Nadya J. Kazzi

Effects of theophylline on plasma lipids in low-birth-weight infants ( 1250 g)

Theophylline is used extensively in the treatment of primary apnea of prematurity. Infants in need of such therapy may receive the drug for a period of several weeks. Previous reports have examined the acute responses of plasma glucose, glucagon and insulin to iv administration of theophylline (1-3). The effects of caffeine on plasma concentrations of free fatty acids have also been examined in preterm infants (4). Methylxanthines, including theophylline and caffeine, have been shown to stimulate lipolysis in vitro (9, in adult animals (6) and in human adults (7). We speculate that continued stimulation of lipolysis associated with prolonged administration of theophylline to low-birthweight infants may induce increases in plasma concentrations of triglycerides, cholesterol and low density lipoprotein cholesterol. In this report, we examine the effects of prolonged administration of theophylline for the treatment of apnea of prematurity on the plasma concentrations of lipids in very low-birth-weight infants.

Simultaneous estimation of neonatal total body water by antipyrine and H218O dilution

Total body water was estimated simultaneously by dilution of antipyrine (antipyrine space; APS) and H2(18)O (18O-space; 18OS) in 5 baboon neonates and 2 two-month-old lambs (total of 14 studies). Calculations of 18OS were made either from a single plasma delta 18O measured 4 h after injection of the marker (18OS4) or by extrapolation to time zero of several plasma delta 18O obtained at precisely timed interval (18OS0). Mean (+/- SD) 18OS4 was on the average 23% lower than mean 18OS0 (796 +/- 70 ml/kg vs. 650 +/- 67 ml/kg, p less than 0.001). Mean APS was not statistically different from mean 18OS0 (664 +/- 127 ml/kg vs. 658 +/- 57 ml/kg), but APS ranged from 41% lower to 30% higher than 18OS0. These data and information from the literature suggest that antipyrine is of doubtful reliability and should be abandoned as a marker for total body water.

1425 NEONATAL COMPLICATIONS FOLLOWING IN-UTERO EXPOSURE TO INTRAVENOUS RITODRINE

Intravenous administration of ritodrine has been shown to prolong pregnancy in selected patients. However, the drug has been associated with maternal cardiovascular and metabolic derangements. If tocolytic therapy fails and the neonate delivers soon after ritodrine is discontinued, significant drug levels could increase neonatal morbidity. The purpose of this study was to examine the following neonatal outcomes: Apgar score 1 min. and 5 min., neonatal pH, plasma bicarbonate, hypotension, hypoglycemia, respiratory distress syndrome & neonatal mortality in infants exposed to IV ritodrine within 12 hours of delivery. Fifty-eight neonates delivered within 12 hours of discontinuing intravenous maternal ritodrine were matched for birthweight and gestational age with 58 control infants without ritodrine exposure. The study infants had a mean GA of 32.8 ± 2.8 wks., & a mean BW of 1744 ± 512 gm. The potential effect of the total ritodrine dose used and the drug discontinuance to delivery intervals (DDDI) on the 8 neonatal outcomes were evaluated. The frequencies of maternal medical and obstetric complications were similar in both groups. PROM and prolonged rupture of membranes >12 hours were more common in the control group (p<0.001). Of the neonatal morbidity variables examined, only hypoglycemia occurred more frequently in the ritodrine exposed neonates as compared to control group. Stepwise discriminant analysis and stepwise multilinear regression failed to reveal an effect of total maternal ritodrine dose, and DDDI on the occurrence of the neonatal morbidity variables. The analysis showed that gestational age was a good predictor of RDS and neonatal death but that ritodrine dose and DDDI did not add significantly to the prediction of any neonatal complications. These findings suggest that ritodrine used per protocol is not associated with a significant increase in neonatal morbidity.