Neuroprotective body hypothermia among newborns with hypoxic ischemic encephalopathy: three-year experience in a tertiary university hospital. A retrospective observational study

Cardiovascular Performance in Neonates with Hypoxic-Ischemic Encephalopathy Under Therapeutic Hypothermia: Evaluation by Conventional and Advanced Echocardiographic Techniques

This study aimed to evaluate the hemodynamic and ventricular performance of neonates with hypoxic-ischemic encephalopathy (HIE) undergoing therapeutic hypothermia using conventional and advanced echocardiographic techniques. This observational, prospective study included 22 neonates with HIE matched with 22 healthy neonates. Echocardiographic studies were performed 24 h after achieving target temperature during hypothermia and 24 h after rewarming. Evaluated echocardiographic parameters included ejection fraction (EF), shortening fraction (SF), right ventricular fractional area change, biventricular Tei index, right ventricular s' wave velocity, tricuspid annular plane systolic excursion, biventricular stroke volume and cardiac output, left ventricular (LV) and right ventricular (RV) global longitudinal strain (GLS), LV circumferential and radial strain, LV twist, and LV torsion. LV EF and SF did not change significantly between the hypothermia and rewarming periods (EF:73 ± 7% vs. 74 ± 5%, p = 0.21; SF:39 ± 6% vs. 41 ± 5%, p = 0.26); however, both were higher after rewarming compared to the control group (EF:70 ± 5%, p = 0.003; SF:36 ± 4%, p = 0.002). There were no significant differences in LV GLS, circumferential and radial strain, twist, and torsion between the HIE and control groups. Pulmonary artery systolic pressure (PASP) and RV GLS were worse in the study group compared to the control group (PASP: hypothermia 45 ± 24 mmHg, p = 0.01; rewarming 53 ± 34 mmHg, p = 0.01; control group 29 ± 11 mmHg; RV GLS: hypothermia 18 ± 5%, p = 0.02; rewarming: 18 ± 4%, p = 0.01; control group 21 ± 2%). Therapeutic hypothermia appears to have no detrimental impact on LV systolic function. RV GLS was the only parameter that demonstrated impaired RV systolic function during therapeutic hypothermia, likely due to elevated PASP.

Incidence of encephalopathy and comorbidity in infants with perinatal asphyxia: a comparative prospective cohort study

Background

Programs that aim to improve the detection hypoxic-ischemic encephalopathy (HIE) should establish which neonates suffering from perinatal asphyxia need to be monitored within the first 6 h of life.

Method

An observational prospective cohort study of infants with gestational age ≥35 weeks, and above 1,800g, were included according to their arterial cord pH value (ApH): ≤7.00 vs. 7.01-7.10. Data was collected including obstetrical history, as well as neonatal comorbidities, including the presence of HIE, that happened within 6 h of life. A standardized neurological exam was performed at discharge.

Results

There were 9,537 births; 176 infants with ApH 7.01-7.10 and 117 infants with ApH ≤7.00. All 9 cases with moderate-to-severe HIE occurred among infants with ApH ≤7.00. The incidence of global and moderate-severe HIE was 3/1,000 and 1/1,000 births, respectively. Outcome at discharge (abnormal exam or death) showed an OR 12.03 (95% CI 1.53, 94.96) in infants with ApH ≤7.00 compared to ApH 7.01-7.10 cohort. Ventilation support was 5.1 times (95% CI 2.87, 9.03) more likely to be needed by those with cord ApH ≤7.00 compared to those with ApH 7.01-7.10, as well as hypoglycemia (37% vs. 25%; p = 0.026). In 55%, hypoglycemia occurred despite oral and/or intravenous glucose administration had been already initiated.

Conclusions

Cord pH 7.00 might be a safe pH cut-off point when developing protocols to monitor infants born with acidemia in order to identify infants with moderate or severe HIE early on. There is non-negligible comorbidity in the ApH ≤7.00 cohort, but also in the 7.01-7.10 cohort.

Ultrasound stimulation of the vagal nerve improves acute septic encephalopathy in mice

Septic encephalopathy (SE) is characterized by symptoms such as coma, delirium, and cognitive dysfunction, and effective therapeutic interventions for SE remain elusive. In this study, we aimed to investigate the potential alleviating effects of vagal nerve stimulation (VNS) on SE-associated signs. To evaluate our hypothesis, we utilized a mouse model of SE induced by intraperitoneal injection of lipopolysaccharide (0.3 mg per mouse) and administered noninvasive, high-frequency ultrasound VNS. To assess the efficacy of ultrasound VNS, we measured inflammation-related molecules, including the α7 nicotinic acetylcholine receptor (α7nAChR) expression in peritoneal macrophages and plasma interleukin 1β (IL-1β) levels. Consistent with our hypothesis, SE mice exhibited reduced α7nAChR expression in macrophages and elevated IL-1β levels in the blood. Remarkably, VNS in SE mice restored α7nAChR expression and IL-1β levels to those observed in control mice. Furthermore, we evaluated the effects of VNS on survival rate, body temperature, and locomotor activity. SE mice subjected to VNS demonstrated a modest, yet significant, improvement in survival rate, recovery from hypothermia, and increased locomotor activity. To investigate the impact on the brain, we examined the hippocampus of SE mice. In control mice, VNS increased the expression of c-fos, a marker of neuronal electrical excitability, in the hippocampus. In SE mice, VNS led to the restoration of aberrant firing patterns in hippocampal neurons. Additionally, proteomic analysis of hippocampal tissue in SE mice revealed abnormal increases in two proteins, tissue factor (TF) and acyl-CoA dehydrogenase family member 9 (ACAD9), which returned to control levels following VNS. Collectively, our findings support the value of exploring the beneficial effects of ultrasound VNS on SE.

Use of high-sensitivity cardiac troponin I levels for early diagnosis of myocardial injury after neonatal asphyxia

Objective

Low-cost diagnostic and prognostic biomarkers could help guide clinical management of neonates with myocardial injury after asphyxia. This study aimed to assess the utility of creatine kinase (CK)-MB, high-sensitivity cardiac troponin I (hs-cTnI), brain natriuretic peptide (BNP), and myoglobin in the early diagnosis of myocardial injury following neonatal asphyxia.

Methods

Eighteen neonates with asphyxia and myocardial injury, 22 neonates with asphyxia and no myocardial injury, and 19 neonates without asphyxia (controls) were enrolled consecutively at the Neonatology Department, First Hospital of Lanzhou University (August 2013 to December 2014). Serum CK-MB, hs-cTnI, BNP, and myoglobin levels were evaluated at 12 hours and 7 days after birth. Their diagnostic value for myocardial injury was assessed by receiver operating characteristic (ROC) curve analysis.

Results

Levels of all four markers were higher in neonates with asphyxia and myocardial injury than in neonates with asphyxia and no myocardial injury or controls 12 hours after birth. The marker hs-cTnI had the highest diagnostic value. Using a cutoff value of 0.087 µg/L for hs-cTnI, the sensitivity, specificity, and diagnostic accuracy for asphyxia-induced myocardial injury were 55.6%, 95.5%, and 77.5%, respectively.

Conclusions

Serum hs-cTnI levels can predict myocardial injury caused by neonatal asphyxia at an early stage.

Complications During Therapeutic Hypothermia After Perinatal Asphyxia: A Comparison with Trial Data

Complications of therapeutic hypothermia (HT) after perinatal asphyxia of a cohort of infants were compared with complications reported in the Cochrane review. The occurrence during moderate HT of bradycardia, arrhythmia, hypotension, use of inotropes, pulmonary hypertension requiring NO inhalation, air leak syndrome, elevated liver enzymes, necrotizing enterocolitis, sepsis, oliguria, thrombocytopenia, coagulopathy, and electrolyte disturbances was assessed in 168 infants with therapeutic HT following perinatal asphyxia and compared to the incidence of complications published previously in the Cochrane review. In our cohort, mortality and adverse neurodevelopmental outcome were 31% and 6%, respectively, and not different from previously published studies. Nine out of 12 complications occurred more often in our cohort, one complication (oliguria) less often compared to previous results. The incidence of bradycardia and subcutaneous fat necrosis was not significantly different from previous reports. Complications during therapeutic HT in our cohort of infants occurred more often than reported previously. A detailed evaluation of possible complications is relevant for optimal monitoring during therapeutic HT.

Relevance of urinary S100B protein levels as a short-term prognostic biomarker in asphyxiated infants treated with hypothermia

The initial diagnosis of neonatal hypoxic-ischemic encephalopathy is based on nervous system clinical manifestations. The use of biomarkers to monitor brain injury and evaluate neuroprotective effects allows early intervention and treatment. This study was designed to determine the short-term prognostic significance of urinary S100B calcium-binding protein (S100B) in asphyxiated newborns treated with hypothermia.An observational prospective study was conducted over a period of 5 years in 31 newborns with hypoxic-ischemic encephalopathy who received therapeutic hypothermia. The patients were divided into 2 groups: Group A (13 newborns with a normal neurological examination before discharge) and Group B (18 newborns who died during admission or had an abnormal neurologic examination before discharge). Urinary S100B was the main variable, serum S100B and neuron-specific enolase (NSE) were considered as secondary variables, and all of them were assessed on the first 3 days of life. The newborns were subsequently divided into groups with normal and abnormal electrophysiological and imaging findings.Mean urinary S100B levels were significantly higher in group B than group A on day 1 (10.58 ± 14.82 vs 4.65 ± 9.16 μg/L, P = .031) and day 2 (5.16 ± 7.63 vs 0.88 ± 2.53, P = .002). The optimal cutoff for urinary S100B on day 1 was >1.11 μg/L of (sensitivity, 100%; specificity 60%) for the prediction of neonatal death and < 0.66 μg/L (sensitivity 83% and specificity 70%) for the prediction of a normal neurological examination before discharge. It was not possible to calculate cutoffs with a similar accuracy for serum S100B or NSE. Urinary S100B on day 1 was higher in patients with abnormal magnetic resonance imaging findings (7.89 ± 8.09 vs 4.49 ± 9.14, P = .039) and abnormal positron emission tomography findings (8.60 ± 9.29 vs 4.30 ± 8.28, P = .038). There were no significant differences in S100B levels between patients with normal and abnormal electroencephalography results.Urinary S100B measured in the first days of life can predict neonatal death and short-term prognosis in asphyxiated newborns treated with hypothermia. The method is convenient, noninvasive, and has a higher sensitivity and specificity than measurement of serum S100B or NSE.