Haemodynamic consequences of phototherapy in term infants

The effect of blue-light phototherapy on cardiac output and brain and kidne y perfusion was studied in 12 term infants with pulsed Doppler ultrasound. Mean (+/- SD) gestational age and birth weight were 39.0 (+/- 1.6) weeks an d 3438 (+/- 533) g respectively. Mean (+/- SD) age of the infants at which phototherapy was initiated was 3.5 (+/- 0.8) days. Left ventricular output (LVO), mean left pulmonary artery blood flow (LPA), mean blood flow velocit ies of the internal carotid (CBFV) and renal (RBFV) arteries were studied i n all infants prior to the onset of phototherapy, 30 min, 2 h, and 12 h aft er initiation of phototherapy, and before and 12-24 h after discontinuation of phototherapy. LVO decreased immediately after the onset of phototherapy . However, after 12 h, LVO returned to pre-phototherapy values. LPA increas ed significantly after 12 h of exposure. LPA returned to pre-phototherapy v alues after discontinuation of phototherapy. CBFV increased, whereas RBFV d ecreased significantly after 2 h of exposure. After discontinuation of phot otherapy CBFV as well as RBFV values returned to pre-phototherapy values. Conclusion Phototherapy does affect cardiac output and organ blood flow vel ocity in term infants, After termination of phototherapy the effect of phot otherapy disappears.