Targeted Temperature Management in Pediatric Neurocritical Care

Pediatric Critical Care Neurologists in the United States and Canada: A Survey of Clinical Practice Experience

OBJECTIVE

To describe the characteristics of pediatric intensive care neurologists and their practice in the United States and Canada.

METHODS

We performed a survey-based study of child neurologists who self-identify as 'intensive care neurologists'. The survey included questions about demographics, training, pediatric neurocritical care service and job structure, teaching, academics, challenges, and views on the future of pediatric neurocritical care.

RESULTS

We analyzed 55 surveys. Most respondents were 31-50 years of age with ≤10 years of practice experience. Fifty-four percent identified as female. Most completed subspecialty training after child neurology residency. The majority practice at highly resourced centers with >45 intensive care unit beds. Respondents cover a variety of inpatient (critical and noncritical care) services, at times simultaneously, for a median of 19.5 weeks/y and work >70 hours/wk when on service for pediatric neurocritical care. The top 3 challenges reported were competing demands for time, excess volume, and communication with critical care medicine. Top priorities for the "ideal pediatric neurocritical care service" were attendings with training in pediatric neurocritical care or a related field and joint rounding with critical care medicine.

CONCLUSION

We report a survey-based analysis of the demographics and scope of practice of pediatric critical care neurologists. We highlight challenges faced and provide a framework for the further development of this rapidly growing field.

Pediatric Hypothermia: An Ambiguous Issue

Hypothermia in pediatrics is mainly about small body size. The key thermal factor here is the large surface-to-volume ratio. Although small mammals, including human infants and children, are adapted to higher heat losses through their elevated metabolic rate and thermogenic capacity, they are still at risk of hypothermia because of a small regulatory range and an impending metabolic exhaustion. However, some small mammalian species (hibernators) use reduced metabolic rates and lowered body temperatures as adaptations to impaired energy supply. Similar to nature, hypothermia has contradictory effects in clinical pediatrics as well: In neonates, it is a serious risk factor affecting respiratory adaptation in term and developmental outcome in preterm infants. On the other hand, it is an important self-protective response to neonatal hypoxia and an evidence-based treatment option for asphyxiated babies. In children, hypothermia first enabled the surgical repair of congenital heart defects and promotes favorable outcome after ice water drowning. Yet, it is also a major threat in various prehospital and clinical settings and has no proven therapeutic benefit in pediatric critical care. All in all, pediatric hypothermia is an ambiguous issue whose harmful or beneficial effects strongly depend on the particular circumstances.

Targeted Temperature Management Protocol in a Pediatric Intensive Care Unit: A Quality Improvement Project

BACKGROUND

In patients with acute neurological injury, abrupt temperature change exacerbates increased intracranial pressures and negatively affects perfusion pressure and cerebral blood flow. Critical care nurses must provide coordinated and effective interventions to maintain normothermia without precipitating shivering immediately after acute neurological injury in pediatric patients.

OBJECTIVE

To improve hyperthermia management in a 40-bed pediatric intensive care unit, an interdisciplinary pediatric critical care team developed, implemented, and evaluated a targeted temperature management protocol.

METHODS

The project was guided by the organization's plan-do-study-act quality improvement process. Quality improvement was assessed retrospectively using electronic medical records of patients meeting eligibility criteria. Samples of pediatric patients who received temperature interventions were compared before and after protocol implementation. The protocol included environmental, pharmacological, and body surface cooling device interventions, as well as use of a bedside shivering assessment scale and stepwise interventions to prevent and control shivering.

RESULTS

Before implementation of the targeted temperature management protocol, 64% of patients had documented temperatures higher than 37.5 °C, and body surface cooling devices were used in 10% of patients. After protocol implementation, more than 80% of patients had documented temperatures higher than 37.5 °C, and body surface cooling devices were used in 62% of patients. Four patients (6%) before and 5 patients (31%) after protocol implementation were treated with body surface cooling without requiring use of neuromuscular blockade.

CONCLUSIONS

Creation and implementation of a targeted temperature management protocol increased nurses' documented use of body surface cooling to manage hyperthermia in pediatric intensive care unit patients with acute neurological injury.

Target Temperature Management and Survival with Favorable Neurological Outcome After Out-of-Hospital Cardiac Arrest in Children: A Nationwide Multicenter Prospective Study in Japan

To assess whether target temperature management (TTM) is effective for 1-month survival with favorable neurological outcome among pediatric patients who achieved return of spontaneous circulation (ROSC) after out-of-hospital cardiac arrest (OHCA). The Japanese Association for Acute Medicine-out-of-hospital cardiac arrest (JAAM-OHCA) Registry, a multicenter prospective observational registry in Japan, included OHCA patients aged ≤17 years who achieved ROSC between June 2014 and December 2017. The primary outcome was 1-month survival with favorable neurological outcomes, defined as pediatric cerebral performance category 1 or 2. We conducted a propensity score analysis with inverse-probability-of-treatment weighting (IPTW) and evaluated the effect of TTM using logistic regression models with IPTW. A total of 167 patients [120 in the non-TTM group (71.9%) and 47 in the TTM group (28.1%)] were eligible for our analysis. The proportion of patients demonstrating 1-month survival with favorable neurological outcomes was 25.5% (12/47) in the TTM group and 16.7% (20/120) in the non-TTM group; there were no significant differences in favorable neurological outcomes (odds ratio, 1.36; 95% confidence interval, 0.55-3.35) between the non-TTM and TTM groups after performing adjustments with IPTW. In our study population composed of pediatric patients who achieved ROSC after OHCA, we did not find a positive association between TTM implementation and 1-month survival with favorable neurological outcomes.

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.

Chronic Pancytopenia due to Centrally Mediated Hypothermia in Two Children with Severe Neurological Impairment

We report on recurrent pancytopenia over five years in two children with severe impairment of the central nervous system. Assessment by hematology did not identify an etiology, including bone marrow biopsy in one. Both patients had sustained normalized blood cell counts following interventions to maintain or return to a temperature above 33 °C. Acute cytopenias following medically induced and environmental hypothermia have been reported. Recurrent pancytopenia due to centrally mediated hypothermia in patients with severe neurological impairment is often not recognized, putting such children at risk for unnecessary testing and transfusions. We provide a practical approach to management that is feasible for caregivers in the home setting with suggestions for monitoring.

Effect of temperature, age and the pons on respiratory rhythm in the rat brainstem-spinal cord

Neonatal animals are extremely tolerant of hypothermia. However, cooling will ultimately lead to ventilatory arrest, or cessation of respiratory movements. Upon rewarming, ventilation can recover spontaneously (autoresuscitation). This study examined the effect of age (P0-P5) and the pons on respiratory-related output during hypothermic ventilatory arrest and recovery using a brainstem-spinal cord preparation of neonatal rats. As temperature fell, burst frequency slowed, burst duration increased, burst shape became fragmented and eventually respiratory arrest occurred in all preparations. Removing the pons had little effect on younger preparations (P0-P2). Older preparations (P4-P5) with the pons removed continued to burst at cooler temperatures compared to pons-intact preparations and burst durations were significantly longer. Episodic breathing patterns were observed in all preparations (all ages, pons on or off) at lower temperatures. At 27 °C, however, episodic breathing was only observed in younger preparations with the pons on. These data suggest that developmental changes occurring at the level of the pons underlie the loss of hypothermic tolerance and episodic breathing.

Postintensive Care Syndrome in Pediatric Critical Care Survivors: Therapeutic Options to Improve Outcomes After Acquired Brain Injury

PURPOSE OF REVIEW

Children surviving the pediatric intensive care unit (PICU) with neurologic illness or injury have long-term morbidities in physical, cognitive, emotional, and social functioning termed postintensive care syndrome (PICS). In this article, we review acute and longitudinal management strategies available to combat PICS in children with acquired brain injury.

RECENT FINDINGS

Few intervention studies in this vulnerable population target PICS morbidities. Small studies show promise for both inpatient- and outpatient-initiated therapies, mainly focusing on a single domain of PICS and evaluating heterogeneous populations. While evaluating the effects of interventions on longitudinal PICS outcomes is in its infancy, longitudinal clinical programs targeting PICS are increasing. A multidisciplinary team with inpatient and outpatient presence is necessary to deliver the holistic integrated care required to address all domains of PICS in patients and families. While PICS is increasingly recognized as a chronic problem in PICU survivors with acquired brain injury, few interventions have targeted PICS morbidities. Research is needed to improve physical, cognitive, emotional, and social outcomes in survivors and their families.

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.