DVT: NOT PREGNANT

Symptoms and signs

• Swelling of limb (arm, calf or leg)
• Pain and stiffness of affected limb
• Pitting oedema
• Increased skin temperature
• Erythema
• Tenderness
• Mild fever

Complications

• In rare cases, arterial circulation may be severely compromised:
• severe pain, swelling, cyanosis
• rapid development of tense blue oedema (phlegmasia cerulea dolens)
• If patient is an injection drug user, examine for:
• localised infection e.g. erythema or fluctuance suggesting infected clot
• deep soft tissue infection, abscess at injection site
• necrotising fasciitis
• acute arterial occlusion, and/or myositis
• systemic infection and septic embolic abscesses e.g. cardiac murmurs suggesting infective endocarditis, sepsis, haemoptysis and cough with purulent sputum

Differential diagnosis

• Ruptured Baker’s cyst
• history of arthritis or trauma to knee
• swelling behind knee
• examine for arthropathy and effusion
• Torn calf muscles/damage to Achilles tendon
• sudden pain in calf following twisting of leg
• examine for haematoma
• disruption of tendon indicates severe rupture
• Cellulitis – see Cellulitis guideline 

• FBC, INR, APTT and U&E
• If patient is an injection drug user or has signs of infection:
• CRP
• blood cultures
• chest X-ray (to exclude septic embolic lung abscesses)
• ultrasound of groin area (localised collection)
• if murmur, positive blood cultures or chest X-ray suggestive of septic embolic lung abscesses, echocardiogram
• offer testing for blood borne viruses (HIV, HBV, HCV) – see HIV infection testing guideline

D-dimer

• Raised in many clinical states. See common causes
• normal D-dimer concentration virtually rules out thrombosis

D-dimer result awaited

• Assess by two-level PE Wells score

D-dimer result available

• Calculate two-level PE Wells score (use Wells score tool in D-dimer results awaited section)
• Assess by two-level PE Wells score with D-dimer result

Doppler scan indicated

• Local booking instructions
• If Doppler ultrasound scan cannot be arranged within 4 hr of request, but patient can otherwise be discharged:
• give suitable single dose of SC dalteparin (see Dalteparin for VTE guideline)
• if there is a delay of >24 hr (e.g. bank holiday), follow local instructions

Doppler and D-dimer results available

• Encourage ambulation
• Elevation of leg when seated
• Simple analgesia (e.g. co-codamol)
• Commence Dalteparin. See Dalteparin for VTE guideline
• if anticoagulation contraindicated, consultant physician, staff physician must decide which carries most risk – complications of therapy (consider a vena caval filter) or the DVT

Complications

Suspected phlegmasia cerulea dolens (painful blue oedema)

• An uncommon manifestation of massive deep vein thrombosis compromising venous outflow and causing ischemia and manifesting as a painfully swollen blue leg
• Elevate bed foot to 40° and ensure fluid replacement adequate to compensate for extravasation
• Refer urgently to on-call general surgical team

Concomitant infection

• Treat cellulitis or sepsis – see Cellulitis guideline and Sepsis guideline
• If evidence of groin abscess, refer to on-call surgical team
• If evidence of septic pulmonary embolism on chest X-ray, admit to respiratory or infectious diseases ward
• start treatment for pneumonia, including cover for staphylococcal infection. See Pneumonia guidelines

Symptomatic ileo-femoral DVT

• Consider catheter guided thrombolysis or mechanical thrombectomy if:
• symptoms of less than 14 days duration
• good functional status
• life expectancy of ≥1 yr
• low risk of bleeding (for thrombolysis)
• Discuss with interventional radiologist and vascular surgeon
• Do not prescribe elastic graduated compression stockings to prevent post-thrombotic syndrome or VTE recurrence after a proximal DVT

Outpatient

• Unless symptoms severe, or patient an injection drug user, or requires admission to hospital for reasons other than suspected DVT, treat as outpatient
• ensure form authorising daily injections of dalteparin is completed once diagnosis confirmed

Dalteparin

• Continue dalteparin (see Dalteparin for VTE guideline) for a minimum of 5 days until:
• INR established within therapeutic range 2–3 (3–4 for recurrent DVT occurring while INR within the range 2–3) for at least 2 consecutive days
• If patient well enough to leave hospital before warfarin initiated
• provide 5 days’ supply of dalteparin
• refer to primary care on discharge
• patients taught to self-inject or arrangements made with the appropriate district nurse team
• Initiate warfarin as outpatient. See Warfarin initiation guideline
• if patient injection drug user or has active cancer, consider continuing therapeutic dalteparin treatment, rather than converting to warfarin

Monitoring dalteparin treatment

• See Dalteparin for VTE guideline

Rivaroxaban

• If LMWH or warfarin not suitable, consider rivaroxaban, particularly if:
• previous intracranial bleed
• ≥12 months anticoagulant therapy is required
• anticipated difficulties with INR monitoring and understanding dose adjustments
• needle phobia
• other comorbidities (e.g. deranged LFT, excessive alcohol intake) increasing risk of bleeding on warfarin
• Discuss with haematologist
• Dosage: 15 mg 12-hrly oral for first 3 weeks, 20 mg daily oral thereafter for duration of therapy
• No monitoring is required
• If eGFR <50 mL/min, discuss with haematologist and renal physician
• Contraindicated if eGFR <15 mL/min, in pregnancy and if breastfeeding

Inferior vena caval filter (IVCF)

• Temporary IVCF can be used if patient:
• cannot have anticoagulation treatment. IVCF will need to be removed when patient becomes eligible for anticoagulation therapy
• recurrent VTE despite increasing INR target range to 3–4 or trial of dalteparin – discuss with haematology
• Ensure strategy for removing IVCF at earliest possible opportunity is planned and documented

Further investigations

• If no clear precipitating cause for thrombosis, particularly if this is a recurrent event, consider occult malignancy or other cause of thrombophilia
• If patient aged <45 yr with unprovoked DVT, discuss screening for inherited or acquired thrombophilia with haematology consultant

Screening for cancer

• Perform chest X-ray, FBC, LFT, calcium and urinalysis in all patients with a confirmed DVT
• If patient aged >40 yr has first unprovoked DVT, consider performing a thoraco-abdominal-pelvic CT scan and (for women) a mammogram

• See Warfarin initiation guideline

Duration of warfarin treatment

• If DVT occurred post-operatively in an otherwise healthy patient, continue for 6 weeks for calf DVT and for 3 months for proximal DVT
• After a first proximal DVT without a clear underlying cause or if permanent risk factors present, continue for 3 months
• If recurrent DVT, discuss duration of treatment with haematology 

Patient

• Advise patient that many drugs (including alcohol) interact with warfarin and to remind their GP, if additional medication is added, that they are taking warfarin
• Give patient a yellow anticoagulation therapy record booklet in which the following information has been entered:
• indication for warfarin
• target INR
• start date and duration of therapy
• the last 4 INR results
• date of next INR
• Document in medical record that patient has been given written and verbal information about warfarin and has been referred to anticoagulation clinic

Monitoring

• Anticoagulant nurse specialist will advise if patient’s GP will take over monitoring as opposed to haematology anticoagulant management service
• If anticoagulation to be monitored by GP, supply GP with written information (on separate sheet, stapled to discharge letter) about:
• indication for anticoagulation
• proposed duration of treatment
• proposed target range for INR
• details of anticoagulation in hospital (give dates, INR results and dosage taken)

Follow-up

• Arrange appointment in 10-12 weeks for appropriate medical clinic
• unless a shorter course of treatment or need for investigation requires earlier follow-up; patients with confirmed DVT remain under the care of duty physician for the day on which diagnosis was confirmed
• advise referring clinician in writing that, unless notified of any change, warfarin will be stopped on the planned date
• send copy of letter to patient’s GP

• If patient has active cancer, reassess risks and benefits of continuing anticoagulation at 6 months
• After a first proximal DVT without a clear underlying cause or if permanent risk factors present, assess VTE risk and discuss with patient, if anticoagulation should be continued