Replacement doses of hydrocortisone may prevent progressive chronic lung disease in extremely low birth weight infants. 1528

At 1-2 weeks of age, a high proportion of extremely low birth wt infants(ELBW, <1000 g BW) with minimal lung disease after surfactant treatment develop increasing oxygen requirements. Although high doses of dexamethasone(DEX) are effective in treating chronic lung disease (CLD), the number of reported side effects of DEX has also increased. We hypothesize that the documented decrease in serum cortisol from 1-3 weeks of age in ELBW infants(<10 μg/dl) may cause early CLD in ELBW infants, and that physiologic doses of hydrocortisone (HC) will attenuate CLD, decreasing the use of DEX for these infants. At Rush Children's Hospital from 1-93 to 7-94 (P1) some ELBW infants with CLD were treated with HC (1 mg/kg) while others were treated with DEX (0.5 mg/kg/d). From 8-94 to 7-96 (P2) all patients who met the following criteria were treated with HC until they reached a post-conceptual age of 31 weeks; BW <800 g, miminal lung disease after birth (FiO2 < 0.3), increase in FiO2 > 0.35 on of age were treated with DEX. We analyzed the use of steroids in the 25 (P1) and 44 (P2) surviving infants with BW between 500-800g Table

Table 1

Infants in the two periods had similar BW (687+17 vs 697+11 g). Compared to P1, a higher percentage of ELBW infants in P2 were treated with HC (Chi Square Test p<0.001) while a lower percentage were treated with DEX (p=0.03). 36%(P1) and 23%(P2) of ELBW infants mechanical ventilation, and serum [cortisol]< 10 mcg/dl. Patients with increasing FiO2 > 0.5 at 14 days treated with HC eventually required DEX. The number of ventilator days was 40% lower in P2(39±3) compared to P1 (65±15, p<0.05) while the number of oxygen days was not different (104±14 vs 83±5). These data reveal that the use of physiologic doses of HC did not result in an increase in CLD, and provide the first evidence that treatment of early CLD in ELBW infants with physiologic doses of HC (14% the glucocorticoid potency of DEX dose) decreased the progression of CLD, and the use of DEX. These findings suggest that low serum [cort] is a cause of early CLD of ELBW infants and support the conduct of a prospective study to demonstrate the effectiveness of HC in treatment of early CLD of ELBW infants.