Cardiac output and ductal reopening during phototherapy in preterm infants

Left ventricular output (LVO), left pulmonary artery blood flow (LPA) and patency of the ductus arteriosus (PDA) were studied with 2D/pulsed Doppler ultrasound before, during and after phototherapy treatment in 27 preterm infants (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 ductal patency was not of haemodynamic importance. LVO initially decreased in preterm infants in whom the ductus did not reopen. From 12 h until discontinuation 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.