VTE Prophylaxis after Joint Replacement

Name of Patient:

Patient medication sensitivities/allergies:

Patient identification e.g. ID number, date of birth:

Current medication:

Medical history:

Independent Prescriber(s):

Contact details: [tel/email/address]

Supplementary prescriber(s):

Contact details: [tel/email/address]

Condition(s) to be treated:

Surgical patients having joint (hip or knee) replacement

Aim of treatment:

Prevention of venous thromboembolism (VTE) after joint replacement

Medicines that may be prescribed by SP:

Preparation

Dalteparin

Indication

VTE prophylaxis after joint replacement

Dose schedule

2500-7500units OD-BD 14-28 days post-operation

Specific indications for referral back to the IP

Patients with –

• Complex haematological conditions

• Serious coagulation disorders

• Recent (within the last three months) stroke

Guidelines or protocols supporting Clinical Management Plan:

NICE Guideline January 2010 (CG92) – Venous thromboembolism: reducing the risk: Reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients admitted to hospital

Western Sussex NHS. Foundation Trust (WSHT) – VTE Prophylaxis Guidelines 2013

SIGN Guideline December 2010 (122) – Prevention and management of venous thromboembolism – A national clinical guideline

Frequency of review and monitoring by:

Independent prescriber

Daily until discharge if patients are borderline for an adjustment in dose required (e.g. renal impairment or borderline weight). If not borderline review at day 3 or on discharge if this is sooner

Supplementary prescriber and independent prescriber

Process for reporting ADRs:

If serious report using to MHRA using Yellow Card

Report ADRs in patients notes

Inform patients consultant

Report ADR on patients drug chart and ensure allergy wrist band in place

Shared record to be used by IP and SP:

Patients hospital notes to be used for all contact with patient, in particular the Orthopaedic pathway should be used for the patient

GP should be communicated with using Electronic Discharge Summary (eTTO) regarding prescribed medication as inpatient and on discharge and any ADRs experienced in hospital

Agreed by independent prescriber(s):

Date

Agreed by supplementary prescriber(s):

Date

Date agreed with patient/carer

Disease area of practice as Supplementary Prescriber:

Surgical Pharmacist specialising in Elective Orthopaedic Joint Replacement Surgery

Drug I will prescribe:

Dalteparin

Presentation: (See BNF Section 2.8.1)

Brand Name – Dalteparin

(Insert Trust dosing guidelines here)

Pharmacodynamics

Dalteparin is an anticoagulant classed as a low molecular weight heparin (LMWH). It is produced through the nitrous acid degradation of unfractionated heparin of porcine intestinal mucosa origin. Its mechanism of action is through strong inhibition of factor Xa and a weaker inhibition of factor IIa (thrombin).

Figure 1.0 Mechanism of action of unfractionated heparin versus low molecular weight heparin

Compared with standard, unfractionated heparin (UFH), dalteparin sodium has a reduced adverse effect on platelet function and platelet adhesion, and thus has only a minimal effect on primary haemostasis thus there is only a slight increase in clotting time for LMWH compared with UFH.

Pharmacokinetics :

Absorption

Bioavialbility – 81-93% through subcutaneous (SC) administration

Peak concentration at 4 hours

Distribution

40-60mL/kg

Metabolism

Half-life after SC administration is approximately 3-5hours. Dalteparin is partially metabolised by desulphation and depolymerisation in the liver and kidneys.

Excretion

Clearance is renal.

Therapeutics:

Indications

Used for the prophylaxis of VTE post-hip or knee replacement surgery in accordance with local (WSHT) guidelines and national (NICE) guidelines.

(Insert local dosing guidelines)

Administration

The SC administration should be given in to the abdominal subcutaneous tissue or the lateral part of the thigh. The needle should be inserted horizontal to the body at a 90 degree angle where possible. The skin should be squeezed between the thumb and the index finger and held throughout the injection.

Cautions

Dalteparin should not be administered intramuscularly due to risk of haematoma. If the 24 hour dose of dalteparin exceeds 5000units other intramuscular drugs should be avoided.

Possibility of an underlying bleeding disorder should be ruled out before initiating dalteparin therapy.

Dalteparin should be used with caution in patients with an increased risk of severe bleeding e.g. severe uncontrolled hypertension, congenital or acquired bleeding disorders, bacterial endocarditis, angiodysplastic GI disease active ulceration, hemorrhagic stroke, recent brain, spinal, or ophthalmologic surgery.

Care should be given to those normally receiving platelet-aggregation inhibitors or oral anticoagulants such as warfarin. Written advice should be given to these patients on the potential stopping/witholding of these medications att ehir pre-operative assessment with the anaestetist or specialist nurse. This is due to the increased risk of bleeding in these patients.

In patients with a reported eGFR <30ml/min dose adjustments may be needed. Please see local guidelines.

NSAIDs are known to reduce the production of vasodilatory prostooglandins which in turn reduces blood flow to the kidneys, therefore special attention to renal function should take place in patients taking these drugs or those with known renal impairment.

Dalteparin causes only a moderate prolongation of the APTT and thrombin time as previously mentioned, therefore dose adjustments based on the APTT could result in bleeding and overdose. Accordingly, prolonged APTT should only be used as a test of overdosage.

Contra-indications

Haemophilia and other haemorrhagic disorders, thrombocytopenia (including history of HIT), recent cerebral haemorrhage, active peptic ulcer, current bacterial endocarditis. Hypersensitivity to unfractionated or low molecular weight heparin.

Drug Interactions

The major drugs which should be monitored with concurrent use of dalteparin are those which effect the clotting cascade or platelet formation e.g. asprin/dipyridamole,Vit K antagonists (phytomenadione), NSAIDS e.g. Ibuprofen, diclofenac and naproxen.

Drugs such as antihistamines, tetracyclines and cardiac glycosides may decrease the anticoagulation effect of dalteparin

It has been shown that dalteparin interacts with intravenous nitroglycerine, high dose penicillin, quinine and tobacco.

Side Effects

Manufacturers state that about 3% of the patients having had prophylactic treatment reported side-effects.

The most common side effects with dalteparin are subcutaneous haematomas at the site of injection, and mild thrombocytopenia, which tends to resolve with continued use. In very rare cases patients can develop thrombocytopenia with a paradoxical thrombosis. This can been seen with excessive bruising or a new thrombosis and any suspicious case must be urgently discussed with a consultant haematologist.

At recommended doses, bleeding occurs rarely. Transient, slight to moderate, elevations of liver transaminases have been observed but no clinical significance has been demonstrated.

Side Effects in order of commonality –

Common: More than 1 in 100 people who have Dalteparin:

• abnormal laboratory test results
• bleeding – some may be fatal
• injection site problems such as pain or haematoma
• thrombocytopenia

Uncommon: More than 1 in 1000 people who have Dalteparin:

• itching
• metabolic problems
• urticaria

Rare: More than 1 in 10,000 people who have Dalteparin:

• allergic reactions
• hair loss
• skin necrosis
• thromboembolism
• thrombosis

Patient examination

Discuss patients weight and renal functions

Observation of haematoma

Investigations

Full patient history – including details of surgery, past medical history (with particular attention paid to haematological contraindications, bleeding disorders, history of stroke and gastric ulceration), drug history (full medication reconciliation including details of allergies, OTC medication, inhalers, tobacco and illicit drug use).

Physical examination –

Monitoring –

Baseline testing –

FBC and U&Es should be assessed pre—operatively and immediately post-operatively (particularly important in assessing patients renal function and platelets). These should then be reassessed prior to discharge (or sooner if there is cause for concern). Any patients with a reduction of 50% platelet from baseline should be referred to consultant or haematologist. Any patients which have a eGFR less than 30ml/min should have their dose adjusted accordingly.

Patients that have a weight which is 5kg either side of the dose adjustment recommendations may need to an individual assessment made to decide on the most appropriate dosage, particularly if their renal clearance is 10ml/min either side of the dose adjustments necessary.

As mentioned above, test APTT should be not be used for testing effectiveness however, is dose have some use if overdose is suspected. Any patients with suspected toxicity should have their dalteparin stopped and discussion with the haematologist should take place to decide whether an alternative VTE prophylaxis drug should be initiated.

Patients can be encouraged to administer the injection themselves on the ward if they are expected to do this at home. In these patients nurses should monitor their self-administration for effectiveness.