Initial dosage	Bolus of 80 units per kg, then 18 units per kg per hour by infusion
APTT < 35 seconds (<1.2 times control)	Bolus of 80 units per kg, then 4 units per kg per hour by infusion
APTT = 35 to 45 seconds (1.2 to 1.5 times control)	Bolus of 40 units per kg, then 2 units per kg per hour by infusion
APTT = 46 to 70 seconds (1.5 to 2.3 times control)	No change
APTT = 71 to 90 seconds (2.3 to 3.0 times control)	Decrease infusion rate by 2 units per kg per hour.
APTT > 90 seconds (>3.0 times control)	Hold infusion for 1 hour, then decrease infusion rate by 3 units per kg per hour.