Table 4.

Institutional Heparin Dosing Protocol Based on Activated Partial Thromboplastin Time Values

	Indication
	Venous Thrombosis	Cardiac	CNS or Postpartum Thrombosis
Starting dose
Bolus	80 U/kg	70 U/kg	None
Starting rate	18 U/kg/h	15 U/kg/h	12 U/kg/h
Monitoring	Check aPTT 6 h after UFH initiation
Dose adjustments by aPTT, s
<64	Bolus: 30 U/kg		Bolus: None
	Infusion: Increase rate by 3 U/kg/h		Infusion: Increase rate by 3 U/kg/h
	Monitoring: Repeat aPTT in 6 h		Monitoring: Repeat aPTT in 6 h
64-70	Bolus: 30 U/kg		Bolus: None
	Infusion: Increase rate by 3 U/kg/h		Infusion: Increase rate by 2 U/kg/h
	Monitoring: Repeat aPTT in 6 h		Monitoring: Repeat aPTT in 6 h
71-105	No change
	Monitoring: Repeat aPTT with next day’s labs
106-116	Infusion: Decrease rate by 1 U/kg/h
	Monitoring: Repeat aPTT in 6 h
117-132	Infusion: Decrease rate by 2 U/kg/h
	Monitoring: Repeat aPTT in 6 h
≥133	Infusion: Hold for 1 h; at restart, decrease rate by 2 U/kg/h
	Monitoring: Repeat aPTT in 6 h

aPTT, activated partial thromboplastin time; CNS, central nervous system; UFH, unfractionated heparin.