Therapeutic hypothermia attenuates paraplegia and neuronal damage in the lumbar spinal cord in a rat model of asphyxial cardiac arrest

Spinal cord ischemia can result from cardiac arrest. It is an important cause of severe spinal cord injury that can lead to serious spinal cord disorders such as paraplegia. Hypothermia is widely acknowledged as an effective neuroprotective intervention following cardiac arrest injury. However, studies on effects of hypothermia on spinal cord injury following asphyxial cardiac arrest and cardiopulmonary resuscitation (CA/CPR) are insufficient. The objective of this study was to examine effects of hypothermia on motor deficit of hind limbs of rats and vulnerability of their spinal cords following asphyxial CA/CPR. Experimental groups included a sham group, a group subjected to CA/CPR, and a therapeutic hypothermia group. Severe motor deficit of hind limbs was observed in the control group at 1 day after asphyxial CA/CPR. In the hypothermia group, motor deficit of hind limbs was significantly attenuated compared to that in the control group. Damage/death of motor neurons in the lumbar spinal cord was detected in the ventral horn at 1 day after asphyxial CA/CPR. Neuronal damage was significantly attenuated in the hypothermia group compared to that in the control group. These results indicated that therapeutic hypothermia after asphyxial CA/CPR significantly reduced hind limb motor dysfunction and motoneuronal damage/death in the ventral horn of the lumbar spinal cord following asphyxial CA/CPR. Thus, hypothermia might be a therapeutic strategy to decrease motor dysfunction by attenuating damage/death of spinal motor neurons following asphyxial CA/CPR.

Treatment options in pediatric super-refractory status epilepticus

BACKGROUND

Super-refractory status epilepticus (SRSE) is a seizure that continues >24 h after anesthesia, or recurs on the reduction of anesthesia. SRSE is extremely difficult-to-control and associated with poor outcome. To date, optimal therapy and outcome data in children is limited.

OBJECTIVE

To assess etiology, treatment options and outcome in pediatric SRSE patients.

METHOD

We reviewed medical records of children <15 years old with SRSE during 2007-2017 at King Chulalongkorn Memorial Hospital. Demographic data, etiology, treatment, complications and discharge outcome were recorded.

RESULTS

Seventeen patients, aged 1 month-13 years were included. The leading etiology was immune-mediated encephalitis (29.4%) and epilepsy (29.4%). The most common anesthetic agents were midazolam (94.1%) and propofol (52.9%) with the average maximal dose of 1.3 and 6.9 mg/kg/h respectively. Other treatments included immunological therapy (76.5%), ketogenic diet (76.5%), pyridoxine/pyridoxal-5-phosphate (70.5%). The most common complications were hypotension (61.5%), drug hypersensitivity (32.5%). Median length of anesthetic and intensive care were 9 and 23 days. The mortality rate was 17.6%, and 2 of 3 febrile infection-related epilepsy syndrome cases died. At discharge, all survivors were seizure free.

CONCLUSION

The majority of pediatric SRSE does not have epilepsy and the etiology is various. Treatment should expand from antiepileptic drugs to other modalities targeting different possible mechanisms such as immunomodulation or specific metabolic treatment. Multiple anesthetic drugs could be tolerated with close monitoring. Ketogenic diet, via enteral or parenteral route, could be considered early if requiring multiple anesthetic drugs. Initial outcome in children is relatively better than in adults.

Fulminant acute disseminated encephalomyelitis in children

Acute disseminated encephalomyelitis (ADEM) is a typically monophasic inflammatory demyelinating disease of the central nervous system with a favorable outcome. However, 2% of ADEM involves acute hemorrhagic leukoencephalitis (AHLE), which is a fulminant and hyperacute variant of ADEM with a poor outcome and high mortality. There are limited case reports of fulminant ADEM including AHLE in children. Herein, we report two pediatric cases of fulminant ADEM. Both cases had a rapid deterioration of consciousness, repetitive seizures, and brain edema on neuroimaging, in addition to atypical neuroradiological findings on magnetic resonance imaging (MRI), a reversible splenial lesion in case 1, and bilateral frontal and occipital cortical lesions in case 2. Both cases were treated with early high-dose methyl-prednisolone and immunoglobulin, while therapeutic hypothermia was also initiated in case 2 after the patient exhibited a decerebrate posture and irregular breathing pattern. Both cases had a favorable outcome. Further case reports on pediatric fulminant ADEM are required to clarify the various clinical types, and to examine the efficacy of various treatment modalities for fulminant ADEM and AHLE in children.

Neonatal Encephalopathy: Current Management and Future Trends

It is well-documented in the literature that infants who suffer from hypoxic ischemic encephalopathy are at high risk for neurologic sequelae or even death. With the addition of therapeutic hypothermia into the treatment regimen for neonatal hypoxic ischemic encephalopathy, newborns afflicted with hypoxic ischemic encephalopathy were given the opportunity for a better outcome. Questions linger as to the most optimal treatment strategy of therapeutic hypothermia for these newborns. The goal of this article is to discuss current management strategies, as well as future trends, for infants with hypoxic ischemic encephalopathy.

Therapeutic hypothermia after global cerebral ischemia due to left ventricular assist device malfunction

Herein we report the case of a patient who suffered from global cerebral ischemia due to pump stoppage of Jarvik2000 Left ventricular assist device (LVAD) for unknown reason and fatal ventricular arrhythmia at home. Cardiopulmonary resuscitation was started by paramedics 6-7 min after the patient fell down. The patient was transferred to our hospital after the restoration of the LVAD function by exchanging external cables. Mild therapeutic hypothermia was induced and body temperature was kept at 33 °C for 24 h. After rewarming, the patient recovered his consciousness without any neurological deficit.

Cerebral oxygen metabolism during and after therapeutic hypothermia in neonatal hypoxic-ischemic encephalopathy: a feasibility study using magnetic resonance imaging

BACKGROUND

Therapeutic hypothermia is the standard-of-care treatment for infants diagnosed with moderate-to-severe hypoxic-ischemic encephalopathy (HIE). MRI for assessing brain injury is usually performed after hypothermia because of logistical challenges in bringing acutely sick infants receiving hypothermia from the neonatal intensive care unit (NICU) to the MRI suite. Perhaps examining and comparing early cerebral oxygen metabolism disturbances to those after rewarming will lead to a better understanding of the mechanisms of brain injury in HIE and the effects of therapeutic hypothermia.

OBJECTIVE

The objectives were to assess the feasibility of performing a novel T2-relaxation under spin tagging (TRUST) MRI technique to measure venous oxygen saturation very early in the time course of treatment, 18-24 h after the initiation of therapeutic hypothermia, to provide a framework to measure neonatal cerebral oxygen metabolism noninvasively, and to compare parameters between early and post-hypothermia MRIs.

MATERIALS AND METHODS

Early (18-24 h after initiating hypothermia) MRIs were performed during hypothermia treatment in nine infants with HIE (six with moderate and three with severe HIE). Six infants subsequently had an MRI after hypothermia. Mean values of cerebral blood flow, oxygen extraction fraction, and cerebral metabolic rate of oxygen from MRIs during hypothermia were compared between infants with moderate and severe HIE; and in those with moderate HIE, we compared cerebral oxygen metabolism parameters between MRIs performed during and after hypothermia.

RESULTS

During the initial hypothermia MRI at 23.5±5.2 h after birth, infants with severe HIE had lower oxygen extraction fraction (P=0.04) and cerebral metabolic rate of oxygen (P=0.03) and a trend toward lower cerebral blood flow (P=0.33) compared to infants with moderate HIE. In infants with moderate HIE, cerebral blood flow decreased and oxygen extraction fraction increased between MRIs during and after hypothermia (although not significantly); cerebral metabolic rate of oxygen (P=0.93) was not different.

CONCLUSION

Early MRIs were technically feasible while maintaining hypothermic goal temperatures in infants with HIE. Cerebral oxygen metabolism early during hypothermia is more disturbed in severe HIE. In infants with moderate HIE, cerebral blood flow decreased and oxygen extraction fraction increased between early and post-hypothermia scans. A comparison of cerebral oxygen metabolism parameters between early and post-hypothermia MRIs might improve our understanding of the evolution of HIE and the benefits of hypothermia. This approach could guide the use of adjunctive neuroprotective strategies in affected infants.

Withdrawal of Life-Support in Neonatal Hypoxic-Ischemic Encephalopathy

PURPOSE

We describe the frequency and timing of withdrawal of life-support (WLS) in moderate or severe hypoxic-ischemic encephalopathy (HIE) and examine its associations with medical and sociodemographic factors.

PROCEDURES

We undertook a secondary data analysis of a prospective multicenter data registry of regional level IV Neonatal Intensive Care Units participating in the Children's Hospitals Neonatal Database. Infants ≥36 weeks gestational age with HIE admitted to a Children's Hospitals Neonatal Database Neonatal Intensive Care Unit between 2010 and 2016, who underwent therapeutic hypothermia were categorized as (1) infants who died following WLST and (2) survivors with severe HIE (requiring tube feedings at discharge).

RESULTS

Death occurred in 267/1,925 (14%) infants with HIE, 87.6% following WLS. Compared to infants with WLS (n = 234), the survived severe group (n = 74) had more public insurance (73% vs 39.3%, P = 0.00001), lower household income ($37,020 vs $41,733, P = 0.006) and fewer [20.3% vs 35.0%, P = 0.0212] were from the South. Among infants with WLS, electroencephalogram was performed within 24 hours in 75% and was severely abnormal in 64% cases; corresponding rates for MRI were 43% and 17%, respectively. Private insurance was independently associated with WLS, after adjustment for HIE severity and center.

CONCLUSIONS

In a multicenter cohort of infants with HIE, WLS occurred frequently and was associated with sociodemographic factors. The rationale for decision-making for WLS in HIE require further exploration.

Reperfusion Changes After Stroke and Practical Approaches for Neuroprotection

Reperfusion is the first line of care in a growing number of eligible acute ischemic stroke patients. Early reperfusion with thrombolytic drugs and endovascular mechanical devices is associated with improved outcome and lower mortality rates compared with natural history. Reperfusion is not without risk, however, and may result in reperfusion injury, which manifests in hemorrhagic transformation, brain edema, infarct progression, and neurologic worsening. In this article, the functional and structural changes and underlying molecular mechanisms of ischemia and reperfusion are reviewed. The pathways that lead to reperfusion injury and novel neuroprotective strategies with endogenous properties are discussed.

Therapeutic Hypothermia in Neonatal Hypoxic-Ischemic Encephalopathy

PURPOSE OF REVIEW

Therapeutic hypothermia reduces death or disability in term and near-term infants with moderate-severe hypoxic-ischemic encephalopathy. Nevertheless, many infants still survive with disability, despite hypothermia, supporting further research in to ways to further improve neurologic outcomes.

RECENT FINDINGS

Recent clinical and experimental studies have refined our understanding of the key parameters for hypothermic neuroprotection, including timing of initiation, depth, and duration of hypothermia, and subsequent rewarming rate. However, important knowledge gaps remain. There is encouraging clinical evidence from a small phase II trial that combined treatment of hypothermia with recombinant erythropoietin further reduces risk of disability but definitive studies are still needed. In conclusion, recent studies suggest that current protocols for therapeutic hypothermia are near-optimal, and that the key to better neurodevelopmental outcomes is earlier diagnosis and initiation of hypothermia after birth. Further research is essential to find and evaluate ways to further improve outcomes after hypoxic-ischemic encephalopathy, including add-on therapies for therapeutic hypothermia and preventing pyrexia during labor and delivery.

Effectiveness and safety of early enteral nutrition for patients who received targeted temperature management after out-of-hospital cardiac arrest

AIM

Early enteral nutrition (EN) is recommended for critically ill patients; however, few reports have examined early EN for patients who received targeted temperature management (TTM) after out-of-hospital cardiac arrest (OHCA). We investigated the effectiveness and safety of early EN for patients who received TTM after OHCA.

METHODS

We used a nationwide Japanese administrative database to identify OHCA patients who received TTM from April 2008 to March 2017. The primary outcome was 30-day mortality; secondary outcomes were incidences of all-cause infection, pneumonia, and intestinal ischemia.

RESULTS

Of the 1932 OHCA patients who received TTM, 1682 met the inclusion criteria. Of these, 294 received early EN within 2 days from the initiation of TTM and 266 propensity-score matched pairs were generated. Cox regression analyses revealed no significant difference in 30-day mortality between groups (hazard ratio (HR): 0.90; 95% confidence interval (95% CI): 0.65-1.25). There was no significant difference in the incidence of all-cause infection (odds ratio (OR): 0.98; 95% CI: 0.66-1.46) or pneumonia (OR: 1.02; 95% CI: 0.68-1.55). Subgroup analyses of patients with a low body mass index (BMI; kg/m2) (< 18.5) revealed a significant decrease of 30-day mortality in the early EN group (HR: 0.30; 95% CI: 0.092-0.97) but no significant difference among patients with a BMI ≥ 18.5 (HR: 1.01; 95% CI: 0.72-1.43).

CONCLUSION

Among patients who received TTM after OHCA, there was no significant association between early EN and 30-day mortality; however, early EN could be beneficial for patients with a low BMI.

Combination therapy with erythropoietin, magnesium sulfate and hypothermia for hypoxic-ischemic encephalopathy: an open-label pilot study to assess the safety and feasibility

BACKGROUND

Although therapeutic hypothermia improves the outcome of neonatal hypoxic-ischemic encephalopathy (HIE), its efficacy is still limited. This preliminary study evaluates the safety and feasibility of the combination therapy with erythropoietin (Epo), magnesium sulfate and hypothermia in neonates with HIE.

METHODS

A combination therapy with Epo (300 U/kg every other day for 2 weeks), magnesium sulfate (250 mg/kg for 3 days) and hypothermia was started within 6 h of birth in neonates who met the institutional criteria for hypothermia therapy. All patients received continuous infusion of dopamine. Vital signs and adverse events were recorded during the therapy. Short-term and long-term developmental outcomes were also evaluated.

RESULTS

Nine patients were included in the study. The mean age at first intervention was 3.9 h (SD, 0.5). Death, serious adverse events or changes in vital signs likely due to intervention were not observed during hospital care. All nine patients completed the therapy. At the time of hospital discharge, eight patients had established oral feeding and did not require ventilation support. Two patients had abnormal MRI findings. At 18 months of age, eight patients received a follow-up evaluation, and three of them showed signs of severe neurodevelopmental disability.

CONCLUSION

The combination therapy with 300 U/kg Epo every other day for 2 weeks, 250 mg/kg magnesium sulphate for 3 days and therapeutic hypothermia is feasible in newborn patients with HIE.

TRIAL REGISTRATION

ISRCTN33604417 retrospectively registered on 14 September 2018.

Hearing impairment and hypoxia ischaemic encephalopathy: Incidence and associated factors

OBJECTIVE

To establish the local incidence of hearing loss in newborns with Hypoxic Ischaemic Encephalopathy (HIE) and to identify associated risk factors.

STUDY DESIGN

Retrospective Cohort Study. Neonatal Intensive Care Unit (NICU) dual stage hearing screening protocol, including automated otoacoustic emissions (AOAE) and automated auditory brainstem response (AABR) testing.

RESULTS

57 newborns received therapeutic hypothermia for HIE. Twelve babies (21%) died. Audiology data was incomplete in 3 babies. Complete data was available for 42 babies (male n = 24), 4 (9.5%) of whom had hearing impairment. The development of hearing loss was associated with abnormal blood glucose levels (p = 0.006), low Apgar score at 1 min (p = 0.0219) and evidence of multi organ dysfunction [high creatinine (p = 0.0172 and 0.0198) and raised liver transaminases (aspartate aminotransferase (AST) p = 0.0012, alanine aminotransferase (ALT) p = 0.0037)]. An association with gentamicin was not found.

CONCLUSION

This study confirms that hearing impairment is common in term infants who have undergone therapeutic hypothermia for moderate/severe HIE. Blood glucose should be monitored carefully in these infants and developmental surveillance should include formal audiology. Further larger studies are needed to clarify the role, if any, of hypothermia per se in causation of hearing loss and to fully identify risk factors for hearing impairment in this population.

WHAT IS NEW

The current study confirms that hearing impairment is common in term infants who have undergone therapeutic hypothermia for moderate/severe HIE. No association between gentamicin use and the development of hearing impairment was found however initial blood glucose outside the normal range was of significance. Other factors associated with hearing impairment were low Apgar scores, greater need for resuscitation and evidence of multi organ dysfunction (renal and liver failure).

Impact of Education on Hypothermia Delivery during Neonatal Transport

BACKGROUND

Moderate therapeutic hypothermia (TH) initiated within 6 h of life reduces adverse neurodevelopmental outcomes in infants after perinatal hypoxic ischaemic insult. For infants born in non-tertiary centres, TH may be initiated manually en route to a neonatal intensive care unit (NICU). However, both over- and undercooling is reported with this strategy, precluding some infants from the benefits of TH.

OBJECTIVES

To evaluate the impact of a region-wide educational programme on the safety and efficacy of manual cooling administered by the Wellington Neonatal Transport Service (NeTS).

METHODS

Clinical records of infants with hypoxic ischaemic encephalopathy (HIE) retrieved by the Wellington NeTS for TH between January 2012 and June 2017 were reviewed retrospectively. Temperature outcomes of infants retrieved before and after the education programme were compared.

RESULTS

A total of 101 infants were cooled manually by Wellington NeTS for TH during the study period. Education and training significantly reduced the rate of overcooling to ≤32.0°C (4/43 [9%] vs. 0/58, p = 0.02). However, there was no difference in the proportion of infants who achieved target rectal temperature within 6 h of life (29/43 [65%] vs. 35/58 [60%], p = 0.57).

CONCLUSIONS

Introduction of a region-wide educational programme may have improved the safety of manual cooling during neonatal transport but it had a negligible impact on its efficacy. The use of servo-controlled cooling during transport should therefore be considered to improve access to the optimal neuroprotective benefits of TH for outborn infants with HIE.

Neonatal encephalopathy and hypoxic-ischemic encephalopathy

Acute hypoxic-ischemic encephalopathy around the time of birth remains a major cause of death and life-long disability. The key insight that led to the modern revival of studies of neuroprotection was that, after profound asphyxia, many brain cells show initial recovery from the insult during a short "latent" phase, typically lasting approximately 6h, only to die hours to days later after a "secondary" deterioration characterized by seizures, cytotoxic edema, and progressive failure of cerebral oxidative metabolism. Studies designed around this framework showed that mild hypothermia initiated as early as possible before the onset of secondary deterioration and continued for a sufficient duration to allow the secondary deterioration to resolve is associated with potent, long-lasting neuroprotection. There is now compelling evidence from randomized controlled trials that mild to moderate induced hypothermia significantly improves survival and neurodevelopmental outcomes in infancy and mid-childhood.

Long-term Survival and Functional Neurological Outcome in Conscious Hospital Survivors Undergoing Therapeutic Hypothermia

Introduction

Therapeutic hypothermia (TH) is the neuroprotective strategy for comatose survivors of cardiac arrest. It improves neurological outcomes at hospital discharge. However, data regarding long-term outcomes are limited. We aimed to study functional ability and survival of the patients after discharge.

Patients and methods

We reviewed data of post-arrest patients undergoing TH in our hospital from 2006 to 2014 and assessed the functional ability of conscious survivors after hospital discharge by using a disability rating scale (DRS). We compared the patients' DRS after discharge with their cerebral performance category (CPC) at hospital discharge. Additionally, we analyzed survival rates at 6 months, 1, 2, and 3 years.

Results

Of 51 patients undergoing TH, 27 survived, and 17 of these were conscious. Approximately 75%, 73%, 71%, and 56% of the hospital survivors were alive at 6 months, 1, 2 and 3 years, respectively. We evaluated the functional ability (DRS) in 15 awake patients. The majority of the patients with good performance (CPC1) at discharge returned to normal function or minimal disability (DRS 0-3). Interestingly, although the patients with worse CPC scores at discharge had a greater risk of functional disability and death, a patient with severe disability (CPC3) at discharge fully recovered and was able to return to work later on.

Conclusion

Long-term survival of conscious patients undergoing TH was quite high. The good CPC score at discharge potentially predicted the favorable forthcoming outcome. However, it was difficult to predict the unfavorable long-term outcome from the poor condition at discharge.

How to cite this article

Kongpolprom N, Cholkraisuwat J. Long-term Survival and Functional Neurological Outcome in Conscious Hospital Survivors Undergoing Therapeutic Hypothermia. Indian Journal of Critical Care Medicine, January 2019; 23(1):20-26.

Electroencephalography and brain magnetic resonance imaging in asphyxia comparing cooled and non-cooled infants

OBJECTIVE

The aim was to establish any differences in the predictive value of EEG and MRI for outcome in infants treated and not-treated with therapeutic hypothermia (HT) for perinatal asphyxia. We hypothesize that they are equally predictive and that combining both has the highest predictive value.

STUDY DESIGN

We retrospectively compared data of infants with hypoxic-ischemic encephalopathy (HIE) who received HT (n = 45) between September 2009 and December 2013 with those of infants with HIE born between January 2004 and August 2009, before HT was available (NT, n = 37). All received conventional and/or amplitude-integrated EEG during the first days and early MRI (day 4-5). Associations of EEG, MRI and severe neurodevelopmental outcome (death or Bayley's -2SD below mean), were tested with a multivariable logistic regression analysis, corrected for HT.

RESULTS

Forty-eight hours' EEG background pattern had a PPV of 92% and a NPV of 81% in HT, versus 100% and 58% in NT. MRI had a PPV of 71% and a NPV of 93% in HT, versus 82% and 75% in NT. The adjusted OR for adverse outcome was 0.013 (95% CI 0.002-0.154, p < 0.001) for EEG background normalization within 48 h and 32.19 (95% CI 4.84-214.25, p < 0.001) for abnormal MRI.

CONCLUSION

The predictive value of EEG and MRI is equal in cooled and non-cooled infants with HIE. Our data show a higher predictive value (death and severe outcome) for EEG compared to MRI. In HIE, persistent abnormal EEG background pattern until 48 h, combined with abnormal early MRI is strongly predictive for poor neurodevelopment.

Outcome of Infants with Therapeutic Hypothermia after Perinatal Asphyxia and Early-Onset Sepsis

BACKGROUND

Animal models suggest that neuroprotective effects of therapeutic hypothermia (TH) after perinatal asphyxia are reduced in infants with early-onset sepsis.

OBJECTIVES

To assess the outcome of infants with perinatal asphyxia, neonatal encephalopathy, and TH in the presence of early-onset sepsis.

METHODS

In a retrospective cohort of 1,084 infants with perinatal asphyxia and TH, the outcome of 42 infants (gestational age 36.1-42.6 weeks and birth weight 2,280-5,240 g) with proven sepsis (n = 14) and probable sepsis (n = 28) was analyzed. Death, cerebral palsy, or a delayed development at 2 years was considered an adverse outcome.

RESULTS

Sepsis was caused mostly by group B streptococci (n = 17), other Gram-positive bacteria (n = 5), and Candida albicans (n = 1). Of the 42 infants, 9 (21.4%) died, and 5 (11.9%) showed impairments on follow-up. The outcome is comparable to the previously reported outcome of infants with TH without early-onset sepsis.

CONCLUSION

A good outcome was reported in the majority of infants with perinatal asphyxia, TH, and early-onset sepsis. Cooling should not be withheld from these infants.

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.

Effect of high flow transnasal dry air on core body temperature in intubated human subjects

PURPOSE

Early initiation of hypothermia is recommended in the setting of cardiac arrest. Current hypothermia methods are invasive and expensive and not applicable in ambulatory settings. We investigated the evaporative cooling effect of high flow transnasal dry air on core esophageal temperature in human volunteers.

METHODS & RESULTS

A total of 32 subjects (mean age 53.2 ± 9.3 yrs., mean weight 90 ± 17 kg) presenting for elective electrophysiological procedures were enrolled for the study. Half of the subjects were men. Following general anesthesia induction, high flow (30 LPM) medical grade ambient dry air with a relative humidity ∼20% was administered through a nasal mask for 60 min. Core temperature was monitored at the distal esophagus. Half of the subjects (16/32) were subject to high flow air and the remainder served as controls. Over a 1-h period, mean esophageal temperature decreased from 36.1 ± 0.3 °C to 35.5 ± 0.1 °C in the test subjects (p < 0.05). No significant change in temperature was observed in the control subjects (36.3 ± 0.3 °C to 36.2 ± 0.2 °C, p = NS). No adverse events occurred.

CONCLUSION

Transnasal high flow dry air through the nasopharynx reduces core body temperature. This mechanism can be harnessed to induce hypothermia in patients where clinically indicated without any deleteriouseffects in a short time exposure.

Prognostic value of continuous electroencephalography in children undergoing therapeutic hypothermia after cardiac arrest: A pilot study

OBJECTIVE

To determine the prognostic value of continuous electroencephalography (EEG) in children undergoing therapeutic hypothermia after cardiac arrest.

METHOD

We retrospectively reviewed medical records and continuous EEG of all patients undergoing therapeutic hypothermia after cardiac arrest from November 2013 to September 2016. Demographic, clinical data and immediate complications were collected. Characteristics of continuous EEG including EEG background, time to normal trace (TTNT) and electrographic seizures were reviewed by investigators. Cerebral performance category scales at 6 months' follow up were evaluated and divided into good (grade 1-2) and poor (grade 3-5) outcome groups.

RESULT

Six patients were included (two boys and four girls) with median age of 19.5 months (range13-128 months). Five patients (83.3%) presented with cardiac arrest from near-drowning and one patient with underlying acute lymphocytic leukemia presented an in-hospital cardiac arrest. Initial EKG rhythm was asystole in 3 patients (50%), pulseless activity in 1 patient (16.7%) and initially unknown in 2 patients (33.3%). Two patients (33.3%) who had EEG reactivity and TTNT within 5minutes and 2.5hours had good neurological outcome (CPC1). Four patients (66.7%) with absent EEG reactivity had poor neurological outcome (CPC4, 5 in 3 and 1 children respectively). Three patients from the poor outcome group had electrographic seizures, of whom 2/3 progressed to status epilepticus. Three out of four patients in the poor outcome group had the following complications: pneumonia, bleeding and pancreatitis.

CONCLUSION

Early TTNT and EEG reactivity help to predict good neurological outcome in children undergoing therapeutic hypothermia after cardiac arrest. Seizures and status epilepticus may predict poor neurological outcome.

Therapeutic hypothermia after paediatric cardiac arrest: Pooled randomized controlled trials

BACKGROUND

Separate trials to evaluate therapeutic hypothermia after paediatric cardiac arrest for out-of-hospital and in-hospital settings reported no statistically significant differences in survival with favourable neurobehavioral outcome or safety compared to therapeutic normothermia. However, larger sample sizes might detect smaller clinical effects. Our aim was to pool data from identically conducted trials to approximately double the sample size of the individual trials yielding greater statistical power to compare outcomes.

METHODS

Combine individual patient data from two clinical trials set in forty-one paediatric intensive care units in USA, Canada and UK. Children aged at least 48 h up to 18 years old, who remained comatose after resuscitation, were randomized within 6 h of return of circulation to hypothermia or normothermia (target 33.0 °C or 36.8 °C). The primary outcome, survival 12 months post-arrest with Vineland Adaptive Behaviour Scales, Second Edition (VABS-II) score at least 70 (scored from 20 to 160, higher scores reflecting better function, population mean = 100, SD = 15), was evaluated among patients with pre-arrest scores ≥70.

RESULTS

624 patients were randomized. Among 517 with pre-arrest VABS-II scores ≥70, the primary outcome did not significantly differ between hypothermia and normothermia groups (28% [75/271] and 26% [63/246], respectively; relative risk, 1.08; 95% confidence interval [CI], 0.81 to 1.42; p = 0.61). Among 602 evaluable patients, the change in VABS-II score from baseline to 12 months did not differ significantly between groups (p = 0.20), nor did, proportion of cases with declines no more than 15 points or improvement from baseline [22% (hypothermia) and 21% (normothermia)]. One-year survival did not differ significantly between hypothermia and normothermia groups (44% [138/317] and 38% [113/ 297], respectively; relative risk, 1.15; 95% CI, 0.95 to 1.38; p = 0.15). Incidences of blood-product use, infection, and serious cardiac arrhythmia adverse events, and 28-day mortality, did not differ between groups.

CONCLUSIONS

Analysis of combined data from two paediatric cardiac arrest targeted temperature management trials including both in-hospital and out-of-hospital cases revealed that hypothermia, as compared with normothermia, did not confer a significant benefit in survival with favourable functional outcome at one year.

Outcomes of preterm infants treated with hypothermia for hypoxic-ischemic encephalopathy

BACKGROUND

Therapeutic hypothermia reduces the risk of death, or moderate to severe neurodevelopmental impairment (NDI) in term infants with hypoxic-ischemic encephalopathy (HIE). Reports of its safety and efficacy in preterm infants are scarce.

OBJECTIVE

Report short and long-term outcomes of preterm infants with HIE who received therapeutic hypothermia.

METHODS

A retrospective cohort analysis of all preterm infants <36 weeks' gestation with HIE who received whole body hypothermia in a single center from January 2007 to April 2015. The primary outcome was death or moderate to severe NDI defined by moderate or severe cerebral palsy, severe hearing or visual impairment, or cognitive score < 85 on the Bayley Scales of Infant Development III (BSID III) at 18-24 months' adjusted age.

RESULTS

30 infants with a median gestational age and birthweight of 35 weeks' (range; 33-35) and 2575 g (1850-4840) and a median first postnatal blood pH of 6.81 (6.58-7.14). Complications included coagulopathy (50%), early clinical seizures (43.3%), arterial hypotension (40%), persistent metabolic acidosis (37%) and thrombocytopenia (20%). Four infants died before or soon after discharge (18.2%). Eighteen surviving infants (69.2%) had follow up data; 7 of them had moderate to severe NDI (38.9%). Cognitive, motor and language mean composite BSID III scores were 84 (54-110), 83 (46-118), and 78 (46-112). Death or moderate to severe NDI occurred in 11/22 (50%) infants with known outcomes.

CONCLUSION

Large randomized trials on efficacy and safety are needed in this highly vulnerable population as the incidence of complications and the combined outcome of death and NDI is concerning.

High electroencephalographic seizure exposure is associated with unfavorable outcomes in neonates with hypoxic-ischemic encephalopathy

PURPOSE

Electroencephalographic seizures (ES) are common among neonates with hypoxic-ischemic encephalopathy (HIE), and they represent a treatable complication that might improve neurodevelopmental outcomes. We aimed to establish whether higher ES exposure was predictive of unfavorable outcomes while adjusting for other important clinical and electroencephalographic parameters.

METHODS

We performed a single-center, retrospective study of consecutive neonates with HIE managed with therapeutic hypothermia from June 2010 through December 2016. Neonates underwent continuous electroencephalographic (cEEG) monitoring during and after therapeutic hypothermia. Outcome measures included abnormal MRIs after rewarming and abnormal motor and language development.

RESULTS

Clinical data from the perinatal period were available for 116 neonates. Follow-up data were available for 93 of 116 (80%) neonates who survived to discharge, with a median follow-up period of 23 months (interquartile range 1236 months). Multivariate analysis demonstrated that high ES exposure (OR 5.2, 95% CI 1.3-21.2, p = 0.02) and moderate/severely abnormal EEG background (OR 8.3, 95% CI 1.6-43.9, p = 0.01) were independent predictors of abnormal motor development. High ES exposure was an independent predictor of abnormal language development (OR 4.2, 95% CI 1.1-15.9, p = 0.04). High ES exposure (OR 7.0, 95% CI 2.2-22.5, p = 0.01) and severe encephalopathy (OR 7.9, 95% CI 1.5-42.7, p = 0.02) were independent predictors of abnormal MRIs.

CONCLUSIONS

Among neonates with HIE managed with therapeutic hypothermia, high ES exposure was the most important predictor of abnormal developmental and neuroimaging outcomes, even after adjustment for multiple clinical and EEG variables. Adequate identification and management of ES with judicious use of anti-seizure medications may optimize outcomes.

Clopidogrel Versus Newer P2Y12 Antagonists for Percutaneous Coronary Intervention in Patients with Out-of-Hospital Cardiac Arrest Managed with Therapeutic Hypothermia: A Meta-Analysis

Introduction

The impact of therapeutic hypothermia (TH) on outcomes of percutaneous coronary intervention (PCI) and the optimal antiplatelet treatment remains debatable.

Methods

Electronic databases were searched for randomized trials and observational studies to evaluate the available clinical evidence comparing the use of clopidogrel versus newer P2Y12 antagonists in cases of TH after PCI. The primary outcome was in-hospital definite stent thrombosis while the secondary outcomes were in-hospital mortality and major bleeding. Fixed-effects risk ratios (RRs) were estimated using Mantel–Haenszel method.

Results

The final analysis included five studies with a total of 290 patients. There was no difference in the incidence of stent thrombosis (RR 0.92; 95% CI 0.35–2.38), in-hospital mortality (RR 1.38; 95% CI 0.72–2.65), and major bleeding (RR 0.89; 95% CI 0.33–2.40) between patients receiving clopidogrel versus those receiving newer agents.

Conclusions

This meta-analysis showed no difference between clopidogrel and newer antiplatelet agents in the incidence of stent thrombosis or in-hospital mortality for PCI in cases of TH. Further randomized studies are needed to explore the optimal dual antiplatelet treatment in TH.

Electronic supplementary material

The online version of this article (10.1007/s40119-018-0118-x) contains supplementary material, which is available to authorized users.

The neuron specific enolase (NSE) ratio offers benefits over absolute value thresholds in post-cardiac arrest coma prognosis

INTRODUCTION

Serum neuron-specific enolase (NSE) levels have been shown to correlate with neurologic outcome in comatose survivors of cardiac arrest but use of absolute NSE thresholds is limited. This study describes and evaluates a novel approach to analyzing NSE, the NSE ratio, and evaluates the prognostic utility of NSE absolute value thresholds and trends over time.

METHODS

100 consecutive adult comatose cardiac arrest survivors were prospectively enrolled. NSE levels were assessed at 24, 48, and 72 h post-arrest. Primary outcome was the Glasgow Outcome Score (GOS) at 6 months post-arrest; good outcome was defined as GOS 3-5. Absolute and relative NSE values (i.e. the NSE ratio), peak values, and the trend in NSE over 72 h were analyzed.

RESULTS

98 patients were included. 42 (43%) had a good outcome. Five good outcome patients had peak NSE >33 µg/L (34.9-46.4 µg/L). NSE trends between 24 and 48 h differed between outcome groups (decrease by 3.0 µg/L (0.9-7.0 µg/L) vs. increase by 13.4 µg/L (-3.7 to 69.4 µg/L), good vs. poor, p = 0.004). The 48:24 h NSE ratio differed between the good and poor outcome groups (0.8 (0.6-0.9) vs. 1.4 (0.8-2.5), p = 0.001), and a 48:24 h ratio of ≥1.7 was 100% specific for poor outcome.

CONCLUSIONS

The NSE ratio is a unique method to quantify NSE changes over time. Values greater than 1.0 indicate increasing NSE and may be reflective of ongoing neuronal injury. The NSE ratio obviates the need for an absolute value cut-off.