clinical features of late-onset circulatory dysfunction in premature infants

Background: Sudden unpredictable hypotension during the post-transitional period, termed late-onset circulatory dysfunction (LCD) of premature infants, has been reported in low birthweight infants who overcame major problems during the early neonatal period. We investigated the clinical features of LCD and factors associated with the occurrence of LCD. Methods: A multicenter retrospective case-control study. The clinical records of 1,004 children born at less than 32 weeks of gestation were reviewed. Patients with LCD were compared with age-matched non-LCD controls. Results: Of the 1,004 infants, 73 (7.3%) were diagnosed with LCD, with the incidence differing significantly among institutions ( P,0.0001). The median age of diagnosis was 16 days of age (range: 4–50 days) and 29 weeks of postmenstrual age (range: 25–35 weeks). The incidence of LCD was inversely correlated with gestational age at birth, except at 22 and 23 weeks. Compared with the control infants, the LCD infants had significantly higher incidences of birth by cesar ean section (61/73 versus 48/73, P,0.05); hyponatremia (sodium ,130 mEq/L) at the time of diagnosis (24/66 versus 3/39, P,0.01); deterioration of respiratory status within 24 hours before diagnosis (36/73 versus 6/73, P,0.0001); and periventricular leukomalacia (14/73 versus 4/73, P,0.05). Corticosteroids were effective in 52 infants who were unresponsive to volume expansion or inotropic agents. None of these infants died of LCD. Conclusion: LCD is common but worthy of attention due to its association with periventricular leukomalacia. A review of institutional differences in treatment policies may contribute to the prevention of LCD.