Murdoch 1998.

Methods	Randomized single center Blinding of randomization: unclear Blinding of intervention: unclear Complete follow‐up: yes Blinding of outcome measurement: unclear
Participants	Study limited to assessing the effects of animal and artificial surfactants on cerebral haemodynamics 20 premature infants born at 25 to 36 weeks gestation receiving mechanical ventilation were randomized to receive Curosurf or colfosceril palmitate (Exosurf Neonatal) surfactant
Interventions	Poractant (Curosurf) vs. colfosceril palmitate (Exosurf Neonatal)
Outcomes	The primary outcome measured was the anterior cerebral artery blood flow velocity (CABFV) using Doppler ultrasound before and up to 2 hours after administration of either colfosceril palmitate (Exosurf Neonatal) or Curosurf. Secondary outcomes included oxygenation index (OI)
Notes	Following animal surfactant there was a rapid reduction in CABFV (median ‐36%, range ‐43% to +8%, P < 0.01), whereas artificial surfactant resulted in a slower rise which was less marked (median +20%, range ‐7% to +62%, P < 0.05). There were no significant changes in blood pressure. Two hours after administration, the oxygenation index (OI) improved significantly only in babies receiving animal surfactant. In this group there was a significant association between the change in CABFV at 1 min and the change in OI at 2 h (n = 0.66, P < 0.05)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomized single center trial
Allocation concealment (selection bias)	Unclear risk	Blinding of randomization: unclear
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Blinding of intervention: unclear
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Blinding of outcome measurement: unclear
Incomplete outcome data (attrition bias) All outcomes	Low risk	Complete follow‐up: yes
Selective reporting (reporting bias)	Low risk