cosyntropin and Chorioamnionitis

Various cosyntropin doses are used to test adrenal function in premature infants, without consensus on appropriate dose or adequate response.. The objective of this study was to test the cortisol response of extremely low birth weight infants to different cosyntropin doses and evaluate whether these doses differentiate between groups of infants with clinical conditions previously associated with differential response to cosyntropin.. The design was a prospective, nested study conducted within a randomized clinical trial of low-dose hydrocortisone from November 1, 2001, to April 30, 2003.. The setting was nine newborn intensive care units.. The patients included infants with 500-999 g birth weight.. The drug used was cosyntropin, at 1.0 or 0.1 microg/kg, given between 18 and 28 d of birth.. We measured the cortisol response to cosyntropin.. Two hundred seventy-six infants were tested. Previous hydrocortisone treatment did not suppress basal or stimulated cortisol values. Cosyntropin, at 1.0 vs. 0.1 microg/kg, yielded higher cortisol values (P < 0.001) and fewer negative responses (2 vs. 21%). The higher dose, but not the lower dose, showed different responses for girls vs. boys (P = 0.02), infants receiving enteral nutrition vs. not (P < 0.001), infants exposed to chorioamnionitis vs. not (P = 0.04), and those receiving mechanical ventilation vs. not (P = 0.02), as well as a positive correlation with fetal growth (P = 0.03). A response curve for the 1.0-microg/kg dose for infants receiving enteral nutrition (proxy for clinically well infants) showed a 10th percentile of 16.96 microg/dl. Infants with responses less than the 10th percentile had more bronchopulmonary dysplasia and longer length of stay.. A cosyntropin dose of 0.1 microg/kg did not differentiate between groups of infants with clinical conditions that affect response. We recommend 1.0 microg/kg cosyntropin to test adrenal function in these infants.

Topics: Bronchopulmonary Dysplasia; Chorioamnionitis; Cosyntropin; Dose-Response Relationship, Drug; Enteral Nutrition; Female; Fetal Development; Humans; Hydrocortisone; Infant, Low Birth Weight; Infant, Newborn; Length of Stay; Male; Pregnancy; Respiration, Artificial; Sex Characteristics

To explore the relationship between chorioamnionitis, postnatal cortisol concentrations, and acute respiratory distress in very low birth weight infants.. Appropriate for gestational age infants weighing between 501 to 1500 g at birth were enrolled into this prospective, observational study, and data regarding respiratory distress on the first day of life were recorded. Serum cortisol concentrations were measured on (a) day 2, (b) day 3 or 4, and (c) day 5, 6, or 7 of life. On day (b) or (c), 3.5 microg/kg of cosyntropin (an adrenocorticotrophic hormone analog) was given, and a repeat specimen was drawn 30 minutes later. Chorioamnionitis was diagnosed by placental examination by one author (R.L.N.).. Forty-two infants exposed to chorioamnionitis and 37 infants not exposed were enrolled. Chorioamnionitis correlated inversely with gestational age, and was associated with decreased measures of acute respiratory support (exogenous surfactant, fraction of inspired oxygen, and ventilator support at 12 and 24 hours). Infants with chorioamnionitis had higher cortisol concentrations, both basal and stimulated. Gestational age was not significantly related to basal cortisol, but did correlate positively with stimulated values. Cortisol values from the 16 infants exposed to prenatal glucocorticoid therapy were excluded from these analyses.. These results provide evidence that prenatal inflammation leads to adrenal stimulation, resulting in increased cortisol secretion and accelerated lung maturation. The enhanced response to cosyntropin stimulation seen in these infants may reflect an increased adrenal capacity to respond to postnatal stressors. Because of the apparent magnitude of the effect of chorioamnionitis on cortisol measures, this factor should be included in future investigations of adrenal function in very low birth weight newborns.

Topics: Chorioamnionitis; Cosyntropin; Female; Gestational Age; Humans; Hydrocortisone; Infant, Newborn; Infant, Very Low Birth Weight; Leukocyte Count; Neutrophils; Pregnancy; Respiratory Distress Syndrome, Newborn