In this prospective , randomised , clinical trial , patients aged 6 months to 17 yr undergoing craniosynostosis and scoliosis surgery received fibrinogen concentrate ( 30 mg kg ( -1 ) ) at two predefined intraoperative fibrinogen concentrations [ ROTEM ( ) FIBTEM maximum clot firmness ( MCF ) of < 8 mm ( conventional ) or < 13 mm ( early substitution ) ] .