Plasmatic profiles of cytokines/chemokines, glial fibrillary acidic protein (GFAP) and MRI brain damage in neonates with hypoxic ischemic encephalopathy (HIE)

BACKGROUND

Perinatal hypoxia triggers the release of cytokines and chemokines by neurons, astrocytes and microglia. In response to hypoxia-ischemia resting/ramified microglia proliferate and undergo activation, producing proinflammatory molecules. The brain damage extension seems to be related to both the severity of hypoxia and the balance between pro and anti-inflammatory response and can be explored with neuroimaging.

AIMS

The aim of this preliminary study was to explore possible relationships between plasma levels of inflammatory cytokines/chemokines and the severe brain damage detectable by Magnetic Resonance Imaging (MRI), performed during the hospitalization.

METHODS

In 10 full terms neonates with hypoxic ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH), divided into cases and controls, according to MRI results, we measured and compared the plasma levels of CCL2/MCP-1, CXCL8, GFAP, IFN y, IL-10, IL-18, IL-6, CCL3, ENOLASE2, GM-CSF, IL-1b, IL-12p70, IL-33, TNFα, collected at four different time points during TH (24, 25-48, 49-72 h of life, and 7-10 days from birth). Five of enrolled babies had pathological brain MRI (cases) and 5 had a normal MRI examination (controls). Cytokines were measured by Magnetic Luminex Assay. MRI images were classified according to Barkovich's score.

RESULTS

Mean levels of all cytokines and molecules at time T1 were not significantly different in the two groups. Comparing samples paired by day of collection, the greatest differences between cases and controls were found at times T2 and T3, during TH. At T4, levels tended to get closer again (except for IL-6, IL10 and IL18). Infants with worse MRI showed higher plasmatic GFAP levels than those with normal MRI, while their IL-18 was lower. The mean levels of CCL3MIP1alpha, GMCSF, IL1BETA overlapped throughout the observation period in both groups.

CONCLUSION

In a small number of infants with worse brain MRI, we found higher levels of GFAP and of IL-10 at T4 and a trend toward low IL-18 levels than in infants with normal MRI, considered early biomarker of brain damage and a predictor of adverse outcome, respectively. The greatest, although not significant, difference between the levels of molecules was found in cases and controls at time points T2 and T3, during TH.

Epilepsy Incidence and Developmental Outcomes After Early Discontinuation of Antiseizure Medication in Neonatal Hypoxic-Ischemic Encephalopathy

BACKGROUND

Neonatal seizures caused by hypoxic-ischemic encephalopathy (HIE) have significant morbidity and mortality. There is variability in clinical practice regarding treatment duration with antiseizure medication (ASM) after resolution of provoked neonatal seizures. We examined epilepsy incidence and developmental outcomes in post-HIE neonates discharged or not on ASM.

METHODS

We conducted a retrospective chart review of all HIE-admitted neonates to the University of Iowa Hospitals & Clinics neonatal intensive care unit between January 2008 and February 2021 who presented with encephalopathy, underwent therapeutic hypothermia, and developed seizures. Neonates were divided into two groups depending on whether ASM was continued or discontinued on discharge. We evaluated the incidence of epilepsy and developmental outcomes on follow-up in these two cohorts up to 12 months.

RESULTS

Sixty-nine neonates met the study criteria. ASM was continued on discharge in 41 neonates (59%) and discontinued before discharge in 28 (41%). At the 12-month follow-up, nine neonates (13%) had a diagnosis of epilepsy, out of which seven neonates had ASM continued on discharge (odds ratio [OR]: 2.84; 95% confidence interval [CI]: 0.48, 29.9)]. There was no statistical difference between the development of postneonatal epilepsy between the two groups (P value 0.29). There was no significant difference in developmental outcome between the two groups after adjusting for covariates like magnetic resonance imaging (MRI) brain abnormality and number of seizure days (OR: 0.68; 95% CI: 0.21, 2.22; P = 0.52).

CONCLUSION

We found no significant risk of seizure recurrence by age 12 months in infants who had discontinued ASM before discharge compared with those who had continued ASM. There was no difference in developmental outcomes at the 12-month follow-up between groups after adjusting for brain MRI abnormality and the number of seizure days during admission. Our results support early discontinuation of ASM after resolution of acute provoked seizures in neonates with HIE.

Hypoxic-ischaemic encephalopathy code: A systematic review for resource-limited settings

It is estimated that 96% of infants with hypoxic-ischaemic encephalopathy (HIE) are born in resource-limited settings with no capacity to provide the standard of care that has been established for nearly 15 years in high-resource countries, which includes therapeutic hypothermia (TH), continuous electroencephalographic monitoring and magnetic resonance imaging (MRI) in addition to close vital signs and haemodynamic monitoring. This situation does not seem to be changing; however, even with these limitations, currently available knowledge can help improve the care of HIE patients in resource-limited settings. The purpose of this systematic review was to provide, under the term "HIE Code", evidence-based recommendations for feasible care practices to optimise the care of infants with HIE and potentially help reduce the risks associated with comorbidity and improve neurodevelopmental outcomes. The content of the HIE code was grouped under 9 headings: (1) prevention of HIE, (2) resuscitation, (3) first 6h post birth, (4) identification and grading of encephalopathy, (5) seizure management, (6) other therapeutic interventions, (7) multiple organ dysfunction, (8) diagnostic tests and (9) family care.

Asphyxia, Therapeutic Hypothermia, and Pulmonary Hypertension

Neonates with a perinatal hypoxic insult and subsequent neonatal encephalopathy are at risk of acute pulmonary hypertension (aPH) in the transitional period. The phenotypic contributors to aPH following perinatal asphyxia include a combination of hypoxic vasoconstriction of the pulmonary vascular bed, right heart dysfunction, and left heart dysfunction. Therapeutic hypothermia is the standard of care for neonates with moderate-to-severe hypoxic ischemic encephalopathy. This review summarizes the underlying risk factors, causes of aPH in neonates with perinatal asphyxia, discusses the unique phenotypical contributors to disease, and explores the impact of the initial insult and subsequent therapeutic hypothermia on aPH.

Transnasal cooling: New prospect of selective hypothermia in acute ischemic stroke

Rapid and selective therapeutic hypothermia is a promising neuroprotective method for acute ischemic stroke. A recent study developed a simple but efficient technique of transnasal cooling, in which air at ambient temperature was passed through standard nasal cannula to induce evaporative cooling of the brain. Selective brain temperature decrease was achieved within 25 minutes in piglets. It is a major step forward to initiate early brain cooling. However, it is still necessary to devise a more comprehensive strategy to enhance the benefits of selective brain cooling in the era of effective reperfusion.

Neurological and Visual Outcomes in Infants and Toddlers Following Therapeutic Hypothermia for Neonatal Hypoxic-Ischemic Encephalopathy

BACKGROUND

The majority of studies have investigated neurodevelopmental outcomes, whereas visual impairment is less explored in children with a history of neonatal (hypoxic-ischemic) encephalopathy. Our aim was to perform a detailed neurological and visual assessment and also to investigate the presence of cerebral visual impairment in infants and toddlers with neonatal encephalopathy.

METHODS

Thirty participants with a history of neonatal encephalopathy, who had been hospitalized for therapeutic hypothermia, underwent a detailed neurological examination at age five to 36 months. Age-matched, 30 healthy children were also enrolled as a control group. All children in the study and control groups received neurological and a comprehensive ophthalmologic examination, including visual field and visual acuity. Presence of cerebral visual impairment was also evaluated clinically.

RESULTS

Rates of cerebral palsy, severe motor impairment, cognitive impairment, epilepsy, and cerebral visual impairment were found to be 20%, 10%, 15.3%, 10%, and 20%, respectively. When compared with healthy controls, oculomotor functions, pupillary light response, refractive parameters, anterior/posterior segment examinations, ocular visual impairment rates, and last, visual acuities were found similar. However, we found a statistically significant increase in visual field defects in our study group.

CONCLUSIONS

It could be better to perform a comprehensive ophthalmologic examination including visual field, visual acuity, and oculomotor functions by a pediatric ophthalmologist to accurately diagnose neurovisual deficits in infants following therapeutic hypothermia. Early identification and rehabilitation of the visual deficits might improve the neurodevelopment in these children.

Motor, cognitive and behavioural outcomes after neonatal hypoxic-ischaemic encephalopathy

INTRODUCTION

The current neurodevelopmental status of patients with neonatal hypoxic-ischaemic encephalopathy (HIE) in Spain is unknown. Recent European studies highlight a shift of severe pathology towards mild motor disorders and emotional problems. The aim of this study was to analyse neurodevelopmental outcomes in a cohort of neonates with HIE at age 3 years.

PATIENTS AND METHOD

Multicentre observational study of neonates born at 35 or more weeks of gestation with moderate to severe HIE in 2011-2013 in 12 hospitals in a large Spanish region (91 217 m2), with the recruitment extended through 2017 in the coordinating hospital. We analysed the findings of neonatal neuroimaging and neurodevelopmental test scores at 3 years (Bayley-III, Peabody Picture Vocabulary Test and Child Behavior Checklist). The sample included 79 controls with no history of perinatal asphyxia.

RESULTS

Sixty-three patients were recruited, of whom 5 (7.9%) were excluded due to other pathology and 14 (24%) died. Of the 44 survivors, 42 (95.5%) were evaluated. Of these 42, 10 (24%) had adverse outcomes (visual or hearing impairment, epilepsy, cerebral palsy or developmental delay). Other detected problems were minor neurological signs in 6 of the 42 (14%) and a higher incidence of emotional problems compared to controls: introversion (10.5% vs. 1.3%), anxiety (34.2% vs. 11.7%) and depression (28.9% vs. 7.8%) (P < .05). The severity of the lesions on neuroimaging was significantly higher in patients with motor impairment (P = .004) or who died or had an adverse outcome (P = .027).

CONCLUSION

In addition to classical sequelae, the followup of patients with neonatal HIE should include the diagnosis and treatment of minor motor disorders and social and emotional problems.

Biochemical profiles and organ dysfunction in neonates with hypoxic-ischemic encephalopathy post-hoc analysis of the THIN trial

BACKGROUND

Therapeutic hypothermia for infants with moderate to severe hypoxic-ischemic encephalopathy is well established as standard of care in high-income countries. Trials from low- and middle-income countries have shown contradictory results, and variations in the level of intensive care provided may partly explain these differences. We wished to evaluate biochemical profiles and clinical markers of organ dysfunction in cooled and non-cooled infants with moderate/severe hypoxic-ischemic encephalopathy.

METHODS

This secondary analysis of the THIN (Therapeutic Hypothermia in India) study, a single center randomized controlled trial, included 50 infants with moderate to severe hypoxic-ischemic encephalopathy randomized to therapeutic hypothermia (n = 25) or standard care with normothermia (n = 25) between September 2013 and October 2015. Data were collected prospectively and compared by randomization groups. Main outcomes were metabolic acidosis, coagulopathies, renal function, and supportive treatments during the intervention.

RESULTS

Cooled infants had lower pH than non-cooled infants at 6-12 h (median (IQR) 7.28 (7.20-7.32) vs 7.36 (7.31-7.40), respectively, p = 0.003) and 12-24 h (median (IQR) 7.30 (7.24-7.35) vs 7.41 (7.37-7.43), respectively, p < 0.001). Thrombocytopenia (< 100 000) was, though not statistically significant, twice as common in cooled compared to non-cooled infants (4/25 (16%) and 2/25 (8%), respectively, p = 0.67). No significant difference was found in the use of vasopressors (14/25 (56%) and 17/25 (68%), p = 0.38), intravenous bicarbonate (5/25 (20%) and 3/25 (12%), p = 0.70) or treatment with fresh frozen plasma (10/25 (40%) and 8/25 (32%), p = 0.56)) in cooled and non-cooled infants, respectively. Urine output < 1 ml/kg/h was less common in cooled infants compared to non-cooled infants at 0-24 h (7/25 (28%) vs. 16/23 (70%) respectively, p = 0.004).

CONCLUSIONS

This post hoc analysis of the THIN study support that cooling of infants with hypoxic-ischemic encephalopathy in a level III neonatal intensive care unit in India was safe. Cooled infants had slightly lower pH, but better renal function during the first day compared to non-cooled infants. More research is needed to identify the necessary level of intensive care during cooling to guide further implementation of this neuroprotective treatment in low-resource settings.

TRIAL REGISTRATION

Data from this article was collected during the THIN-study (Therapeutic Hypothermia in India; ref. CTRI/2013/05/003693 Clinical Trials Registry - India).

Association of body temperature and mortality in critically ill patients: an observational study using two large databases

BACKGROUND

Body temperature (BT) is routinely measured and can be controlled in critical care settings. BT can impact patient outcome, but the relationship between BT and mortality has not been well-established.

METHODS

A retrospective cohort study was conducted based on the MIMIC-IV (N = 43,537) and eICU (N = 75,184) datasets. The primary outcome and exposure variables were hospital mortality and first 48-h median BT, respectively. Generalized additive models were used to model the associations between exposures and outcomes, while adjusting for patient age, sex, APS-III, SOFA, and Charlson comorbidity scores, temperature gap, as well as ventilation, vasopressor, steroids, and dialysis usage. We conducted subgroup analysis according to ICU setting, diagnoses, and demographics.

RESULTS

Optimal BT was 37 °C for the general ICU and subgroup populations. A 10% increase in the proportion of time that BT was within the 36-38 °C range was associated with reduced hospital mortality risk in both MIMIC-IV (OR 0.91; 95% CI 0.90-0.93) and eICU (OR 0.86; 95% CI 0.85-0.87). On the other hand, a 10% increase in the proportion of time when BT < 36 °C was associated with increased mortality risk in both MIMIC-IV (OR 1.08; 95% CI 1.06-1.10) and eICU (OR 1.18; 95% CI 1.16-1.19). Similarly, a 10% increase in the proportion of time when BT > 38 °C was associated with increased mortality risk in both MIMIC-IV (OR 1.09; 95% CI 1.07-1.12) and eICU (OR 1.09; 95% CI 1.08-1.11). All patient subgroups tested consistently showed an optimal temperature within the 36-38 °C range.

CONCLUSIONS

A BT of 37 °C is associated with the lowest mortality risk among ICU patients. Further studies to explore the causal relationship between the optimal BT and mortality should be conducted and may help with establishing guidelines for active BT management in critical care settings.

Prediction of the neurological outcomes post-cardiac arrest: A prospective validation of the CAST and rCAST

INTRODUCTION

The neurologic prognosis of out-of-hospital cardiac arrest (OHCA) patients in whom return of spontaneous circulation (ROSC) is achieved remains poor. The aim of this study was to externally and prospectively validate two scoring systems developed by us: the CAST score, a scoring system to predict the neurological prognosis of OHCA patients undergoing targeted temperature management (TTM), and a simplified version of the same score developed for improved ease of use in clinical settings, the revised CAST (rCAST) score.

METHODS

This study was a prospective, multicenter, observational study conducted using the SOS KANTO 2017 registry, an OHCA registry involving hospitals in the Kanto region (including Tokyo) of Japan. The primary outcome was favorable neurological outcome (defined as Cerebral Performance Category score of 1 or 2) at 30 days and the secondary outcomes were favorable neurological outcome at 90 days and survival at 30 and 90 days. The predictive accuracies of the original CAST (oCAST) and rCAST scores were evaluated by using area under the receiver operating characteristic curve (AUC).

RESULTS

Of 9909 OHCA patients, 565 showed ROSC and received TTM. Of these, we analyzed the data of 259 patients in this study. The areas under the receiver operating characteristic curve (AUCs) of the oCAST and rCAST scores for predicting a favorable neurological outcome at 30 days were 0.86 and 0.87, respectively, and those for predicting a favorable neurological outcome at 90 days were 0.87 and 0.88, respectively. The rCAST showed a higher predictive accuracy for the neurological outcome as compared with the NULL-PLEASE score. The patients with a favorable neurological outcome who had been classified into the high severity group based on the rCAST tended to have hypothermia at hospital arrival and to not show any signs of loss of gray-white matter differentiation on brain CT. Neurological function at 90 days was correlated with the rCAST (r = 0.63, p < 0.001).

CONCLUSIONS

rCAST showed high predictive accuracy for the neurological prognosis of OHCA patients managed by TTM, comparable to that of the oCAST score. The scores on the rCAST were strongly correlated with the neurological functions at 90 days, implying that the rCAST is a useful scale for assessing the severity of brain injury after cardiac arrest.

Perinatal Hypoxic-Ischemic Encephalopathy: Incidence Over Time Within a Modern US Birth Cohort

BACKGROUND

Recent studies suggest that the incidence of perinatal hypoxic-ischemic encephalopathy (HIE) may be increasing in developed countries. However, this observed increase may be due to increased ascertainment and increased treatment with therapeutic hypothermia rather than an increase in disease burden. In a US population-based cross-sectional study, we determined the incidence of perinatal HIE over time.

METHODS

The study population included all 289,793 live-born infants ≥35 weeks gestational age born at 15 Kaiser Permanente Northern California hospitals between 2012 and 2019. Perinatal HIE was defined as the presence of both neonatal acidosis (i.e., cord blood pH < 7 or base deficit ≥10, or base deficit ≥10 on first infant gas) and neonatal encephalopathy confirmed by medical record review. Hospital discharge diagnoses of HIE were determined by extracting International Classification of Disease diagnostic codes for HIE assigned upon hospital discharge.

RESULTS

The population incidence of perinatal HIE was 1.7 per 1000. Although the incidence of perinatal HIE did not change significantly, both hospital discharge diagnoses of HIE and treatment with therapeutic hypothermia increased significantly during the study period. The sensitivity and positive predictive value of a hospital discharge diagnosis of HIE for identifying perinatal HIE confirmed by chart review were 72% and 79%, respectively.

CONCLUSIONS

During the study years, the incidence of perinatal HIE remained stable despite increases in hospital discharge diagnoses of HIE and in the use of therapeutic hypothermia. Our findings underscore the importance of applying stringent diagnostic criteria when diagnosing this complex condition.

Characteristics of neonatal hypoxic-ischemic encephalopathy at high altitude and early results of therapeutic hypothermia

BACKGROUND

Altitude hypoxia and limited socioeconomic conditions may result in distinctive features of neonatal hypoxic-ischemic encephalopathy (HIE). Therapeutic hypothermia (TH) has not been used at altitude. We examined characteristics of HIE and early outcomes of TH in 3 centers at two high altitudes, 2 at 2,261 m and 1 at 3,650 m.

METHODS

The incidence of HIE at NICUs was noted. TH was conducted when personnel and devices were available in 2019~2020. Standard inclusion criteria were used, with the addition of admission age >6 hours and mild HIE. Demographic and clinical data included gestational age, gender, weight, Apgar score, ethnics, age on admission, age at TH and clinical degree of HIE. EEG was monitored for 96 hours during hypothermia and rewarming. MRI was performed before discharge.

RESULTS

There was significant difference in ethnics, HIE degree, age at TH across 3 centers. The overall NICU incidence of HIE was 4.0%. Among 566 HIE patients, 114 (20.1%) received TH. 63 (55.3%) patients had moderate/severe HIE. Age at TH >6 hours occurred in 34 (29.8%) patients. EEG discharges showed seizures in 7~11% of patients, whereas spikes/sharp waves in 94~100%, delta brushes in 50~100%. After TH, MRI showed moderate to severe brain injury in 77% of patients, and correlated with center, demographic and clinical variables (Ps≤0.0003). Mortality was 5% during hospitalization and 11% after discharge until 1 year.

CONCLUSIONS

At altitude, the incidence of HIE was high and brain injury was severe. TH was limited and often late >6 hours. EEG showed distinct patterns attributable to altitude hypoxia. TH was relatively safe.

TRIAL REGISTRATION

The study was registered on February 23, 2019 in Chinese Clinical Trial Register (ChiCTR1900021481).

Association between continuous glucose profile during therapeutic hypothermia and unfavorable outcome in neonates with hypoxic-ischemic encephalopathy209 23-32

BACKGROUND

The detection and management of blood glucose abnormalities in high-risk neonates are crucial for clinical care. The objective of the study was to investigate the continuous glucose profile of hypoxic-ischemic encephalopathy (HIE) patients in the whole-process of therapeutic hypothermia (TH) and its association with clinical and neurological outcomes.

METHOD

In this single-center retrospective study, HIE patients who received both TH and continuous glucose monitoring (CGM) were recruited from March 2016 to September 2021.

RESULTS

Of 47 neonates recruited, 24 had unfavorable outcome. Dysglycemia was most prevalent in the first 24 h of TH, among which hyperglycemia occurred more frequently. CGM showed that the duration, episodes and area under curve (AUC) of hypoglycemia were statistically different in neonates with different outcomes. The occurrence, longer duration, greater AUC of hypoglycemia and an early high coefficient of variation (CV%, CV = SD/mean) were associated with unfavorable outcomes (aOR 26.55 [2.02-348.5], aOR 2.11 [1.08-4.14], aOR 1.80 [1.11-2.91] and aOR respectively), while hyperglycemia was not.

CONCLUSION

During the whole process of TH, hypoglycemia and early unstable glycemic variability were strongly associated with unfavorable outcomes. CGM can instantly detect dysglycemia and facilitate precise glucose management in HIE neonates.

Long-term motor development after hypothermia-treated hypoxic-ischaemic encephalopathy

AIMS

To describe longitudinal motor development in children treated with therapeutic- hypothermia (TH) due to neonatal hypoxic-ischaemic encephalopathy (HIE) and to explore motor functioning in early adolescence.

MATERIAL AND METHODS

Children treated with TH due to HIE during 2007-2009, in Stockholm, participated in a prospective follow-up study. Motor development was assessed on four occasions, reported as percentiles and at mean ages. Alberta Infant Motor Scale was used at 0.35 years of age, Bayley Scales of Infant and Toddler Development-III at 2.1 years and Movement Assessment Battery for Children (MABC-2) at 7.3 and 11.1 years of age. MABC-2 Checklist was completed by parents at 7.3 and 11.1 years of age. General cognition was assessed using Wechsler Intelligence Scales for Children Fifth Edition (WISC-V).

RESULTS

Thirty-one percent (14/45) of the children had a motor score ≤ 15th percentile, indicating risk of motor difficulties at 11.1 years of age, and simultaneously the scores from parents of 52% (23/44), indicating risk of motor difficulties in the everyday context. These children had significantly lower motor percentile at 2.1 years of age, but within the normal range. Longitudinal motor development displayed a weak association with WISC-V Full Scale IQ (rs0.38, p = 0.013).

CONCLUSION

Among survivors of hypothermia-treated HIE free of moderate/severe cerebral palsy, a third had MABC-2 scores indicating risk of motor difficulties at 11.1 years of age. As motor difficulties became more apparent over time, we suggest that children treated with TH due to neonatal HIE should be followed into at least middle school age.

Therapeutic Hypothermia Is Limited in Preventing Developmental Impairments after Neonatal Hypoxia-Ischemia

The only current treatment for neonatal hypoxia-ischemia (HI) is therapeutic hypothermia (TH), which still shows some limitations. Specific effects of TH in the several processes involved in brain injury progression remain unclear. In this study, the effects of TH treatment on developmental parameters, behavioral outcomes, and peripheral leukocytes were evaluated in neonatal male and female rats. In P7, animals were submitted to right common carotid artery occlusion followed by hypoxia (8% oxygen). TH was performed by reducing the animal scalp temperature to 32°C for 5 h. Behavioral parameters and developmental landmarks were evaluated. Animals were euthanized at P9 or P21, and cerebral hemispheres, spleen, and thymus were weighed. White blood cells (WBCs) were counted in blood smears. There was a reduction in the weight of the brain hemisphere ipsilateral to the carotid occlusion in HI and TH groups, as well as a reduction in body weight gain and a delay in the opening of the ipsilateral eye. Latency in negative geotaxis was increased by HI at P12. TH did not prevent brain weight loss, developmental impairments, or WBC number changes but prevented negative geotaxis impairment and spleen weight reduction. These data reinforce that a better understanding of the events that occur after HI and TH in both males and females is necessary and would allow the development of more adequate and sex-specific therapeutic approaches.

Safety and efficacy of therapeutic hypothermia in neonates with mild hypoxic-ischemic encephalopathy

BACKGROUND

Though there has been an increase in the number of neonates with hypoxic-ischemic encephalopathy (HIE) treated by therapeutic hypothermia (TH) in recent years, the effect of therapeutic hypothermia on mild HIE neonates is still uncertain.

OBJECTIVES

This study aims to explore the safety and efficacy of therapeutic hypothermia in neonates with mild HIE.

METHODS

Retrospectively collected between January 2010 to December 2022 at Children's Hospital of Fudan University, neonates with mild HIE were divided into TH and non-TH groups. Clinical data of the mild HIE neonates and their mothers' general information during pregnancy were collected. SPSS 23.0 was used to compare the general condition, the incidence of adverse events, and efficacy in the two groups.

RESULTS

A total of 71 neonates with mild HIE were included, including 31 in the TH group and 40 in the non-TH group. Compared with the non-TH group, the TH group had significantly lower 5-minute Apgar scores [6 (5-7) points vs. 7 (5-8) points, p = 0.033 ], but a higher rate of tracheal intubation at birth (68%, 21/31 vs. 40%, 16/40, p = 0.02), a higher rate of chest compressions > 30 s (39%, 12/31 vs. 15%, 6/40, p = 0.023), the later initiation enteral feeding [4 (3-4) days vs. 1 (1-2) days, p < 0.001], a higher usage rate of analgesic and sedative drugs (45%, 14/31 vs. 18%, 7/40, p = 0.011) and the longer hospital stay [12.5 (11-14) days vs. 9 (7-13.9) days, p = 0.003]. There was no death in 71 mild HIE neonates. TH group had lower incidence of brain injury (16%, 5/31 vs. 43%, 17/40, p = 0.017) and encephalopathy progression (10%, 3/31 vs. 45%, 18/40, p = 0.001) than the non-TH group. There was no statistical significance in the incidence of adverse events between the two groups.

CONCLUSION

Therapeutic hypothermia can reduce the incidence of brain injury in neonates with mild HIE.

Magnesium Sulfate as an Adjunct to Therapeutic Hypothermia in the Management of Term Infants with Hypoxic-Ischemic Encephalopathy: A Randomized, Parallel-Group, Controlled Trial

OBJECTIVE

To evaluate whether magnesium sulfate and therapeutic hypothermia in combination decreases mortality and/or major neurodevelopmental disability at 1 y of age among term neonates with hypoxic-ischemic encephalopathy.

METHODS

A total of 134 term neonates were randomized to receive intravenous magnesium sulfate at a dose of 250 mg/kg (at 8 mg/kg/min) once daily for 3 d starting within 6 h after birth along with therapeutic hypothermia in the intervention group and therapeutic hypothermia alone in the comparator group. The primary outcome was the composite outcome of mortality and/or major neurodevelopmental disability (Developmental Assessment Scale for Indian Infants score < 70) at 1 y of age.

RESULTS

A total of 115 infants were included in the primary analysis. The composite primary outcome occurred in 14 (24%) infants in the intervention group and 19 (33%) infants in the comparator group, and the difference was not statistically significant (p = 0.30; relative risk 0.72; 95% confidence interval 0.40-1.30). The secondary outcomes including neonatal mortality, major neurodevelopmental disability at 1 y of age, neurological status at discharge, level of oxidative stress markers, and adverse effects including hypotension and respiratory depression requiring support were also comparable between the groups.

CONCLUSIONS

The combination of magnesium sulfate and therapeutic hypothermia did not improve the composite outcome of neonatal mortality and/or major neurodevelopmental disability at 1 y of age.

TRAIL REGISTRATION

Clinical Trials Registry of India (CTRI/2018/06/014594), prospectively registered.

Prognostic value of neutrophil-lymphocyte ratio in out-of-hospital cardiac arrest patients receiving targeted temperature management: An observational cohort study

BACKGROUND

Out-hospital cardiac arrest (OHCA) is a major cause of mortality and morbidity worldwide. The magnitude of the post-resuscitation inflammatory response is closely related to the severity of the circulatory dysfunction. Currently, targeted temperature management (TTM) has become an essential part of the post-resuscitation care for unconscious OHCA survivors. Some novel prognostic inflammatory markers may help predict outcomes of OHCA patients after TTM.

METHODS

A retrospective observational cohort study of 65 OHCA patients treated with TTM was conducted in a tertiary hospital in Taiwan. The primary outcome measure was in-hospital mortality. Baseline and post-TTM neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte (PLR), and the systemic immune inflammation index (SII) were identified as potential predictors.

RESULTS

These patients had a mean age of 62.2 ± 17.0 years. Among the total sample, 53.8% had an initial shockable rhythm and 61.5% had a presumed cardiac etiology. The median resuscitation duration was 20 min (IQR 13.5-28.5) and 60% received subsequent percutaneous coronary intervention. The mean baseline NLR, PLR and SII were 7.5 ± 16.7, 118 ± 207, 1395 ± 3004, and the mean post-TTM NLR, PLR and SII were 15.0 ± 11.6, 206 ± 124, 2369 ± 2569, respectively. Using multiple logistic regression analysis, post-TTM NLR was one of the independent factors which predicted in-hospital mortality (adjusted odds ratio (aOR): 1.249, 95% confidence interval (CI): 1.040-1.501, p = 0.017).

CONCLUSION

Post-TTM NLR is a predictor of in-hospital mortality in OHCA patients who underwent TTM.

Renal oximetry for early acute kidney injury detection in neonates with hypoxic ischemic encephalopathy receiving therapeutic hypothermia

BACKGROUND

Neonates with hypoxic ischemic encephalopathy (HIE) receiving therapeutic hypothermia are at high risk of acute kidney injury (AKI).

METHODS

We performed a two-site prospective observational study from 2018 to 2019 to evaluate the utility of renal near-infrared spectroscopy (NIRS) in detecting AKI in 38 neonates with HIE receiving therapeutic hypothermia. AKI was defined by a delayed rate of serum creatinine decline (< 33% on day 3 of life, < 40% on day 5, and < 46% on day 7). Renal saturation (Rsat) and systemic oxygen saturation (SpO2) were continuously measured for the first 96 h of life (HOL). Renal fractional tissue oxygen extraction (RFTOE) was calculated as (SpO2 - Rsat)/(SpO2). Using renal NIRS, urine biomarkers, and perinatal factors, logistic regression was performed to develop a model that predicted AKI.

RESULTS

AKI occurred in 20 of 38 neonates (53%). During the first 96 HOL, Rsat was higher, and RFTOE was lower in the AKI group vs. the no AKI group (P < 0.001). Rsat > 70% had a fair predictive performance for AKI at 48-84 HOL (AUC 0.71-0.79). RFTOE ≤ 25 had a good predictive performance for AKI at 42-66 HOL (AUC 0.8-0.83). The final statistical model with the best fit to predict AKI (AUC = 0.88) included RFTOE at 48 HOL (P = 0.012) and pH of the infants' first postnatal blood gas (P = 0.025).

CONCLUSIONS

Lower RFTOE on renal NIRS and pH on infant first blood gas may be early predictors for AKI in neonates with HIE receiving therapeutic hypothermia. A higher resolution version of the Graphical abstract is available as Supplementary information.

Association of cerebral metabolic rate following therapeutic hypothermia with 18-month neurodevelopmental outcomes after neonatal hypoxic ischemic encephalopathy

BACKGROUND

Therapeutic hypothermia (TH) is standard of care for moderate to severe neonatal hypoxic ischemic encephalopathy (HIE) but many survivors still suffer lifelong disabilities and benefits of TH for mild HIE are under active debate. Development of objective diagnostics, with sensitivity to mild HIE, are needed to select, guide, and assess response to treatment. The objective of this study was to determine if cerebral oxygen metabolism (CMRO2) in the days after TH is associated with 18-month neurodevelopmental outcomes as the first step in evaluating CMRO2's potential as a diagnostic for HIE. Secondary objectives were to compare associations with clinical exams and characterise the relationship between CMRO2 and temperature during TH.

METHODS

This was a prospective, multicentre, observational, cohort study of neonates clinically diagnosed with HIE and treated with TH recruited from the tertiary neonatal intensive care units (NICUs) of Boston Children's Hospital, Brigham and Women's Hospital, and Beth Israel Deaconess Medical Center between December 2015 and October 2019 with follow-up to 18 months. In total, 329 neonates ≥34 weeks gestational age admitted with perinatal asphyxia and suspected HIE were identified. 179 were approached, 103 enrolled, 73 received TH, and 64 were included. CMRO2 was measured at the NICU bedside by frequency-domain near-infrared and diffuse correlation spectroscopies (FDNIRS-DCS) during the late phases of hypothermia (C), rewarming (RW) and after return to normothermia (NT). Additional variables were body temperature and clinical neonatal encephalopathy (NE) scores, as well as findings from magnetic resonance imaging (MRI) and spectroscopy (MRS). Primary outcome was the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) at 18 months, normed (SD) to 100 (15).

FINDINGS

Data quality for 58 neonates was sufficient for analysis. CMRO2 changed by 14.4% per °C (95% CI, 14.2-14.6) relative to its baseline at NT while cerebral tissue oxygen extraction fraction (cFTOE) changed by only 2.2% per °C (95% CI, 2.1-2.4) for net changes from C to NT of 91% and 8%, respectively. Follow-up data for 2 were incomplete, 33 declined and 1 died, leaving 22 participants (mean [SD] postnatal age, 19.1 [1.2] month; 11 female) with mild to moderate HIE (median [IQR] NE score, 4 [3-6]) and 21 (95%) with BSID-III scores >85 at 18 months. CMRO2 at NT was positively associated with cognitive and motor composite scores (β (SE) = 4.49 (1.55) and 2.77 (1.00) BSID-III points per 10-10 moL/dl × mm2/s, P = 0.009 and P = 0.01 respectively; linear regression); none of the other measures were associated with the neurodevelopmental outcomes.

INTERPRETATION

Point of care measures of CMRO2 in the NICU during C and RW showed dramatic changes and potential to assess individual response to TH. CMRO2 following TH outperformed conventional clinical evaluations (NE score, cFTOE, and MRI/MRS) at predicting cognitive and motor outcomes at 18 months for mild to moderate HIE, providing a promising objective, physiologically-based diagnostic for HIE.

FUNDING

This clinical study was funded by an NIH grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, United States (R01HD076258).

Melatonin Alters Innate Immune Function in Infants with Neonatal Encephalopathy

INTRODUCTION

Melatonin has been suggested an adjunctive therapy in neonatal encephalopathy (NE). Melatonin reduces oxidative stress and neutrophil activation; however, the immunological effects in NE have not been studied.

METHODS

Infants with NE and neonatal controls were prospectively recruited. Whole blood was sampled in the first week of life. Following endotoxin and or melatonin treatment, diurnal variation was measured by RT PCR for circadian rhythm genes (brain and Muscle Arnt-Like protein [BMAL1], circadian locomotor output cycles kaput [CLOCK], Nuclear Receptor Subfamily 1 Group D Member 2 [REV Erβ], and cryptochrome circadian clock [CRY]). Neutrophil and monocyte cell surface markers of activation CD11b, reactive oxygen intermediates (ROIs), and Toll-like receptor (TLR)-4 were also examined by flow cytometry in matching samples.

RESULTS

Serum and RNA samples from forty infants were included (controls n = 20; NE n = 20) over the first week of life. Melatonin reduced neutrophil CD11b and TLR-4 expression in response to LPS in infants with NE compared to controls. There were no differences in ROIs. BMAL1 and CLOCK baseline gene expression levels were similar. BMAL1 was significantly decreased with LPS stimulation in NE. There was no significant diurnal variation in melatonin, neutrophil, and monocyte function or circadian genes.

CONCLUSIONS

Melatonin alters immune function ex vivo in infants with NE. Infants with NE have altered immune circadian responses following LPS stimulation, which have potential for modulation.

Target temperature in post-arrest comatous patients. Is something changed in the postpandemic era?

INTRODUCTION

The recommended target temperature in the treatment of comatous patients after cardiac arrest has recently changed. We analyzed the impact on the neurological outcome of a change in the target temperature from July 2021.

MATERIAL AND METHODS

This was a retrospective analysis comparing the discharge status of 78 patients with a target temperature of 33 °C (group 1) with that of 24 patients with a target temperature of 36.5 °C (group 2). Pearson chi-square and Mann-Whitney U tests were used.

RESULTS

The initial rhythm was defibrillable in 65% of group 1 and 71% of group 2, and cardiac arrest was witnessed in 93% of group 1 and 96% of group 2. There was an adverse outcome (death or vegetative state) in 37 patients in group 1 (47%) compared to 18 in group 2 (74%) (Pearson chi-square 5.612, p = 0.018).

CONCLUSIONS

In our series of patients, the temperature control target temperature change from 33 °C to 36.5 °C was associated with worse neurological outcome. Further studies are needed to evaluate the outcome of a generalized modification of temperature control targets in comatose patients after cardiac arrest in our postpandemic era.

Design and rationale of the CHILL phase II trial of hypothermia and neuromuscular blockade for acute respiratory distress syndrome

The Cooling to Help Injured Lungs (CHILL) trial is an open label, two group, parallel design multicenter, randomized phase IIB clinical trial assessing the efficacy and safety of targeted temperature management with combined external cooling and neuromuscular blockade to block shivering in patients with early moderate-severe acute respiratory distress syndrome (ARDS). This report provides the background and rationale for the clinical trial and outlines the methods using the Consolidated Standards of Reporting Trials guidelines. Key design challenges include: [1] protocolizing important co-interventions; [2] incorporation of patients with COVID-19 as the cause of ARDS; [3] inability to blind the investigators; and [4] ability to obtain timely informed consent from patients or legally authorized representatives early in the disease process. Results of the Reevaluation of Systemic Early Neuromuscular Blockade (ROSE) trial informed the decision to mandate sedation and neuromuscular blockade only in the group assigned to therapeutic hypothermia and proceed without this mandate in the control group assigned to a usual temperature management protocol. Previous trials conducted in National Heart, Lung, and Blood Institute ARDS Clinical Trials (ARDSNet) and Prevention and Early Treatment of Acute Lung Injury (PETAL) Networks informed ventilator management, ventilation liberation and fluid management protocols. Since ARDS due to COVID-19 is a common cause of ARDS during pandemic surges and shares many features with ARDS from other causes, patients with ARDS due to COVID-19 are included. Finally, a stepwise approach to obtaining informed consent prior to documenting critical hypoxemia was adopted to facilitate enrollment and reduce the number of candidates excluded because eligibility time window expiration.