Deep Vein Thrombosis
Suspected DVT can now be managed by the general practitioner. There is currently a surge of referrals for ?DVT leading to delays in scanning ~3 weeks, felt by the Thrombosis team to be due to a lower threshold to refer where an alternative diagnosis already exists (OA, cellulitis , HF etc). These scans are often negative. It remains the responsibility of the referring GP to establish whether risk vs benefit of anticoagulating for that long for an unknown diagnosis is in the patients best interests. Thrombosis and anticoagulation in the month following AstraZeneca Covid vaccination requires special consideration (see VITT section)
Screen for suspected DVT using the two-level Wells (DVT) score and possibly D-dimer:
If Wells score is ≥2 or D-dimer test is positive the patient should be referred for Doppler scanning using the DVT referral form (see Step 3). Interim anticoagulation should be considered for all patients referred for doppler imaging (see Step 2)
D-dimer testing may not be clinically beneficial in some patient groups:
• patients already on anticoagulation (see VTE ‘mythbusters’ below)
• patients who have received 2 or more doses of LMWH
• cancer patients
• post-operative patients
Baseline D-dimer levels are also known to increase with age and are more likely to be falsely positive in the older population and those patients in residential or nursing homes
Obesity - There is lack of evidence currently for efficacy of DOACs in patients >150kg. These patients should be given Enoxaparin 1mg/kg Twice daily pending Doppler scan. (updated on recent KCH evidence advice 7/6/21)
Patients already receiving therapeutic anticoagulation are very unlikely to develop new VTE in the absence of malignancy. GP’s should consider the possibility of non-concordance with medications in these instances including reviewing previous INR results as well as checking an up-to-date INR in patients who are Warfarinised prior to referring for a scan.
New DVT/PE despite therapeutic anticoagulation in patients with good concordance will likely be as a result of underlying occult malignancy. In these cases the patient’s current anticoagulation should be switched to LMWH daily until ultrasound scanning has been performed.
Bilateral DVT are clinically very rare and alternative diagnoses should be given due consideration prior to referring for bilateral Doppler scan
GP should consider interim anticoagulation if the patient cannot be scanned within 24 hours of referral. Patients should have routine blood tests taken – LFT’s, U+Es, FBC and coagulation screen prior to commencing anticoagulation and any anticoagulation given pending Doppler scan should be given in line with their current licenses for treatment of confirmed VTE (DVT/PE). DOACs should not be given to women who are pregnant or breast feeding or to patients with active cancer; these patients should be commenced on therapeutic LMWH.
There is no longer any need to contact the DVT clinic by phone to arrange a Doppler USS scan although pregnant patients or patients where anticoagulation is contra-indicated should be discussed directly with the Thrombosis team at RCHT (01872-253597).
If a referral is needed please complete the e-referral form below and email this directly to the Thrombosis Team at Royal Cornwall Hospital:
Please note this referral form is for patients with suspected venous thromboembolism only, please ensure you have excluded any arterial/ischaemic cause for symptoms before completing referral
Upon receipt of the completed referral form the thrombosis team will contact the patient directly to organise a Doppler USS scan; the referring GP surgery will be informed of the agreed scan appointment date/time by return email. There are 8 scan slots available on a daily basis (Mon-Fri) between 09:00am and 14:30pm, please state on the referral form if there are any dates/times which will not be suitable for your patient to attend. Please note there is likely to be a delay >24 hours from initial receipt of referral to Doppler scan being performed, it will remain the referring GP's responsibility to commence any anticoagulation pending Doppler scan if not being undertaken within 24 hours. Where transport is required for the scan this will need to be organised by the referring GP surgery.
NB Incomplete referral forms will be returned to the referring surgery/clinician
If the DVT scan is positive the patient will reviewed in the thrombosis clinic and the GP surgery informed regarding appropriate on-going management.
If the DVT scan is negative, GP should review the patient and consider an alternative diagnosis.
For general anticoagulation or thrombosis management queries please continue to contact the Thrombosis nursing team direct on 01872 253597 (for urgent clinical queries only) or at rch-tr.ThrombosisNurses@nhs.net for all routine enquiries. The Thrombosis nurses will reply to all email enquiries within 24 hours (Mon-Fri).