Multicenter cohort study of out-of-hospital pediatric cardiac arrest

Association of left ventricular systolic function and vasopressor support with survival following pediatric out-of-hospital cardiac arrest

OBJECTIVES

To characterize the association of hospital discharge survival with left ventricular systolic function evaluated by transthoracic echocardiography and vasoactive infusion support following return of spontaneous circulation after pediatric out-of-hospital cardiac arrest.

DESIGN

Retrospective case series.

SETTING

Single-center tertiary care pediatric cardiac arrest and critical care referral center.

PATIENTS

Consecutive out-of-hospital cardiac arrest patients less than 18 years surviving to PICU admission who had a transthoracic echocardiography obtained by the clinical team within 24 hours of admission from January 2006 to May 2012.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Fifty-eight patients had a post-return of spontaneous circulation transthoracic echocardiography performed within 24 hours of admission. The median time from return of spontaneous circulation to echo was 6.5 hours (interquartile range, 4.7, 15.0 hr). Left ventricular systolic function was decreased in 24 of 58 patients (41%). The mortality rate was 67% (39 of 58). Thirty-six patients (62%) received vasoactive infusions at the time of transthoracic echocardiography, and increased vasopressor inotropic score was associated with increased mortality on univariate analysis (p < 0.001). After controlling for defibrillation, vasopressor inotropic score, and interaction between vasopressor inotropic score and left ventricular systolic function, decreased left ventricular systolic function was associated with increased mortality (odds ratio, 13.7; 95% CI, 1.54-122).

CONCLUSIONS

In patients receiving transthoracic echocardiography within the first 24 hours following return of spontaneous circulation after pediatric out-of-hospital cardiac arrest, decreased left ventricular systolic function and vasopressor use were common. Decreased left ventricular systolic function was associated with increased mortality.

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.

Impact of catecholamines in cardiac arrest due to acute asphyxia--a study in piglets

BACKGROUND

Early intravenous epinephrine administration may help to achieve return of spontaneous circulation in cardiac arrest (CA). However, venous access can be challenging in small children. This study investigates the effect of intravenous and intramuscular epinephrine in treatment of asphyxial CA.

METHODS

Twenty-eight, 2-5-weeks-old, anesthetized piglets were asphyxiated by ventilation withdrawal. CA was untreated for 8 min, followed by 2 min of basic life support. Following this, epinephrine iv (10 μg·kg(-1) , group IV), epinephrine im (100 μg·kg(-1) , group IM), or normal saline (group NS) were administered. Further doses of epinephrine were given in group IV every 4 min, in group IM after 10 min if required. After twenty-two minutes of CA, iv epinephrine was given to all animals still in CA. Outcome measures were survival and epinephrine plasma concentrations.

RESULTS

Ten animals regained spontaneous circulation after 2 min of basic life support. Therefore, no drug treatment was administered (drop out). Resuscitation was effective in 2 pigs of group IM (n = 6), in 6 of group NS (n = 8) and in all of group IV (n = 4). Nonsurvivors had higher epinephrine (P < 0.01) and norepinephrine (P < 0.01) plasma concentrations prior to start of resuscitation. Median increase in epinephrine plasma concentration from T0 to T5 was 138, 134, and 29 nm in group IV, IM, and NS, respectively.

CONCLUSIONS

Intravenous and intramuscular administered epinephrine led to similar increase in plasma concentrations during resuscitation of asphyxial CA without hemodynamic or survival benefit. High endogenous epinephrine and norepinephrine plasma concentrations were negative predictors for survival.

Early postresuscitation hypotension is associated with increased mortality following pediatric cardiac arrest

OBJECTIVE

To describe the association of systolic hypotension during the first 6 hours after successful resuscitation from pediatric cardiopulmonary arrest with in-hospital mortality.

DESIGN

Retrospective cohort study.

SETTING

Fifteen children's hospitals associated with the Pediatric Emergency Care Applied Research Network.

PATIENTS

Patients between 1 day and 18 years old who had a cardiopulmonary arrest, received chest compressions more than 1 minute, had a return of spontaneous circulation more than 20 minutes, and had a systolic blood pressure documented within 6 hours of arrest.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Three hundred eighty-three patients had complete data for analysis. Patients with a documented minimum systolic blood pressure less than fifth percentile for age and sex within the first 6 hours following return of spontaneous circulation were considered to have early postresuscitation hypotension. Two hundred fourteen patients (56%) had early postresuscitation hypotension. One hundred eighty-four patients (48%) died prior to hospital discharge. After controlling for patient and cardiopulmonary arrest characteristics, hypotension in the first 6 hours following return of spontaneous circulation was associated with a significantly increased odds of in-hospital mortality (adjusted odds ratio = 1.71; 95% CI, 1.02-2.89; p = 0.042) and odds of unfavorable outcome (adjusted odds ratio = 1.83; 95% CI, 1.06-3.19; p = 0.032).

CONCLUSIONS

In the first 6 hours following successful resuscitation from pediatric cardiac arrest, systolic hypotension was documented in 56% and was associated with a higher rate of in-hospital mortality and worse hospital discharge neurologic outcomes.

Stridor in asphyxiated neonates undergoing therapeutic hypothermia

Therapeutic hypothermia is an established standard of care in the treatment of hypoxic-ischemic encephalopathy. Application of therapeutic hypothermia in the clinical setting may reveal a wider spectrum of adverse events than previously reported. We report 5 cases of transient respiratory stridor in 51 infants, occurring at different time points in the cooling process, which appeared to be unrelated to the intubation procedure. Therapeutic hypothermia was associated with transient stridor in this case series. Formal laryngoscopy is required to determine the underlying pathologic etiology.

Decision tree model for predicting long-term outcomes in children with out-of-hospital cardiac arrest: a nationwide, population-based observational study

Introduction

At hospital arrival, early prognostication for children after out-of-hospital cardiac arrest (OHCA) might help clinicians formulate strategies, particularly in the emergency department. In this study, we aimed to develop a simple and generally applicable bedside tool for predicting outcomes in children after cardiac arrest.

Methods

We analyzed data of 5,379 children who had undergone OHCA. The data were extracted from a prospectively recorded, nationwide, Utstein-style Japanese database. The primary endpoint was survival with favorable neurological outcome (Cerebral Performance Category (CPC) scale categories 1 and 2) at 1 month after OHCA. We developed a decision tree prediction model by using data from a 2-year period (2008 to 2009, n = 3,693), and the data were validated using external data from 2010 (n = 1,686).

Results

Recursive partitioning analysis for 11 predictors in the development cohort indicated that the best single predictor for CPC 1 and 2 at 1 month was the prehospital return of spontaneous circulation (ROSC). The next predictor for children with prehospital ROSC was an initial shockable rhythm. For children without prehospital ROSC, the next best predictor was a witnessed arrest. Use of a simple decision tree prediction model permitted stratification into four outcome prediction groups: good (prehospital ROSC and initial shockable rhythm), moderately good (prehospital ROSC and initial nonshockable rhythm), poor (prehospital non-ROSC and witnessed arrest) and very poor (prehospital non-ROSC and unwitnessed arrest). By using this model, we identified patient groups ranging from 0.2% to 66.2% for 1-month CPC 1 and 2 probabilities. The validated decision tree prediction model demonstrated a sensitivity of 69.7% (95% confidence interval (CI) = 58.7% to 78.9%), a specificity of 95.2% (95% CI = 94.1% to 96.2%) and an area under the receiver operating characteristic curve of 0.88 (95% CI = 0.87 to 0.90) for predicting 1-month CPC 1 and 2.

Conclusions

With our decision tree prediction model using three prehospital variables (prehospital ROSC, initial shockable rhythm and witnessed arrest), children can be readily stratified into four groups after OHCA. This simple prediction model for evaluating children after OHCA may provide clinicians with a practical bedside tool for counseling families and making management decisions soon after patient arrival at the hospital.

Fallat ME. Withholding or termination of resuscitation in pediatric out-of-hospital traumatic cardiopulmonary arrest

This multiorganizational literature review was undertaken to provide an evidence base for determining whether or not recommendations for out-of-hospital termination of resuscitation could be made for children who are victims of traumatic cardiopulmonary arrest. Although there is increasing acceptance of out-of-hospital termination of resuscitation for adult traumatic cardiopulmonary arrest when there is no expectation of a good outcome, children are routinely excluded from state termination-of-resuscitation protocols. The decision to withhold resuscitative efforts in a child under specific circumstances (decapitation or dependent lividity, rigor mortis, etc) is reasonable. If there is any doubt as to the circumstances or timing of the traumatic cardiopulmonary arrest, under the current status of limiting termination of resuscitation in the field to persons older than 18 years in most states, resuscitation should be initiated and continued until arrival to the appropriate facility. If the patient has arrested, resuscitation has already exceeded 30 minutes, and the nearest facility is more than 30 minutes away, involvement of parents and family of these children in the decision-making process with assistance and guidance from medical professionals should be considered as part of an emphasis on family-centered care, because the evidence suggests that either death or a poor outcome is inevitable.

Standardising paediatric resuscitation training in New South Wales, Australia: RESUS4KIDS

AIM

A key competency for all health-care workers (HCWs) who care for children is the ability to respond to a child in respiratory or cardiorespiratory arrest. However, evidence suggests that medical and nursing staff may not have the knowledge and clinical skills to respond to these emergencies. The aim of this project was to create a standardised, evidence-based, paediatric life support course that would be available free to all HCWs in New South Wales (NSW), including NSW Ambulance.

METHODS

A paediatric life support course was designed along current education principles. It used e-learning as pre-learning and a face-to-face short practical course, combining team work and communication with practical paediatric resuscitation skills training. The programme was designed to empower local trainers to deliver a standardised course to local participants.

RESULTS

A total of 14,000 participants have completed the mandatory e-learning component, and over 8600 participants have completed the short practical course, across all NSW Local Health Districts, including NSW Ambulance. RESUS4KIDS has also been adopted by the universities of Sydney and Newcastle undergraduate medical and nursing programmes. Outside of NSW and ACT, over 400 participants have completed the course in facilities in Queensland, South Australia, Victoria and the Northern Territory.

CONCLUSION

We have developed a course that is available, at no cost to individuals or facilities, to all HCWs in NSW, including students, paramedics and general practitioners. We would encourage all other jurisdictions to consider adopting the programme.

Withholding or termination of resuscitation in pediatric out-of-hospital traumatic cardiopulmonary arrest

This multiorganizational literature review was undertaken to provide an evidence base for determining whether recommendations for out-of-hospital termination of resuscitation could be made for children who are victims of traumatic cardiopulmonary arrest. Although there is increasing acceptance of out-of-hospital termination of resuscitation for adult traumatic cardiopulmonary arrest when there is no expectation of a good outcome, children are routinely excluded from state termination-of-resuscitation protocols. The decision to withhold resuscitative efforts in a child under specific circumstances (decapitation or dependent lividity, rigor mortis, etc) is reasonable. If there is any doubt as to the circumstances or timing of the traumatic cardiopulmonary arrest, under the current status of limiting termination of resuscitation in the field to persons older than 18 years in most states, resuscitation should be initiated and continued until arrival to the appropriate facility. If the patient has arrested, resuscitation has already exceeded 30 minutes, and the nearest facility is more than 30 minutes away, involvement of parents and family of these children in the decision-making process with assistance and guidance from medical professionals should be considered as part of an emphasis on family-centered care because the evidence suggests that either death or a poor outcome is inevitable.

Serum biomarkers of brain injury to classify outcome after pediatric cardiac arrest*

OBJECTIVES

Morbidity and mortality in children with cardiac arrest largely result from neurologic injury. Serum biomarkers of brain injury can potentially measure injury to neurons (neuron-specific enolase), astrocytes (S100b), and axons (myelin basic protein). We hypothesized that serum biomarkers can be used to classify outcome from pediatric cardiac arrest.

DESIGN

Prospective observational study.

SETTING

Single tertiary pediatric hospital.

PATIENTS

Forty-three children with cardiac arrest.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We measured serum neuron-specific enolase, S100b, and myelin basic protein on days 1-4 and 7 after cardiac arrest. We recorded demographics, details of the cardiac arrest and resuscitation, and Pediatric Cerebral Performance Category at hospital discharge and 6 months. We analyzed the association of biomarker levels at 24, 48, and 72 hours with favorable (Pediatric Cerebral Performance Category 1-3) or unfavorable (Pediatric Cerebral Performance Category 4-6) outcome and mortality. Forty-three children (49% female; mean age of 5.9 ± 6.3) were enrolled and 17 (40%) died. Serum S100b concentrations peaked earliest, followed by neuron-specific enolase and finally myelin basic protein. Serum neuron-specific enolase and S100b concentrations were increased in the unfavorable versus favorable outcome group and in subjects who died at all time points (all p < 0.05). Serum myelin basic protein at 24 and 72 hours correctly classified survival but not good versus poor outcome. Using best specificity, serum S100b and neuron-specific enolase had optimal positive and negative predictive values at 24 hours to classify both favorable versus unfavorable outcome and survival, whereas serum myelin basic protein's best accuracy occurred at 48 hours. Receiver operator curves for serum S100b and neuron-specific enolase to classify favorable versus unfavorable outcome at 6 months were superior to clinical variables.

CONCLUSIONS

Preliminary data show that serum S100b, neuron-specific enolase, and myelin basic protein may aid in outcome classification of children surviving cardiac arrest.

Early microcirculatory impairment during therapeutic hypothermia is associated with poor outcome in post-cardiac arrest children: a prospective observational cohort study

AIMS OF THE STUDY

This study aimed to evaluate if the microcirculation is impaired during and after therapeutic hypothermia (TH) in children with return of spontaneous circulation after cardiac arrest (CA) and to assess if microcirculatory impairment predicts mortality. This has been reported for post-CA adults, but results might be different for children because etiology, pathophysiology, and mortality rate differ.

METHODS

This prospective observational cohort study included consecutive, non-neonatal post-CA children receiving TH upon intensive care admission between June 2008 and June 2012. Also included were gender-matched and age-matched normothermic, control children without cardiorespiratory disease. The buccal microcirculation was non-invasively assessed with Sidestream Dark Field Imaging at the start of TH, halfway during TH, at the start of re-warming, and at normothermia. Macrocirculatory, respiratory, and biochemical parameters were also collected.

RESULTS

Twenty post-CA children were included of whom 9 died. During hypothermia, the microcirculation was impaired in the post-CA patients and did not change over time. At normothermia, the core body temperature and the microcirculation had increased and no longer differed from the controls. Microcirculatory deterioration was associated with mortality in the post-CA patients. In particular, the microcirculation was more severely impaired at TH start in the non-survivors than in the survivors - positive predictive value: 73-83, negative predictive value: 75-100, sensitivity: 63-100%, and specificity: 70-90%.

CONCLUSIONS

The microcirculation is impaired in post-CA children during TH and more severe impairment at TH start was associated with mortality. After the stop of TH, the microcirculation improves rapidly irrespective of outcome.

The incidence and significance of bacteremia in out of hospital cardiac arrest

BACKGROUND

The most common etiology of cardiac arrest is presumed of myocardial origin. Recent retrospective studies indicate that preexisting pneumonia, a form of sepsis, is frequent in patients who decompensate with abrupt cardiac arrest without preceding signs of septic shock, respiratory failure or severe metabolic disorders shortly after hospitalization. The contribution of pre-existing infection on pre and post cardiac arrest events remains unknown and has not been studied in a prospective fashion. We sought to examine the incidence of pre-existing infection in out-of hospital cardiac arrest (OHCA) and assess characteristics associated with bacteremia, the goal standard for presence of infection.

METHODS AND RESULTS

We prospectively observed 250 OHCA adult patients who presented to the Emergency Department (ED) between 2007 and 2009 to an urban academic teaching institution. Bacteremia was defined as one positive blood culture with non-skin flora bacteria or two positive blood cultures with skin flora bacteria. 77 met pre-defined exclusion criteria. Of the 173 OHCA adults, 65 (38%) were found to be bacteremic with asystole and PEA as the most common presenting rhythms. Mortality in the ED was significantly higher in bacteremic OHCA (75.4%) compared to non-bacteremic OHCA (60.2%, p<0.05). After adjustment for potential confounders, predictive factors associated with bacteremic OHCA were lower initial arterial pH, higher lactate, WBC, BUN and creatinine.

CONCLUSIONS

Over one-third of OHCA adults were bacteremic upon presentation. These patients have greater hemodynamic instability and significantly increased short-term mortality. Further studies are warranted to address the epidemiology of infection as possible cause of cardiac arrest.

Early lactate elevations following resuscitation from pediatric cardiac arrest are associated with increased mortality*

OBJECTIVE

To describe the association of lactate levels within the first 12 hours after successful resuscitation from pediatric cardiopulmonary arrest with hospital mortality.

DESIGN

Retrospective cohort study.

SETTING

Fifteen children's hospital associated with the Pediatric Emergency Care Applied Research Network.

PATIENTS

Patients between 1 day and 18 years old who had a cardiopulmonary arrest, received chest compressions more than 1 minute, had a return of spontaneous circulation more than 20 minutes, and had lactate measurements within 6 hours of arrest.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Two hundred sixty-four patients had a lactate sampled between 0 and 6 hours (lactate(0-6)) and were evaluable. Of those, 153 patients had a lactate sampled between 7 and 12 hours (lactate(7-12)). One hundred thirty-eight patients (52%) died. After controlling for arrest location, total number of epinephrine doses, initial rhythm, and other potential confounders, the odds of death per 1 mmol/L increase in lactate(0-6) was 1.14 (1.08, 1.19) (p < 0.001) and the odds of death per 1 mmol/L increase in lactate(7-12) was 1.20 (1.11, 1.30) (p < 0.0001). Area under the curve for in-hospital arrest mortality for lactate(0-6) was 0.72 and for lactate(7-12) was 0.76. Area under the curve for out-of-hospital arrest mortality for lactate(0-6) was 0.8 and for lactate(7-12) was 0.75.

CONCLUSIONS

Elevated lactate levels in the first 12 hours after successful resuscitation from pediatric cardiac arrest are associated with increased mortality. Lactate levels alone are not able to predict outcomes accurately enough for definitive prognostication but may approximate mortality observed in this large cohort of children's hospitals.

Long-term outcomes following pediatric out-of-hospital cardiac arrest*

OBJECTIVES

Pediatric out-of-hospital cardiac arrest is an uncommon event with measurable short-term survival to hospital discharge. For those who survive to hospital discharge, little is known regarding duration of survival. We sought to evaluate the arrest circumstances and long-term survival of pediatric patients who experienced an out-of-hospital cardiac arrest and survived to hospital discharge.

DESIGN

Retrospective cohort study

SETTING

King County, WA Emergency Medical Service Catchment and Quaternary Care Children's Hospital

PATIENTS

Persons less than 19 years old who had an out-of-hospital cardiac arrest and were discharged alive from the hospital between 1976 and 2007.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

During the study period, 1,683 persons less than 19 years old were treated for pediatric out-of-hospital cardiac arrest in the study community, with 91 patients surviving to hospital discharge. Of these 91 survivors, 20 (22%) subsequently died during 1449 person-years of follow-up. Survival following hospital discharge was 92% at 1 year, 86% at 5 years, and 77% at 20 years. Compared to those who subsequently died, long-term survivors were more likely at the time of discharge to be older (mean age, 8 vs 1 yr), had a witnessed arrest (83% vs 56%), presented with a shockable rhythm (40% vs 10%), and had a favorable Pediatric Cerebral Performance Category of 1 or 2 (67% vs 0%).

CONCLUSIONS

In this population-based cohort study evaluating the long-term outcome of pediatric survivors of out-of-hospital cardiac arrest, we observed that long-term survival was generally favorable. Age, arrest characteristics, and functional status at hospital discharge were associated with prognosis. These findings support efforts to improve pediatric resuscitation, stabilization, and convalescent care.

Simplified dispatcher instructions improve bystander chest compression quality during simulated pediatric resuscitation

AIM

Cardiopulmonary resuscitation (CPR) quality is associated with survival outcomes after out-of-hospital cardiac arrest. The objective of this study was to evaluate the effectiveness of simplified dispatcher CPR instructions to improve the chest compression (CC) quality during simulated pediatric cardiac arrest in public places.

METHODS

Adult bystanders recruited in public places were randomized to receive one of two scripted dispatcher CPR instructions: (1) "Push as hard as you can" (PUSH HARD) or (2) "Push approximately 2 inches" (TWO INCHES). A pediatric manikin with realistic CC characteristics (similar to a 6-year-old child), and a CPR recording defibrillator was used for quantitative CC data collection during a 2-min simulated pediatric scenario. The primary outcome was average CC depth treated as a continuous variable. Secondary outcomes included compliance with American Heart Association (AHA) CPR targets. Analysis was by two-sided unpaired t-test and Chi-square test, as appropriate.

RESULTS

128 out of 140 providers screened met inclusion/exclusion criteria and all 128 consented. The average CC depth (mean (SEM)) was greater in PUSH HARD compared to TWO INCHES (43 (1) vs. 36 (1) mm, p<0.01) and met AHA targets more often (39% (25/64) vs. 20% (13/64), p=0.02). CC rates trended higher in the PUSH HARD group (93 (4) vs. 82 (4) CC/min, p=0.06). More providers did not achieve full chest recoil with PUSH HARD compared to TWO INCHES (53% (34/64) vs. 75% (48/64), p=0.01).

CONCLUSIONS

Simplified dispatcher assisted pediatric CPR instructions: "Push as hard as you can" was associated with lay bystanders providing deeper and faster CCs on a simulated, 6-year-old pediatric manikin. However, percentage of providers leaning between CC increased. The potential effect of these simplified instructions in younger children remains unanswered.

Rationale, timeline, study design, and protocol overview of the therapeutic hypothermia after pediatric cardiac arrest trials

OBJECTIVE

To describe the rationale, timeline, study design, and protocol overview of the Therapeutic Hypothermia after Pediatric Cardiac Arrest trials.

DESIGN

Multicenter randomized controlled trials.

SETTING

Pediatric intensive care and cardiac ICUs in the United States and Canada.

PATIENTS

Children from 48 hours to 18 years old, who have return of circulation after cardiac arrest, who meet trial eligibility criteria, and whose guardians provide written consent.

INTERVENTIONS

Therapeutic hypothermia or therapeutic normothermia.

MEASUREMENTS AND MAIN RESULTS

From concept inception in 2002 until trial initiation in 2009, 7 years were required to plan and operationalize the Therapeutic Hypothermia after Pediatric Cardiac Arrest trials. Two National Institute of Child Health and Human Development clinical trial planning grants (R21 and R34) supported feasibility assessment and protocol development. Two clinical research networks, Pediatric Emergency Care Applied Research Network and Collaborative Pediatric Critical Care Research Network, provided infrastructure resources. Two National Heart Lung Blood Institute U01 awards provided funding to conduct separate trials of in-hospital and out-of-hospital cardiac arrest. A pilot vanguard phase that included half the clinical sites began on March 9, 2009, and this was followed by full trial funding through 2015.

CONCLUSIONS

Over a decade will have been required to plan, design, operationalize, and conduct the Therapeutic Hypothermia after Pediatric Cardiac Arrest trials. Details described in this report, such as participation of clinical research networks and clinical trial planning grants utilization, may be of utility for individuals who are planning investigator-initiated, federally supported clinical trials.

Advances in pediatric neurocritical care

Because pediatric intensive care units (PICUs) improve survival for a range of acute diseases, attention has turned toward ensuring the best possible functional outcomes after critical illness. The neurocritical care of children is of increasing interest. However, the pediatric population encompasses a heterogeneous set of neurologic conditions, with several possible models of how best to address them. This article reviews the special challenges faced by PICUs with regards to diseases, technologies, and skills and the progress that has been made in treatment, monitoring, and prognostication. Recent advances in translational research expected to modify the field in the near-term are described.

Advances in recognition, resuscitation, and stabilization of the critically ill child

Advances in early recognition, effective response, and high-quality resuscitation before, during, and after cardiac arrest have resulted in improved survival for infants and children over the past 10 years. This review addresses several key factors that can make a difference in survival outcomes, including the etiology of pediatric cardiac arrests in and out of hospital, mechanisms and techniques of circulation of blood flow during cardiopulmonary resuscitation (CPR), quality of CPR, meticulous postresuscitative care, and effective training. Monitoring and quality improvement of each element in the system of resuscitation care are increasingly recognized as key factors in saving lives.

Early oxygenation and ventilation measurements after pediatric cardiac arrest: lack of association with outcome

OBJECTIVES

To explore oxygenation and ventilation status early after cardiac arrest in infants and children. We hypothesize that hyperoxia is common and associated with worse outcome after pediatric cardiac arrest.

DESIGN

Retrospective cohort study.

SETTING

Fifteen hospitals within the Pediatric Emergency Care Applied Research Network.

PATIENTS

Children who suffered a cardiac arrest event and survived for at least 6 hours after return of circulation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Analysis of 195 events revealed that abnormalities in oxygenation and ventilation are common during the initial 6 hours after pediatric cardiac arrest. Hyperoxia was frequent, affecting 54% of patients. Normoxia was documented in 34% and hypoxia in 22% of patients. These percentages account for a 10% overlap of patients who had both hyperoxia and hypoxia. Ventilation status was more evenly distributed with hyperventilation observed in 38%, normoventilation in 29%, and hypoventilation in 46%, with a 13% overlap of patients who had both hyperventilation and hypoventilation. Derangements in both oxygenation and ventilation were common early after cardiac arrest such that both normoxia and normocarbia were documented in only 25 patients (13%). Neither oxygenation nor ventilation status was associated with outcome. After controlling for potential confounders, arrest location and rhythm were significantly associated with worse outcome; however, hyperoxia was not (odds ratio for good outcome, 1.02 [0.46, 2.84]; p = 0.96).

CONCLUSIONS

Despite recent resuscitation guidelines that advocate maintenance of normoxia and normoventilation after pediatric cardiac arrest, this is uncommonly achieved in practice. Although we did not demonstrate an association between hyperoxia and worse outcome, the small proportion of patients kept within normal ranges limited our power. Preclinical data suggesting potential harm with hyperoxia remain compelling, and further investigation, including prospective, large studies involving robust recording of physiological derangements, is necessary to further advance our understanding of this important topic.

Brain resuscitation in the drowning victim

Drowning is a leading cause of accidental death. Survivors may sustain severe neurologic morbidity. There is negligible research specific to brain injury in drowning making current clinical management non-specific to this disorder. This review represents an evidence-based consensus effort to provide recommendations for management and investigation of the drowning victim. Epidemiology, brain-oriented prehospital and intensive care, therapeutic hypothermia, neuroimaging/monitoring, biomarkers, and neuroresuscitative pharmacology are addressed. When cardiac arrest is present, chest compressions with rescue breathing are recommended due to the asphyxial insult. In the comatose patient with restoration of spontaneous circulation, hypoxemia and hyperoxemia should be avoided, hyperthermia treated, and induced hypothermia (32-34 °C) considered. Arterial hypotension/hypertension should be recognized and treated. Prevent hypoglycemia and treat hyperglycemia. Treat clinical seizures and consider treating non-convulsive status epilepticus. Serial neurologic examinations should be provided. Brain imaging and serial biomarker measurement may aid prognostication. Continuous electroencephalography and N20 somatosensory evoked potential monitoring may be considered. Serial biomarker measurement (e.g., neuron specific enolase) may aid prognostication. There is insufficient evidence to recommend use of any specific brain-oriented neuroresuscitative pharmacologic therapy other than that required to restore and maintain normal physiology. Following initial stabilization, victims should be transferred to centers with expertise in age-specific post-resuscitation neurocritical care. Care should be documented, reviewed, and quality improvement assessment performed. Preclinical research should focus on models of asphyxial cardiac arrest. Clinical research should focus on improved cardiopulmonary resuscitation, re-oxygenation/reperfusion strategies, therapeutic hypothermia, neuroprotection, neurorehabilitation, and consideration of drowning in advances made in treatment of other central nervous system disorders.

Public access defibrillation improved the outcome after out-of-hospital cardiac arrest in school-age children: a nationwide, population-based, Utstein registry study in Japan

AIMS

The purpose of this study was to determine whether implementation of public access defibrillation (PAD) improves the outcome after out-of-hospital cardiac arrest (OHCA) in school-age children at national level.

METHODS AND RESULTS

We conducted a prospective, nationwide, population-based Japanese Utstein registry study of consecutive OHCA cases in elementary and middle school children (7-15 years of age) who had a bystander-witnessed arrest of presumed cardiac origin during 2005-09 and received pre-hospital resuscitation by emergency responders. The primary endpoint was a favourable neurological outcome 1 month after an arrest. Among 230 eligible patients enrolled, 128 had ventricular fibrillation (VF) as an initial rhythm. Among these 128 patients, 29 (23%) children received a first shock by a bystander. Among these 29 patients, the proportion of the favourable neurological outcome after OHCA was 55%. During the study period, the proportion of patients initially shocked by a bystander among eligible patients increased from 2 to 21% (P = 0.002 for trend). The proportion of patients with a favourable neurological outcome after OHCA increased from 12 to 36% overall (P = 0.006). The collapse to defibrillation time was shorter in bystander-initiated defibrillation when compared with defibrillation by emergency responders (3.3 ± 3.7 vs. 12.9 ± 5.8 min, P < 0.001), and was independently associated with a favourable neurological outcome after OHCA [P = 0.03, odds ratio (OR) per 1 min increase, 0.90 (95% confidence interval 0.82-0.99)]. A non-family member's witness was independently associated with VF as the initial rhythm [P < 0.001, OR 4.03 (2.08-7.80)].

CONCLUSION

Implementation of PAD improved the outcome after OHCA in school-age children at national level in Japan.

Therapeutic hypothermia associated with increased survival after resuscitation in children

Brain injury after resuscitation is associated with high morbidity and mortality in children. Therapeutic hypothermia has theoretical benefits on brain preservation. It has been shown to be effective in improving neurological outcomes after adult ventricular arrhythmia-induced cardiac arrest and neonatal asphyxia. However, there have only been a few reports about therapeutic hypothermia after pediatric resuscitation. We conducted this retrospective cohort study in a tertiary pediatric intensive care unit between January 2010 and June 2012. All children from 2 months to 18 years of age with resuscitation and a history of at least 3 minutes of chest compressions with survival for 12 hours or more after return of circulation were eligible. Forty-three patients met the eligibility criteria for the study. Forty-two patients (97.6%) were asphyxial in etiology; 29 (67.4%) of them occurred out-of-hospital. Excluding one child with cardiac etiology, the overall survival rate to hospital discharge was 57.1%. Fourteen (33.3%) patients received hypothermia therapy and were cooled to 33°C for 72 hours. The survival rate was higher in the therapeutic hypothermia group (11/14, 78.6%) than in the normothermia group (13/28, 46.4%). In conclusion, therapeutic hypothermia was associated with increased survival rate after pediatric resuscitation.

Hypothermia for neuroprotection in children after cardiopulmonary arrest

BACKGROUND

Cardiopulmonary arrest in paediatric patients often results in death or survival with severe brain injury. Therapeutic hypothermia, lowering of the core body temperature to 32°C to 34°C, may reduce injury to the brain in the period after the circulation has been restored. This therapy has been effective in neonates with hypoxic ischaemic encephalopathy and adults after witnessed ventricular fibrillation cardiopulmonary arrest. The effect of therapeutic hypothermia after cardiopulmonary arrest in paediatric patients is unknown.

OBJECTIVES

To assess the clinical effectiveness of therapeutic hypothermia after paediatric cardiopulmonary arrest.

SEARCH METHODS

We searched the Cochrane Anaesthesia Review Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 11); Ovid MEDLINE (1966 to December 2011); Ovid EMBASE (1980 to December 2011); Ovid CINAHL (1982 to December 2011); Ovid BIOSIS (1923 to December 2011); and Web of Science (1945 to December 2011). We searched the trials registry databases for ongoing trials. We also contacted international experts in therapeutic hypothermia and paediatric critical care to locate further published and unpublished studies.

SELECTION CRITERIA

We planned to include randomized and quasi-randomized controlled trials comparing therapeutic hypothermia with normothermia or standard care in children, aged 24 hours to 18 years, after paediatric cardiopulmonary arrest.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed articles for inclusion.

MAIN RESULTS

We found no studies that satisfied the inclusion criteria. We found four on-going randomized controlled trials which may be available for analysis in the future. We excluded 18 non-randomized studies. Of these 18 non-randomized studies, three compared therapeutic hypothermia with standard therapy and demonstrated no difference in mortality or the proportion of children with a good neurological outcome; a narrative report was presented.

AUTHORS' CONCLUSIONS

Based on this review, we are unable to make any recommendations for clinical practice. Randomized controlled trials are needed and the results of on-going trials will be assessed when available.

Therapeutic hypothermia after pediatric cardiac arrest trials: the vanguard phase experience and implications for other trials

OBJECTIVE

To determine whether an 18-month vanguard phase, in the Therapeutic Hypothermia after Pediatric Cardiac Arrest trials, confirmed study feasibility and patient safety, a prerequisite to continued funding by the sponsor.

DESIGN

Randomized controlled trial.

SETTING

Pediatric intensive care and pediatric cardiac care units in 15 clinical sites in the United States and Canada.

PATIENTS

Children aged 48 hrs to 18 yrs of age, with return of circulation after cardiac arrest.

INTERVENTIONS

Therapeutic hypothermia vs. therapeutic normothermia.

MEASUREMENTS AND MAIN RESULTS

The first 15 of 20 potential sites to obtain Institutional Review Board and subcontract approvals were selected as vanguard sites. Institutional Review Board approvals were obtained 92 days (median, interquartile range 65-114) and subcontracts signed 34 days (interquartile range 20-48) after distribution. Sites screened subjects at 13 days (interquartile range 9-21) and enrolled the first subjects 64 days (interquartile range 13-154) after study launch. The recruitment milestone was reached 4 months ahead of schedule, with no safety concerns identified. Overall recruitment in this ongoing trial remains on target.

CONCLUSIONS

The Therapeutic Hypothermia after Pediatric Cardiac Arrest vanguard phase proved beneficial for the investigators and funding agency. Because complex multicenter trials are rarely ready to launch when grant funds are received, the vanguard allowed time to refine the protocol and recruitment approaches. Competition for vanguard positions led to expedient Institutional Review Board and subcontract completion. Early success and sustained momentum contributed to recruitment at or above goals. Financial risks to the sponsor were minimized by tying funding for the full trial to achieving prespecified milestones. A vanguard phase may be a desirable strategy for the successful conduct of other complex clinical trials.

Female sex is not associated with improved rates of ROSC or short term survival following prolonged porcine ventricular fibrillation

OBJECTIVES

There may be a survival benefit in female patients experiencing cardiac arrest, which could affect the interpretation of in vivo animal studies. We hypothesized that sex predicts return of spontaneous circulation (ROSC) and short-term survival (SURV) in porcine studies of prolonged ventricular fibrillation (VF).

METHODS

Retrospective analysis of eight comparable experiments performed in our lab using mixed-breed domestic swine of either sex. All experiments included prolonged untreated VF, CPR, defibrillation, and drugs. We defined ROSC as systolic blood pressure ≥80 mm Hg for ≥1 min. Short-term survival was defined 20 or 60 min, depending on protocol. Categorical variables were compared with chi-square test and Fisher's exact test. Continuous variables were compared with two-sample t-test and one-way ANOVA. Multiple logistic regression determined predictors of ROSC and SURV, utilizing cluster analysis by experimental protocol. Candidate variables were sex, weight, anesthesia duration, VF duration, and CPR ratio.

RESULTS

Of 263 swine analyzed (53.2% male), 58.6% of males and 68.3% of females had ROSC (p=0.10), whereas 50.0% of males and 61.0% of females experienced SURV (p=0.07).

RESULTS

Of 263 swine analyzed (53.2% male), 58.6% of males and 68.3% of females had ROSC (p=0.10), whereas 50.0% of males and 61.0% of females experienced SURV (p=0.07). Neither sex nor any identified candidate variable predicted ROSC or SURV. Both models had acceptable fit with Hosmer-Lemeshow values of 0.35 and 0.31, respectively.

CONCLUSIONS

Sex predicts neither ROSC nor SURV in a swine model of prolonged VF.

Relationship between arterial partial oxygen pressure after resuscitation from cardiac arrest and mortality in children

BACKGROUND

Observational studies in adults have shown a worse outcome associated with hyperoxia after resuscitation from cardiac arrest. Extrapolating from adult data, current pediatric resuscitation guidelines recommend avoiding hyperoxia. We investigated the relationship between arterial partial oxygen pressure and survival in patients admitted to the pediatric intensive care unit (PICU) after cardiac arrest.

METHODS AND RESULTS

We conducted a retrospective cohort study using the Pediatric Intensive Care Audit Network (PICANet) database between 2003 and 2010 (n=122,521). Patients aged <16 years with documented cardiac arrest preceding PICU admission and arterial blood gas analysis taken within 1 hour of PICU admission were included. The primary outcome measure was death within the PICU. The relationship between postarrest oxygen status and outcome was modeled with logistic regression, with nonlinearities explored via multivariable fractional polynomials. Covariates included age, sex, ethnicity, congenital heart disease, out-of-hospital arrest, year, Pediatric Index of Mortality-2 (PIM2) mortality risk, and organ supportive therapies. Of 1875 patients, 735 (39%) died in PICU. Based on the first arterial gas, 207 patients (11%) had hyperoxia (Pa(O)(2) ≥300 mm Hg) and 448 (24%) had hypoxia (Pa(O)(2) <60 mm Hg). We found a significant nonlinear relationship between Pa(O)(2) and PICU mortality. After covariate adjustment, risk of death increased sharply with increasing hypoxia (odds ratio, 1.92; 95% confidence interval, 1.80-2.21 at Pa(O)(2) of 23 mm Hg). There was also an association with increasing hyperoxia, although not as dramatic as that for hypoxia (odds ratio, 1.25; 95% confidence interval, 1.17-1.37 at 600 mm Hg). We observed an increasing mortality risk with advancing age, which was more pronounced in the presence of congenital heart disease.

CONCLUSIONS

Both severe hypoxia and, to a lesser extent, hyperoxia are associated with an increased risk of death after PICU admission after cardiac arrest.

Pediatric neurocritical care

Pediatric neurocritical care is an emerging multidisciplinary field of medicine and a new frontier in pediatric critical care and pediatric neurology. Central to pediatric neurocritical care is the goal of improving outcomes in critically ill pediatric patients with neurological illness or injury and limiting secondary brain injury through optimal critical care delivery and the support of brain function. There is a pressing need for evidence based guidelines in pediatric neurocritical care, notably in pediatric traumatic brain injury and pediatric stroke. These diseases have distinct clinical and pathophysiological features that distinguish them from their adult counterparts and prevent the direct translation of the adult experience to pediatric patients. Increased attention is also being paid to the broader application of neuromonitoring and neuroprotective strategies in the pediatric intensive care unit, in both primary neurological and primary non-neurological disease states. Although much can be learned from the adult experience, there are important differences in the critically ill pediatric population and in the circumstances that surround the emergence of neurocritical care in pediatrics.

[Therapeutic hypothermia after pediatric cardiac arrest]

INTRODUCTION

Therapeutic hypothermia (TH) improves neurological outcome in adults after ventricular fibrillation cardiac arrest and in neonates with hypoxic ischemic encephalopathy. The effect of TH in children is under investigation.

OBJECTIVES

To assess the feasibility, efficacy and safety of a pilot program of TH in pediatric cardiac arrest.

MATERIAL AND METHODS

Prospective study in a pediatric intensive care unit. An external cooling method with a servo system was used on all patients according to an established protocol. Values expressed as median (IQ range).

RESULTS

Six patients were included, of whom 5 had an out of hospital cardiac arrest. The mean age was 33 months (16-120) and Glasgow coma scale 6 (4-7). The T° prior to the induction of TH was 39.2° C (39.1-39.4). The median T° used was 34.0° C (33.5-34.8° C), which was reached in 4h. (3-7) after the start and maintained for 48h. (45-54). The rewarming was carried out over a period of 14h. (12-16). Hypokalemia was the most common adverse event found. Five patients survived to hospital discharge with a Glasgow Coma Scale of 13 (11-14). At 6 months follow up the Pediatric Cerebral Performance Category score was ≤ 2 in three patients.

CONCLUSION

In this pilot study, the use of mild therapeutic hypothermia with a protocol that included rapid sequence induction with an external surface cooling technique was feasible, effective and safe in children with cardiac arrest.

Cardiac arrest and post resuscitation of the brain

Primary out-of-hospital cardiac arrest in childhood is rare but survival is a little better for children than for adults, although the prognosis for infants is very poor. Hypoxic-ischaemic encephalopathy after in-hospital cardiac arrest in children undergoing complicated treatment for previously untreatable conditions is now a common problem and is probably increasing. An additional ischaemic insult worsens the prognosis for other encephalopathies, such as that occurring after accidental or non-accidental head injury. For near-drowning, the prognosis is often good, provided that cardiopulmonary resuscitation (CPR) is commenced immediately, and the child gasps within 40 minutes of rescue and regains consciousness soon afterwards. The prognosis is much worse for the nearly drowned child admitted to casualty or the emergency room deeply unconscious with fixed dilated pupils, requiring continuing CPR and with an arterial pH <7, especially if there is little recovery by the time of admission to the intensive care unit. The use of adrenaline, sodium bicarbonate and calcium appears to worsen prognosis. Neurophysiology, specifically serial electroencephalography and evoked potentials, is the most useful tool prognostically, although neuroimaging and biomarkers may play a role. In a series of 89 patients studied after cardiac arrest in three London centres between 1982 and 1985, 39% recovered consciousness within one month. Twenty seven percent died a cardiac death whilst in coma, and the outcome in the remainder was either brain death or vegetative state. EEG and initial pH were the best predictors of outcome in this study. Seizures affected one third and were associated with deterioration and worse outcome. The advent of extracorporeal membrane oxygenation (ECMO) and the positive results of hypothermia trials in neonates and adults have rekindled interest in timely management of this important group of patients.

Protecting the future: neuroprotective strategies in the pediatric intensive care unit

PURPOSE OF REVIEW

Brain injury is the leading cause of death in pediatric intensive care units, and improvements in therapy and in understanding the pathogenesis are urgently needed. This review presents recent advances in the understanding of neuroprotective therapy and brain-specific monitoring for critically ill pediatric patients.

RECENT FINDINGS

Two neuroprotective strategies are becoming increasingly accepted as they are applied to different mechanisms of brain injury. The rapid application of hypothermia and avoidance of hyperoxia after cardiac arrest and other brain injuries are each being more commonly used as both human and animal data advocating for these approaches accumulate. In addition, more advanced and noninvasive technologies are emerging that are designed to serve as surrogates for brain function and may be used to help predict outcome. Near-infrared spectroscopy is one such commonly used technique that has prompted many studies to understand how to incorporate it into practice.

SUMMARY

Protection of the pediatric brain from both a primary insult and the common subsequent secondary injury is essential for improving long-term neurologic outcomes. Whereas monitoring technology is being constantly modified, it must be proven efficacious in order to understand the utility of new and presumed neuroprotective therapies like hypothermia and avoidance of hyperoxia.