Pharmacologic strategies in neonatal pulmonary hypertension other than nitric oxide.

Inhaled nitric oxide (iNO) is approved for use in persistent pulmonary hypertension of the newborn (PPHN) but does not lead to sustained improvement in oxygenation in one-third of patients with PPHN. Inhaled NO is less effective in the management of PPHN secondary to congenital diaphragmatic hernia (CDH), extreme prematurity, and bronchopulmonary dysplasia (BPD). Intravenous pulmonary vasodilators such as prostacyclin, alprostadil, sildenafil, and milrinone have been successfully used in PPHN resistant to iNO. Oral pulmonary vasodilators such as endothelin receptor antagonist bosentan and phosphodiesterase-5 inhibitors such as sildenafil and tadalafil are used both during acute and chronic phases of PPHN. In the absence of infection, glucocorticoids may also be effective in PPHN. Many of these pharmacologic agents are not approved for use in PPHN and our knowledge is based on case reports and small trials. Large multicenter randomized controlled trials with long-term follow-up are required to evaluate alternate pharmacologic strategies in PPHN.

Growth and neurodevelopmental outcomes after early low-dose hydrocortisone treatment in extremely low birth weight infants.

BACKGROUND: Low cortisol concentrations in premature infants have been correlated with increased severity of illness, hypotension, mortality, and development of bronchopulmonary dysplasia. A total of 360 mechanically ventilated infants with a birth weight of 500 to 999 g were enrolled in a randomized, multicenter trial of prophylaxis of early adrenal insufficiency to prevent bronchopulmonary dysplasia. Mortality and bronchopulmonary dysplasia were decreased in the hydrocortisone-treated patients exposed to chorioamnionitis. We now report outcomes at 18 to 22 months' corrected age. PATIENTS AND METHODS: Surviving infants were evaluated with standardized neurologic examination and Bayley Scales of Infant Development-II. Neurodevelopmental impairment was defined as a Mental Developmental Index or Psychomotor Developmental Index of <70, cerebral palsy, blindness or deafness. RESULTS: A total of 252 (87%) of 291 survivors were evaluated. Cerebral palsy was diagnosed in 13% of hydrocortisone-treated versus 14% of placebo-treated infants. Fewer hydrocortisone-treated infants had a Mental Development Index <70, and more of the hydrocortisone-treated infants showed evidence of awareness of object permanence. Incidence of neurodevelopmental impairment was not different (39% [hydrocortisone] vs 44% [placebo]). There were no differences in physical growth measures. Chorioamnionitis-exposed infants treated with hydrocortisone were shorter and weighed less than controls but had no evidence of neurodevelopmental impairment. Among infants not exposed to chorioamnionitis, hydrocortisone-treated patients were less likely to have a Mental Development Index of <70 or to be receiving glucocorticoids at follow-up. CONCLUSIONS: Early, low-dose hydrocortisone treatment was not associated with increased cerebral palsy. Treated infants had indicators of improved developmental outcome. Together with the short-term benefit previously reported, these data support additional studies of hydrocortisone treatment of adrenal insufficiency in extremely premature infants.

Effect of dose on response to adrenocorticotropin in extremely low birth weight infants.

CONTEXT: Various cosyntropin doses are used to test adrenal function in premature infants, without consensus on appropriate dose or adequate response. OBJECTIVE: 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. DESIGN: 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. SETTING: The setting was nine newborn intensive care units. PATIENTS: The patients included infants with 500-999 g birth weight. INTERVENTION: The drug used was cosyntropin, at 1.0 or 0.1 microg/kg, given between 18 and 28 d of birth. MAIN OUTCOME MEASURE: We measured the cortisol response to cosyntropin. RESULTS: 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. CONCLUSIONS: 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.

Prophylaxis of early adrenal insufficiency to prevent bronchopulmonary dysplasia: a multicenter trial.

BACKGROUND: Infants developing bronchopulmonary dysplasia (BPD) show decreased cortisol response to adrenocorticotropic hormone. A pilot study of low-dose hydrocortisone therapy for prophylaxis of early adrenal insufficiency showed improved survival without BPD at 36 weeks' postmenstrual age, particularly in infants exposed to histologic chorioamnionitis. METHODS: Mechanically ventilated infants with birth weights of 500 to 999 g were enrolled into this multicenter, randomized, masked trial between 12 and 48 hours of life. Patients received placebo or hydrocortisone, 1 mg/kg per day for 12 days, then 0.5 mg/kg per day for 3 days. BPD at 36 weeks' postmenstrual age was defined clinically (receiving supplemental oxygen) and physiologically (supplemental oxygen required for O2 saturation > or =90%). RESULTS: Patient enrollment was stopped at 360 patients because of an increase in spontaneous gastrointestinal perforation in the hydrocortisone-treated group. Survival without BPD was similar, defined clinically or physiologically, as were mortality, head circumference, and weight at 36 weeks. For patients exposed to histologic chorioamnionitis (n = 149), hydrocortisone treatment significantly decreased mortality and increased survival without BPD, defined clinically or physiologically. After treatment, cortisol values and response to adrenocorticotropic hormone were similar between groups. Hydrocortisone-treated infants receiving indomethacin had more gastrointestinal perforations than placebo-treated infants receiving indomethacin, suggesting an interactive effect. CONCLUSIONS: Prophylaxis of early adrenal insufficiency did not improve survival without BPD in the overall study population; however, treatment of chorioamnionitis-exposed infants significantly decreased mortality and improved survival without BPD. Low-dose hydrocortisone therapy did not suppress adrenal function or compromise short-term growth. The combination of indomethacin and hydrocortisone should be avoided.