22 HEMODYNAMIC CONSEQUENCES OF PHOTOTHERAPY (PT) IN PRETERM INFANTS

Abstract

Hemodynamic effects were determined in 18 preterm infants undergoing blue-light PT for hyperbilirubinemia using 2D/pulsed Doppler ultrasound. Mean±SD birth weight and gestational age were 1475±757 g and 30.0±4.5 wks respectively. The mean age at which PT was initiated was 4.4±3.7 days. Left ventricular output (LVO), blood flow velocities in the left pulmonary artery (PBFV), right internal carotid artery (CBFV), and the right renal artery (RBFV) were studied in all infants just prior to the onset of PT, 1/2 h, 2 h, 12 h after initiation of PT and before and 12-24 h after discontinuation of PT. Patency of the ductus arteriosus (PDA) was assessed at all ultrasound examinations. Mean CBFV increased significantly (15.3%; p<0.05) and mean RBFV decreased significantly (19.2%; p<0.05) during the first 12 h of PT. After discontinuation of PT, CBFV as well as RBFV values returned to baseline values. LVO and mean PBFV increased significantly ≥ 12 h of PT: 26.3%; p<0.05 and 22.6%; p<0.01 respectively. LVO as well as mean PBFV remained at higher levels after the withdrawal of PT than they had been before the onset of PT. It appeared that 9 of the 18 infants developed PDA during PT. These infants had a significantly higher mean PBFV ≥ 12 h of PT than the infants without PDA had.