Part 4: Advanced Life Support: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

[Recommendation on temperature management after cardiopulmonary arrest and severe traumatic brain injury in childhood beyond the neonatal period : Statement of the German Society for Neonatology and Pediatric Intensive Care Medicine (GNPI) and the scientific Working Group for Paediatric Anaesthesia (WAKKA) of the German Society of Anaesthesiology and Intensive Care (DGAI)]

The available data on the effectiveness of therapeutic hypothermia in different patient groups are heterogeneous. Although the benefits have been proven for some collectives, recommendations for the use of hypothermia treatment in other groups are based on less robust data and conclusions by analogy. This article gives a review of the current evidence of temperature management in all age groups and based on this state of knowledge, recommends active temperature management with the primary aim of strict normothermia (36-36.5 °C) for 72 hours after cardiopulmonary arrest or severe traumatic brain injury for children beyond the neonatal period.

Cardioversion Efficacy Using Pulsed Biphasic or Biphasic Truncated Exponential Waveforms: A Randomized Clinical Trial

Background

Several different defibrillators are currently used for cardioversion and defibrillation of cardiac arrhythmias. The efficacy of a novel pulsed biphasic (PB) waveform has not been compared to other biphasic waveforms. Accordingly, this study aims to compare the efficacy and safety of PB shocks with biphasic truncated exponential (BTE) shocks in patients undergoing cardioversion of atrial fibrillation or ‐flutter.

Methods and Results

This prospective, randomized study included patients admitted for elective direct current cardioversion. Patients were randomized to receive cardioversion using either PB or BTE shocks. We used escalating shocks until sinus rhythm was obtained or to a maximum of 4 shocks. Patients randomized to PB shocks received 90, 120, 150, and 200 J and patients randomized to BTE shocks received 100, 150, 200, and 250 J, as recommended by the manufacturers. In total, 69 patients (51%) received PB shocks and 65 patients (49%) BTE shocks. Successful cardioversion, defined as sinus rhythm 4 hours after cardioversion, was achieved in 43 patients (62%) using PB shocks and in 56 patients (86%) using BTE shocks; ratio 1.4 (95% CI 1.1–1.7) (P=0.002). There was no difference in safety (ie, myocardial injury judged by changes in high‐sensitive troponin I levels; ratio 1.1) (95% CI 1.0–1.3), P=0.15. The study was terminated prematurely because of an adverse event.

Conclusions

Cardioversion using a BTE waveform was more effective when compared with a PB waveform. There was no difference in safety between the 2 waveforms, as judged by changes in troponin I levels.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02317029.

Amiodarone Compared with Lidocaine for Out-Of-Hospital Cardiac Arrest with Refractory Ventricular Fibrillation on Hospital Arrival: a Nationwide Database Study

PURPOSE

The latest resuscitation guidelines recommend the use of amiodarone in adult patients with out-of-hospital cardiac arrest (OHCA) and refractory ventricular fibrillation (VF) to improve the rates of return of spontaneous circulation. However, there is limited evidence to suggest that amiodarone is superior to lidocaine with respect to survival at discharge. The purpose of the present study was to evaluate the hypothesis that amiodarone is superior to lidocaine with regard to the rate of survival to hospital discharge for OHCA patients with VF/pulseless VT (pVT) on hospital arrival.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database, we identified 3951 patients from 795 hospitals who experienced cardiogenic OHCA and had refractory ventricular fibrillation on hospital arrival between July 2007 and March 2013. The patients were categorized into amiodarone (n = 1743) and lidocaine (n = 2208) groups, from which 801 propensity score-matched pairs were generated.

RESULTS

There was no significant difference in the rate of survival to hospital discharge between the amiodarone and lidocaine groups (15.2 % vs. 17.1 %; difference, -1.9 %; 95 % CI, -5.5 to 1.7) in propensity score-matched analyses. Cox regression analyses did not indicate significant in-hospital mortality differences between the amiodarone and lidocaine groups for the propensity score-matched groups (hazard ratio, 1.05; 95 % CI, 0.94 to 1.17).

CONCLUSIONS

The present nationwide study suggested that there was no significant difference in the rate of survival to hospital discharge between cardiogenic OHCA patients with persistent ventricular fibrillation on hospital arrival treated with amiodarone or lidocaine.

Recent developments in the management of patients resuscitated from cardiac arrest

Cardiac arrest is the leading cause of death in Europe and the United States. Many patients who are initially resuscitated die in the hospital, and hospital survivors often have substantial neurologic dysfunction. Most cardiac arrests are caused by coronary artery disease; patients with coronary artery disease likely benefit from early coronary angiography and intervention. After resuscitation, cardiac arrest patients remain critically ill and frequently suffer cardiogenic shock and multiorgan failure. Early cardiopulmonary stabilization is important to prevent worsening organ injury. To achieve best patient outcomes, comprehensive critical care management is needed, with primary goals of stabilizing hemodynamics and preventing progressive brain injury. Targeted temperature management is frequently recommended for comatose survivors of cardiac arrest to mitigate the neurologic injury that drives outcomes. Accurate neurologic assessment is central to managing care of cardiac arrest survivors and should combine physical examination with objective neurologic testing, with the caveat that delaying neurologic prognosis is essential to avoid premature withdrawal of supportive care. A combination of clinical findings and diagnostic results should be used to estimate the likelihood of functional recovery. This review focuses on recent advances in care and specific cardiac intensive care strategies that may improve morbidity and mortality for patients after cardiac arrest.

Association Between Tracheal Intubation During Adult In-Hospital Cardiac Arrest and Survival

IMPORTANCE

Tracheal intubation is common during adult in-hospital cardiac arrest, but little is known about the association between tracheal intubation and survival in this setting.

OBJECTIVE

To determine whether tracheal intubation during adult in-hospital cardiac arrest is associated with survival to hospital discharge.

DESIGN, SETTING, AND PARTICIPANTS

Observational cohort study of adult patients who had an in-hospital cardiac arrest from January 2000 through December 2014 included in the Get With The Guidelines-Resuscitation registry, a US-based multicenter registry of in-hospital cardiac arrest. Patients who had an invasive airway in place at the time of cardiac arrest were excluded. Patients intubated at any given minute (from 0-15 minutes) were matched with patients at risk of being intubated within the same minute (ie, still receiving resuscitation) based on a time-dependent propensity score calculated from multiple patient, event, and hospital characteristics.

EXPOSURE

Tracheal intubation during cardiac arrest.

MAIN OUTCOMES AND MEASURES

The primary outcome was survival to hospital discharge. Secondary outcomes included return of spontaneous circulation (ROSC) and a good functional outcome. A cerebral performance category score of 1 (mild or no neurological deficit) or 2 (moderate cerebral disability) was considered a good functional outcome.

RESULTS

The propensity-matched cohort was selected from 108 079 adult patients at 668 hospitals. The median age was 69 years (interquartile range, 58-79 years), 45 073 patients (42%) were female, and 24 256 patients (22.4%) survived to hospital discharge. Of 71 615 patients (66.3%) who were intubated within the first 15 minutes, 43 314 (60.5%) were matched to a patient not intubated in the same minute. Survival was lower among patients who were intubated compared with those not intubated: 7052 of 43 314 (16.3%) vs 8407 of 43 314 (19.4%), respectively (risk ratio [RR] = 0.84; 95% CI, 0.81-0.87; P < .001). The proportion of patients with ROSC was lower among intubated patients than those not intubated: 25 022 of 43 311 (57.8%) vs 25 685 of 43 310 (59.3%), respectively (RR = 0.97; 95% CI, 0.96-0.99; P < .001). Good functional outcome was also lower among intubated patients than those not intubated: 4439 of 41 868 (10.6%) vs 5672 of 41 733 (13.6%), respectively (RR = 0.78; 95% CI, 0.75-0.81; P < .001). Although differences existed in prespecified subgroup analyses, intubation was not associated with improved outcomes in any subgroup.

CONCLUSIONS AND RELEVANCE

Among adult patients with in-hospital cardiac arrest, initiation of tracheal intubation within any given minute during the first 15 minutes of resuscitation, compared with no intubation during that minute, was associated with decreased survival to hospital discharge. Although the study design does not eliminate the potential for confounding by indication, these findings do not support early tracheal intubation for adult in-hospital cardiac arrest.

Single versus Serial Measurements of Neuron-Specific Enolase and Prediction of Poor Neurological Outcome in Persistently Unconscious Patients after Out-Of-Hospital Cardiac Arrest - A TTM-Trial Substudy

BACKGROUND

Prediction of neurological outcome is a crucial part of post cardiac arrest care and prediction in patients remaining unconscious and/or sedated after rewarming from targeted temperature management (TTM) remains difficult. Current guidelines suggest the use of serial measurements of the biomarker neuron-specific enolase (NSE) in combination with other predictors of outcome in patients admitted after out-of-hospital cardiac arrest (OHCA). This study sought to investigate the ability of NSE to predict poor outcome in patients remaining unconscious at day three after OHCA. In addition, this study sought to investigate if serial NSE measurements add incremental prognostic information compared to a single NSE measurement at 48 hours in this population.

METHODS

This study is a post-hoc sub-study of the TTM trial, randomizing OHCA patients to a course of TTM at either 33°C or 36°C. Patients were included from sites participating in the TTM-trial biobank sub study. NSE was measured at 24, 48 and 72 hours after ROSC and follow-up was concluded after 180 days. The primary end point was poor neurological function or death defined by a cerebral performance category score (CPC-score) of 3 to 5.

RESULTS

A total of 685 (73%) patients participated in the study. At day three after OHCA 63 (9%) patients had died and 473 (69%) patients were not awake. In these patients, a single NSE measurement at 48 hours predicted poor outcome with an area under the receiver operating characteristics curve (AUC) of 0.83. A combination of all three NSE measurements yielded the highest discovered AUC (0.88, p = .0002). Easily applicable combinations of serial NSE measurements did not significantly improve prediction over a single measurement at 48 hours (AUC 0.58-0.84 versus 0.83).

CONCLUSION

NSE is a strong predictor of poor outcome after OHCA in persistently unconscious patients undergoing TTM, and NSE is a promising surrogate marker of outcome in clinical trials. While combinations of serial NSE measurements may provide an increase in overall prognostic information, it is unclear whether actual clinical prognostication with low false-positive rates is improved by application of serial measurements in persistently unconscious patients. The findings of this study should be confirmed in another prospective cohort.

TRIAL REGISTRATION

NCT01020916.

Novel CPR system that predicts return of spontaneous circulation from amplitude spectral area before electric shock in ventricular fibrillation

AIM

Amplitude spectral area (AMSA), an index for analysing ventricular fibrillation (VF) waveforms, is thought to predict the return of spontaneous circulation (ROSC) after electric shocks, but its validity is unconfirmed. We developed an equation to predict ROSC, where the change in AMSA (ΔAMSA) is added to AMSA measured immediately before the first shock (AMSA1). We examine the validity of this equation by comparing it with the conventional AMSA1-only equation.

METHOD

We retrospectively investigated 285 VF patients given prehospital electric shocks by emergency medical services. ΔAMSA was calculated by subtracting AMSA1 from last AMSA immediately before the last prehospital electric shock. Multivariate logistic regression analysis was performed using post-shock ROSC as a dependent variable.

RESULTS

Analysis data were subjected to receiver operating characteristic curve analysis, goodness-of-fit testing using a likelihood ratio test, and the bootstrap method. AMSA1 (odds ratio (OR) 1.151, 95% confidence interval (CI) 1.086-1.220) and ΔAMSA (OR 1.289, 95% CI 1.156-1.438) were independent factors influencing ROSC induction by electric shock. Area under the curve (AUC) for predicting ROSC was 0.851 for AMSA1-only and 0.891 for AMSA1+ΔAMSA. Compared with the AMSA1-only equation, the AMSA1+ΔAMSA equation had significantly better goodness-of-fit (likelihood ratio test P<0.001) and showed good fit in the bootstrap method.

CONCLUSIONS

Post-shock ROSC was accurately predicted by adding ΔAMSA to AMSA1. AMSA-based ROSC prediction enables application of electric shock to only those patients with high probability of ROSC, instead of interrupting chest compressions and delivering unnecessary shocks to patients with low probability of ROSC.

Neuroprotective Effects of the Glucagon-Like Peptide-1 Analog Exenatide After Out-of-Hospital Cardiac Arrest

Background:

In-hospital mortality in comatose patients resuscitated from out-of-hospital cardiac arrest (OHCA) is ≈50%. In OHCA patients, the leading cause of death is neurological injury secondary to ischemia and reperfusion. Glucagon-like peptide-1 analogs are approved for type 2 diabetes mellitus; preclinical and clinical data have suggested their organ-protective effects in patients with ischemia and reperfusion injury. The aim of this trial was to investigate the neuroprotective effects of the glucagon-like peptide-1 analog exenatide in resuscitated OHCA patients.

Methods:

We randomly assigned 120 consecutive comatose patients resuscitated from OHCA in a double-blind, 2-center trial. They were administered 17.4 μg exenatide (Byetta) or placebo over a 6-hour and 15-minute infusion, in addition to standardized intensive care including targeted temperature management. The coprimary end points were feasibility, defined as initiation of the study drug in >90% patients within 240 minutes of return of spontaneous circulation, and efficacy, defined as the geometric area under the neuron-specific enolase curve from 24 to 72 hours after admission. The main secondary end points included a composite end point of death and poor neurological function, defined as a Cerebral Performance Category score of 3 to 5 assessed at 30 and 180 days.

Results:

The study drug was initiated within 240 minutes of return of spontaneous circulation in 96% patients. The median blood glucose 8 hours after admission in patients receiving exenatide was lower than that in patients receiving placebo (5.8 [5.2–6.7] mmol/L versus 7.3 [6.2–8.7] mmol/L, P <0.0001). However, there were no significant differences in the area under the neuron-specific enolase curve, or a composite end point of death and poor neurological function between groups. Adverse events were rare with no significant difference between groups.

Conclusions:

Acute administration of exenatide to comatose patients in the intensive care unit after OHCA is feasible and safe. Exenatide did not reduce neuron-specific enolase levels and did not significantly improve a composite end point of death and poor neurological function after 180 days.

Clinical Trial Registration:

URL: http://www.clinicaltrials.gov . Unique identifier: NCT02442791.

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.

Development of new equipment for intra-arrest brain cooling that uses cooled oxygen in the lungs: volunteer study

Aims

Many experimental studies have reported that intra-arrest cooling during cardiac arrest is a promising treatment to mitigate brain injury. However, there is no clinically established method for cooling the brain during cardiac arrest. We hypothesized that, as blood flow in the lungs must be very slow during cardiopulmonary resuscitation, the blood could be cooled by ventilating the lungs with cooled oxygen like a radiator, and that this cooled blood would in turn cool the brain. The aim of this study was to develop equipment to cool oxygen for this purpose and to confirm its safety on a group of volunteers.

Methods

We developed new equipment that cools oxygen by running it through a vinyl chloride coil submerged in a bottle of water and frozen at -80°C. Using this equipment, seven volunteers were given oxygen by mask, and their blood pressure, heart rate, and peripheral saturation of oxygen were measured. The temperature in the mask was also measured.

Results

This equipment was able to decrease the temperature in the mask to -5°C at the Jackson Rees circuit for an oxygen flow of 10 L/min. Among the volunteer group, vital signs were unchanged and the temperature in the mask decreased from 30.1 ± 2.6°C (mean ± standard deviation) to 15.9 ± 9.6°C. No adverse effects were observed in the volunteers after experimentation.

Conclusion

We successfully developed new equipment to cool oxygen and established its safety in a volunteer study.

Association Between Tracheal Intubation During Pediatric In-Hospital Cardiac Arrest and Survival

IMPORTANCE

Tracheal intubation is common during pediatric in-hospital cardiac arrest, although the relationship between intubation during cardiac arrest and outcomes is unknown.

OBJECTIVE

To determine if intubation during pediatric in-hospital cardiac arrest is associated with improved outcomes.

DESIGN, SETTING, AND PARTICIPANTS

Observational study of data from United States hospitals in the Get With The Guidelines-Resuscitation registry. Pediatric patients (<18 years) with index in-hospital cardiac arrest between January 2000 and December 2014 were included. Patients who were receiving assisted ventilation, had an invasive airway in place, or both at the time chest compressions were initiated were excluded.

EXPOSURES

Tracheal intubation during cardiac arrest .

MAIN OUTCOMES AND MEASURES

The primary outcome was survival to hospital discharge. Secondary outcomes included return of spontaneous circulation and neurologic outcome. A favorable neurologic outcome was defined as a score of 1 to 2 on the pediatric cerebral performance category score. Patients being intubated at any given minute were matched with patients at risk of being intubated within the same minute (ie, still receiving resuscitation) based on a time-dependent propensity score calculated from multiple patient, event, and hospital characteristics.

RESULTS

The study included 2294 patients; 1308 (57%) were male, and all age groups were represented (median age, 7 months [25th-75th percentiles, 21 days, 4 years]). Of the 2294 included patients, 1555 (68%) were intubated during the cardiac arrest. In the propensity score-matched cohort (n = 2270), survival was lower in those intubated compared with those not intubated (411/1135 [36%] vs 460/1135 [41%]; risk ratio [RR], 0.89 [95% CI, 0.81-0.99]; P = .03). There was no significant difference in return of spontaneous circulation (770/1135 [68%] vs 771/1135 [68%]; RR, 1.00 [95% CI, 0.95-1.06]; P = .96) or favorable neurologic outcome (185/987 [19%] vs 211/983 [21%]; RR, 0.87 [95% CI, 0.75-1.02]; P = .08) between those intubated and not intubated. The association between intubation and decreased survival was observed in the majority of the sensitivity and subgroup analyses, including when accounting for missing data and in a subgroup of patients with a pulse at the beginning of the event.

CONCLUSIONS AND RELEVANCE

Among pediatric patients with in-hospital cardiac arrest, tracheal intubation during cardiac arrest compared with no intubation was associated with decreased survival to hospital discharge. Although the study design does not eliminate the potential for confounding, these findings do not support the current emphasis on early tracheal intubation for pediatric in-hospital cardiac arrest.

Current and Future Status of Extracorporeal Cardiopulmonary Resuscitation for In-Hospital Cardiac Arrest

Numerous series, propensity-matched trials, and meta-analyses suggest that appropriate use of extracorporeal cardiopulmonary resuscitation (E-CPR) for in-hospital cardiac arrest (IHCA) can be lifesaving. Even with an antecedent cardiopulmonary resuscitation (CPR) duration in excess of 45 minutes, 30-day survival with favourable neurologic outcome using E-CPR is approximately 35%-45%. Survival may be related to age, duration of CPR, or etiology. Associated complications include sepsis, renal failure, limb and neurologic complications, hemorrhage, and thrombosis. However, methodological biases-including small sample size, selection bias, publication bias, and inability to control for confounders-in these series prevent definitive conclusions. As such, the 2015 American Heart Association Advanced Cardiac Life Support guidelines update recommended E-CPR as a Level of Evidence IIb recommendation in appropriate cases. The absence of high-quality evidence presents an opportunity for clinician/scientists to generate practice-defining data through collaborative investigation and prospective trials. A multidisciplinary dialogue is required to standardize the field and promote multicentre investigation of E-CPR with data sharing and the development of a foundation for high-quality trials. The objectives of this review are to (1) provide an overview of the strengths and limitations of currently available studies investigating the use of E-CPR in patients with IHCA and highlight knowledge gaps; (2) create a framework for the standardization of terminology, clinical practice, data collection, and investigation of E-CPR for patients with IHCA that will help ensure congruence in future work in this area; and (3) propose suggestions to guide future research by the cardiovascular community to advance this important field.

End-of-Life Issues in Cardiac Critical Care: The Option of Organ Donation

Despite important advances in the care of postcardiac arrest patients, severe brain injury remains one of the major causes of death in the cardiac intensive care unit. Neurological prognostication after cardiac arrest has evolved significantly since the introduction of therapeutic hypothermia. It now relies on a multimodal approach and a minimal observation period of 72 hours is usually advocated. However, when brain injury is severe and the prognosis considered dismal, patients become eligible for organ donation. Patients with severe anoxic encephalopathy might evolve toward brain death and be candidates for donation after brain death. In the presence of severe brain injury without brain death criteria, when withdrawal of life-sustaining therapy is considered, patients might be eligible for donation after cardiocirculatory death. The diagnosis of brain death, the differences between donation after brain death and donation after cardiocirculatory death, family approach, and donor management in the intensive care unit are discussed. Because these are increasingly encountered situations in the cardiac intensive care unit, it is essential that physicians involved in cardiac critical care be familiar with these concepts.

Early antibiotics administration during targeted temperature management after out-of-hospital cardiac arrest: a nationwide database study

Background

Patients resuscitated after cardiac arrest are reportedly at high risk for infection and sepsis, especially those treated with targeted temperature management (TTM). There is, however, limited evidence suggesting that early antibiotic use improves patient outcomes. We examined the hypothesis that early treatment with antibiotics reduces mortality in patients with cardiac arrest receiving TTM.

Methods

We identified 2803 patients with cardiogenic out-of-hospital cardiac arrest (OHCA) that were treated with TTM and were admitted to 371 hospitals that contribute to the Japanese Diagnosis Procedure Combination inpatient database between July 2007 and March 2013. Of these, 1272 received antibiotics within the first 2 days (antibiotics) and 1531 did not (control). We generated 802 propensity score-matched pairs.

Results

There was no significant difference in 30-day mortality between the groups (control vs. antibiotics; 33.0 % vs. 29.9 %; difference, 3.1 %; 95 % confidence interval [CI], −1.4 to 7.7 %, p = 0.18). Analysis using the hospital antibiotics prescribing rate as an instrumental variable showed that antibiotic use was not significantly associated with a reduction in 30-day mortality (6.6 %, CI 95 %, −0.5 to 13.7 %, p = 0.28). A subgroup analysis of patients who required extracorporeal membrane oxygenation (ECMO) indicated a significant difference in 30-day mortality between the 2 groups (62.9 % vs. 43.5 %; difference 19.3 %, CI 95 %, 5.9 to 32.7 %, p = 0.005). In the instrumental variable model, the estimated reduction in 30-day mortality associated with antibiotics was 18.2 % (CI 95 %, 21.3 to 34.4 %, p = 0.03) in ECMO patients.

Conclusions

Although there was no significant association between the use of antibiotics and mortality after overall cardiogenic OHCA treated with TTM, antibiotics may be beneficial in patients who require ECMO.

The impact of hospital experience with out-of-hospital cardiac arrest patients on post cardiac arrest care

OBJECTIVE

Patient volume as a surrogate for institutional experience has been associated with quality of care indicators for a variety of illnesses. We evaluated the association between hospital experience with comatose out-of-hospital cardiac arrest (OHCA) patients and important care processes.

METHODS

This was a population-based, retrospective cohort study using data from 37 hospitals in Southern Ontario from 2007 to 2013. We included adults with atraumatic OHCA who were comatose on emergency department arrival and survived at least 6h. We excluded patients with a Do-Not-Resuscitate order or severe bleeding within 6h of hospital arrival. Multi-level logistic regression models estimated the association between average annual hospital volume of OHCA patients and outcomes. The primary outcome was successful targeted temperature management (TTM) and secondary outcomes included TTM initiation, premature withdrawal of life-sustaining therapy, and survival with good neurologic function.

RESULTS

Our analysis included 2723 patients. For every increase of 10 in the average annual volume of eligible patients, the adjusted odds increased by 30% for successful TTM (OR 1.29, 95% CI 1.03-1.62) and by 38% for initiating TTM (OR 1.38, 95% CI 1.11-1.72). No significant association between patient volume and other secondary outcomes was observed.

CONCLUSIONS

Patients arriving at hospitals with more experience treating comatose post cardiac arrest patients are more likely to have TTM initiated and to successfully reach target temperature. Our findings have implications for regional systems of care and knowledge translation efforts aiming to improve quality of care for this patient population.

Amiodarone or nifekalant upon hospital arrival for refractory ventricular fibrillation after out-of-hospital cardiac arrest

BACKGROUND

We evaluated the association between nifekalant or amiodarone on hospital admission and in-hospital mortality for cardiac arrest patients with persistent ventricular fibrillation on hospital arrival.

METHODS

This was a retrospective cohort study using the Japanese Diagnosis Procedure Combination inpatient database. We identified 2961 patients who suffered cardiogenic out-of-hospital cardiac arrest and who had ventricular fibrillation on hospital arrival between July 2007 and March 2013. Patients were categorized into amiodarone (n=2353) and nifekalant (n=608) groups, from which 525 propensity score-matched pairs were generated.

RESULTS

We found a significant difference in the admission rate between the nifekalant and amiodarone groups in propensity score-matched groups (75.6% vs. 69.3%, respectively; difference, 6.3%; 95% confidence interval (CI), 0.9-11.7). An analysis using the hospital nifekalant/amiodarone rate as an instrumental variable found that receiving nifekalant was associated with an improved admission rate (22.2%, 95% CI, 11.9-32.4). We found no significant difference in in-hospital mortality between the nifekalant and amiodarone groups (81.5% vs. 82.1%, respectively; difference, -0.6%; 95% CI, -5.2 to 4.1). Instrumental variable analysis showed that receiving nifekalant was not associated with reduced in-hospital mortality (6.2%, 95% CI, -2.4 to 14.8).

CONCLUSIONS

This nationwide study suggested no significant in-hospital mortality association between nifekalant and amiodarone for cardiogenic out-of-hospital cardiac arrest patients with ventricular fibrillation/persistent ventricular tachycardia on hospital arrival. Although nifekalant may potentially improve hospital admission rates compared with amiodarone for these patients, further studies are required to confirm our results.

Long-term efficacy of an extracorporeal membrane oxygenation simulation with a novel, low-cost vascular model "Endo-Circuit"

AIMS

This study investigated the long-term efficacy of a half-day extracorporeal membrane oxygenation simulation and low-cost vascular model for practitioner knowledge, skills, and attitudes in clinical settings and also assessed the usefulness of the vascular model.

METHODS

We included participants who attended a half-day extracorporeal membrane oxygenation simulation focused on the veno-arterial method between April 2013 and January 2016 at Tohoku University Simulation Center (Sendai, Japan). A survey questionnaire form was sent to each participant in March 2016. Ninety-six survey respondents engaged in real extracorporeal membrane oxygenation practice after the simulation were eligible for this study, and their answers were analyzed for differences between doctors and nurses. The survey asked questions regarding occupation, workplace, course date, years of experience, extracorporeal membrane oxygenation practice before simulation, problems and fears before the simulation, usefulness of reference materials, long-term efficacy of the simulation for practice, usefulness of the vascular model, and intensive care data review.

RESULTS

Among all eligible answers, every average self-reported score (ranging from 0 to 10) of the long-term efficacy for extracorporeal membrane oxygenation practice was above 4. Nurses reported experiencing fears more frequently than doctors before the simulation. The usefulness of an original low-cost vascular model was evaluated at a median score of 7.

CONCLUSION

A half-day extracorporeal membrane oxygenation simulation with an original low-cost vascular model had long-term positive efficacy for knowledge, skills, and attitudes of practitioners who engaged in real practice after the simulation, and the practitioners considered the model to be useful for them.

Sudden Cardiac Death in the Young

Although the occurrence of sudden cardiac death (SCD) in a young person is a rare event, it is traumatic and often widely publicized. In recent years, SCD in this population has been increasingly seen as a public health and safety issue. This review presents current knowledge relevant to the epidemiology of SCD and to strategies for prevention, resuscitation, and identification of those at greatest risk. Areas of active research and controversy include the development of best practices in screening, risk stratification approaches and postmortem evaluation, and identification of modifiable barriers to providing better outcomes after resuscitation of young SCD patients. Institution of a national registry of SCD in the young will provide data that will help to answer these questions.

Cardiopulmonary resuscitation quality and beyond: the need to improve real-time feedback and physiologic monitoring

High-quality cardiopulmonary resuscitation (CPR) has been shown to improve survival outcomes after cardiac arrest. The current standard in studies evaluating CPR quality is to measure CPR process measures—for example, chest compression rate, depth, and fraction. Published studies evaluating CPR feedback devices have yielded mixed results. Newer approaches that seek to optimize CPR by measuring physiological endpoints during the resuscitation may lead to individualized patient care and improved patient outcomes.

Controversies in the temperature management of critically ill patients

Although body temperature is a classic primary vital sign, its value has received little attention compared with the others (blood pressure, heart rate, and respiratory rate). This may result from the fact that unlike the other primary vital signs, aging and diseases rarely affect the thermoregulatory system. Despite this, when humans are exposed to various anesthetics and analgesics and acute etiologies of non-infectious and infectious diseases in perioperative and intensive care settings, abnormalities may occur that shift body temperature up and down. A recent upsurge in clinical evidence in the perioperative and critical care field resulted in many clinical trials in temperature management. The results of these clinical trials suggest that aggressive body temperature modifications in comatose survivors after resuscitation from shockable rhythm, and permissive fever in critically ill patients, are carried out in critical care settings to improve patient outcomes; however, its efficacy remains to be elucidated. A recent, large multicenter randomized controlled trial demonstrated contradictory results, which may disrupt the trends in clinical practice. Thus, updated information concerning thermoregulatory interventions is essential for anesthesiologists and intensivists. Here, recent controversies in therapeutic hypothermia and fever management are summarized, and their relevance to the physiology of human thermoregulation is discussed.

Improving Survival From Cardiac Arrest: A Review of Contemporary Practice and Challenges

Cardiac arrest is a common and lethal condition frequently encountered by emergency medicine providers. Resuscitation of persons after cardiac arrest remains challenging, and outcomes remain poor overall. Successful resuscitation hinges on timely, high-quality cardiopulmonary resuscitation. The optimal method of providing chest compressions and ventilator support during cardiac arrest remains uncertain. Prompt and effective defibrillation of ventricular arrhythmias is one of the few effective therapies available for treatment of cardiac arrest. Despite numerous studies during several decades, no specific drug delivered during cardiac arrest has been shown to improve neurologically intact survival after cardiac arrest. Extracorporeal circulation can rescue a minority of highly selected patients with refractory cardiac arrest. Current management of pulseless electrical activity is associated with poor outcomes, but it is hoped that a more targeted diagnostic approach based on electrocardiography and bedside cardiac ultrasonography may improve survival. The evolution of postresuscitation care appears to have improved cardiac arrest outcomes in patients who are successfully resuscitated. The initial approach to early stabilization includes standard measures, such as support of pulmonary function, hemodynamic stabilization, and rapid diagnostic assessment. Coronary angiography is often indicated because of the high frequency of unstable coronary artery disease in comatose survivors of cardiac arrest and should be performed early after resuscitation. Optimizing and standardizing our current approach to cardiac arrest resuscitation and postresuscitation care will be essential for developing strategies for improving survival after cardiac arrest.

Sex differences in the prehospital management of out-of-hospital cardiac arrest

BACKGROUND

Sex differences exist in the diagnosis and treatment of several cardiovascular diseases. Our objective was to determine whether sex differences exist in the use of guideline-recommended treatments in out-of-hospital cardiac arrest (OHCA).

METHODS

We included adult patients with non-traumatic OHCA treated by emergency medical services (EMS) in the Resuscitation Outcomes Consortium Prehospital Resuscitation using an IMpedance valve and Early versus Delayed (ROC PRIMED) database during 2007-2009. Outcomes included prehospital treatment intervals, procedures, and medications. Data were analysed using multivariable linear and logistic regression models that adjusted for sex, age, witnessed arrest, public location, bystander cardiopulmonary resuscitation (CPR), and first known rhythm of ventricular tachycardia/fibrillation.

RESULTS

We studied 15,584 patients; 64% were male and median age was 68 years (interquartile range 55-80). In multivariable analyses, intervals from EMS dispatch to first rhythm capture (p=0.001) and first EMS CPR (p=0.001) were longer in women than in men. Women were less likely to receive successful intravenous or intraosseous access (OR 0.78, 95% CI 0.71-0.86) but equally likely to receive a successful advanced airway (OR 0.94, 95% CI 0.86-1.02). Women were less likely to receive adrenaline (OR 0.81, 95% CI 0.74-0.88), atropine (OR 0.86, 95% CI 0.80-0.92), and lidocaine or amiodarone (OR 0.68, 95% CI 0.61-0.75).

CONCLUSION

Women were less likely than men to receive guideline-recommended treatments for OHCA. The reasons for these differences require further exploration, and EMS provider education and training should specifically address these sex differences in the treatment of OHCA.

Pre-hospital versus in-hospital initiation of cooling for survival and neuroprotection after out-of-hospital cardiac arrest

BACKGROUND

Targeted temperature management (also known under 'therapeutic hypothermia', 'induced hypothermia'", or 'cooling') has been shown to be beneficial for neurological outcome in patients who have had successful resuscitation from sudden cardiac arrest, but it remains unclear when this intervention should be initiated.

OBJECTIVES

To assess the effects of pre-hospital initiation of cooling on survival and neurological outcome in comparison to in-hospital initiation of cooling for adults with pre-hospital cardiac arrest.

SEARCH METHODS

We searched CENTRAL, MEDLINE, EMBASE, CINAHL, BIOSIS, and three trials registers from inception to 5 March 2015, and carried out reference checking, citation searching, and contact with study authors to identify additional studies.

SELECTION CRITERIA

We searched for randomized controlled trials (RCTs) in adults with out-of-hospital cardiac arrest comparing cooling in the pre-hospital setting to in-hospital cooling. Our primary outcomes were survival and neurological outcome; our secondary outcomes were adverse events, quality of life, and length of stay in the intensive care unit (ICU) and in the hospital.

DATA COLLECTION AND ANALYSIS

We used Cochrane's standard methodological procedures.

MAIN RESULTS

We included seven RCTs (2369 participants randomized) on the induction of pre-hospital cooling in comparison to in-hospital cooling. There was considerable methodological heterogeneity and risk of bias mainly due to deficits in the administration of cooling, therefore we refrained from pooling the results for survival and neurological outcome and we presented the results for each study separately. Adverse events were rare: based on four studies with 1713 adults pre-hospital induction of cooling may increase the risk of cardiac re-arrests. Risk of bias within the seven individual studies was generally moderate. Overall the quality of the evidence was very low. This was mainly driven by inconsistency and low precision.

AUTHORS' CONCLUSIONS

Currently, there is no convincing evidence to clearly delineate beneficial or harmful effects of pre-hospital induction of cooling in comparison to in-hospital induction of cooling. This conclusion is based on very low quality evidence.

[New guidelines on resuscitation in adults: What has changed?]

In October 2015, new guidelines for cardiopulmonary resuscitation (CPR) were published, which represent a revision of the guidelines 2010. The new recommendations are based on an update of knowledge on resuscitation, which was evaluated for the first time by GRADE (Grading of Recommendations Assessment, Development and Evaluation). The key messages of the guidelines 2010 were retained in 2015. Adult basic life support consists of a sequence of 30 chest compressions at a rate of 100-120/min with a depth of 5 to maximally 6 cm and 2 ventilations. As soon as possible, an automated external defibrillator (AED) should be applied. Interruptions of chest compressions should be minimized. To improve bystander CPR emergency medical dispatchers should diagnose cardiac arrest when informed about unconscious persons not breathing normally. In this case, emergency medical staff should inform bystanders to resuscitate with compression only CPR until the arrival of an emergency team. In postresuscitation care, mild hypothermia (body temperature 32-34 °C) has been replaced by targeted temperature management in unconscious patients. Now, the guidelines recommend a constant body temperature between 32-36 °C for at least 24 h. Fever should be prevented or treated.

Hypothermia for neuroprotection in adults after cardiopulmonary resuscitation

BACKGROUND

Good neurological outcome after cardiac arrest is difficult to achieve. Interventions during the resuscitation phase and treatment within the first hours after the event are critical. Experimental evidence suggests that therapeutic hypothermia is beneficial, and several clinical studies on this topic have been published. This review was originally published in 2009; updated versions were published in 2012 and 2016.

OBJECTIVES

We aimed to perform a systematic review and meta-analysis to assess the influence of therapeutic hypothermia after cardiac arrest on neurological outcome, survival and adverse events.

SEARCH METHODS

We searched the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 10); MEDLINE (1971 to May 2015); EMBASE (1987 to May 2015); the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1988 to May 2015); and BIOSIS (1989 to May 2015). We contacted experts in the field to ask for information on ongoing, unpublished or published trials on this topic.The original search was performed in January 2007.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) conducted to assess the effectiveness of therapeutic hypothermia in participants after cardiac arrest, without language restrictions. We restricted studies to adult populations cooled by any cooling method, applied within six hours of cardiac arrest.

DATA COLLECTION AND ANALYSIS

We entered validity measures, interventions, outcomes and additional baseline variables into a database. Meta-analysis was performed only for a subset of comparable studies with negligible heterogeneity. We assessed the quality of the evidence by using standard methodological procedures as expected by Cochrane and incorporated the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach.

MAIN RESULTS

We found six RCTs (1412 participants overall) conducted to evaluate the effects of therapeutic hypothermia - five on neurological outcome and survival, one on only neurological outcome. The quality of the included studies was generally moderate, and risk of bias was low in three out of six studies. When we compared conventional cooling methods versus no cooling (four trials; 437 participants), we found that participants in the conventional cooling group were more likely to reach a favourable neurological outcome (risk ratio (RR) 1.94, 95% confidence interval (CI) 1.18 to 3.21). The quality of the evidence was moderate.Across all studies that used conventional cooling methods rather than no cooling (three studies; 383 participants), we found a 30% survival benefit (RR 1.32, 95% CI 1.10 to 1.65). The quality of the evidence was moderate.Across all studies, the incidence of pneumonia (RR 1.15, 95% CI 1.02 to 1.30; two trials; 1205 participants) and hypokalaemia (RR 1.38, 95% CI 1.03 to 1.84; two trials; 975 participants) was slightly increased among participants receiving therapeutic hypothermia, and we observed no significant differences in reported adverse events between hypothermia and control groups. Overall the quality of the evidence was moderate (pneumonia) to low (hypokalaemia).

AUTHORS' CONCLUSIONS

Evidence of moderate quality suggests that conventional cooling methods provided to induce mild therapeutic hypothermia improve neurological outcome after cardiac arrest, specifically with better outcomes than occur with no temperature management. We obtained available evidence from studies in which the target temperature was 34°C or lower. This is consistent with current best medical practice as recommended by international resuscitation guidelines for hypothermia/targeted temperature management among survivors of cardiac arrest. We found insufficient evidence to show the effects of therapeutic hypothermia on participants with in-hospital cardiac arrest, asystole or non-cardiac causes of arrest.

Comparing extracorporeal cardiopulmonary resuscitation with conventional cardiopulmonary resuscitation: A meta-analysis

INTRODUCTION

The objective was to determine whether extracorporeal cardiopulmonary resuscitation (ECPR), when compared with conventional cardiopulmonary resuscitation (CCPR), improves outcomes in adult patients, and to determine appropriate conditions that can predict good survival outcome in ECPR patients through a meta-analysis.

METHODS

We searched the relevant literature of comparative studies between ECPR and CCPR in adults, from the MEDLINE, EMBASE, and Cochrane databases. The baseline information and outcome data (survival, good neurologic outcome at discharge, at 3-6 months, and at 1 year after arrest) were extracted. Beneficial effect of ECPR on outcome was analyzed according to time interval, location of arrest (out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA)), and pre-defined population inclusion criteria (witnessed arrest, initial shockable rhythm, cardiac etiology of arrest and CPR duration) by using Review Manager 5.3. Cochran's Q test and I(2) were calculated.

RESULTS

10 of 1583 publications were included. Although survival to discharge did not show clear superiority in OHCA, ECPR showed statistically improved survival and good neurologic outcome as compared to CCPR, especially at 3-6 months after arrest. In the subgroup of patients with pre-defined inclusion criteria, the pooled meta-analysis found similar results in studies with pre-defined criteria.

CONCLUSION

Survival and good neurologic outcome tended to be superior in the ECPR group at 3-6 months after arrest. The effect of ECPR on survival to discharge in OHCA was not clearly shown. As ECPR showed better outcomes than CCPR in studies with pre-defined criteria, strict indications criteria should be considered when implementation of ECPR.

Severe acidemia on arrival not predictive of neurologic outcomes in post-cardiac arrest patients

PURPOSE

This study aimed to determine whether severe acidemia (pH <7.2) on arrival at the emergency department (ED) is a predictive factor for neurologic outcomes of post-cardiac arrest patients treated with targeted temperature management (TTM).

MATERIALS AND METHODS

Data in the National Disaster Medical Center, a tertiary care hospital, were used to perform a case-control study on post-cardiac arrest patients treated with TTM from January 2013 to April 2015. The case group comprised patients with good neurologic outcomes (cerebral performance categories 1 and 2), whereas the control group comprised patients with poor neurologic outcomes (cerebral performance categories 3-5). Exposure was defined as arterial pH less than 7.2 on arrival at the ED.

RESULTS

We identified 32 patients matching our criteria, of which 13 had good outcomes and 19 poor outcomes. Arterial pH on arrival was not significantly associated with neurologic outcomes (P = .47; odds ratio, 0.5; 95% confidence interval, 0.09-2.61). In 24 patients with cardiogenic causes of cardiac arrest, pH on arrival was not significantly associated with neurologic outcomes (P = .68; odds ratio, 0.5; 95% confidence interval, 0.09-2.73) after matched-pair analysis by age, sex, and presence of light reflex.

CONCLUSION

Severe acidemia on arrival at the ED is not a significant predictive factor for neurologic outcomes in post-cardiac arrest patients treated with TTM, particularly in patients with cardiogenic causes of cardiac arrest. These results suggest that treatment should not be withheld in post-cardiac arrest patients with severe acidemia.

Cardiac arrest and therapeutic hypothermia

Therapeutic hypothermia for patients who remain comatose following resuscitation from a cardiac arrest improves both survival and neurologic outcomes. Although this therapy has been incorporated into the guidelines for routine post-resuscitation care and has been in clinical use for over a decade, significant questions and controversies remain. In this review, we discuss these questions in the context of the current evidence and provide a practical framework to help guide clinicians.