The DVT half of NG158 by recommendation number, the BCSH 2012 unusual-site positions, NG89 prophylaxis, and the CHEST 2021 differences. Anticoagulant doses, renal and weight rules, cancer, antiphospholipid syndrome and reversal are in the PE clinical chapter and are not repeated.
1. Diagnosis (NG158 1.1.1–1.1.14)
History and examination (1.1.1); two-level DVT Wells (1.1.2)
≥2 likely; ≤1 unlikely.
Likely (1.1.3–1.1.7)
Proximal leg vein US within 4 h; if not achievable, D-dimer then interim anticoagulation and US within 24 h. US positive: treat. US negative, D-dimer positive: stop interim anticoagulation (not long-term secondary prevention), repeat US at 6–8 days. Both negative: stop, consider alternatives, safety-net.
Unlikely (1.1.8–1.1.11)
D-dimer within 4 h, or interim anticoagulation while waiting. Positive: US within 4 h or interim anticoagulation and US within 24 h, then as above. Negative: as 1.1.7.
D-dimer (1.1.12–1.1.14)
Laboratory preferred; fully quantitative POCT acceptable; age-adjusted threshold over 50.
Baseline bloods (1.3.4)
FBC, U&E, LFT, PT, APTT before the first dose; do not wait; review within 24 h.
2. Treatment (NG158 1.3–1.7)
| Question | NICE NG158 | CHEST 2021 (US) |
|---|---|---|
| First line | Apixaban or rivaroxaban (1.3.8); else LMWH ≥5 d then dabigatran or edoxaban, or LMWH+VKA | DOAC over VKA |
| Duration | ≥3 months (1.3.5); then the 1.4 review (provoked: stop; unprovoked: consider continuing; HAS-BLED ≥4; annual review) | 3 months, then extended-phase decision; reduced-dose DOAC named |
| Home treatment | Implicit in the DOAC-first pathway; outpatient management standard | Home treatment recommended for DVT where circumstances allow |
| Distal (calf) DVT | Not scanned in the pathway; local practice | Serial imaging for 2 weeks in low-risk, anticoagulation for higher-risk or symptomatic; 3 months if treated |
| Iliofemoral DVT: CDT | Consider if symptoms <14 days, good function, life expectancy ≥1 year, low bleeding risk (1.6.1); IPG523 for ultrasound-enhanced CDT | Anticoagulation alone suggested over CDT for most; CDT for limb-threatening or severe symptoms in selected patients (ATTRACT) |
| IVC filter | Only if anticoagulation contraindicated or PE on treatment after the treatment-failure steps; documented removal plan (1.7.1–1.7.4) | Same indications |
| Compression stockings | Not to prevent PTS or recurrence (1.7.5); may be used for leg symptoms (1.7.6) | Not routinely for PTS prevention (SOX) |
| Treatment failure | Check adherence; address hypercoagulability; increase dose or change class (1.3.21) | Same |
| Cancer investigation; thrombophilia testing | 1.8 and 1.9, as in the PE topic | Same |
3. Unusual sites
| Site | Diagnosis | UK position (BCSH 2012 unless stated) | Notes |
|---|---|---|---|
| Upper-limb DVT | Compression US; CTV/MRV if central | Anticoagulate ≥3 months; a functioning, needed catheter may remain in situ; effort thrombosis to a vascular centre for CDT and thoracic outlet decompression | 4–10% of DVT; lower PE rate than leg |
| Splanchnic (portal, mesenteric, hepatic) | CT or MR with venous phase | Anticoagulate ≥3 months, longer with a persistent cause; test JAK2 V617F and PNH clone if no local cause; liver centre for Budd–Chiari | Cirrhosis, malignancy, pancreatitis, IBD, surgery, MPN, PNH |
| Cerebral venous thrombosis | CTV or MRV; plain CT often normal; D-dimer normal in a minority | ESO 2017: LMWH acutely, including with haemorrhage; VKA or DOAC 3–12 months (RE-SPECT CVT, ACTION-CVT); endovascular treatment for deterioration despite anticoagulation; decompressive surgery for large haemorrhagic lesions with mass effect; stop oestrogen permanently | AHA 2024 statement concurs and endorses DOACs more explicitly |
| Superficial vein thrombosis, leg | Whole-leg US: deep veins, clot length, distance from SFJ/SPJ | ≤3 cm from the junction: treat as DVT, 3 months. ≥5 cm and >3 cm from the junction: fondaparinux 2.5 mg od 45 days (CALISTO) or prophylactic LMWH ~30 days; rivaroxaban 10 mg od an alternative (SURPRISE). Short and distant: NSAID, compression, repeat US if extending | ~20% have concurrent DVT; migratory or non-varicose SVT prompts a search for malignancy or thrombophilia |
4. Prophylaxis (NG89)
| Setting | NG89 |
|---|---|
| All admissions | VTE and bleeding risk assessment on admission (national tool) and at 24 h or on change; reassess |
| Medical, increased risk | LMWH (or fondaparinux) for the admission; IPC or AES not recommended for stroke; AES not for medical patients; extended post-discharge not routine |
| Acute stroke | IPC from admission for immobile patients (CLOTS 3); no heparin, no AES |
| Elective hip replacement | LMWH 10 days then aspirin 28 days; or LMWH 28 days plus AES to discharge; or rivaroxaban (apixaban or dabigatran if rivaroxaban unsuitable) |
| Elective knee replacement | Aspirin 14 days; or LMWH 14 days plus AES to discharge; or rivaroxaban (apixaban or dabigatran if unsuitable) |
| Hip fracture | LMWH from admission (withhold pre-op per timing rules) to 1 month, or fondaparinux post-op to 1 month |
| Abdominal or pelvic cancer surgery | LMWH 28 days post-op |
| Other major abdominal, thoracic, gynaecological, urological, bariatric | LMWH ≥7 days plus mechanical; extended in selected high-risk |
| Lower-limb immobilisation in a cast or brace | Consider LMWH for the duration after risk assessment |
| Pregnancy and postpartum | RCOG Green-top 37a, not NG89: scored antenatal and postnatal assessment; LMWH 10 days to 6 weeks postpartum by score |
5. Where UK and US guidance differ
- Imaging: proximal-only with a repeat scan (NICE) against whole-leg with serial scanning or treatment of distal DVT (CHEST).
- CDT for iliofemoral DVT: both "consider"; NICE's four criteria against CHEST's "limb-threatening or severe" framing.
- SVT thresholds: BCSH 3 cm / 5 cm against CHEST's ≥5 cm; same trial.
- Joint-replacement prophylaxis: CHEST accepts aspirin alone for both hip and knee; NG89 requires a LMWH lead-in for hips.
- Everything shared with PE — DOAC first line, three months, the review, cancer and thrombophilia rules — is identical and is written once in the PE clinical chapter.
Reference only. Local protocols, the SmPC and the BNF take precedence for dosing; the prophylaxis durations above are as NG89 states them and should be confirmed against the current guideline and the local VTE policy.