Background Rapid Intratracheal instillation of surfactant (SF) in preterm neonates with respiratory distress syndrome (RDS) has been associated with cerebral haemodynamic disturbances. Aerosolized surfactant might potentially avoid these disturbances through a gradual improvement of lung function.
Objetive To compare carotid blood flow (CBF) and regional cerebral blood flow (RCBF) distribution in preterm lambs after treatment with instilled or aerosolized surfactant.
Methods 12 preterm lambs (133d GA) were randomized to receive instilled (SF-Bolus, n=6) or aerosolized (SF-Aero, n=6) surfactant. CBF was measured at foetal life, baseline, 5, 15 and 30 minutes after the initiation of surfactant therapy and thereafter, every 30 minutes until the end of the experiment. RCBF was determined using coloured microspheres technique at foetal life and 5, 60, 180 and 360 minutes after the start of surfactant therapy. Brain samples of striatum, thalamus and hippocampus grouped as inner zones, cortical zones and cerebellum and brain-stem (CB-B) were analyzed. ANOVA, p<0.05.
Results Following SF-Bolus administration a marked increase in CBF was observed for the first 30 min in comparison to SF-Aero group. 1 hour after treatment, however, both groups had similar CBF values. Immediately after SF instillation and during the ventilatory support, RCBF in inner (thalamus and hippcampus) and in CB-B zones was increased in SF-bolus group in comparison with SF-Aero group. No significant differences were detected in cortical blood flow.
Conclusion In preterm lambs with RDS, aerosolized surfactant produced a different cerebral haemodynamic pattern than did SF bolus instillation. These observations should be carefully explored (FIS10/00943).