac arrest outcomes: a systematic review and meta-analysis

Introduction

The aim of this study was to conduct a systematic review and meta-analysis for determining the effects of prehospital adrenaline administration on return of spontaneous circulation, hospital admission, survival to discharge and discharge with cerebral performance category 1 or 2 in out-of-hospital cardiac arrest patients.

Methods

MEDLINE and Scopus databases were searched to identify studies reported to March 2014. Study selection and data extraction were independently completed by two reviewers (PA and SR). The baseline characteristics of each study and number of events were extracted. Risk ratios (RR) and 95% confidence interval (CI) were estimated. Heterogeneity and publication bias were also explored.

Results

In total 15 studies were eligible and included in the study. Of 13 adult observational studies, four to eight studies were pooled for each outcome. These yielded a total sample size that ranged from 2,381 to 421,459. A random effects model suggested that patients receiving prehospital adrenaline were 2.89 times (95% CI: 2.36, 3.54) more likely to achieve prehospital return of spontaneous circulation than those not administered adrenaline. However, there were no significant effects on overall return of spontaneous circulation (RR = 0.93, 95% CI: 0.5, 1.74), admission (RR = 1.05, 95% CI: 0.80, 1.38) and survival to discharge (RR = 0.69, 95% CI: 0.48, 1.00).

Conclusions

Prehospital adrenaline administration may increase prehospital return of spontaneous circulation, but it does not improve overall rates of return of spontaneous circulation, hospital admission and survival to discharge.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0463-7) contains supplementary material, which is available to authorized users.

Hypoxic cardiopulmonary arrest with full recovery after induced hypothermic therapy

Case

The patient's chart was reviewed, summarized, and presented.

Outcome

A 41-year-old male collapsed after complaining of dyspnea just before the end of a hemodialysis session. He was just being introduced to hemodialysis. The patient's percutaneous oxygen saturation dropped to 50% even under inhalation of 10 L/minute of oxygen and he developed pulseless electrical activity. After tracheal intubation, a return of spontaneous circulation was noted. His truncal CT disclosed a bilateral diffuse ground glass appearance and pleural effusion were noted. Induced mild hypothermic therapy and mechanical ventilation resulted in the improvement of his respiratory function and consciousness. A coronary angiogram and left ventriculography showed no significant lesion, and his pulmonary edema was considered to have been induced by over-hydration due to renal failure, diastolic heart failure or dialysis disequilibrium syndrome. He was discharged without any neurological deficit.

Conclusion

Tracheal intubation with ventilation for hypoxic cardiopulmonary arrest and induced hypothermic therapy after obtaining spontaneous circulation may be factors of favorable outcome of this case.

Airways in out-of-hospital cardiac arrest: systematic review and meta-analysis

OBJECTIVE

To determine the differences in survival for out-of-hospital advanced airway intervention (AAI) compared with basic airway intervention (BAI) in cardiac arrest.

BACKGROUND

AAI is commonly utilized in cardiac arrest in the out-of-hospital setting as a means to secure the airway. Observational studies and clinical trials of AAI suggest that AAI is associated with worse outcomes in terms of survival. No controlled trials exist that compares AAI to BAI.

METHODS

We conducted a bias-adjusted meta-analysis on 17 observational studies. The outcomes were survival, short-term (return of spontaneous circulation and to hospital admission), and longer-term (to discharge, to one month survival). We undertook sensitivity analyses by analyzing patients separately: those who were 16 years and older, nontrauma only, and attempted versus successful AAI.

RESULTS

This meta-analysis included 388,878 patients. The short-term survival for AAI compared to BAI were overall OR 0.84(95% CI 0.62 to 1.13), for endotracheal intubation (ETI) OR 0.79 (95% CI 0.54 to 1.16), and for supraglottic airways (SGA) OR 0.59 (95% CI 0.39 to 0.89). Long-term survival for AAI were overall OR 0.49 (95% CI 0.37 to 0.65), for ETI OR 0.48 (95% CI 0.36 to 0.64), and for SGA OR 0.35 (95% CI 0.28 to 0.44). Sensitivity analyses shows that limiting analyses to adults, non-trauma victims, and instances where AAI was both attempted and successful did not alter results meaningfully. A third of all studies did not adjust for any other confounding factors that could impact on survival.

CONCLUSIONS

This meta-analysis shows decreased survival for AAIs used out-of-hospital in cardiac arrest, but are likely biased due to confounding, especially confounding by indication. A properly conducted prospective study or a controlled trial is urgently needed and are possible to do.

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.

The key to advanced airways during cardiac arrest: well trained and early

Airway management during cardiac arrests is a controversial area. There are advantages to the provision of a patent airway with an airway adjunct, especially as this can optimize oxygenation and carbon dioxide clearance as well as facilitate continuous compressions. These advantages come at a potential cost, in particular errors in placement of the devices and interruption to compressions necessitated for insertion. The widespread availability of supraglottic airways (SGAs), their ease of insertion, and their ability to be inserted without interruptions to compressions have meant that the role of the definitive airway device - the endotracheal tube - is being challenged. In the previous issue of Critical Care, a study from Japan reported the use of advanced airways in more than 5,000 victims of cardiac arrests. The authors were not able to demonstrate a survival advantage with either SGAs or endotracheal intubation (ETI). They did, however, demonstrate improved outcomes when the emergency life-saving technicians had been trained to perform ETI and when the advanced airway device was inserted earlier.