Joshua Koch

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 childrens 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.).

Brief exposure to hyperoxia depletes the glial progenitor pool and impairs functional recovery after hypoxic-ischemic brain injury

Patterns of hypoxic-ischemic brain injury in infants and children suggest vulnerability in regions of white matter development, and injured patients develop defects in myelination resulting in cerebral palsy and motor deficits. Reperfusion exacerbates the oxidative stress that occurs after such injuries and may impair recovery. Resuscitation after hypoxic-ischemic injury is routinely performed using 100% oxygen, and this practice may increase the oxidative stress that occurs during reperfusion and further damage an already compromised brain. We show that brief exposure (30 mins) to 100% oxygen during reperfusion worsens the histologic injury in young mice after unilateral brain hypoxia—ischemia, causes an accumulation of the oxidative metabolite nitrotyrosine, and depletes preoligodendrocyte glial progenitors present in the cortex. This damage can be reversed with administration of the antioxidant ebselen, a glutathione peroxidase mimetic. Moreover, mice recovered in 100% oxygen have a more disrupted pattern of myelination and develop a static motor deficit that mimics cerebral palsy and manifests itself by significantly worse performance on wire hang and rotorod motor testing. We conclude that exposure to 100% oxygen during reperfusion after hypoxic-ischemic brain injury increases secondary neural injury, depletes developing glial progenitors, interferes with myelination, and ultimately impairs functional recovery.

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 childrens 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.)

Echocardiographic predictors of symptomatic patent ductus arteriosus in extremely-low-birth-weight preterm neonates

Objective:Identify echocardiographic parameters at ⩽4 day postnatal that predict the subsequent need for closure of a clinically significant patent ductus arteriosus (sPDA) in extremely-low-birth-weight neonates (ELBW).Study Design:Serial echocardiograms obtained in 115 ELBW at ⩽10 day postnatal were examined to estimate PDA size using the PDA:left pulmonary artery (LPA) diameter ratio: ⩾1 indicated a large PDA, <1 but ⩾0.5 moderate, and <0.5 small. Sensitivity, specificity, and positive predictive values (PPV) were determined for ELBW <27 weeks and ⩾27 weeks gestational age.Result:Neonates with moderate to large PDA at ⩽4 day had 15-times greater likelihood of requiring treatment for sPDA than those with a small PDA (95% confidence interval (CI): 5.6–41). Sensitivity, specificity and PPV of the PDA:LPA at <27 weeks was 80, 86 and 92%, respectively.Conclusion:A moderate to large PDA determined from the PDA:LPA ratio at ⩽4 day postnatal identifies neonates <27 week gestation who subsequently require closure of a PDA.

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.

The association of congenital heart disease with necrotizing enterocolitis in preterm infants: a birth cohort study

Objective:To test the hypothesis that congenital heart disease (CHD) in preterm infants with severe CHD (cyanotic or left-sided obstructive lesions, or congestive heart failure) is independently associated with necrotizing enterocolitis (NEC, stage II or greater).Study design:Single-institution retrospective birth cohort of preterm infants with gestational age 230/7 to 346/7 weeks delivered between 1 January 2002 and 31 December 2011, excluding infants who received comfort care. Patients were classified into severe CHD, mild CHD and control groups.Results:Among 4678 infants, 170 (3.6%) had CHD and 118 (2.5%) developed NEC. The risk for NEC increased with severe CHD (adjusted relative risk (RR)=3.72; 95% confidence interval (CI)=1.37 to 10.10) but not with mild CHD (RR=0.65; CI=0.27 to 1.55).Conclusion:In this cohort, severe but not mild CHD was independently associated with increased risk for NEC. This finding, if confirmed by other studies, may help identify patients at risk for NEC.

Pediatric cardiac arrest due to drowning and other respiratory etiologies: Neurobehavioral outcomes in initially comatose children

AIM To describe the 1-year neurobehavioral outcome of survivors of cardiac arrest secondary to drowning, compared with other respiratory etiologies, in children enrolled in the Therapeutic Hypothermia after Pediatric Cardiac Arrest Out-of-Hospital (THAPCA-OH) trial. METHODS Exploratory analysis of survivors (ages 1-18 years) who received chest compressions for ≥2min, were comatose, and required mechanical ventilation after return of circulation (ROC). Participants recruited from 27 pediatric intensive care units in North America received targeted temperature management [therapeutic hypothermia (33°C) or therapeutic normothermia (36.8°C)] within 6h of ROC. Neurobehavioral outcomes included 1-year Vineland Adaptive Behavior Scales, Second Edition (VABS-II) total and domain scores and age-appropriate cognitive performance measures (Mullen Scales of Early Learning or Wechsler Abbreviated Scale of Intelligence). RESULTS Sixty-six children with a respiratory etiology of cardiac arrest survived for 1-year; 60/66 had broadly normal premorbid functioning (VABS-II≥70). Follow up was obtained on 59/60 (30 with drowning etiology). VABS-II composite and domain scores declined significantly from premorbid scores in drowning and non-drowning groups (p<0.001), although declines were less pronounced for the drowning group. Seventy-two percent of children had well below average cognitive functioning at 1-year. Younger age, fewer doses of epinephrine, and drowning etiology were associated with better VABS-II composite scores. Demographic variables and treatment with hypothermia did not influence neurobehavioral outcomes. CONCLUSIONS Risks for poor neurobehavioral outcomes were high for children who were comatose after out-of-hospital cardiac arrest due to respiratory etiologies; survivors of drowning had better outcomes than those with other respiratory etiologies.

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.

Association of early postresuscitation hypotension with survival to discharge after targeted temperature management for pediatric out-of-hospital cardiac arrest secondary analysis of a randomized clinical trial

Importance Out-of-hospital cardiac arrest (OHCA) occurs in more than 6000 children each year in the United States, with survival rates of less than 10% and severe neurologic morbidity in many survivors. Post–cardiac arrest hypotension can occur, but its frequency and association with survival have not been well described during targeted temperature management. Objective To determine whether hypotension is associated with survival to discharge in children and adolescents after resuscitation from OHCA. Design, Setting, and Participants This post hoc secondary analysis of the Therapeutic Hypothermia After Pediatric Cardiac Arrest (THAPCA) trial included 292 pediatric patients older than 48 hours and younger than 18 years treated in 36 pediatric intensive care units from September 1, 2009, through December 31, 2012. Participants underwent therapeutic hypothermia (33.0°C) vs therapeutic normothermia (36.8°C) for 48 hours. All participants had hourly systolic blood pressure measurements documented during the initial 6 hours of temperature intervention. Hourly blood pressures beginning at the time of temperature intervention (time 0) were normalized for age, sex, and height. Early hypotension was defined as a systolic blood pressure less than the fifth percentile during the first 6 hours after temperature intervention. With use of forward stepwise logistic regression, covariates of interest (age, sex, initial cardiac rhythm, any preexisting condition, estimated duration of cardiopulmonary resuscitation [CPR], primary cause of cardiac arrest, temperature intervention group, night or weekend cardiac arrest, witnessed status, and bystander CPR) were evaluated in the final model. Data were analyzed from February 5, 2016, through June 13, 2017. Exposures Hypotension. Main Outcomes and Measure Survival to hospital discharge. Results Of 292 children (194 boys [66.4%] and 98 girls [33.6%]; median age, 23.0 months [interquartile range, 5.0-105.0 months]), 78 (26.7%) had at least 1 episode of early hypotension. No difference was observed between the therapeutic hypothermia and therapeutic normothermia groups in the prevalence of hypotension during induction and maintenance (73 of 153 [47.7%] vs 72 of 139 [51.8%]; P = .50) or rewarming (35 of 118 [29.7%] vs 19 of 95 [20.0%]; P = .10) during the first 72 hours. Participants who had early hypotension were less likely to survive to hospital discharge (20 of 78 [25.6%] vs 93 of 214 [43.5%]; adjusted odds ratio, 0.39; 95% CI, 0.20-0.74). Conclusions and Relevance In this post hoc secondary analysis of the THAPCA trial, 26.7% of participants had hypotension within 6 hours after temperature intervention. Early post–cardiac arrest hypotension was associated with lower odds of discharge survival, even after adjusting for covariates of interest.

Elevated cranial ultrasound resistive indices are associated with improved neurodevelopmental outcomes one year after pediatric cardiac surgery: A single center pilot study

Objective To determine if a non‐invasive, repeatable test can be used to predict neurodevelopmental outcomes in patients with congenital heart disease. Methods This was a prospective study of pediatric patients less than two months of age undergoing congenital heart surgery at the Childrens Health Childrens Medical Center at Dallas. Multichannel near‐infrared spectroscopy (NIRS) was utilized during the surgery, and ultrasound (US) resistive indices (RI) of the major cranial vessels were obtained prior to surgery, immediately post‐operatively, and prior to discharge. Pearsons correlation, Fischer exact t test, and Fischer r to z transformation were used where appropriate. Results A total of 16 patients were enrolled. All had US data. Of the sixteen patients, two died prior to the neurodevelopmental testing, six did not return for the neurodevelopmental testing, and eight patients completed the neurodevelopmental testing. There were no significant correlations between the prior to surgery and prior to discharge US RI and neurodevelopmental outcomes. The immediate post‐operative US RI demonstrated a strong positive correlation with standardized neurodevelopmental outcome measures. We were able to demonstrate qualitative differences using multichannel NIRS during surgery, but experienced significant technical difficulties implementing consistent monitoring. Conclusions A higher resistive index in the major cerebral blood vessels following cardiac surgery in the neonatal period is associated with improved neurological outcomes one year after surgery. Obtaining an ultrasound with resistive indices of the major cerebral vessels prior to and after surgery may yield information that is predictive of neurodevelopmental outcomes.