Carol Hartenberger

Comparison of Skin Sites for Estimating Serum Total Bilirubin in In-Patients and Out-Patients: Chest Is Superior to Brow

OBEJECTIVE: To compare transcutaneous bilirubin readings from the chest and forehead of inpatient and outpatient infants to investigate whether one site is more accurate for estimating serum bilirubin concentration.METHODS: In all, 31 infants were followed with serum and transcutaneous bilirubins using BiliChek™ at two skin sites.RESULTS: For inpatients average chest bilirubin was 0.4 mg/dl (7 μmol/l) higher than serum while brow was 0.3 mg/dl (5μmol/l) lower. For outpatients, skin readings from both sites underestimated serum values. Chest estimates were 0.6 mg/dl (10 μmol/l) lower; brow was 2.1 mg/dl (36 μmol/l) lower (p<0.0001). Correlation coefficients and mean differences between skin and serum values for Hispanic and non-Hispanic infants were similar.CONCLUSIONS: In our inpatients, chest and brow readings approximated serum values. After discharge, brow readings were lower than serum values by almost 20%, while chest readings were underestimated by 5%. We recommend using the chest for transcutaneous bilirubin estimates.

Endothelin concentrations in preterm infants treated with human recombinant erythropoietin.

Background: Increased endothelin-1 (ET-1) production following recombinant erythropoietin (Epo) administration is a presumed etiology for the hypertension reported in some adults. It is unknown whether Epo has similar effects in preterm infants. Methods: Serum ET-1 and Epo concentrations were measured prior to study, and following the second and third doses in 20 preterm infants receiving intravenous (IV) or subcutaneous (SC) Epo. Blood pressures were monitored prior to Epo administration and during the first, second, and third dose. Results: Infants (963 ± 54 g birth weight, 27.4 ± 0.6 weeks gestational age, 18 ± 3 days of life; mean ± SEM) had baseline Epo concentrations of 5.5 ± 1.3 mU/ml and ET-1 concentrations below the lower limits of detection (<1 pg/ml). Epo concentrations were 1,848 ± 274 and 1,672 ± 295 mU/ml following the second and third IV dose, respectively, while Epo concentrations were 420 ± 92 and 290 ± 35 mU/ml after the second and third SC dose, respectively (p < 0.005, SC versus IV). ET-1 concentrations remained below the limits of detection in all but 6 infants, whose concentrations were <3.3 pg/ml. Blood pressures did not increase above baseline in either group during the study period. Conclusion: Despite the wide range of Epo concentrations measured, no correlation was observed between Epo concentrations, ET-1 concentrations, and blood pressure during the 1-week study period. The long-term effects of Epo on ET-1 concentrations and blood pressure in preterm infants require further study.

Positive Relationship of Cortisol Concentrations and Oral Nutrition to Epidermal Growth Factor Concentrations in Preterm Infants

We have suggested from previous studies that increases in early neonatal epidermal growth factor (EGF) concentrations were dependent on adequate glucocorticoid hormone concentrations. In order to examine this relationship, matched values for cortisol and EGF in 193 preterm infants on days 2 and 6 were compared. Gestational age had a significant positive effect on EGF concentrations for those infants receiving oral nutrition and there was also a positive relationship between nutrition and cortisol concentration. Cortisol was then used as an independent factor and was significantly (p = 0.01) related to EGF values such that as cortisol concentrations increased, EGF values also increased. In summary, we suggest that these results are consistent with a role for cortisol in the control of the EGF pattern in the newborn period.