Can methadone concentrations predict the severity of withdrawal in infants at risk of neonatal abstinence syndrome?

AIM: To assess the usefulness of cord and serum methadone concentrations at 2 days of age in predicting the severity of neonatal abstinence syndrome (NAS) in infants whose mothers received methadone during pregnancy. METHODS: After informed consent, infants were enrolled if they were delivered at 35 weeks gestation or greater. Relevant information was collected from maternal notes. A sample of cord blood was taken at delivery, with a follow up sample at 48 hours of age. The samples were analysed in batches, and the results were unavailable to the attending clinical staff. Infants were treated for NAS on clinical grounds according to a standardised scoring system. RESULTS: Twenty five of 36 eligible infants over the 21 month period of the study were enrolled. Of these, 12 required treatment for NAS. Maternal methadone dose did not predict the need for treatment. However, infants who required treatment had significantly lower methadone concentrations in cord blood than the group who did not receive treatment (31 v 88 ng/ml respectively; p = 0.029). Paired blood samples for methadone concentrations were available for 17 infants. All but one of the 12 infants who required treatment had undetectable concentrations of methadone in the postnatal sample, whereas the median postnatal methadone concentration in untreated infants was 23 ng/ml (p = 0.002). CONCLUSIONS: Methadone concentrations taken from cord blood may identify infants at greater risk of neonatal withdrawal and therefore requiring treatment.

Chest physiotherapy and porencephalic brain lesions in very preterm infants.

OBJECTIVE: National Women's Hospital is one of two hospitals to report a destructive brain lesion, namely encephaloclastic porencephaly (ECPE), in extremely preterm infants. It has been associated with non-cephalic presentation, early hypotension and the number of chest physiotherapy treatments in the first month. The aim of the present study was to determine the temporal relationship between ECPE and chest physiotherapy use in very low-birth weight (VLBW) infants in our unit. METHODOLOGY: Cerebral ultrasound scan reports, post-mortem reports, clinical and physiotherapy records and, if indicated, original ultrasound films were reviewed for all VLBW babies admitted between 1985 and 1998. RESULTS: Over the 14 year period in question, 2219 babies with a birth weight < or = 1500 g were admitted. Encephaloclastic porencephaly was found in only the 13 previously reported babies born between 1992 and 1994. Encephaloclastic porencephaly was excluded in 1564 (70%) babies. In 621 (28%) babies who did not have late ultrasound scans, ECPE was thought to be unlikely either because the babies never had any chest physiotherapy (n=479) or because they had chest physiotherapy but were known to be neurodevelopmentally normal on follow up (n=142). Data were incomplete for 21 babies (0.9%). The number of chest physiotherapy treatments per baby decreased from a median of 95 prior to 1989 to 38 and the age of starting treatment increased from 5 to 8 days after 1990. The use of chest physiotherapy ceased in 1995. CONCLUSIONS: Encephaloclastic porencephaly emerged as a problem at a time when the use of chest physiotherapy had decreased. The cluster of cases seen between 1992 and 1994, although associated with the number of chest physiotherapy treatments given, began to appear because of some other factor.

Malrotation in newborns following antenatal diagnosis of intra-abdominal cyst.

Two newborn girls had malrotation, small bowel in a subdiaphragmatic location on the right and leftward displacement of the liver. On antenatal scans, each had been diagnosed as having a large intra-abdominal cyst, but this had disappeared in both by the time of delivery. Both infants were asymptomatic at birth. One baby had a wrinkled abdominal wall, which is typically a component of prune belly syndrome. Both babies underwent Ladd procedure for their malrotation. In one, plate-like calcification over the hepatic capsule was the only residue of the previous cyst. In the other, mesenchymal hamartoma of the liver was diagnosed from histology of a collapsed adherent cyst.