Hypothermia therapy after pediatric cardiac arrest

Neurological Impact of Slower Rewarming during Bypass Surgery in Infants

BACKGROUND

 Hypothermia is a neuroprotective strategy during cardiopulmonary bypass. Rewarming entailing a rapid rise in cerebral metabolism might lead to secondary neurological sequelae. In this pilot study, we aimed to validate the hypothesis that a slower rewarming rate would lower the risk of cerebral hypoxia and seizures in infants.

METHODS

 This is a prospective, clinical, single-center study. Infants undergoing cardiac surgery in hypothermia were rewarmed either according to the standard (+1°C in < 5 minutes) or a slow (+1°C in > 5-8 minutes) rewarming strategy. We monitored electrocortical activity via amplitude-integrated electroencephalography (aEEG) and cerebral oxygenation by near-infrared spectroscopy during and after surgery.

RESULTS

 Fifteen children in the standard rewarming group (age: 13 days [5-251]) were cooled down to 26.6°C (17.2-29.8) and compared with 17 children in the slow-rewarming group (age: 9 days [4-365]) with a minimal temperature of 25.7°C (20.1-31.4). All neonates in both groups (n = 19) exhibited suppressed patterns compared with 28% of the infants > 28 days (p < 0.05). During rewarming, only 26% of the children in the slow-rewarming group revealed suppressed aEEG traces (vs. 41%; p = 0.28). Cerebral oxygenation increased by a median of 3.5% in the slow-rewarming group versus 1.5% in the standard group (p = 0.9). Our slow-rewarming group revealed no aEEG evidence of any postoperative seizures (0 vs. 20%).

CONCLUSION

 These results might indicate that a slower rewarming rate after hypothermia causes less suppression of electrocortical activity and higher cerebral oxygenation during rewarming, which may imply a reduced risk of postoperative seizures.

Association between Serum Lactate and Morbidity and Mortality in Neonates: A Systematic Review and Meta-Analysis

OBJECTIVE

Lactate is a marker of hypoperfusion in critically ill patients. Whether lactate is useful for identifying and stratifying neonates with a higher risk of adverse outcomes remains unknown. This study aimed to investigate the association between lactate and morbidity and mortality in neonates.

METHODS

A meta-analysis was performed to determine the association between blood lactate levels and outcomes in neonates. Ovid MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov were searched from inception to 1 May 2021. A total of 49 observational studies and 14 data accuracy test studies were included. The risk of bias was assessed using the Newcastle-Ottawa Scale for observational studies and the QUADAS-2 tool for data accuracy test studies. The primary outcome was mortality, while the secondary outcomes included acute kidney injury, necessity for renal replacement therapy, neurological outcomes, respiratory morbidities, hemodynamic instability, and retinopathy of prematurity.

RESULTS

Of the 3184 articles screened, 63 studies fulfilled all eligibility criteria, comprising 46,069 neonates. Higher lactate levels are associated with mortality (standard mean difference, -1.09 [95% CI, -1.46 to -0.73]). Using the estimated sensitivity (0.769) and specificity (0.791) and assuming a prevalence of 15% for adverse outcomes (median of prevalence among studies) in a hypothetical cohort of 10,000 neonates, assessing the lactate level alone would miss 346 (3.46%) cases (false negative) and wrongly diagnose 1776 (17.76%) cases (false positive).

CONCLUSIONS

Higher lactate levels are associated with a greater risk of mortality and morbidities in neonates. However, our results do not support the use of lactate as a screening test to identify adverse outcomes in newborns. Research efforts should focus on analyzing serial lactate measurements, rather than a single measurement.

Targeted temperature management at 36°C is a risk factor for ventilator-associated pneumonia

BACKGROUND

In contrast to the adult population, limited information is currently available on risk factors for ventilator-associated pneumonia (VAP) in children. Therapeutic hypothermia has been identified as a risk factor for the early onset of VAP in adults; however, the relationship between VAP and normothermia remains unclear. The present study investigated risk factors for VAP in children, with a focus on the deleterious effects of therapeutic normothermia on VAP.

METHODS

We retrospectively investigated the clinical characteristics of children treated with mechanical ventilation for more than 48 h and analyzed risk factors for VAP. The endpoint was the onset of VAP by the seventh day after the initiation of mechanical ventilation.

RESULTS

Among the 288 patients enrolled, seven (2.4%) developed VAP. No significant differences were observed in clinical backgrounds between the VAP and non-VAP groups. A univariate analysis identified target temperature management (TTM) at 36°C (p < 0.0001) and methylprednisolone (mPSL) pulse therapy (p = 0.02) as risk factors for VAP. An analysis of the time to the onset of VAP by the Kaplan-Meier plot and log-rank test revealed a significantly higher incidence of VAP in the TTM group (p < 0.0001) and mPSL pulse group (p = 0.001).

CONCLUSION

TTM at 36°C and mPSL pulse therapy may be risk factors for VAP in the pediatric population.

Selective Brain Cooling: A New Horizon of Neuroprotection

Therapeutic hypothermia (TH), which prevents irreversible neuronal necrosis and ischemic brain damage, has been proven effective for preventing ischemia-reperfusion injury in post-cardiac arrest syndrome and neonatal encephalopathy in both animal studies and clinical trials. However, lowering the whole-body temperature below 34°C can lead to severe systemic complications such as cardiac, hematologic, immunologic, and metabolic side effects. Although the brain accounts for only 2% of the total body weight, it consumes 20% of the body's total energy at rest and requires a continuous supply of glucose and oxygen to maintain function and structural integrity. As such, theoretically, temperature-controlled selective brain cooling (SBC) may be more beneficial for brain ischemia than systemic pan-ischemia. Various SBC methods have been introduced to selectively cool the brain while minimizing systemic TH-related complications. However, technical setbacks of conventional SBCs, such as insufficient cooling power and relatively expensive coolant and/or irritating effects on skin or mucosal interfaces, limit its application to various clinical settings. This review aimed to integrate current literature on SBC modalities with promising therapeutic potential. Further, future directions were discussed by exploring studies on interesting coping skills in response to environmental or stress-induced hyperthermia among wild animals, including mammals and birds.

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.

Acute kidney injury after in-hospital cardiac arrest

AIM

Determine 1) frequency and risk factors for acute kidney injury (AKI) after in-hospital cardiac arrest (IHCA) in the Therapeutic Hypothermia after Pediatric Cardiac Arrest In-Hospital (THAPCA-IH) trial and associated outcomes; 2) impact of temperature management on post-IHCA AKI.

METHODS

Secondary analysis of THAPCA-IH; a randomized controlled multi-national trial at 37 children's hospitals.

ELIGIBILITY

Serum creatinine (Cr) within 24 h of randomization.

OUTCOMES

Prevalence of severe AKI defined by Stage 2 or 3 Kidney Disease Improving Global Outcomes Cr criteria. 12-month survival with favorable neurobehavioral outcome. Analyses stratified by entire cohort and cardiac subgroup. Risk factors and outcomes compared among cohorts with and without severe AKI.

RESULTS

Subject randomization: 159 to hypothermia, 154 to normothermia. Overall, 80% (249) developed AKI (any stage), and 66% (207) developed severe AKI. Cardiac patients (204, 65%) were more likely to develop severe AKI (72% vs 56%,p = 0.006). Preexisting cardiac or renal conditions, baseline lactate, vasoactive support, and systolic blood pressure were associated with severe AKI. Comparing hypothermia versus normothermia, there were no differences in severe AKI rate (63% vs 70%,p = 0.23), peak Cr, time to peak Cr, or freedom from mortality or severe AKI (p = 0.14). Severe AKI was associated with decreased hospital survival (48% vs 65%,p = 0.006) and decreased 12-month survival with favorable neurobehavioral outcome (30% vs 53%,p < 0.001).

CONCLUSION

Severe post-IHCA AKI occurred frequently especially in those with preexisting cardiac or renal conditions and peri-arrest hemodynamic instability. Severe AKI was associated with decreased survival with favorable neurobehavioral outcome. Hypothermia did not decrease incidence of severe AKI post-IHCA.

Clinical application of target temperature management in children with acute encephalopathy-A practical review

Acute encephalopathy is a life-threatening disease involving acute brain dysfunction, and it is one of the most important causes of mortality and severe neurological sequelae in infants and children. Approximately 30% of cases of acute encephalopathy result in some degree of neurological sequelae. Although many strategies have been proposed, effective therapies to ameliorate the outcomes of acute encephalopathy have not yet been established. Target temperature management (TTM), previously termed therapeutic hypothermia, has been shown to be effective for various brain injuries due to multiple neuroprotective mechanisms, and it may be considered to be the cornerstone of neuroprotective strategies. Consequently, TTM is currently used in the neurocritical care of adult patients with cardiac arrest with shockable rhythm and perinatal asphyxia. In addition, increasing evidence also indicates that TTM could be useful in other acute encephalopathies, including status epilepticus, acute encephalitis/encephalopathy and traumatic brain injury. In this review, we discuss the recent practical aspects of TTM as a potential intervention for various acute encephalopathies in children.

Associations of therapeutic hypothermia with clinical outcomes in patients receiving ECPR after cardiac arrest: systematic review with meta-analysis

BACKGROUND

Therapeutic hypothermia has been recommended for eligible patients after cardiac arrest (CA) in order to improve outcomes. Up to now, several comparative observational studies have evaluated the combined use of extracorporeal cardiopulmonary resuscitation (ECPR) and therapeutic hypothermia in adult patients with CA. However, the effects of therapeutic hypothermia in adult CA patients receiving ECPR are inconsistent.

METHODS

Relevant studies in English databases (PubMed, ISI web of science, OVID, and Embase) were systematically searched up to September 2019. Odds ratios (ORs) from eligible studies were extracted and pooled to summarize the associations of therapeutic hypothermia with favorable neurological outcomes and survival in adult CA patients receiving ECPR.

RESULTS

13 articles were included in the present meta-analysis study. There were nine studies with a total of 806 cases reporting the association of therapeutic hypothermia with neurological outcomes in CA patients receiving ECPR. Pooling analysis suggested that therapeutic hypothermia was significantly associated with favorable neurological outcomes in overall (N = 9, OR = 3.507, 95%CI = 2.194-5.607, P < 0.001, fixed-effects model) and in all subgroups according to control type, regions, sample size, CA location, ORs obtained methods, follow-up period, and modified Newcastle Ottawa Scale (mNOS) scores. There were nine studies with a total of 806 cases assessing the association of therapeutic hypothermia with survival in CA patients receiving ECPR. After pooling the ORs, therapeutic hypothermia was found to be significantly associated with survival in overall (N = 9, OR = 2.540, 95%CI = 1.245-5.180, P = 0.010, random-effects model) and in some subgroups. Publication bias was found when evaluating the association of therapeutic hypothermia with neurological outcomes in CA patients receiving ECPR. Additional trim-and-fill analysis estimated four "missing" studies, which adjusted the effect size to 2.800 (95%CI = 1.842-4.526, P < 0.001, fixed-effects model) for neurological outcomes.

CONCLUSIONS

Therapeutic hypothermia may be associated with favorable neurological outcomes and survival in adult CA patients undergoing ECPR. However, the result should be treated carefully because it is a synthesis of low-level evidence and other limitations exist in present study. It is necessary to perform randomized controlled trials to validate our result before considering the result in clinical practices.

2019 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

The International Liaison Committee on Resuscitation has initiated a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation science. This is the third annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. It addresses the most recent published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. This summary addresses the role of cardiac arrest centers and dispatcher-assisted cardiopulmonary resuscitation, the role of extracorporeal cardiopulmonary resuscitation in adults and children, vasopressors in adults, advanced airway interventions in adults and children, targeted temperature management in children after cardiac arrest, initial oxygen concentration during resuscitation of newborns, and interventions for presyncope by first aid providers. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the certainty of the evidence on the basis of the Grading of Recommendations, Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence to Decision Framework Highlights sections. The task forces also listed priority knowledge gaps for further research.

2019 American Heart Association Focused Update on Pediatric Advanced Life Support: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

This 2019 focused update to the American Heart Association pediatric advanced life support guidelines follows the 2018 and 2019 systematic reviews performed by the Pediatric Life Support Task Force of the International Liaison Committee on Resuscitation. It aligns with the continuous evidence review process of the International Liaison Committee on Resuscitation, with updates published when the International Liaison Committee on Resuscitation completes a literature review based on new published evidence. This update provides the evidence review and treatment recommendations for advanced airway management in pediatric cardiac arrest, extracorporeal cardiopulmonary resuscitation in pediatric cardiac arrest, and pediatric targeted temperature management during post-cardiac arrest care. The writing group analyzed the systematic reviews and the original research published for each of these topics. For airway management, the writing group concluded that it is reasonable to continue bag-mask ventilation (versus attempting an advanced airway such as endotracheal intubation) in patients with out-of-hospital cardiac arrest. When extracorporeal membrane oxygenation protocols and teams are readily available, extracorporeal cardiopulmonary resuscitation should be considered for patients with cardiac diagnoses and in-hospital cardiac arrest. Finally, it is reasonable to use targeted temperature management of 32°C to 34°C followed by 36°C to 37.5°C, or to use targeted temperature management of 36°C to 37.5°C, for pediatric patients who remain comatose after resuscitation from out-of-hospital cardiac arrest or in-hospital cardiac arrest.

Pediatric Post–Cardiac Arrest Care: A Scientific Statement From the American Heart Association

Successful resuscitation from cardiac arrest results in a post–cardiac arrest syndrome, which can evolve in the days to weeks after return of sustained circulation. The components of post–cardiac arrest syndrome are brain injury, myocardial dysfunction, systemic ischemia/reperfusion response, and persistent precipitating pathophysiology. Pediatric post–cardiac arrest care focuses on anticipating, identifying, and treating this complex physiology to improve survival and neurological outcomes. This scientific statement on post–cardiac arrest care is the result of a consensus process that included pediatric and adult emergency medicine, critical care, cardiac critical care, cardiology, neurology, and nursing specialists who analyzed the past 20 years of pediatric cardiac arrest, adult cardiac arrest, and pediatric critical illness peer-reviewed published literature. The statement summarizes the epidemiology, pathophysiology, management, and prognostication after return of sustained circulation after cardiac arrest, and it provides consensus on the current evidence supporting elements of pediatric post–cardiac arrest care.

Paediatric targeted temperature management post cardiac arrest: A systematic review and meta-analysis

INTRODUCTION

The International Liaison Committee on Resuscitation prioritized the need to update the review on the use of targeted temperature management (TTM) in paediatric post cardiac arrest care. In this meta-analysis, the effectiveness of TTM at 32-36 °C was compared with no target or a different target for comatose children who achieve a return of sustained circulation after cardiac arrest.

METHODS

Electronic databases were searched from inception to December 13, 2018. Randomized controlled trials and non-randomized studies with a comparator group that evaluated TTM in children were included. Pairs of independent reviewers extracted the demographic and outcome data, appraised risk of bias, and assessed GRADE certainty of effects. A random effects meta-analysis was undertaken where possible.

RESULTS

Twelve studies involving 2060 patients were included. Two randomized controlled trials provided the evidence that TTM at 32-34 °C compared with a target at 36-37.5 °C did not statistically improve long-term good neurobehavioural survival (risk ratio: 1.15; 95% CI: 0.69-1.93), long-term survival (RR: 1.14; 95% CI: 0.93-1.39), or short-term survival (risk ratio: 1.14; 95% CI: 0.96-1.36). TTM at 32-34 °C did not show statistically increased risks of infection, recurrent cardiac arrest, serious bleeding, or arrhythmias. A novel analysis suggests that another small RCT might provide enough evidence to show benefit for TTM in out-of-hospital cardiac arrest.

CONCLUSION

There is currently inconclusive evidence to either support or refute the use of TTM at 32-34 °C for comatose children who achieve return of sustained circulation after cardiac arrest. Future trials should focus on children with out-of-hospital cardiac arrest.

Targeted Temperature Management in Pediatric Neurocritical Care

Targeted temperature management encompasses a range of clinical interventions to regulate systemic temperature, and includes both induction of varying degrees of hypothermia and fever prevention ("targeted normothermia"). Targeted temperature management plays a key role in the contemporary management of critically ill neonates and children with acute brain injury. Yet, many unanswered questions remain regarding optimal temperature management in pediatric neurocritical care. The introduction highlights experimental studies that have evaluated the neuroprotective efficacy of therapeutic hypothermia and explored possible mechanisms of action in several brain injury models. The next section focuses on three major clinical conditions in which therapeutic hypothermia has been evaluated in randomized controlled trials in pediatric populations: neonatal hypoxic-ischemic encephalopathy, postcardiac arrest encephalopathy, and traumatic brain injury. Clinical implications of targeted temperature management in pediatric neurocritical care are also discussed. The final section examines some of the factors that may underlie the limited neuroprotective efficacy of hypothermia that has been observed in several major pediatric clinical trials, and outlines important directions for future research.

Singapore Paediatric Resuscitation Guidelines 2016

We present the revised 2016 Singapore paediatric resuscitation guidelines. The International Liaison Committee on Resuscitation's Pediatric Taskforce Consensus Statements on Science and Treatment Recommendations, as well as the updated resuscitation guidelines from the American Heart Association and European Resuscitation Council released in October 2015, were debated and discussed by the workgroup. The final recommendations for the Singapore Paediatric Resuscitation Guidelines 2016 were derived after carefully reviewing the current available evidence in the literature and balancing it with local clinical practice.

Cardiopulmonary Resuscitation in Infants and Children With Cardiac Disease: A Scientific Statement From the American Heart Association

Cardiac arrest occurs at a higher rate in children with heart disease than in healthy children. Pediatric basic life support and advanced life support guidelines focus on delivering high-quality resuscitation in children with normal hearts. The complexity and variability in pediatric heart disease pose unique challenges during resuscitation. A writing group appointed by the American Heart Association reviewed the literature addressing resuscitation in children with heart disease. MEDLINE and Google Scholar databases were searched from 1966 to 2015, cross-referencing pediatric heart disease with pertinent resuscitation search terms. The American College of Cardiology/American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. The recommendations in this statement concur with the critical components of the 2015 American Heart Association pediatric basic life support and pediatric advanced life support guidelines and are meant to serve as a resuscitation supplement. This statement is meant for caregivers of children with heart disease in the prehospital and in-hospital settings. Understanding the anatomy and physiology of the high-risk pediatric cardiac population will promote early recognition and treatment of decompensation to prevent cardiac arrest, increase survival from cardiac arrest by providing high-quality resuscitations, and improve outcomes with postresuscitation care.

Thermoregulate, autoregulate and ventilate: brain-directed critical care for pediatric cardiac arrest

PURPOSE OF REVIEW

Cardiac arrest in childhood is associated with a high risk for mortality and poor long-term functional outcome. This review discusses the current evidence for neuroprotective therapies and goals for postarrest care in the context of the pathophysiology of hypoxic-ischemic injury, modalities for neurologic prognostication in these children and potential future monitoring paradigms for maximizing cerebral perfusion in the postarrest period.

RECENT FINDINGS

The recent publication of the in-hospital and out-of-hospital Therapeutic Hypothermia After Cardiac Arrest trials demonstrated a lack of statistically significant benefit for the use of postarrest therapeutic hypothermia. As a result, targeted normothermic temperature management has become standard of care. Continuous electroencephalographic monitoring during the acute postarrest period provides useful additional data for neurologic prognostication, in addition to its value for detection of seizures. Ongoing research into noninvasive monitoring of cerebrovascular autoregulation has the potential to individualize blood pressure goals in the postarrest period, maximizing cerebral perfusion in these patients.

SUMMARY

Therapeutic strategies after cardiac arrest seek to maximize cerebral perfusion while mitigating the effects of secondary brain injury and loss of autoregulation. Future research into new monitoring strategies and better long-term outcome measures may allow more precise targeting of therapies to these goals.

[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.

Therapeutic Hypothermia after In-Hospital Cardiac Arrest in Children

BACKGROUND

Targeted temperature management is recommended for comatose adults and children after out-of-hospital cardiac arrest; however, data on temperature management after in-hospital cardiac arrest are limited.

METHODS

In a trial conducted at 37 children's hospitals, we compared two temperature interventions in children who had had in-hospital cardiac arrest. Within 6 hours after the return of circulation, comatose children older than 48 hours and younger than 18 years of age were randomly assigned to therapeutic hypothermia (target temperature, 33.0°C) or therapeutic normothermia (target temperature, 36.8°C). The primary efficacy outcome, survival at 12 months after cardiac arrest with a score of 70 or higher on the Vineland Adaptive Behavior Scales, second edition (VABS-II, on which scores range from 20 to 160, with higher scores indicating better function), was evaluated among patients who had had a VABS-II score of at least 70 before the cardiac arrest.

RESULTS

The trial was terminated because of futility after 329 patients had undergone randomization. Among the 257 patients who had a VABS-II score of at least 70 before cardiac arrest and who could be evaluated, the rate of the primary efficacy outcome did not differ significantly between the hypothermia group and the normothermia group (36% [48 of 133 patients] and 39% [48 of 124 patients], respectively; relative risk, 0.92; 95% confidence interval [CI], 0.67 to 1.27; P=0.63). Among 317 patients who could be evaluated for change in neurobehavioral function, the change in VABS-II score from baseline to 12 months did not differ significantly between the groups (P=0.70). Among 327 patients who could be evaluated for 1-year survival, the rate of 1-year survival did not differ significantly between the hypothermia group and the normothermia group (49% [81 of 166 patients] and 46% [74 of 161 patients], respectively; relative risk, 1.07; 95% CI, 0.85 to 1.34; P=0.56). The incidences of blood-product use, infection, and serious adverse events, as well as 28-day mortality, did not differ significantly between groups.

CONCLUSIONS

Among comatose children who survived in-hospital cardiac arrest, therapeutic hypothermia, as compared with therapeutic normothermia, did not confer a significant benefit in survival with a favorable functional outcome at 1 year. (Funded by the National Heart, Lung, and Blood Institute; THAPCA-IH ClinicalTrials.gov number, NCT00880087 .).

Feasibility Study Evaluating Therapeutic Hypothermia for Refractory Status Epilepticus in Children

Pediatric refractory status epilepticus (RSE) is a neurological emergency with significant morbidity and mortality, which lacks consensus regarding diagnosis and treatment(s). Therapeutic hypothermia (TH) is an effective treatment for RSE in preclinical models and small series. In addition, TH is a standard care for adults after cardiac arrest and neonates with hypoxic-ischemic encephalopathy. The purpose of this study was to identify the feasibility of a study of pediatric RSE within a research group (Pediatric Neurocritical Care Research Group [PNCRG]). Pediatric intensive care unit (PICU) admissions at seven centers were prospectively screened from October 2012 to July 2013 for RSE. Experts within the PNCRG estimated that clinicians would be unwilling to enroll a child, unless the child required at least two different antiepileptic medications and a continuous infusion of another antiepileptic medication with ongoing electrographic seizure activity for ≥2 hours after continuous infusion initiation. Data for children meeting the above inclusion criteria were collected, including the etiology of RSE, history of epilepsy, and maximum dose of continuous antiepileptic infusions. There were 8113 PICU admissions over a cumulative 52 months (October 2012-July 2013) at seven centers. Of these, 69 (0.85%) children met inclusion criteria. Twenty children were excluded due to acute diagnoses affected by TH, contraindications to TH, or lack of commitment to aggressive therapies. Sixteen patients had seizure cessation within 2 hours, resulting in 33 patients who had inadequate seizure control after 2 hours and a continuous antiepileptic infusion. Midazolam (21/33, 64%) and pentobarbital (5/33, 15%) were the most common infusions with a wide maximum dose range. More than one infusion was required for seizure control in four patients. There are substantial numbers of subjects at clinical sites within the PNCRG with RSE that would meet the proposed inclusion criteria for a study of TH. The true feasibility of such a study depends on the sample size necessary to achieve therapeutic effects on justifiable clinical outcomes.

Cardiopulmonary Resuscitation in Children With In-Hospital and Out-of-Hospital Cardiopulmonary Arrest: Multicenter Study From Turkey

OBJECTIVES

The objectives of this study were to determine the causes, location of cardiopulmonary arrest (CPA) in children, and demographics of cardiopulmonary resuscitation (CPR) in Turkish pediatric emergency departments and pediatric intensive care units (PICUs) and to determine survival rates and morbidities for both in-hospital and out-of-hospital CPA.

METHODS

This multicenter descriptive study was conducted prospectively between January 15 and July 15, 2011, at 18 centers (15 PICUs, 3 pediatric emergency departments) in Turkey.

RESULTS

During the study period, 239 children had received CPR. Patients' average age was 42.4 (SD, 58.1) months. The most common cause of CPA was respiratory failure (119 patients [49.8%]). The location of CPA was the PICU in 168 (68.6%), hospital wards in 43 (18%), out-of-hospital in 24 (10%), and pediatric emergency department in 8 patients (3.3%). The CPR duration was 30.7 (SD, 23.6) minutes (range, 1-175 minutes) and return of spontaneous circulation was achieved in 107 patients (44.8%) after the first CPR. Finally, 58 patients (24.2%) were discharged from hospital; survival rates were 26% and 8% for in-hospital and out-of-hospital CPA, respectively (P = 0.001). Surviving patients' average length of hospital stay was 27.4 (SD, 39.2) days. In surviving patients, 19 (32.1%) had neurologic disability.

CONCLUSION

Pediatric CPA in both the in-hospital and out-of-hospital setting has a poor outcome.

Time on the scene and interventions are associated with improved survival in pediatric out-of-hospital cardiac arrest

BACKGROUND

Survival is less than 10% for pediatric patients following out-of-hospital cardiac arrest. It is not known if more time on the scene of the cardiac arrest and advanced life support interventions by emergency services personnel are associated with improved survival.

AIM

This study was performed to determine which times on the scene and which prehospital interventions were associated with improved survival.

METHODS

We studied patients aged 3 days to 19 years old with out-of-hospital cardiac arrest, using the Resuscitation Outcomes Consortium cardiac arrest database from 11 North American regions, from 2005 to 2012. We evaluated survival to hospital discharge according to on-scene times (<10, 10 to 35 and >35 min).

RESULTS

Data were available for 2244 patients (1017 infants, 594 children and 633 adolescents). Infants had the lowest rate of survival (3.7%) compared to children (9.8%) and adolescents (16.3%). Survival improved over the 7 year study period especially among adolescents. Survival was highest in the 10 to 35 min on-scene time group (10.2%) compared to the >35 min. group (6.9%) and the <10 min. group (5.3%, p=0.01). Intravenous or intra-osseous access attempts and fluid administration were associated with improved survival, whereas advanced airway attempts were not associated with survival and resuscitation drugs were associated with worse survival.

CONCLUSIONS

In this observational study, a scene time of 10 to 35 min was associated with the highest survival, especially among adolescents. Access for fluid resuscitation was associated with increased survival but advanced airway and resuscitation drugs were not.

Observational study of children admitted to United Kingdom and Republic of Ireland Paediatric Intensive Care Units after out-of-hospital cardiac arrest

AIMS

To estimate the prevalence of children admitted after out-of-hospital cardiac arrest (OHCA) to UK and Republic of Ireland (RoI) Paediatric Intensive Care Units (PICUs) and factors associated with mortality to inform future clinical trial feasibility.

METHOD

Observational study using a prospectively collected dataset of the Paediatric Intensive Care Audit Network (PICANet) of 33 UK and RoI PICUs (January 2003 to June 2010). Cases (0 to <16 years), with documented OHCA surviving to PICU admission and requiring mechanical ventilation were included. Main outcomes were prevalence for admission and death within PICU. Factors associated with mortality were examined with multiple logistic regression analysis.

RESULTS

827 of 111,170 admissions (0.73%; 95% CI [0.48 to 0.98%]) were identified as children admitted following OHCA. PICU mortality for OHCA was 50.5% (418/827). Recruitment into an adequately sized clinical trial would not be feasible with the current prevalence rate. Characteristics at PICU admission associated with increased risk of death included; bilateral unreactive pupils, genetically inherited condition, inter-hospital transfer to PICU, requirement for vasoactive drugs and greater base deficit. Factors associated with reduced risk of death were submersion or a respiratory aetiology and pre-existing respiratory or cardiac conditions.

CONCLUSIONS

Less than 120 children a year are admitted to PICUs in the UK and RoI after OHCA, limiting options for conducting UK intervention trials. The risk factors associated with mortality identified in this study will allow risk stratification in future studies.

Evaluating processes of care and outcomes of children in hospital (EPOCH): study protocol for a randomized controlled trial

Background

The prevention of near and actual cardiopulmonary arrest in hospitalized children is a patient safety imperative. Prevention is contingent upon the timely identification, referral and treatment of children who are deteriorating clinically. We designed and validated a documentation-based system of care to permit identification and referral as well as facilitate provision of timely treatment. We called it the Bedside Paediatric Early Warning System (BedsidePEWS). Here we describe the rationale for the design, intervention and outcomes of the study entitled Evaluating Processes and Outcomes of Children in Hospital (EPOCH).

Methods/Design

EPOCH is a cluster-randomized trial of the BedsidePEWS. The unit of randomization is the participating hospital. Eligible hospitals have a Pediatric Intensive Care Unit (PICU), are anticipated to have organizational stability throughout the study, are not using a severity of illness score in hospital wards and are willing to be randomized. Patients are >37 weeks gestational age and <18 years and are hospitalized in inpatient ward areas during all or part of their hospital admission.

Randomization is to either BedsidePEWS or control (no severity of illness score) in a 1:1 ratio within two strata (<200, ≥200 hospital beds). All-cause hospital mortality is the selected primary outcome. It is objective, independent of do-not-resuscitate status and can be reliably measured. The secondary outcomes include (1) clinical outcomes: clinical deterioration, severity of illness at and during ICU admission, and potentially preventable cardiac arrest; (2) processes of care outcomes: immediate calls for assistance, hospital and ICU readmission, and perceptions of healthcare professionals; and (3) resource utilization: ICU days and use of ICU therapies.

Discussion

Following funding by the Canadian Institutes of Health Research and local ethical approvals, site enrollment started in 2010 and was closed in February 2014. Patient enrollment is anticipated to be complete in July 2015. The results of EPOCH will strengthen the scientific basis for local, regional, provincial and national decision-making and for the recommendations of national and international bodies. If negative, the costs of hospital-wide implementation can be avoided. If positive, EPOCH will have provided a scientific justification for the major system-level changes required for implementation.

Trial registration: NCT01260831 ClinicalTrials.gov date: 14 December 2010.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-015-0712-3) contains supplementary material, which is available to authorized users.

Therapeutic hypothermia after out-of-hospital cardiac arrest in children

BACKGROUND

Therapeutic hypothermia is recommended for comatose adults after witnessed out-of-hospital cardiac arrest, but data about this intervention in children are limited.

METHODS

We conducted this trial of two targeted temperature interventions at 38 children's hospitals involving children who remained unconscious after out-of-hospital cardiac arrest. Within 6 hours after the return of circulation, comatose patients who were older than 2 days and younger than 18 years of age were randomly assigned to therapeutic hypothermia (target temperature, 33.0°C) or therapeutic normothermia (target temperature, 36.8°C). The primary efficacy outcome, survival at 12 months after cardiac arrest with a Vineland Adaptive Behavior Scales, second edition (VABS-II), score of 70 or higher (on a scale from 20 to 160, with higher scores indicating better function), was evaluated among patients with a VABS-II score of at least 70 before cardiac arrest.

RESULTS

A total of 295 patients underwent randomization. Among the 260 patients with data that could be evaluated and who had a VABS-II score of at least 70 before cardiac arrest, there was no significant difference in the primary outcome between the hypothermia group and the normothermia group (20% vs. 12%; relative likelihood, 1.54; 95% confidence interval [CI], 0.86 to 2.76; P=0.14). Among all the patients with data that could be evaluated, the change in the VABS-II score from baseline to 12 months was not significantly different (P=0.13) and 1-year survival was similar (38% in the hypothermia group vs. 29% in the normothermia group; relative likelihood, 1.29; 95% CI, 0.93 to 1.79; P=0.13). The groups had similar incidences of infection and serious arrhythmias, as well as similar use of blood products and 28-day mortality.

CONCLUSIONS

In comatose children who survived out-of-hospital cardiac arrest, therapeutic hypothermia, as compared with therapeutic normothermia, did not confer a significant benefit in survival with a good functional outcome at 1 year. (Funded by the National Heart, Lung, and Blood Institute and others; THAPCA-OH ClinicalTrials.gov number, NCT00878644.).

Evolution, safety and efficacy of targeted temperature management after pediatric cardiac arrest

BACKGROUND

It is unknown whether targeted temperature management (TTM) improves survival after pediatric out-of-hospital cardiac arrest (OHCA). The aim of this study was to assess the evolution, safety and efficacy of TTM (32-34 °C) compared to standard temperature management (STM) (<38 °C).

METHODS

Retrospective, single center cohort study. Patients aged >one day up to 16 years, admitted to a UK Paediatric Intensive Care Unit (PICU) after OHCA (January 2004-December 2010). Primary outcome was survival to hospital discharge; efficacy and safety outcomes included: application of TTM, physiological, hematological and biochemical side effects.

RESULTS

Seventy-three patients were included. Thirty-eight patients (52%) received TTM (32-34 °C). Prior to ILCOR guidance adoption in January 2007, TTM was used infrequently (4/25; 16%). Following adoption, TTM (32-34 °C) use increased significantly (34/48; 71% Chi(2); p < 0.0001). TTM (32-34 °C) and STM (<38 °C) groups were similar at baseline. TTM (32-34 °C) was associated with bradycardia and hypotension compared to STM (<38 °C). TTM (32-34 °C) reduced episodes of hyperthermia (>38 °C) in the 1st 24h; however, excessive hypothermia (<32 °C) and hyperthermia (>38 °C) occurred in both groups up to 72 h, and all patients (n = 11) experiencing temperature <32 °C died. The study was underpowered to determine a difference in hospital survival (34% (TTM (32-34 °C)) versus 23% (STM (<38 °C)); p = 0.284). However, the TTM (32-34 °C) group had a significantly longer PICU length of stay.

CONCLUSIONS

TTM (32-34 °C) was feasible but associated with bradycardia, hypotension, and increased length of stay in PICU. Temperature <32 °C had a universally grave prognosis. Larger studies are required to assess effect on survival.

Therapeutic hypothermia in children after cardiac arrest: a systematic review and meta-analysis

BACKGROUND

Therapeutic hypothermia (TH) has been shown to be effective in resuscitation of some adults following cardiac arrest and infants with hypoxic ischemic encephalopathy, but has not been well studied in children.

OBJECTIVES

The purpose of this systematic review/meta-analysis was to examine mortality, neurologic outcomes, and adverse events in children following use of TH.

RESULTS

A search of PubMed, the Cumulative Index to Nursing and Allied Health Literature, and the Institute for Scientific Information's Web of Knowledge from 1946 to 2014 yielded 6 studies (3 retrospective and 3 prospective cohort studies) that met our inclusion criteria. Quantitative synthesis of mortality following TH (136 subjects) was 44% (95% confidence interval, 32-57) with 28% (95% confidence interval, 11-53) of survivors (42 subjects) demonstrating poor neurologic outcome. The most frequently reported adverse events were electrolyte imbalances and pneumonia.

CONCLUSIONS

Evidence is insufficient to support the advantage of TH compared with normothermia in pediatric resuscitation. The adverse event profile appears to be different than that reported in adults. Further studies are needed before TH may be considered a standard protocol for children after cardiac arrest.

Targeted Temperature Management in Pediatric Central Nervous System Disease

Acute central nervous system conditions due to hypoxic-ischemic encephalopathy, traumatic brain injury (TBI), status epilepticus, and central nervous system infection/inflammation, are a leading cause of death and disability in childhood. There is a critical need for effective neuroprotective therapies to improve outcome targeting distinct disease pathology. Fever, defined as patient temperature > 38°C, has been clearly shown to exacerbate brain injury. Therapeutic hypothermia (HT) is an intervention using targeted temperature management that has multiple mechanisms of action and robust evidence of efficacy in multiple experimental models of brain injury. Prospective clinical evidence for its neuroprotective efficacy exists in narrowly-defined populations with hypoxic-ischemic injury outside of the pediatric age range while trials comparing hypothermia to normothermia after TBI have failed to demonstrate a benefit on outcome but consistently demonstrate potential use in decreasing refractory intracranial pressure. Data in children from prospective, randomized controlled trials using different strategies of targeted temperature management for various outcomes are few but a large study examining HT versus controlled normothermia to improve neurological outcome in cardiac arrest is underway.

Transcranial Doppler ultrasound in therapeutic hypothermia for children after resuscitation

AIM OF THE STUDY

The aim of the present study was to assess the cerebral flow in children receiving therapeutic hypothermia after resuscitation. The prognostic value of transcranial Doppler findings was correlated with the clinical outcomes in these children.

METHODS

A retrospective cohort study was conducted at the paediatric intensive care unit of Chang Gung Children's Hospital between January 2011 and December 2012. All children from 1 month to 18 years of age who received therapeutic hypothermia after resuscitation were eligible. Serial transcranial Doppler examinations were performed and the findings were reviewed.

RESULTS

Seventeen children met the eligibility criteria for this study. Fourteen patients (82.3%) were asphyxial in aetiology, and 12 (70.5%) of these cases occurred outside of the hospital. Eight patients (47.1%) had a Paediatric Cerebral Performance Score of 1 or 2 at 3 months after the events. Reversal diastolic or undetectable flow patterns during therapeutic hypothermia were associated with unfavourable prognosis. Normal mean flow velocity in the rewarming phase and normal pulsatility index in the hypothermia and rewarming phases were associated with favourable outcome.

CONCLUSION

The transcranial Doppler examinations provided additional information for cerebral perfusion during therapeutic hypothermia, which may in the future be used to guide changes to hypothermia management. Mean cerebral blood flow velocity and pulsatility index by transcranial Doppler sonography can serve as a prognostic factor for children who receive therapeutic hypothermia after resuscitation.

High cumulative oxygen levels are associated with improved survival of children treated with mild therapeutic hypothermia after cardiac arrest

AIM

The aim of this study was to analyze the relationship between the partial pressure of arterial oxygen (PaO2) and in-hospital (IH) mortality in children after cardiac arrest (CA) using the conventional cutoff analysis, which was compared with the cumulative analysis, a new method in PaO2 analysis. Additionally, we analyzed this relationship for children with and without mild therapeutic hypothermia (MTH; 32-34 °C).

METHODS

This observational cohort study included all children (aged >28 days) with CA and return of spontaneous circulation (ROSC) between 2002 and 2011. The first research question was the association between PaO2 and IH mortality after ROSC. This was analyzed for three hyperoxia cutoff values, and for three time intervals using the cumulative PaO2 determined with the area under the curve (AUC). For the second research question, these analyses were repeated for children with and without MTH.

RESULTS

Of the 200 patients included (median age 2.6 years), 84 (42%) survived to hospital discharge. Fifty-eight children (29%) were treated with MTH. With the cutoff analysis and the AUC analysis we found no relationship between PaO2 and IH mortality. However, analysis of the MTH-group showed a lower IH mortality in children with high cumulative PaO2 levels on two of the three time intervals. Multivariable analysis showed significantly higher odds of survival (0.643 (95% confidence interval (CI) 0.424-0.976), 0.554 (95% CI 0.335-0.916)).

CONCLUSIONS

Cumulative PaO2 analysis showed that the IH mortality is significantly lower in MTH-treated children with high PaO2 levels. The effects of cumulative PaO2 on the outcome need to be studied further, and this will help us to achieve individualized goal-directed therapy.

Special considerations in infants and children

Head injury in children is one of the most common causes of death and disability in the US and, increasingly, worldwide. This chapter reviews the causes, patterns, pathophysiology, and treatment of head injury in children across the age spectrum, and compares pediatric head injury to that in adults. Classification of head injury in children can be organized according to severity, pathoanatomic type, or mechanism. Response to injury and repair mechanisms appear to vary at different ages, and these may influence optimal treatment; however, much work is still needed before investigation leads to clearly effective clinical interventions. This is true both for the more severe injuries as well as those at the milder end of the injury spectrum, the latter of which have received increasing attention. In this chapter, neuroassessment tools for each age, newer imaging modalities including magnetic resonance imaging (MRI), and specific pediatric management issues, including intracranial pressure (ICP) monitoring and seizure prophylaxis, are reviewed. Finally, specific head injury patterns and functional outcomes relevant to pediatric patients are discussed. While head injury is common, the number of head-injured children is significantly smaller than the corresponding adult head-injured population. When divided further by specific ages, injury types, and other sources of heterogeneity, properly powered clinical research is likely to require large data sets that will allow for stratification across variables, including age. While much has been learned in the past several decades, further study will be required to determine the best management practices for optimizing recovery in individual pediatric patients. This approach is likely to depend on collaborative international head injury databases that will allow researchers to better understand the nuanced evolution of different types of head injury in patients at each age, and the pathophysiologic, treatment-related, and genetic factors that influence recovery.

Clinical applications of targeted temperature management

Targeted temperature management (TTM) has been investigated experimentally and used clinically for over 100 years. The initial rationale for the clinical application of TTM, historically referred to as therapeutic hypothermia, was to decrease the metabolic rate, allowing the injured brain time to heal. Subsequent research demonstrated the temperature dependence of diverse cellular mechanisms including endothelial dysfunction, production of reactive oxygen species, and apoptosis. Consequently, modern use of TTM centers on neuroprotection following focal or global neurologic injury. Despite a solid basic science rationale for applying TTM in a variety of disease processes, including cardiac arrest, traumatic brain injury, ischemic stroke, neonatal ischemic encephalopathy, sepsis-induced encephalopathy, and hepatic encephalopathy, human efficacy data are limited and vary greatly from disease to disease. Ten years ago, two landmark investigations yielded high-quality data supporting the application of TTM in comatose survivors of out-of-hospital cardiac arrest. Additionally, TTM has been demonstrated to improve outcomes for neonatal patients with anoxic brain injury secondary to hypoxic ischemic encephalopathy. Trials are currently under way, or have yielded conflicting results in, examining the utility of TTM for the treatment of ischemic stroke, traumatic brain injury, and acute myocardial infarction. In this review, we place TTM in historic context, discuss the pathophysiologic rationale for its use, review the general concept of a TTM protocol for the management of brain injury, address some of the common side effects encountered when lowering human body temperature, and examine the data for its use in diverse disease conditions with in-depth examination of TTM for postarrest care and pediatric applications.

A novel mouse model of pediatric cardiac arrest and cardiopulmonary resuscitation reveals age-dependent neuronal sensitivities to ischemic injury

BACKGROUND

Pediatric sudden cardiac arrest (CA) is an unfortunate and devastating condition, often leading to poor neurologic outcomes. However, little experimental data on the pathophysiology of pediatric CA is currently available due to the scarcity of animal models.

NEW METHOD

We developed a novel experimental model of pediatric cardiac arrest and cardiopulmonary resuscitation (CA/CPR) using postnatal day 20-25 mice. Adult (8-12 weeks) and pediatric (P20-25) mice were subjected to 6min CA/CPR. Hippocampal CA1 and striatal neuronal injury were quantified 3 days after resuscitation by hematoxylin and eosin (H&E) and Fluoro-Jade B staining, respectively.

RESULTS

Pediatric mice exhibited less neuronal injury in both CA1 hippocampal and striatal neurons compared to adult mice. Increasing ischemia time to 8 min CA/CPR resulted in an increase in hippocampal injury in pediatric mice, resulting in similar damage in adult and pediatric brains. In contrast, striatal injury in the pediatric brain following 6 or 8 min CA/CPR remained extremely low. As observed in adult mice, cardiac arrest causes delayed neuronal death in pediatric mice, with hippocampal CA1 neuronal damage maturing at 72 h after insult. Finally, mild therapeutic hypothermia reduced hippocampal CA1 neuronal injury after pediatric CA/CPR.

COMPARISON WITH EXISTING METHOD

This is the first report of a cardiac arrest and CPR model of global cerebral ischemia in mice.

CONCLUSIONS

Therefore, the mouse pediatric CA/CPR model we developed is unique and will provide an important new tool to the research community for the study of pediatric brain injury.