MR Spectroscopy Shows Long Propylene Glycol Half-Life in Neonatal Brain.

INTRODUCTION: Neonatal propylene glycol (PG) clearance is low with long plasma half-life. We hypothesized that neonatal brain PG clearance is diminished and may be related to perinatal asphyxia, infection, or stroke, via different blood-brain barrier permeability. This study aimed to estimate cerebral PG half-life with a clearance model including PG measured with MR spectroscopy (MRS) in neonates that received phenobarbital as the only PG source and to evaluate whether PG clearance was related to intracerebral pathology, for example, perinatal asphyxia, infection, or stroke. METHODS: In this retrospective cohort study, 45 neonates receiving any dose of phenobarbital underwent MRS (short echo time single-voxel MRS at 1.5 T). Cumulative phenobarbital/PG doses were calculated. MRS indications were perinatal asphyxia (n = 22), infection (n = 4), stroke (n = 10), metabolic disease (n = 4), and others (n = 5). RESULTS: Medians (interquartile range) included gestational age 39.4 (3.1) weeks, birth weight 3,146 (1,340) g, and cumulative PG dose 700 (1,120) mg/kg. First-order kinetics with mono-exponential decay showed cerebral PG half-life of 40.7 h and volume of distribution of 1.6 L/kg. Zero-order kinetics showed a rate constant of 0.048 mM/h and a volume of distribution of 2.3 L/kg, but the fit had larger residuals than the first-order model. There were no differences in ΔPG (i.e., PG estimated with clearance model minus PG observed with MRS) in infants with perinatal asphyxia, infection, or stroke. DISCUSSION/CONCLUSION: This study showed a long cerebral PG half-life of 40.7 h in neonates, unrelated to perinatal asphyxia, infection, or stroke. These findings should increase awareness of possible toxic PG concentrations in neonatal brain due to intravenous PG-containing drugs.

Supplementation of vitamins, trace elements and electrolytes in the PEPaNIC Randomised Controlled Trial: Composition and preparation of the prescription.

BACKGROUND AND AIMS: Following the results of the paediatric early versus late parenteral nutrition in critical illness (PEPaNIC) multicentre, randomised, controlled trial, the new ESPGHAN/ESPEN/ESPR/CSPEN and ESPNIC guidelines recommend to consider withholding parenteral macronutrients for 1 week, while providing micronutrients, in critically ill children if enteral nutrition is insufficient. Critically ill children are suspected to be vulnerable to micronutrient deficiencies due to inadequate enteral nutrition, increased body's demands and excessive losses. Hitherto, micronutrient requirements in PICU are estimated based on recommended daily intakes for healthy children and expert opinion. We aimed to provide an overview of the current practice of micronutrient administration and practical considerations in the three participating centres of the PEPaNIC study, and compare these therapies with the recommendations in the new ESPGHAN/ESPEN/ESPR/CSPEN guidelines. METHODS: We describe the current composition and preparation of the prescribed parenteral micronutrients (consisting of vitamins, trace elements and electrolytes) in the three centres (Leuven, Rotterdam and Edmonton) that participated in the PEPaNIC RCT, and compare this per micronutrient with the ESPGHAN/ESPEN/ESPR/CSPEN guidelines recommendations. RESULTS: The three centres use a different micronutrient supplementation protocol during the first week of critical illness in children, with substantial differences regarding the amounts administered. Leuven administers commercial vitamins, trace elements and electrolytes in separate infusions both in 4 h. Rotterdam provides commercial vitamins and trace elements simultaneously via 8-h infusion and electrolytes continuously over 24 h. Lastly, Edmonton administers commercial vitamins and institutionally prepared trace elements solutions in 1 h and electrolytes on demand. Comparison with the ESPGHAN/ESPEN/ESPR/CSPEN guidelines yields in differences between the recommendations and the administered amounts, which are most substantial for vitamins. CONCLUSION: The practice of intravenous micronutrient administration differs substantially between the three PEPaNIC centres and in comparison with the current guideline recommendations. This deviation is at least partially explained by the inability to provide all recommended amounts with the currently available commercial products and by the lack of strong evidence supporting these recommendations.

An Accidental Repetitive 10-Fold Overdose of Sildenafil in a Young Infant with Pulmonary Hypertension.

Sildenafil is a selective phosphodiesterase type-5 inhibitor that is increasingly used to treat pulmonary hypertension (PH) in neonates. Only little is known about the relation between the dose of sildenafil, plasma concentrations, and the degree of toxicity. Here, we present a young infant with congenital diaphragmatic hernia and PH who received an unintentional 10-fold overdose of oral sildenafil for 6 consecutive days. This overdose, compared to the therapeutic dose, resulted in increased plasma concentrations of sildenafil from 42 to 521 mcg/L and desmethylsildenafil from 81 to 393 mcg/L. However, the high exposure only led to diarrhea, without any other serious adverse events. This case describes the mild symptoms upon an overdose with the role of therapeutic drug monitoring to monitor exposure in relation to symptoms and therewith support clinical decision-making.

Spectroscopic detection of brain propylene glycol in neonates: Effects of different pharmaceutical formulations of phenobarbital.

BACKGROUND: The first choice for treatment of neonatal convulsions is intravenous phenobarbital, which contains propylene glycol (PG) as a solvent. Although PG is generally considered safe, the dosage can exceed safety thresholds in neonates. High PG levels can cause lactic acidosis. PURPOSE/HYPOTHESIS: To investigate a relationship between brain PG concentration and medication administered to neonates, and to study if a correlation between spectroscopically detected PG and lactate was present. STUDY TYPE: Retrospective. POPULATION: Forty-one neonates who underwent MRI/MRS. FIELD STRENGTH/SEQUENCE: Short echo time single voxel MRS at 1.5T. ASSESSMENT: Spectra were quantified. Concentrations of PG were correlated with medication administered, because intravenously administered phenobarbital solutions contained 10, 25, or 50 mg phenobarbital per ml, all containing 350 mg PG per ml. The interval between medication and MRI/MRS was determined. STATISTICAL TESTS: Chi-square test, Student's t-test, Mann-Whitney U-test and Spearman correlation. RESULTS: Eighteen neonates had brain PG >1 mM (median 3.4 mM, maximum 9.5 mM). All 18 neonates with high brain PG and 14 neonates with low brain PG (<1 mM) received phenobarbital as the only source of PG. Nine neonates did not receive any phenobarbital/PG-containing medication. Neonates with high brain PG more often received 10 mg/ml phenobarbital, resulting in higher PG dose (high vs. low brain PG (median [interquartile range]: 1400 [595] vs. 350 [595] mg/kg, respectively, P < 0.01). In addition, the interval between the last phenobarbital dose and MRI was shorter in the high brain PG group (high vs. low brain PG: 16 [21] vs. 95 [83] hours, respectively, P < 0.001). Within neonates that received phenobarbital, there was no conclusive correlation between spectroscopically detected PG and lactate (Spearman's rho = 0.23, P = 0.10). DATA CONCLUSION: These MRS findings may increase awareness of potentially toxic PG concentrations in the neonatal brain due to intravenous phenobarbital administration and its dependence on the phenobarbital formulation used. LEVEL OF EVIDENCE: 4 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;49:1062-1068.