Late-onset glucocorticoid-responsive circulatory collapse in preterm infants: clinical characteristics of 14 patients.

Preterm infants may develop acute systemic hypotension that responds to glucocorticoid therapy, but not to volume loading or vasopressors, during the postnatal period. This condition is termed late-onset circulatory collapse (LCC) that develops a few weeks after birth in relatively stable infants. LCC may cause periventricular leukomalacia, periventricular necrosis in the white matter. The aim of this study was to identify the clinical characteristics of LCC. We retrospectively reviewed the clinical data of infants with LCC. Among 41 infants born at < 29 weeks of gestation between 2010 and 2014, we identified 14 infants (median gestational age 25.6 weeks) with LCC. All infants were stable before the acute onset of circulatory collapse at a median age of 21 days, which is characterized by the decreased physical activity, systolic blood pressure (12 mmHg decrease), urine output (76% decrease), and serum sodium level (4 mEq/L decrease), and the increased resistance index in the cerebral and renal arteries on Doppler ultrasonography. Both left ventricular dimension and contraction were well preserved. Three infants developed hyperkalemia. The median time from the initial hydrocortisone dose to improvements was 4 h (interquartile range 3-5 h). Hydrocortisone therapy was effective, but had to be withdrawn slowly to prevent relapse. The median duration of hydrocortisone therapy was 23 days. There was no evidence of periventricular leukomalacia in any of the infants. None of the infants developed adrenal insufficiency during the follow-up period. During the acute stage of LCC, the main priority is the early initiation of glucocorticoid therapy.