The effect of on-site extracorporeal membrane oxygenation on the therapy choice and outcomes of neonates with persistent pulmonary hypertension.

The effect of on-site extracorporeal membrane oxygenation (OS-ECMO) and selection criteria on the utilization rate of this technology is unknown. We retrospectively studied 55 neonates who were admitted to Arkansas Children's Hospital from 1985 to 1993. We compared the ECMO utilization, mortality, and morbidity rates for outborn neonates with moderate and severe persistent pulmonary hypertension (PPHN) before and after the establishment of an ECMO program with guidelines for its use at our institution. The rate of ECMO use was three times higher and the mortality rate was 13 times lower in the period after OS-ECMO compared with the period when ECMO was available only at other institutions. No differences were observed in the morbidity rates between the two periods. Physician decisions to initiate ECMO involved more than guidelines, since 37% of the increased ECMO use was not associated with use of the guidelines. Possible reasons for noncompliance with the guidelines are discussed. Neonates who had received medical therapy only and who had an oxygenation index > or = 30 and < 40 had no mortality. Our findings suggest that the need for ECMO in this group of neonates is low.

A differential effect of thyroxine and glucocorticoids on fetal brain and heart insulin receptor.

We investigated the effect of thyroxine (T4), glucocorticoids, and T4 + glucocorticoids on the maturation of fetal rabbit brain and heart insulin receptors. Five doses of T4 over 10 days (50 micrograms/kg body weight per dose) were administered to the mother; significant amounts crossed the placenta (fetal serum free T4 = 0.75 +/- 0.08 versus a control of 0.21 +/- 0.02 ng/dl, p less than 0.02) and increased the specific binding of [125I]insulin to 30-day-old fetal heart membranes from a control of 3.6 +/- 0.74% per 100 micrograms protein to 5.8 +/- 0.19% (p less than 0.05). Curvilinear Scatchard plots revealed an increase in receptor number X 10(7) micrograms protein-1 from 137 +/- 4 to 244 +/- 39 (p less than 0.05) with no change in receptor affinity. No appreciable alteration by T4 in the [125I]insulin-specific binding and receptor number of 30-day fetal brains was noted. Fetal heart glycogen content was decreased and there was a small increase in plasma glucose concentration in the T4-treated group (each p less than 0.02). Betamethasone at 0.17 mg/kg did not affect the specific binding of [125I]insulin to 27-day fetal heart or brain plasma membranes, although a decrease in heart glycogen content and an increase in plasma glucose concentration were observed (each p less than 0.02). Also T4 + betamethasone did not alter the [125I]insulin binding to 27-day fetal heart or brain plasma membranes, but resulted in an additive effect (a marked depletion) on cardiac glycogen (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)