The aim of the study was to determine if high-dose bovine surfactant (
Alveofact, initially 100 mg/kg birth weight) would improve oxygenation
compared with low-dose surfactant (50 mg/kg birth weight) administere
d intratracheally within 1 h after birth. Inclusion criteria included
gestational age 24-29 weeks and birth weight 500-1500 g, intubation an
d mechanical ventilation, absence of congenital malformations and bact
erial infections. Retreatment was considered if the fraction of inspir
ed oxygen (FiO(2)) was > 0.4 (dose 50 mg/kg birth weight). The primary
endpoint was level of oxygenation (PaO2/FiO(2)) 2 h after treatment.
The study design was a sequential analysis using a triangular test wit
h alpha = 0.05 and 95% power to detect a 25% improvement in the endpoi
nt. Oxygenation was improved significantly with high-dose (n = 42) com
pared to low-dose treatment (n = 48): 30.9 +/- 15.0 kPa (231.5 +/- 112
.7 mmHg) versus 24.1 +/- 15.7 kPa (180.6 +/- 118.0 mmHg) (mean +/- SD)
. The survival rate was 83% in both groups and the incidence of pulmon
ary interstitial emphysema was 33% versus 14% with the high-dose treat
ment. We conclude that high-dose surfactant significantly improved oxy
genation and reduced lung barotrauma. An initial dose greater than 50
mg/kg birth weight of surfactant is required for optimal acute respons
e.