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Table 2. Heparin dosing based on APTT levels (therapeutic range 60-85 seconds)
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| bet | 260/654 | | Sana | 03.01.2022 | | Hajmi | 1,5 Mb. | | #14803 |
Table 2. Heparin dosing based on APTT levels (therapeutic range 60-85 seconds).1,4
APTT (seconds)
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Bolus (units/kg)
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Hold (min)
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Rate change (%)
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Time until repeat APTT
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<50
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50
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0
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+10
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6 h
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50-59
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0
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0
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+10
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6 h
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60-85
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0
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0
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No change
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Next day or as per haematologist advice
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86-95
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0
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0
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-10
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6 h
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96-120
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0
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30
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-10
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6 h
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>120
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0
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60
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-10
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6 h
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Obtain blood for APTT 6 hours after administration of loading dose and 6 hours after every change.
When APTT values are therapeutic, blood count and APTT daily or as per the advice of haematologist.
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APTT: Activated partial thromboplastin time
Vascular catheter patency.1,2,5-7,18-21
Maintenance of patency of peripheral arterial catheters: 0.5 units/mL of IV fluid.
Maintenance of patency of central vascular catheters: 0.5 units/kg/hour
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Dose adjustment
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Therapeutic hypothermia – No information.
ECMO – Refer to local ECMO protocols for anticoagulation.
Renal impairment – Dose adjustment may be required in severe renal impairment. Discuss with haematologist.
Hepatic impairment – No dose adjustment is required.8
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Maximum dose
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Total cumulative dose
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Route
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IV
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Preparation
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Antithrombotic prophylaxis
The concentrations varying from 100 to 500 units/mL can be used for loading doses and concentrations of 10 to 500 units/mL can be used for continuous IV infusion.
Vascular catheter patency
To prepare 0.5 unit/mL solution, withdraw 5 mL 0.9% sodium chloride from a 100 mL bag, then add 5 mL of 50 units/5 mL (50 units) to make 50 units in 100 mL bag.
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Administration
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Systemic antithrombotic therapy
Administer IV loading dose over 30 minutes.
Administer maintenance dose as a continuous IV infusion and titrate dose by anti-Xa (or APTT if anti-Xa is not available).
Vascular catheter patency
Arterial lines: Continuous IV infusion of 0.5 units/mL at 0.5-1 mL/hour.
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Monitoring
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Antithrombotic prophylaxis
Six hours after initiating therapy, measure anti-Xa (or APTT if anti-Xa is not available), then adjust dose to achieve anti-Xa level of 0.3 to 0.7 unit/mL (equivalent to APTT of 60 to 85 seconds) – Refer to tables 1 and 2 in the dosing section.
Platelet count before the commencement and then weekly.
Assess for signs of bleeding and thrombosis.
Vascular catheter patency
Standard observations for intravascular catheters.
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Contraindications
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Known hypersensitivity to heparin, uncontrolled bleeding.
Intraventricular haemorrhage, gastrointestinal haemorrhage, thrombocytopenia < 50 x 109/L, severe hypertension,
Eye, brain or spinal cord surgery- Surgeons to give clearance regarding when to start heparin.7
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Precautions
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Bleeding disorders – Discuss with haematologist.
Store heparinised saline ampoules separately from other heparin products and sodium chloride 0.9% ampoules to reduce the risk of selection errors
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