ROYAL HOSPITAL FOR WOMEN

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1 Therapeutic & Drug Utilisation Commmittee 20/4/10 INTRODUCTION Heparin prevents the conversion of prothrombin to thrombin and fibrinogen by increasing the activity of antithrombin III. This action prevents the formation of fibrin clot thus prevents the extension of already formed clots and the formation of fresh clot. The effect of standard heparin is measured by the APTT. INDICATIONS: Atrial Fibrillation Pulmonary embolism Deep venous thrombosis Ventricular thrombi Valvular replacement Acute coronary syndromes Control of DIC CONTRAINDICATIONS: Recent cerebral haemorrhage Recent trauma or surgery to brain, spinal cord or eyes Active peptic ulceration Bleeding disorders Uncontrolled hypertension Renal or Hepatic disease Bacterial endocarditis Previous heparin induced thrombocytopenia PRECAUTIONS: Hypersensitivity reactions Heparin induced thrombocytopaenia and thrombosis syndrome: see HITS guideline. Measure platelets 24 hours after commencing heparin and every second day thereafter. A fall of 15% or 20,000 whichever is lesser should be discussed with haematology and the platelet count repeated in 12 hours. Epidural/spinal anaesthesia (confirm with anaesthetic team if current or recent epidural/spinal therapy involved) Severe renal or hepatic disease. Avoid intramuscular injection. PREGNANCY Heparin does not cross the placenta during pregnancy. Care should be taken when using weight based protocols, taking into account the weight of the conceptus. A reduction from actual weight of 5 10 kg may be appropriate for calculating the heparin loading and starting dose. Anticoagulation in the immediate post-partum period is associated with a significant risk of bleeding. Close clinical observation is required and all such patients should be managed in the ACC. OVERDOSAGE The usual sign of overdosage is bleeding or haemorrhage eg bleeding from venepuncture sites or recent surgical sites, nosebleeds, vaginal bleeding, bruising, haematuria, melaena, If bleeding occurs: Turn off infusion. Contact MO. Check APTT urgently. Protamine sulfate is used to neutralise the anticoagulant effects of heparin. INCOMPATIBILE DRUGS-As Heparin Sodium is incompatible with many drugs (see product leaflet) it is administered separate to any other drugs.../2

2 Therapeutic & Drug Utilisation Commmittee 20/4/10 2. cont d COMPATIBLE FLUIDS- NS,5%D,Hartmanns solution. PROTOCOL Depending on the indications for heparin, less or more intensive anticoagulation may be required. For venous thromboembolism (VTE) and atrial fibrillation (AF), a higher therapeutic range is required compared with arterial thromboembolism eg angina, myocardial infarction, TIA or stroke. The following protocols are used for: Protocol 1: Venous thromboembolism, atrial fibrillation requiring full anticoagulation Protocol 2A: ST elevated myocardial infarction (STEMI) Protocol 2B: Non-ST elevated myocardial infarction (non-stemi) or cerebrovascular accident with atrial fibrillation (CVA with AF). PROCEDURE: Obtain pt weight.the RMO orders the baseline APTT and FBC. MO to prescribe, in full, the name of the protocol, the bolus dosage and the starting rate on the fluid order chart each day. BOLUS Select appropriate protocol 1,2A,or 2B. To administer intravenous bolus of heparin sodium, use the 5000 units in 1ml ampoules and calculate the bolus dosage per body weight as specified in column 2 of the relevant table. Up to units of heparin sodium can be delivered as a bolus, undiluted over 3 minutes. Anticoagulation in the immediate post-partum period is associated with a significant risk of bleeding. Close clinical observation is required and all such patients should be managed in the ACC. OVERDOSAGE The usual sign of overdosage is bleeding or haemorrhage eg bleeding from venepuncture sites or recent surgical sites, nosebleeds, vaginal bleeding, bruising, haematuria, melaena, If bleeding occurs: Turn off infusion. Contact MO. Check APTT urgently. Protamine sulfate is used to neutralise the anticoagulant effects of heparin. INCOMPATIBILE DRUGS-As Heparin Sodium is incompatible with many drugs (see product leaflet) it is administered separate to any other drugs. COMPATIBLE FLUIDS- NS,5%D,Hartmanns solution. PROTOCOL Depending on the indications for heparin, less or more intensive anticoagulation may be required. For venous thromboembolism (VTE) and atrial fibrillation (AF), a higher therapeutic range is required compared with arterial thromboembolism eg angina, myocardial infarction, TIA or stroke. The following protocols are used for: Protocol 1: Venous thromboembolism, atrial fibrillation requiring full anticoagulation Protocol 2A: ST elevated myocardial infarction (STEMI) Protocol 2B: Non-ST elevated myocardial infarction (non-stemi) or cerebrovascular accident with atrial fibrillation (CVA with AF).../3

3 Therapeutic & Drug Utilisation Commmittee 20/4/10 3. cont d PROCEDURE: Obtain pt weight.the RMO orders the baseline APTT and FBC. MO to prescribe, in full, the name of the protocol, the bolus dosage and the starting rate on the fluid order chart each day. BOLUS Select appropriate protocol 1,2A,or 2B. To administer intravenous bolus of heparin sodium, use the 5000 units in 1ml ampoules and calculate the bolus dosage per body weight as specified in column 2 of the relevant table. Up to units of heparin sodium can be delivered as a bolus, undiluted over 3 minutes INFUSION Reconstitute heparin infusion (25,000 units in 250ml bag of N/S) as per protocol and as per RHW medications policy in the Clinical policies and procedure manual. Administer heparin via an infusion pump through a peripheral or central venous access. Heparin must have its own designated line and lumen if CVL used and canula if peripheral line used. The APTT is ordered and checked by the RMO 4 hours after the commencement of the infusion. Phlebotomy is performed on opposite limb to the infusion. The result is recorded on the APTT results chart. The heparin infusion rate is adjusted according to the nomogram which also indicates when further APTT estimations should be ordered and performed. Ensure the correct dosage adjustment nomogram is followed for the correct protocol 1,2A,or 2B. The RMO will re-prescribe the order on the fluid order chart if any rate changes are to occur. All rate or volume to be infused changes on the infusion pump are to be checked by two RNs. The RMO is responsible for ordering and checking results of all APTTs. The heparin rate, APTT results, signatures after a rate change are documented on the APTT results chart - see page 82C. Heparin infusions are discontinued without weaning. REFERENCES POWH Intravenous Heparin Infusion policy. RELATED GUIDELINES 1. Warfarin 2. Anticoagulation in the perioperative period (bridging anticoagulation) 3. HITS./4

4 Therapeutic & Drug Utilisation Commmittee 20/4/10 4. cont d PROTOCOL 1 HEPARIN SODIUM PROTOCOL FOR VTE OR AF REQUIRING FULL ANTICOAGULATION Load 25,000 units heparin sodium in 250ml normal saline (100 units per ml). Commence as per following Table 1. Table 1. WEIGHT BOLUS UNITS PER HOUR Starting rate ml per hour* > Perform APTT after 4 hours and adjust dose as per following Table 2. IV HEPARIN Dosage Adjustment Protocol for AF/VTE Based on APTT Normal Range of Seconds & Infusion of 25,000units in 250mL Table 2. APTT (seconds) Bolus Dose IV Stop Infusion IV Rate Change (ml/hr) < 35 5,000 NO 1mL/hr from current rate 4 hours units Nil NO 1mL/hr from current rate 4 hours Therapeutic Range No Change from current rate Daily Nil NO 1mL/hr from current rate 4 hours Nil NO 2mL/hr from current rate 4 hours > 105 Nil 90 mins (then repeat APTT) Inform RMO Restart after 2hours at 2mL/h less than previous rate until APTT is available, then as per nomogram. Repeat APTT 90 min after stopping and 4 hrs after recommencing../5

5 Therapeutic & Drug Utilisation Commmittee 20/4/10 5. PROTOCOL 2A HEPARIN PROTOCOL FOR STEMI LOAD: 25,000 units heparin sodium in 250ml normal saline 100 units per ml) Commence as per following Table 3. MAX:1000units/hr Table 3. WEIGHT(kg) BOLUS UNITS PER HOUR Starting rate ml per hour* > Perform APTT after 4 hours and adjust dose as per following Table 5. PROTOCOL 2B HEPARIN PROTOCOL FOR NON-STEMI OR CVA WITH AF LOAD: 25, 000 units heparin sodium in 250ml normal saline 100 units per ml) Commence as per following Table 4. MAX:1000 units/hr Table 4. WEIGHT(kg) BOLUS UNITS PER HOUR Starting rate ml per hour* > Perform APTT after 4 hours and adjust dose as per following Table 5.../6

6 Therapeutic & Drug Utilisation Commmittee 20/4/10 6. DOSAGE ADJUSTMENTS FOR PROTOCOLS 2A & 2B Based on APTT Normal Range of Seconds & Infusion of 25,000units in 250mL Table 5. APTT (seconds) Bolus Dose IV Stop Infusion IV Rate Change (ml/hr) Repeat APTT <45 Nil NO 1mL/hr from current rate 4 hours Therapeutic Range - No Change from current Daily rate Nil NO 1mL/hr from current rate 4 hours Nil NO 2mL/hr from current rate 4 hours > 105 Nil 90 mins (then repeat APTT) Inform RMO Restart after 2hours at 2mL/h less than previous rate until APTT is available, then as per nomogram 90 mins after stopping and 4 hrs after recommencing../7

7 Therapeutic & Drug Utilisation Commmittee 20/4/10 7. Place addressograph here HEPARIN INFUSION & APPT RESULTS CHART Date: APPT therapeutic ranges ; Careful monitoring of APPT will reduce the Protocol 1: secs risk of overdosage and consequent Protocol 2A&B: secs haemorrhage. Pt weight:.. Bolus dose given:.b:blood taken for APTT levels Date Time Infusion Rate APPT result (& time) Signatures after rate adjustment Next APPT due../8

8 Therapeutic & Drug Utilisation Commmittee 20/4/10 8. Date Time Infusion Rate APPT result (& time) Signatures after rate adjustment Next APPT due/comments