Randomization and Blinding
Patients were randomized in a 1:1 ratio to either the fibrinogen or placebo groups in a double-blind manner. Randomization was stratified per centre with a block size of 4; IMP containers were sequentially numbered according to the computer-generated randomization sequence. Reconstitution of fibrinogen and formulation of the placebo (2 vials = 3 g of fibrinogen or placebo per patient) were carried out by trained research personnel not involved in the patients’ care. Blinding of care providers and patients was maintained throughout by use of a masking system and tinted tubing. Each vial of fibrinogen concentrate (1.5 g) and placebo was reconstituted in 100 mL of sterile water and administered at a flow rate ≤ 20 mL/min within 30 min following the start of the sulprostone infusion.