Closed-loop oxygen system in late preterm/term, ventilated infants with different severities of respiratory disease.

AIM: To evaluate closed-loop automated oxygen control (CLAC) in ventilated infants >33 weeks of gestation with different respiratory disease severities. METHODS: Infants were studied on two consecutive days for 6 h each day. They were randomised to receive standard care or standard care with CLAC (Oxygenie) first. Analyses were performed of the results of infants with or without an FiO2 ≥ 0.3 and infants with congenital diaphragmatic hernia (CDH). RESULTS: Thirty-one infants with a median (IQR) gestational age of 37.9 (37.1-38.9) weeks were studied at a median postmenstrual age (IQR) of 38.9 (37.4-39.8) weeks. In infants with an FiO2 ≥ 0.3 (n = 8), CLAC increased the time spent in target oxygen range (92-96%) by 61.6% (p = 0.018), whereas in infants with an FiO2 < 0.3, the time in target was increased by 3.8% (p = 0.019). During CLAC, only infants with an FiO2 ≥ 0.3 spent less time in hyperoxemia (SpO2 > 96%) (p = 0.012) and hyperoxemic episodes were shorter (p = 0.012). In both groups, CLAC reduced the duration of desaturations (SpO2 < 92%, p < 0.001). In CDH infants, CLAC increased the time spent in target oxygen range by 34% (p = 0.036) and the median duration of desaturations was reduced (p = 0.028). CONCLUSION: CLAC may be more useful in infants with more severe respiratory distress.

A case of cutaneous Paecilomyces formosus infection in an extremely premature infant.

BACKGROUND: Many types of weak pathogenic microorganisms often cause opportunistic infections in extremely preterm infants. Paecilomyces formosus is one such opportunistic fungus that can lead to a serious infection. Here, we report the clinical course of P. formosus infection in an extremely preterm infant. CASE PRESENTATION: An extremely preterm male infant was born at 23 weeks of gestation. Six days after birth, he developed yellowish-brown nodules on the skin of the back extending to the buttocks. P. formosus was identified by culture of samples from the cutaneous lesions. We treated the infection with intravenous micafungin and lanoconazole ointment application. The skin lesions improved dramatically and healed without scar tissue formation. CONCLUSION: Neonatologists should consider opportunistic P. formosus infections. This is the first report to describe that micafungin is effective for P. formosus cutaneous infection in extremely premature infants.

Improvement of point of care testing device for accurate whole blood glucose measurement in early neonates.

BACKGROUND: It is important that blood glucose concentrations be accurately and conveniently measured in infants. However, especially in the early neonatal period, point-of-care testing devices used for adults may not accurately measure blood glucose concentrations in neonates. METHODS: In Study 1, the accuracy of neonatal whole-blood glucose measurements was evaluated for the existing glucose analyser Glutest Mint® (hereinafter MINT1; Sanwa Kagaku Kenkyusho, Nagoya, Japan) by comparing the data with reference blood glucose concentrations. In Study 2, we used MINT2, which was modified based on the findings from Study 1, to measure whole-blood glucose concentrations in newborns, and the accuracy of the measurements was compared with that of MINT1. RESULTS: Blood glucose concentrations were measured in 100 infants each in Study 1 and 2. In Study 1, the whole-blood glucose concentrations measured using MINT1 were found to be significantly lower than the reference blood glucose concentrations in early neonates. The results of Study 1 suggested that characteristics of erythrocyte membranes in early neonates affected the measurements. Therefore, we conducted Study 2 using MINT2, which was modified to be less susceptible. MINT2 was found to accurately measure whole-blood glucose concentrations in the early neonatal period. CONCLUSION: The study showed that the point-of-care testing device could be improved to allow for accurate whole-blood glucose measurements in the early neonatal period.

Serum caffeine concentrations in preterm infants: a retrospective study.

Therapeutic drug monitoring is generally unnecessary in caffeine treatment for apnea of prematurity, as serum caffeine concentrations in preterm infants are normally markedly lower than those at which caffeine intoxication occurs. However, several studies have reported preterm infants having developed toxicity. This retrospective observational study, conducted at a tertiary center in Kagawa, Japan, aimed to evaluate the correlation between the maintenance dose and serum caffeine concentrations and determine the maintenance dose leading to suggested toxic caffeine levels. We included 24 preterm infants (gestational age, 27 ± 2.9 weeks; body weight, 991 ± 297 g) who were treated with caffeine citrate for apnea of prematurity between 2018 and 2021, and 272 samples were analyzed. Our primary outcome measure was the maintenance dose leading to suggested toxic caffeine levels. We found a positive correlation between caffeine dose and serum caffeine concentrations (p < 0.05, r = 0.72). At doses of ≥ 8 mg/kg/day, 15% (16/109) of patients had serum caffeine concentrations above the suggested toxic levels. Patients who receive doses ≥ 8 mg/kg/day risk reaching the suggested toxic serum caffeine levels. It remains unclear whether suggested toxic caffeine concentrations are detrimental to neurological prognosis. Further investigation is required to understand the clinical effects/outcomes of high serum levels of caffeine and to obtain long-term neurodevelopmental follow-up data.

Cerebral hemodynamics during neonatal transition according to mode of delivery.

Cerebral haemodynamics during the immediate transition period in neonates may differ depending on whether delivery is vaginal or by caesarean section. However, these differences have never been confirmed by near-infrared time-resolved spectroscopy (TRS). Therefore, the purpose of this study was to compare cerebral blood volume (CBV) and cerebral haemoglobin oxygen saturation (ScO2) between healthy term neonates by mode of delivery. Subjects were 31 healthy term neonates who did not require resuscitation. Thirteen neonates were delivered vaginally (VD group) and 18 were delivered by elective caesarean section (CS group). Absolute oxyhaemoglobin, deoxyhaemoglobin, and total haemoglobin concentrations were measured continuously by TRS; oxyHb × 100/totalHb (ScO2) (%) and CBV (mL/100 g brain tissue) were also calculated. Measurements were started as soon as possible after birth, obtained from 1 to 2 min after birth, and continued until 15 min after birth. CBV was significantly higher in the VD group than in the CS group in the 4 min after birth but not thereafter. There were no significant between-group differences in ScO2 and SpO2. These findings indicate that there is a difference in cerebral haemodynamic patterns in the first 4 min after delivery between term neonates by mode of delivery when CBV is monitored by TRS.

Intravenous Edaravone plus Therapeutic Hypothermia Offers Limited Neuroprotection in the Hypoxic-Ischaemic Newborn Piglet.

BACKGROUND: Therapeutic hypothermia (TH) is a standard therapy for neonatal hypoxic-ischaemic encephalopathy. One potential additional therapy is the free radical scavenger edaravone (EV; 3-methyl-1-phenyl-2-pyrazolin-5-one). OBJECTIVES AND METHODS: This study aimed to compare the neuroprotective effects of edaravone plus therapeutic hypothermia (TH + EV) with those of TH alone after a hypoxic-ischaemic insult in the newborn piglet. Anaesthetized piglets were subjected to 40 min of hypoxia (3-5% inspired oxygen), and cerebral ischaemia was assessed using cerebral blood volume. Body temperature was maintained at 39.0 ± 0.5°C in the normothermia group (NT, n = 8) and at 33.5 ± 0.5°C (24 h after the insult) in the TH (n = 7) and TH + EV (3 mg/kg intravenous every 12 h for 3 days after the insult; n = 6) groups under mechanical ventilation. RESULTS: Five days after the insult, the mean (standard deviation) neurological scores were 10.9 (5.7) in the NT group, 17.0 (0.4) in the TH group (p = 0.025 vs. NT), and 15.0 (3.9) in the TH + EV group. The histopathological score of the TH + EV group showed no significant improvement compared with that of the other groups. CONCLUSION: TH + EV had no additive neuroprotective effects after hypoxia-ischaemia in neurological and histopathological assessments.

Hydrogen ventilation combined with mild hypothermia improves short-term neurological outcomes in a 5-day neonatal hypoxia-ischaemia piglet model.

Despite its poor outcomes, therapeutic hypothermia (TH) is the current standard treatment for neonatal hypoxic-ischaemic encephalopathy (HIE). In this study, due to its antioxidant, anti-inflammatory, and antiapoptotic properties, the effectiveness of molecular hydrogen (H2) combined with TH was evaluated by means of neurological and histological assessments. Piglets were divided into three groups: hypoxic-ischaemic insult with normothermia (NT), insult with hypothermia (TH, 33.5 ± 0.5 °C), and insult with hypothermia with H2 ventilation (TH-H2, 2.1-2.7%). H2 ventilation and TH were administered for 24 h. After ventilator weaning, neurological assessment was performed every 6 h for 5 days. On day 5, the brains of the piglets were harvested for histopathological analysis. Regarding the neurological score, the piglets in the TH-H2 group consistently had the highest score from day 2 to 5 and showed a significantly higher neurological score from day 3 compared with the NT group. Most piglets in the TH-H2 group could walk at day 3 of recovery, whereas walking ability was delayed in the two other groups. The histological results revealed that TH-H2 tended to improve the status of cortical gray matter and subcortical white matter, with a considerable reduction in cell death. In this study, the combination of TH and H2 improved short-term neurological outcomes in neonatal hypoxic-ischaemic piglets.

Bilirubin photoisomers in rhesus monkey serum.

As rhesus monkeys exhibit physiological jaundice during the neonatal period, we used rhesus monkey serum to examine changes in bilirubin photoisomers. Bilirubin-rhesus monkey serum solution was irradiated with blue light-emitting diode, and changes in the absorbance and bilirubin fraction were compared with those in bilirubin- human serum albumin (HSA) and bilirubin-rat albumin solutions. The λmax decreased with light irradiation. The mean production rate of cyclobilirubin IXα was 1.98, 199 and 0.76 × 10-2/min in rhesus monkey serum, HSA and rat albumin, respectively. There was no significant difference between rhesus monkey serum and HSA. The (ZE)-bilirubin IXα/(ZZ)-bilirubin IXα ratio was 0.33, 0.45, and 0.10, respectively, differing significantly among the groups. The (EZ)-bilirubin IXα/(ZZ)-bilirubin IXα ratio was 0.020, 0.010, and 0.062, respectively, with no significant difference between rhesus monkey serum and HSA. The production rate of (EZ)-cyclobilirubin XIIIα(= (ZE)-cyclobilirubin XIIIα) was 0.73, 1.60, and 0.51 × 10-2/min, respectively, with differing significantly among the groups. The (EZ)-bilirubin IIIα/(ZZ)-bilirubin IIIα ratio was significantly different among the groups at 0.20, 0.38, and 0.15, respectively. This is the first report demonstrating the photoisomerization of bilirubin in rhesus monkey serum and the animal with the same cyclobilirubin production rate as HSA.Rhesus monkeys may be used as an animal model for neonatal hyperbilirubinemia in humans to evaluate the efficacy of phototherapy.