Low levels of circulating plasma cortisol have been reported in extremely low birthweight infants (ELBW) with hypotension refractory to vasopressors and volume expansion (Pediatrics 1993; 92:715). This is thought to be related to adrenal immaturity and has been shown to respond to glucocorticoid therapy. Based on clinical observations we theorized that a subset of term infants might also be incapable of synthesizing/secreting adequate cortisol in response to prolonged stress. Serum cortisol levels were obtained prior to initiating steroid therapy in term infants with refractory hypotension. Five were identified who had significant hypocortisolemia (2.3, 3.3, 5.6, 9.1, 15.4 mcg/dl). All had required inotropes and repeated volume expansion to maintain adequate blood pressure and urine output. Birthweight was 2.4 to 3.5 kg, gestational age 38-41 weeks and age 1-5 days. Diagnoses were congenital diaphragmatic hernia (n=2), meconium aspiration syndrome, meconium peritonitis, and hypoplastic left heart syndrome. Four were on dopamine (5-20 mcg/kg/min) and dobutamine (4-15 mcg/kg/min) and one was on epinephrine. All had received between 20 and 94 cc/kg of 5% albumin and/or fresh frozen plasma in the 24 hours prior to measurement of plasma cortisol. Blood cultures were negative. Echocardiograms revealed normal systolic function. All five infants were treated with dexamethasone 0.2 mg/kg/day. Vasopressors were weaned rapidly and discontinued within 72 hours in 4/5 patients. In 2/5 no volume expanders were required after initiation of steroids; none needed volume after 3 days. Urine output improved from 1.6 to 5.2 cc/kg/hr. All five infants survived. We conclude that a subset of critically ill term infants with refractory hypotension lack the ability to mount either an immediate or a sustained glucocorticoid response to stress. Steroid therapy results in rapid improvement in blood pressure and urine output. Whether, as in ELBW infants, this is the result of developmental delay or is secondary to some other mechanism remains to be determined.

Funded by the Hastings Foundation.