Bolus delivery is the standard SF dosing procedure but is difficult to standardize and may cause acute adverts events at dosing. Aim. To prove if slow SF delivery via a double-lumen tracheal tube could decrease incidence of hypoxia and bradycardia (drop SaO220%, HR<80 bpm) at dosing without affecting its efficacy. Subjects. Infants with RDS(IPPB, FiO2≥0.4) randomly received 200 mg/Kg Curosurf by either bolus (n=99) or `side-tube' method (n=99): full dose given in 60-s by double-lumen of tracheal tube, without positional changes, or IPPB interruption. Two more SF doses (100 mg/Kg) were allowed for FiO2>0.3 on IPPB. Results. At entry birth weight(1294±362 vs 1296±384 g), gestational age (29±2; 29±2 wks), prenatal steroids, Apgar scores, gender, IPPB setting and blood gases were similar in both groups. Fewer episodes of hypoxia were seen in `side-tube' group (38.0 vs 17.5%; p=0.002). Number of doses required, incidence of air leaks (12.5 vs 6.1%), IVH (37.4 vs 26.2%), ductus (48.5 vs 36.4%), BPD (20.2 vs 15.9%), survival (85 vs 83%), and survival without BPD(67.7 vs. 69.7%) were similar.

Conclusion. In infants with RDS, SF delivered via a double-lumen tube in 60-s without fractioning, positioning or IPPB interruption was as effective as the standard bolus dosing method, and produced a decreased number of episodes of hypoxia at dosing.