Cardiac output and ductal reopening during phototherapy in preterm infants

Left ventricular output (LVO), left pulmonary artery blood flow (LPA) and p atency of the ductus arteriosus (PDA) were studied with 2D/pulsed Doppler u ltrasound before, during and after phototherapy treatment in 27 preterm inf ants (gestational age less than or equal to 32 wk), who were exposed for a minimum of 12h to phototherapy for non-haemolytic hyperbilirubinemia. In 14 infants (52%) the ductus arteriosus reopened during phototherapy. but duct al patency was not of haemodynamic importance. LVO initially decreased in p reterm infants in whom the ductus did not reopen. From 12 h until discontin uation of phototherapy, LVO and LPA were higher than before phototherapy in all infants. After withdrawal of phototherapy, LVO and LPA returned to pre -phototherapy values.