Clinical Features of Late-onset Circulatory Collapse in Preterm Infants

Abstract

Purpose : We aimed to describe the clinical features of late-onset circulatory collapse (LCC) in preterm infants. Methods : The records of preterm infants with a gestational age of <33 weeks who were admitted to a single neonatal intensive care unit and survived more than 72 hrs between March 2006 and August 2012 were reviewed retrospectively. Results : Of the total of 659 patients, 44 (6.7%) were diagnosed with LCC. Their mean gestational age was 26.0±1.9 weeks and their median birth weight 830 g. The median time of onset of LCC was 16.5 postnatal days. The patients exhibited oliguria that responded to hydrocortisone but not to hydration or catecholamines. Other clinical features of LCC were hypotension (73%), hyponatremia (52%), and hyperkalemia (34%). These abnormalities resolved in sequence: oliguria resolved first, after a median of 2.2 hrs, followed by hypotension after a median of 3.0 hrs, and the serum Na level became normal after 12.9 hrs. The incidence of LCC increased as the gestational age and/or birth weight decreased. A total of 26 patients (59%) developed LCC within 2 weeks after the initiation of levothyroxine therapy. Conclusions : LCC in preterm infants was a relatively reversible condition but could be associated with severe morbidity. We therefore recommend the implementation of careful measures for early detection and prompt management of LCC, particularly after stressful events.