Is extubation associated with changes in ductal and pulmonary blood flow in extremely preterm neonates?

Abstract

Early extubation is desirable in preterm neonates to minimise the risk of complications associated with prolonged intubation. The association of significant pulmonary haemorrhage (PH) with extubation in a cluster of very preterm infants instigated an assessment of ductal and pulmonary haemodynamic effects of early extubation. This is a prospective observational study in 20 neonates (gestation <28 weeks) undergoing early extubation. Echocardiography was performed 5 min pre-extubation and 20 min post-extubation to continuous positive airway pressure. Normal cardiac anatomy was ascertained. Left pulmonary artery (LPA) and ductus arteriosus diameter and flows were recorded. Doppler spectral pattern of velocity was recorded over a minimum of four cycles. Median (range) gestation, birthweight and age at extubation were 26.5 (24.0-28.0) weeks, 932 (595-1260) g and 18 (6-51) h, respectively. There was no significant change in pulmonary flow post-extubation: ductal size: (pre--1.2 (0-3.3) mm, post--1.0 (0-3.5) mm); ductal flow: (pre--44 (0-515), post--49 (0-441) mL/kg/min); LPA diameter: (pre--2.4 (1.9-3.8) mm, post--2.6 (1.9-3.4) mm); LPA flow: (pre--112 (59-255), post--122 (58-188) mL/kg/min. There were 3 out of 20 infants who developed PH at the post-natal age of 2, 11 and 16 days after extubation. Ductal and LPA flow did not change significantly after extubation in infants with or without PH irrespective of the ductal status. Early extubation was not associated with a significant change from baseline in ductal and pulmonary flow in extremely preterm infants.