Venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common and frequently preventable complication of hospital admission. Many hospital-associated clots occur during or within weeks after a stay, especially after surgery, during acute illness or with reduced mobility. Nurses are central to prevention, from risk assessment to getting patients moving, and are often the first to notice warning signs.
Why clots form: Virchow’s triad
- Stasis: immobility, long surgery, bed rest, long flights.
- Hypercoagulability: cancer, pregnancy and postpartum, oestrogen-containing contraceptives or HRT, dehydration, sepsis, inherited thrombophilias, sickle cell disease.
- Vessel wall damage: surgery (especially hip/knee replacement), trauma, central lines.
Risk assessment
Most guidelines recommend that all adult inpatients are assessed for VTE and bleeding risk on admission, and reassessed when their condition changes (for example, after surgery). Many hospitals use a national or local tool. Nurses should check that assessment is done and that prescribed prophylaxis is actually given.
Prevention
Everyone
- Early mobilisation: get patients out of bed and walking as soon as safe.
- Hydration.
- Leg exercises in bed: ankle pumps and circles.
Drug prophylaxis
- Low molecular weight heparin (e.g. enoxaparin) subcutaneously is common; DOACs are used after some orthopaedic surgery.
- Check platelet count and kidney function as advised; watch for bleeding and injection site bruising.
- Don’t miss doses: missed prophylaxis is a common, preventable cause of hospital-acquired clots.
- Some patients need extended prophylaxis after discharge (e.g. after hip replacement or major cancer surgery). Teach self-injection.
Mechanical prophylaxis
- Anti-embolism stockings or intermittent pneumatic compression devices, particularly when anticoagulants are contraindicated.
- Measure legs to fit stockings correctly; check skin daily. Don’t use stockings in patients with peripheral arterial disease, severe neuropathy or leg skin problems, or in acute stroke patients (where they’re not recommended).
Recognising DVT
- Usually one leg: swelling (compare calf circumference), pain or tenderness, warmth, redness, dilated superficial veins.
- Many DVTs have few or no symptoms.
- Diagnosis uses a clinical score (such as Wells), D-dimer blood tests and compression ultrasound.
Recognising pulmonary embolism
- Sudden breathlessness, often with no obvious cause.
- Pleuritic chest pain (sharp, worse on breathing in).
- Tachycardia, tachypnoea, falling SpOâ‚‚.
- Haemoptysis (coughing blood).
- Collapse, hypotension or cardiac arrest in massive PE.
- Anxiety, a feeling that something is wrong.
If you suspect PE
- Call for urgent medical review; use SBAR.
- A–E assessment; oxygen to maintain target saturations.
- Full observations, 12-lead ECG, IV access, bloods as requested.
- Keep the patient at rest, sitting up if breathless.
- Prepare for imaging (CT pulmonary angiogram or V/Q scan).
- Anticoagulation is often started before confirmation if suspicion is high and bleeding risk acceptable. Massive PE with shock may require thrombolysis.
See our guide on recognising shock for obstructive shock.
Pregnancy and postpartum
The risk of VTE is raised in pregnancy and particularly in the weeks after birth, especially after caesarean section. Thromboembolism is a significant direct cause of maternal death in many high-income countries. Midwives and nurses should ensure risk assessment antenatally and postnatally, and teach women to report leg swelling or breathlessness promptly.
Patient education at discharge
- Keep moving and drink fluids.
- How to take and store anticoagulants or give injections.
- Seek urgent help for leg swelling or pain, sudden breathlessness, chest pain or coughing blood.
- Long-distance travel tips: move around, calf exercises, hydration.
Related: Anticoagulants for nurses · Post-operative nursing care · Chest pain assessment
Based on NICE NG89 (Venous thromboembolism in over 16s: reducing the risk of hospital-acquired DVT or PE), NICE NG158 and RCOG Green-top Guideline 37a. Educational content: follow local protocols.