Effects of in-hospital low targeted temperature after out of hospital cardiac arrest: A systematic review with meta-analysis of randomized clinical trials

Mild Therapeutic Hypothermia Protects from Acute and Chronic Renal Ischemia-Reperfusion Injury in Mice by Mitigated Mitochondrial Dysfunction and Modulation of Local and Systemic Inflammation

Renal ischemia-reperfusion (IR) injury can lead to acute kidney injury, increasing the risk of developing chronic kidney disease. We hypothesized that mild therapeutic hypothermia (mTH), 34 °C, applied during ischemia could protect the function and structure of kidneys against IR injuries in mice. In vivo bilateral renal IR led to an increase in plasma urea and acute tubular necrosis at 24 h prevented by mTH. One month after unilateral IR, kidney atrophy and fibrosis were reduced by mTH. Evaluation of mitochondrial function showed that mTH protected against IR-mediated mitochondrial dysfunction at 24 h, by preserving CRC and OX-PHOS. mTH completely abrogated the IR increase of plasmatic IL-6 and IL-10 at 24 h. Acute tissue inflammation was decreased by mTH (IL-6 and IL1-β) in as little as 2 h. Concomitantly, mTH increased TNF-α expression at 24 h. One month after IR, mTH increased TNF-α mRNA expression, and it decreased TGF-β mRNA expression. We showed that mTH alleviates renal dysfunction and damage through a preservation of mitochondrial function and a modulated systemic and local inflammatory response at the acute phase (2–24 h). The protective effect of mTH is maintained in the long term (1 month), as it diminished renal atrophy and fibrosis, and mitigated chronic renal inflammation.

Targeted Hypothermia vs Targeted Normothermia in Survivors of Cardiac Arrest: A Systematic Review and Meta-Analysis of Randomized Trials

BACKGROUND

The role of targeted hypothermia in patients with coma after cardiac arrest has been challenged in a recent randomized clinical trial.

METHODS

We performed a computerized search of MEDLINE, EMBASE, and Cochrane databases through July 2021 for randomized trials evaluating the outcomes of targeted hypothermia vs normothermia in patients with coma after cardiac arrest with shockable or non-shockable rhythm. The main study outcome was mortality at the longest reported follow-up.

RESULTS

The final analysis included 8 randomized studies with a total of 2927 patients, with a weighted follow-up period of 4.9 months. The average targeted temperature in the hypothermia arm in the included trials varied from 31.7°C to 34°C. There was no difference in long-term mortality between the hypothermia and normothermia groups (56.2% vs 56.9%, risk ratio [RR] 0.96; 95% confidence interval [CI], 0.87-1.06). There was no significant difference between hypothermia and normothermia groups in rates of favorable neurological outcome (37.9% vs 34.2%, RR 1.31; 95% CI, 0.99-1.73), in-hospital mortality (RR 0.88; 95% CI, 0.77-1.01), bleeding, sepsis, or pneumonia. Ventricular arrhythmias were more common among the hypothermia vs normothermia groups (RR 1.36; 95% CI, 1.17-1.58; P = .42). Sensitivity analysis, excluding the Targeted Hypothermia vs Targeted Normothermia after Out-of-Hospital Cardiac Arrest (TTM2) trial, showed favorable neurological outcome with hypothermia vs normothermia (RR 1.45; 95% CI, 1.17-1.79).

CONCLUSION

Targeted temperature management was not associated with improved survival or neurological outcomes compared with normothermia in comatose patients after cardiac arrest. Further studies are warranted to further clarify the value of targeted hypothermia compared with targeted normothermia.

Targeted Temperature Management after Cardiac Arrest: A Systematic Review and Meta-Analysis with Trial Sequential Analysis

Target temperature management (TTM) in cardiac arrest (CA) survivors is recommended after hospital admission for its possible beneficial effects on survival and neurological outcome. Whether a lower target temperature (i.e., 32–34 °C) improves outcomes is unclear. We conducted a systematic review and meta-analysis on Pubmed and EMBASE to evaluate the effects on mortality and neurologic outcome of TTM at 32–34 °C as compared to controls (patients cared with “actively controlled” or “uncontrolled” normothermia). Results were analyzed via risk ratios (RR) and 95% confidence intervals (CI). Eight randomized controlled trials (RCTs) were included. TTM at 32–34 °C was compared to “actively controlled” normothermia in three RCTs and to “uncontrolled” normothermia in five RCTs. TTM at 32–34 °C does not improve survival as compared to normothermia (RR:1.06 (95%CI 0.94, 1.20), p = 0.36; I² = 39%). In the subgroup analyses, TTM at 32–34 °C is associated with better survival when compared to “uncontrolled” normothermia (RR: 1.31 (95%CI 1.07, 1.59), p = 0.008) but shows no beneficial effects when compared to “actively controlled” normothermia (RR: 0.97 (95%CI 0.90, 1.04), p = 0.41). TTM at 32–34 °C does not improve neurological outcome as compared to normothermia (RR: 1.17 (95%CI 0.97, 1.41), p = 0.10; I² = 60%). TTM at 32–34 °C increases the risk of arrhythmias (RR: 1.35 (95%CI 1.16, 1.57), p = 0.0001, I² = 0%). TTM at 32–34 °C does not improve survival nor neurological outcome after CA and increases the risk of arrhythmias.

Efficacy of Targeted Temperature Management after Pediatric Cardiac Arrest: A Meta-Analysis of 2002 Patients

Cardiac arrest (CA) is associated with high mortality and poor life quality. Targeted temperature management (TTM) or therapeutic hypothermia is a therapy increasing the survival of adult patients after CA. The study aim was to assess the feasibility of therapeutic hypothermia after pediatric CA. We performed a systematic review and meta-analysis of randomized controlled trials and observational studies evaluating the use of TTM after pediatric CA. The primary outcome was survival to hospital discharge or 30-day survival. Secondary outcomes included a one-year survival rate, survival with a Vineland adaptive behavior scale (VABS-II) score ≥ 70, and occurrence of adverse events. Ten articles (n = 2002 patients) were included, comparing TTM patients (n = 638) with controls (n = 1364). In a fixed-effects meta-analysis, survival to hospital discharge in the TTM group was 49.7%, which was higher than in the non-TTM group (43.5%; odds ratio, OR = 1.22; 95% confidence interval, CI: 1.00, 1.50; p = 0.06). There were no differences in the one-year survival rate or the occurrence of adverse events between the TTM and non-TTM groups. Altogether, the use of TTM was associated with a higher survival to hospital discharge; however, it did not significantly increase the annual survival. Additional high-quality prospective studies are necessary to confer additional TTM benefits.

Post-cardiac arrest care and targeted temperature management: A consensus of scientific statement from the Taiwan Society of Emergency & Critical Care Medicine, Taiwan Society of Critical Care Medicine and Taiwan Society of Emergency Medicine

BACKGROUND

Post-cardiac arrest care is critically important in bringing cardiac arrest patients to functional recovery after the detrimental event. More high quality studies are published and evidence is accumulated for the post-cardiac arrest care in the recent years. It is still a challenge for the clinicians to integrate these scientific data into the real clinical practice for such a complicated intensive care involving many different disciplines.

METHODS

With the cooperation of the experienced experts from all disciplines relevant to post-cardiac arrest care, the consensus of the scientific statement was generated and supported by three major scientific groups for emergency and critical care in post-cardiac arrest care.

RESULTS

High quality post-cardiac arrest care, including targeted temperature management, early evaluation of possible acute coronary event and intensive care for hemodynamic and respiratory care are inevitably needed to get full recovery for cardiac arrest. Management of these critical issues were reviewed and proposed in the consensus CONCLUSION: The goal of the statement is to provide help for the clinical physician to achieve better quality and evidence-based care in post-cardiac arrest period.

Esophageal Cooling for Hypoxic Ischemic Encephalopathy: A Feasibility Study

Targeted temperature management (TTM) is a recognized treatment to decrease mortality and improve neurological function in hypoxic ischemic encephalopathy. An esophageal cooling device (ECD) has been studied in animal models, but human data are limited. An ECD appears to offer similar benefits to intravascular cooling catheters, with potentially less risk to the patient. We studied whether the ECD could act as a substitute for intravascular cooling catheters in delivering adequate TTM after cardiac arrest. Nine patients admitted to the intensive care unit after cardiac arrest who required TTM were enrolled prospectively. The primary outcome measures were timeliness of insertion, ease of insertion, user Likert ratings, time to achieve a target temperature of 36°C, and time during which target temperature was maintained within 1°C of the 36°C goal for 24 hours by using an ECD. Time to reach target temperature was 0 to 540 minutes (mean: 113.33 minutes, median: 0 minute, standard deviation [SD]: 179.22). Maintenance of a target temperature of 36°C over 24 hours had a range of 58.33% to 100% (mean: 91.67%, median: 95.83%, SD: 13.34). Ease of insertion related to Likert ratings with a range of 1-9 (mean: 5.38, median: 5.5, SD: 3.43) and a simplicity of ECD uses a range of 4-10 (mean: 7.63, median: 8.0, SD: 1.65). Overall, there was preference for the ECD over intravascular cooling methods (mean: 6.71, mean: 6, SD: 3.01) and external cooling methods (mean: 8.0, median: 9.0, SD: 2.33). For patients requiring TTM, use of an ECD adequately allowed for TTM goals to be achieved and maintained. Overall, user evaluation was positive.

The protective effects of simvastatin in Cadmium-Induced preosteoblast injury through Nox4

Cadmium (Cd) has a direct toxic effect on bones. Statins such as simvastatin have protective effects on various diseases, including on tissue injury. The current study revealed the efficacy of simvastatin on Cd-induced preosteoblast injury. Preosteoblast MC3T3-E1 cells were incubated with various doses of CdCl₂ for 12 h, 24 h and 48 h, and then the cell cytotoxicity was assessed using MTT assay and flow cytometry, respectively. The expression level of Nox4 was assessed by Western blot and qRT-PCR. The morphological appearance of MC3T3-E1 cells was observed under a microscope. Cells exposed to CdCl₂ (5 µM) were further treated by simvastatin at various doses, subsequently cell viability, apoptosis and the expression of Nox4 were measured. Furthermore, to confirm the protective effects of simvastatin on Cd-induced pre-osteoblast injury, functional rescue assays were performed after corresponding cell treatment by simvastatin (10^-8 M), CdCl₂ (5 µM), and overexpression of Nox4. Expressions of cell apoptosis-related markers were measured by Western blot and qRT-PCR. The results revealed that CdCl₂ caused MC3T3-E1 cell injury because the cell viability was decreased and the apoptosis was increased. Nox4 expression was up-regulated with the increase of CdCl₂ concentrations. Simvastatin increased the cell viability, relieved the cell apoptosis and Nox4 expression previously increased by CdCl₂. The effects of CdCl₂ on MC3T3-E1 cells and Nox4 expression could be attenuated by simvastatin, and promoted by Nox4 overexpression. The current study found that simvastatin protects Cd-induced preosteoblast injury via Nox4, thus, it can be used as a potential drug for treating cadmium-induced bone injury.

Hypermetabolism in critically ill patients with COVID-19 and the effects of hypothermia: A case series

Background

We have observed that critically ill patients with COVID-19 are in an extreme hypermetabolic state. This may be a major contributing factor to the extraordinary ventilatory and oxygenation demands seen in these patients. We aimed to quantify the extent of the hypermetabolic state and report the clinical effect of the use of hypothermia to decrease the metabolic demand in these patients.

Methods

Mild hypothermia was applied on four critically ill patients with COVID-19 for 48 h. Metabolic rates, carbon dioxide production and oxygen consumption were measured by indirect calorimetry.

Results

The average resting energy expenditure (REE) was 299% of predicted. Mild hypothermia decreased the REE on average of 27.0% with resultant declines in CO₂ production (VCO₂) and oxygen consumption (VO₂) by 29.2% and 25.7%, respectively. This decrease in VCO₂ and VO₂ was clinically manifested as improvements in hypercapnia (average of 19.1% decrease in pCO₂ levels) and oxygenation (average of 50.4% increase in pO₂).

Conclusion

Our case series demonstrates the extent of hypermetabolism in COVID-19 critical illness and suggests that mild hypothermia reduces the metabolic rate, improves hypercapnia and hypoxia in critically ill patients with COVID-19.

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COVID-19 critical illness induces an extreme hypermetabolic state.

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Hypothermia attenuates the hypermetabolic response seen in patients with COVID-19.

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Hypothermia in patients with COVID-19 may improve carbon dioxide and oxygen levels.

Effect of Therapeutic Hypothermia on Liver Enzymes in Patients With Stroke

Introduction:

A promising strategy that can lead to longer brain cell survival after an acute stroke is therapeutic hypothermia. It represents a controlled decrease in body temperature for therapeutic reasons. It is increasingly represented as a therapeutic option and is one of the most challenging treatments that improves neurological recovery and treatment outcome in patients with acute stroke.

Aim:

To examine the effect of therapeutic hypothermia on liver enzymes in patients with diagnosis of stroke.

Methods:

A total of 101 patients diagnosed with acute stroke were treated. The first group (n=40) were treated with conventional treatment and therapeutic hypothermia, while the second group (n=61) only with conventional treatment. Cooling of the body to a target body temperature of 34°C to 35°C was performed for up to 24 hours. Outcome (survival or death) of treatment was monitored, degree of disability was determined by National Institutes of Health Stroke Scale (NIHSS) and assessment of consciousness using the Glasgow Coma Scale (GCS). Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values were taken at admission, after 24 hours, and were monitored upon discharge.

Results:

There was a significant difference in AST values at admission relative to disease outcome (p = 0.002), as well as for ALT (p = 0.008). In patients treated with therapeutic hypothermia, mean AST values decreased after 24 hours (32.50 to 31.00 IU/mL) as well as ALT values (27.50 to 26.50 IU/mL), without statistical significance. In the group of subjects who survived with sequela, AST values correlated with GCS (rho = -0.489; p = 0.002) and NIHSS (rho = 0.492; p = 0.003), ALT values correlated with GCS (rho = -0.356; p = 0.03) but not with NIHSS.

Conclusion:

AST and ALT values at admission correlate with the severity of the clinical picture. Therapeutic hypothermia is hepatoprotective and lowers AST and ALT values.

Management of Out-of-Hospital Cardiac Arrest Complicating Acute Coronary Syndromes

PURPOSE OF THE REVIEW

Out-of-hospital cardiac arrest (OHCA) complicating acute coronary syndromes (ACS) continues to carry a high rate of morbidity and mortality despite significant advances in EMS and interventional cardiology services. In this review, we discuss an evidence-based approach to the initial care and management of patients with OHCA complicating ACS from the pre-hospital response and initial resuscitation strategy, to advanced therapies such as coronary angiography, targeted-temperature management, neuro-prognostication, and care of the post-arrest patient.

RECENT FINDINGS

Early recognition of cardiac arrest and prompt initiation of bystander CPR are the most important factors associated with improved survival. A comprehensive and coordinated approach to in-hospital management, including PCI, targeted temperature management, critical care, and hemodynamic support represents a significant critical link in the chain of survival. OHCA complicated by ACS continues to be one of the most challenging disease states facing healthcare practitioners and maintains a high mortality rate despite substantial advancements in healthcare delivery. A comprehensive approach to in-hospital management and further exploration of novel interventions, including ECMO, may yield opportunities to optimize care and improve outcomes for cardiac arrest patients.

Evidence-Based Review of Clinical Trials in Neurocritical Care

Neurocritical care is a rapidly growing specialty of complex care for the critically ill patient with neurological injury. This rapid growth has led to an increase in the number of important clinical trials to guide clinical practice and evidence-based care of the critically ill patient with neurological injury. Specialty-trained critical care nurses and advanced practice providers are integral members of neurocritical care teams and must remain informed about pivotal trials shaping practice recommendations. This article presents a summary of recent trials that have affected current practice and influenced care recommendations in the neurocritical care setting.

Impact of Targeted Temperature Management on ED Patients with Drug Overdose-Related Cardiac Arrest

INTRODUCTION

Drug overdose is the leading cause of non-traumatic out-of-hospital cardiac arrest (OHCA) among young adults. This study investigates whether targeted temperature management (TTM) improves hospital survival from presumed overdose-related cardiac arrest.

METHODS

Retrospective chart review of consecutive cardiac arrests presenting to an urban tertiary care hospital ED from 2011 to 2015. ED patients with cardiac arrest were included if < 50 years old, and excluded if there was a non-overdose etiology (e.g., trauma, ST-elevation myocardial infarction, subarachnoid hemorrhage). The main intervention was TTM, carried out with a combination of the Arctic Sun device and refrigerated crystalloid/antipyretics (goal temperature 33-36 °C). The primary outcome was survival to hospital discharge; neurologically intact survival was the secondary outcome.

RESULTS

Of 923 patients with cardiac arrest, 802 (86.9%) met exclusion criteria, leaving 121 patients for final analysis. There were 29 patients in the TTM group (24.0%) vs 92 patients in the non-TTM group (76.0%). Eleven patients (9.1%) survived to hospital discharge. TTM was associated with increased odds of survival to hospital discharge (OR 11.3, 95% CI 2.8-46.3, p < 0.001), which increased substantially when palliative outcomes were excluded from the cohort (OR 117.3, 95% CI 17.0-808.4, p < 0.001). Despite achieving statistical significance (OR 1.1, 95% CI 1.0-1.3), TTM had no clinically significant effect on neurologically intact survival.

CONCLUSIONS

TTM was associated with improved survival in ED patients with presumed drug overdose-related cardiac arrest. The impact of TTM on neurologically intact survival among these patients requires further study.

Targeted temperature management in the ICU: Guidelines from a French expert panel

Over the recent period, the use of induced hypothermia has gained an increasing interest for critically ill patients, in particular in brain-injured patients. The term "targeted temperature management" (TTM) has now emerged as the most appropriate when referring to interventions used to reach and maintain a specific level temperature for each individual. TTM may be used to prevent fever, to maintain normothermia, or to lower core temperature. This treatment is widely used in intensive care units, mostly as a primary neuroprotective method. Indications are, however, associated with variable levels of evidence based on inhomogeneous or even contradictory literature. Our aim was to conduct a systematic analysis of the published data in order to provide guidelines. We present herein recommendations for the use of TTM in adult and paediatric critically ill patients developed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method. These guidelines were conducted by a group of experts from the French Intensive Care Society (Société de réanimation de langue française [SRLF]) and the French Society of Anesthesia and Intensive Care Medicine (Société francaise d'anesthésie réanimation [SFAR]) with the participation of the French Emergency Medicine Association (Société française de médecine d'urgence [SFMU]), the French Group for Pediatric Intensive Care and Emergencies (Groupe francophone de réanimation et urgences pédiatriques [GFRUP]), the French National Association of Neuro-Anesthesiology and Critical Care (Association nationale de neuro-anesthésie réanimation française [ANARLF]), and the French Neurovascular Society (Société française neurovasculaire [SFNV]). Fifteen experts and two coordinators agreed to consider questions concerning TTM and its practical implementation in five clinical situations: cardiac arrest, traumatic brain injury, stroke, other brain injuries, and shock. This resulted in 30 recommendations: 3 recommendations were strong (Grade 1), 13 were weak (Grade 2), and 14 were experts' opinions. After two rounds of rating and various amendments, a strong agreement from voting participants was obtained for all 30 (100%) recommendations, which are exposed in the present article.

Targeted temperature management in the ICU: guidelines from a French expert panel

Over the recent period, the use of induced hypothermia has gained an increasing interest for critically ill patients, in particular in brain-injured patients. The term “targeted temperature management” (TTM) has now emerged as the most appropriate when referring to interventions used to reach and maintain a specific level temperature for each individual. TTM may be used to prevent fever, to maintain normothermia, or to lower core temperature. This treatment is widely used in intensive care units, mostly as a primary neuroprotective method. Indications are, however, associated with variable levels of evidence based on inhomogeneous or even contradictory literature. Our aim was to conduct a systematic analysis of the published data in order to provide guidelines. We present herein recommendations for the use of TTM in adult and paediatric critically ill patients developed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method. These guidelines were conducted by a group of experts from the French Intensive Care Society (Société de Réanimation de Langue Française [SRLF]) and the French Society of Anesthesia and Intensive Care Medicine (Société Francaise d’Anesthésie Réanimation [SFAR]) with the participation of the French Emergency Medicine Association (Société Française de Médecine d’Urgence [SFMU]), the French Group for Pediatric Intensive Care and Emergencies (Groupe Francophone de Réanimation et Urgences Pédiatriques [GFRUP]), the French National Association of Neuro-Anesthesiology and Critical Care (Association Nationale de Neuro-Anesthésie Réanimation Française [ANARLF]), and the French Neurovascular Society (Société Française Neurovasculaire [SFNV]). Fifteen experts and two coordinators agreed to consider questions concerning TTM and its practical implementation in five clinical situations: cardiac arrest, traumatic brain injury, stroke, other brain injuries, and shock. This resulted in 30 recommendations: 3 recommendations were strong (Grade 1), 13 were weak (Grade 2), and 14 were experts’ opinions. After two rounds of rating and various amendments, a strong agreement from voting participants was obtained for all 30 (100%) recommendations, which are exposed in the present article.

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.

Changes in cardiac arrest patients' temperature management after the 2013 "TTM" trial: results from an international survey

BACKGROUND

Therapeutic hypothermia (TH between 32 and 34 °C) was recommended until recently in unconscious successfully resuscitated cardiac arrest (CA) patients, especially after initial shockable rhythm. A randomized controlled trial published in 2013 observed similar outcome between a 36 °C-targeted temperature management (TTM) and a 33 °C-TTM. The main aim of our study was to assess the impact of this publication on physicians regarding their TTM practical changes.

METHODS

A declarative survey was performed using the webmail database of the French Intensive Care Society including 3229 physicians (from May 2014 to January 2015).

RESULTS

Five hundred and eighteen respondents from 264 ICUs in 11 countries fulfilled the survey (16 %). A specific attention was generally paid by 94 % of respondents to TTM (hyperthermia avoidance, normothermia, or TH implementation) in CA patients, whereas 6 % did not. TH between 32 and 34 °C was declared as generally maintained during 12-24 h by 78 % of respondents or during 24-48 h by 19 %. Since the TTM trial publication, 56 % of respondents declared no modification of their TTM practice, whereas 37 % declared a practical target temperature change. The new temperature targets were 35-36 °C for 23 % of respondents, and 36 °C for 14 %. The duration of overall TTM (including TH and/or normothermia) was declared as applied between 12 and 24 h in 40 %, and between 24 and 48 h in 36 %. In univariate analysis, the physicians' TTM modification seemed related to hospital category (university versus non-university hospitals, P = 0.045), to TTM-specific attention paid in CA patients (P = 0.008), to TH durations (<12 versus 24-48 h, P = 0.01), and to new targets temperature (32-34 versus 35-36 °C, P < 0.0001).

CONCLUSIONS

The TTM trial publication has induced a modification of current practices in one-third of respondents, whereas the 32-34 °C target temperature remained unchanged for 56 %. Educational actions are needed to promote knowledge translations of trial results into clinical practice. New international guidelines may contribute to this effort.

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.

Ventricular fibrillation: triggers, mechanisms and therapies

Ventricular fibrillation (VF) is a common, life-threatening arrhythmia responsible for significant morbidity and mortality. Due to challenges in safely mapping VF, a comprehensive understanding of its mechanisms remains elusive. Recent findings have provided new insights into mechanisms that sustain early VF. Notably, the central role of electrical rotors and catheter-based ablation of VF rotor substrate have been recently reported. In this article, we will review data regarding four stages of VF: initiation, transition, maintenance and evolution. We will discuss the particular mechanisms for each stage and therapies targeting these mechanisms. We also examine inherited arrhythmia syndromes, including the mechanisms and therapies specific to each. We hope that the overview of VF outlined in this work will assist other investigators in designing future therapies to interrupt this life-threatening arrhythmia.

Rationale, design, and profile of Comprehensive Registry of In-Hospital Intensive Care for OHCA Survival (CRITICAL) study in Osaka, Japan

Background

We established a multi-center, prospective cohort that could provide appropriate therapeutic strategies such as criteria for the introduction and the effectiveness of in-hospital advanced treatments, including percutaneous coronary intervention (PCI), target temperature management, and extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) patients.

Methods

In Osaka Prefecture, Japan, we registered all consecutive patients who were suffering from an OHCA for whom resuscitation was attempted and who were then transported to institutions participating in this registry since July 1, 2012. A total of 11 critical care medical centers and one hospital with an emergency care department participated in this registry. The primary outcome was neurological status after OHCA, defined as cerebral performance category (CPC) scale.

Results

A total of 688 OHCA patients were documented between July 2012 and December 2012. Of them, 657 were eligible for our analysis. Patients’ average age was 66.2 years old, and male patients accounted for 66.2 %. The proportion of OHCAs having a cardiac origin was 50.4 %. The proportion as first documented rhythm of ventricular fibrillation/pulseless ventricular tachycardia was 11.6 %, pulseless electrical activity 23.4 %, and asystole 54.5 %. After hospital arrival, 10.5 % received defibrillation, 90.8 % tracheal intubation, 3.0 % ECPR, 3.5 % PCI, and 83.1 % adrenaline administration. The proportions of 90-day survival and CPC 1/2 at 90 days after OHCAs were 5.9 and 3.0 %, respectively.

Conclusions

The Comprehensive Registry of In-hospital Intensive Care for OHCA Survival (CRITICAL) study will enroll over 2000 OHCA patients every year. It is still ongoing without a set termination date in order to provide valuable information regarding appropriate therapeutic strategies for OHCA patients (UMIN000007528).

What is the proper target temperature for out-of-hospital cardiac arrest?

The implementation of target temperature management (TTM) or therapeutic hypothermia has been demonstrated in several major studies to be an effective neuroprotective strategy in postresuscitation care after cardiac arrest. Although several landmark studies found the promising results of lower targeted temperature (32-34 °C) in terms of survival and neurological outcomes, recent evidence showed no difference in either survival or long-term neurological outcome when compared with higher targeted temperature (36 °C). Thus, recent data suggest that avoiding hyperpyrexia, rather than cooling "per se," may be considered the main therapeutic target to avoid secondary brain damage after out-of-hospital cardiac arrest. Many questions are still debated about the exact protocol of TTM to be used, including whether temperature control is more beneficial than standard of care without active temperature control, the optimal cooling temperature, patient selection, and duration of cooling. The aim of this review article was to discuss the physiology of hypothermia, available cooling methods, and current evidence about the optimal target temperature and timing of hypothermia.

Post resuscitation care of out-of-hospital cardiac arrest patients in the Nordic countries: a questionnaire study

Background

Aim of this study was to compare post resuscitation care of out-of-hospital cardiac arrest (OHCA) patients in Nordic (Denmark, Finland, Iceland, Norway, Sweden) intensive care units (ICUs).

Methods

An online questionnaire was sent to Nordic ICUs in 2012 and was complemented by an additional one in 2014.

Results

The first questionnaire was sent to 188 and the second one to 184 ICUs. Response rates were 51 % and 46 %. In 2012, 37 % of the ICUs treated all patients resuscitated from OHCA with targeted temperature management (TTM) at 33 °C. All OHCA patients admitted to the ICU were treated with TTM at 33 °C more often in Norway (69 %) compared to Finland (20 %) and Sweden (25 %), p 0.02 and 0.014. In 2014, 63 % of the ICUs still use TTM at 33 °C, but 33 % use TTM at 36 °C. Early coronary angiography (CAG) and possible percutaneous coronary intervention (PCI) was routinely provided for all survivors of OHCA in 39 % of the hospitals in 2012 and in 28 % of the hospitals in 2014. Routine CAG for all actively treated victims of OHCA was performed more frequently in Sweden (51 %) and in Norway (54 %) compared to Finland (13 %), p 0.014 and 0.042.

Conclusions

Since 2012, TTM at 36 °C has been implemented in some ICUs, but TTM at 33 °C is used in majority of the ICUs. TTM at 33 or 36 °C and primary CAG are not routinely provided for all OHCA survivors and the criteria for these and ICU admission are variable. Best practices as a uniform approach to the optimal care of the resuscitated patient should be sought in the Nordic Countries.

Electronic supplementary material

The online version of this article (doi:10.1186/s13049-015-0141-z) contains supplementary material, which is available to authorized users.