Cardiovascular & Renal · Full case

DVT

NICE NG158Wells · D-dimer · USSPE red flag

Wells decides the pathwayThe two-level DVT Wells score stratifies "DVT likely" (≥2) vs "DVT unlikely" (≤1) and drives the whole pathway — it determines whether you go straight to ultrasound or use a D-dimer first

Likely → USS ≤4h (or interim anticoag)DVT likely (Wells ≥2): proximal leg vein ultrasound within 4 hours; if not available within 4 hours, give a D-dimer AND interim therapeutic anticoagulation and scan within 24 hours

Unlikely → D-dimerDVT unlikely (Wells ≤1): D-dimer (with results within 4 hours, or interim anticoagulation if delayed). Negative D-dimer excludes DVT; positive → proximal USS within 4 hours

DOAC first-lineConfirmed DVT: anticoagulate — apixaban or rivaroxaban first-line (NICE NG158), for at least 3 months. No bridging needed. Choose by renal function, comorbidity, adherence and patient factors

D-dimer ≠ diagnosisD-dimer is sensitive but not specific — raised in infection, malignancy, pregnancy, surgery, age. Use it only to rule OUT in the "unlikely" group; never to rule in. A negative D-dimer in a "likely" patient does not exclude DVT

Provoked vs unprovokedProvoked (surgery, immobility, pregnancy, hormones, cancer, long-haul travel) vs unprovoked — determines anticoagulation duration and the need to consider occult cancer and thrombophilia in unprovoked cases

Unprovoked → think cancerUnprovoked VTE can be the first sign of occult malignancy. NICE NG158: review the history and baseline bloods (FBC, renal and hepatic function, PT, APTT) and offer a physical examination; do not offer further cancer investigations unless there are relevant symptoms or signs — don't ignore the cancer association

Breathless = ?PEDVT can embolise. Pleuritic chest pain, breathlessness, haemoptysis, tachycardia or hypoxia → suspect pulmonary embolism; haemodynamic instability is a medical emergency requiring immediate admission

📋 Clinical Stem — DVT

A 46-year-old woman with 3 days of a painful, swollen right calf two weeks after a long-haul flight, who is otherwise well but quietly worried about a clot

Grace Adeyemi, 46, presents with 3 days of an aching, swollen right calf that came on without injury. It is warm and tender, and the leg looks bigger than the left. She flew back from Lagos (an 8-hour flight) two weeks ago and has been less active since with a sprained ankle. She takes the combined oral contraceptive pill and is a non-smoker. She has no breathlessness, chest pain or haemoptysis. She is worried because a colleague "had a clot that went to the lungs." She has had some recent unintentional weight loss she attributes to a diet, and is otherwise well.

This stem tests the ability to: recognise the clinical picture of a possible DVT and apply the two-level Wells score to choose the correct pathway (USS within 4 hours if "likely"; D-dimer first if "unlikely", with interim anticoagulation if scanning is delayed); exclude pulmonary embolism (breathlessness, chest pain, haemoptysis, instability); identify provoking factors (flight, immobility, oestrogen-containing contraception) and address them (stop the COCP, switch to a non-oestrogen method); anticoagulate appropriately with a DOAC for confirmed DVT; and consider occult malignancy and thrombophilia where the event is unprovoked. The SCA challenge is communicating uncertainty and the testing pathway clearly while managing the patient's anxiety and the contraception implications.

Scenario A — Provoked DVT (this stem) Long-haul flight + immobility + COCP. Wells, USS pathway, DOAC ≥3 months, stop COCP and switch contraception; address modifiable factors; safety-net for PE.

Scenario B — Unprovoked DVT No identifiable provoking factor. Anticoagulate; consider extended anticoagulation; review for occult cancer (history, examination and baseline bloods — further tests only if symptoms or signs, NICE NG158) and consider thrombophilia/antiphospholipid testing only in the narrow groups NG158 describes.

Scenario C — Suspected PE DVT symptoms + pleuritic chest pain/breathlessness/haemoptysis/tachycardia/hypoxia. PE Wells + pathway; haemodynamic instability → emergency admission.

Scenario D — DVT in pregnancy Wells/D-dimer not validated; proceed to USS; treat with LMWH (not DOAC/warfarin); obstetric/haematology input.

Scenario E — DVT mimics Cellulitis, ruptured Baker's cyst, calf muscle tear/haematoma, chronic venous insufficiency, lymphoedema, superficial thrombophlebitis. Bilateral swelling → cardiac/renal/hepatic or IVC/pelvic obstruction.

Key variables to adapt for Wells category (likely vs unlikely → USS vs D-dimer); PE features; provoked vs unprovoked (duration, cancer/thrombophilia work-up); pregnancy (LMWH, no DOAC); oestrogen contraception/HRT; renal function and bleeding risk (DOAC choice); proximal vs distal; recurrence; massive/phlegmasia (limb-threatening); active cancer (LMWH/DOAC choice).

Steps:

Step 1

History — The Leg · Wells Factors · Exclude PE · Provoking Factors · ICE · Background

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The history simultaneously builds the Wells score (which chooses the diagnostic pathway), screens for pulmonary embolism (the dangerous complication), and identifies provoking factors that shape treatment duration and the cancer/thrombophilia question. Grace's flight, immobility and oestrogen-containing pill are provoking factors; her quiet mention of weight loss is a thread to pull in case this is the rare unprovoked event heralding cancer.

🎓 SCA framing — explain the "test then treat" pathway and the uncertainty

"Your symptoms could well be a clot in the leg, and we have a clear pathway to check — a score, sometimes a blood test, and a scan. I'll explain each step. The most important thing first is to make sure it hasn't affected your breathing."

Grace is anxious about a clot reaching the lungs. The skill is to take that fear seriously (exclude PE explicitly), explain the structured pathway, and be honest that we test before we can be certain.

1A — The leg, the Wells factors and the PE screen

Question	Why it matters	Changes what?
🟢 OPEN QUESTION"Tell me about the leg — when it started, and whether anything brought it on."	Captures onset, laterality and the story. Unilateral calf pain/swelling that came on without trauma is the classic DVT picture; bilateral swelling points elsewhere (cardiac/renal/hepatic, or IVC/pelvic obstruction). The narrative also surfaces provoking factors and the patient's concern.In SCA: eliciting laterality, the provoking story (flight/immobility) and the PE screen in the opening exchange is efficient, safe data-gathering.	Unilateral → DVT likely; bilateral → systemic/obstructive
Wells clinical factors"Is the whole leg swollen? Is the calf much bigger than the other side? Any tenderness along the deep veins? Any pitting?"	The two-level Wells score combines clinical features (active cancer, immobilisation/recent surgery, localised deep-vein tenderness, entire leg swollen, calf >3cm larger, pitting oedema, collateral superficial veins, previous DVT) and "alternative diagnosis as likely or more likely (−2)". The total (≥2 = likely; ≤1 = unlikely) chooses the pathway.	Wells ≥2 → USS pathway. Wells ≤1 → D-dimer first.	Wells score selects USS vs D-dimer
🚩 PE screen"Have you had any breathlessness, chest pain (especially on breathing in), coughing up blood, or palpitations?"	The safety core. A DVT can embolise to the lungs. Pleuritic chest pain, breathlessness, haemoptysis, tachycardia or hypoxia raise PE; haemodynamic instability (hypotension, collapse) is a medical emergency. Grace has none — but it must be asked and documented.	PE features → PE pathway / emergency admission if unstable.	Unstable PE → 999/admit
Provoking factors"Any recent long journeys, operations, illness keeping you in bed, the pill or HRT, pregnancy, or a previous clot?"	Provoked (surgery, immobility, long-haul travel, oestrogen-containing contraception/HRT, pregnancy, active cancer) vs unprovoked determines anticoagulation duration and the cancer/thrombophilia question. Grace has a flight, reduced mobility and the COCP — provoked. The COCP must be stopped and contraception switched.	Provoked → treat ≥3 months, address factor. Oestrogen → stop COCP/HRT, switch method.	Stop COCP; switch contraception
🚩 Occult cancer screen (esp. if unprovoked)"Any weight loss, change in bowel habit, bleeding, lumps, or feeling generally unwell?"	Unprovoked VTE can be the first manifestation of cancer. Grace mentions unintentional weight loss — worth clarifying (genuine diet vs unexplained). NICE NG158: in unprovoked VTE, review the history and baseline bloods (FBC, renal and hepatic function, PT, APTT) and offer a physical examination; do not offer further investigations for cancer unless there are relevant clinical symptoms or signs. Here the weight loss is exactly such a symptom to clarify.	Unprovoked, or a symptom such as weight loss → cancer review (history, examination, baseline bloods) + targeted investigation of that symptom.	Unprovoked VTE → cancer review (NG158/NG12)
Bleeding risk & comorbidity"Any bleeding problems, ulcers, recent bleeds, liver or kidney problems? What other medicines do you take?"	Anticoagulation is the treatment, so assess bleeding risk, renal/hepatic function and interacting drugs up front — these guide DOAC choice and dose, and flag patients who need specialist input.	High bleeding risk / renal impairment → tailor anticoagulant; specialist advice.	Bleeding/renal status → DOAC choice

1B — Red flags

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Red Flags — the dangerous ends of DVT

Red flag	Why dangerous	Action
Pulmonary embolism — breathlessness, pleuritic chest pain, haemoptysis, tachycardia, hypoxia	PE is the lethal complication of DVT; massive PE causes haemodynamic collapse and death.	Haemodynamically unstable → 999/immediate admission; otherwise urgent PE pathway/assessment
Phlegmasia (massive proximal DVT) — severely swollen, painful, discoloured limb ± compromised perfusion	Limb-threatening; risk of venous gangrene and compartment syndrome.	Emergency vascular/admission; urgent anticoagulation ± thrombolysis
Bilateral leg swelling / suspected IVC or pelvic obstruction	Bilateral DVT or extrinsic compression (pelvic mass/malignancy) needs imaging beyond a leg scan.	Urgent imaging; consider pelvic/abdominal cause
Unprovoked VTE with cancer warning features	May be the presenting sign of occult malignancy.	Cancer review (history, examination, baseline bloods — NG158); symptom-directed urgent referral if indicated (NICE NG12)
DVT in pregnancy	Wells/D-dimer not validated; untreated VTE risks PE; DOACs/warfarin contraindicated.	Proceed to USS; treat with LMWH; obstetric/haematology input
High bleeding risk needing anticoagulation	Anticoagulation in a high-bleeding-risk patient requires careful balance and sometimes specialist input.	Assess risk/benefit; haematology advice; tailor agent/duration

1C — ICE

💭 Ideas

"What do you think might be going on — and is there something particular you're worried about?"

Grace has connected her symptoms to her colleague's clot and the flight. Engaging her (largely correct) model lets you validate her for coming in promptly and explain the pathway, rather than talking past a fear she already holds.

😟 Concerns

"Is it the idea of a clot going to the lungs that's worrying you most?"

Naming her fear of PE lets you address it directly — explaining that you are specifically checking her breathing now, and that prompt treatment greatly reduces the risk — which is more reassuring than generic comfort.

🎯 Expectations

"What were you hoping we'd do today?"

She may expect an immediate scan or an instant answer. Naming this lets you set realistic expectations about the timed pathway (Wells, possible D-dimer, ultrasound) and the possibility of interim anticoagulation if the scan is delayed.

1D — Psychosocial context

A suspected clot is frightening — patients have often heard of someone who died of a PE. Alongside the diagnostic pathway sit two human conversations: stopping the combined pill (and sorting alternative contraception, with its own implications) and, if DVT is confirmed, starting months of anticoagulation with its bleeding precautions and lifestyle adjustments. Handling the anxiety with clear, staged information, and treating the contraception and anticoagulation conversations as shared decisions, turns a scary episode into a managed one.

😟 Fear of PE

Acknowledge it and act on it visibly by screening the chest; explain that treatment markedly reduces embolism risk.

"I can hear the worry about a clot reaching the lungs — that's exactly why I've checked your breathing carefully, and why, if it is a clot, we start treatment quickly to stop that happening."

💊 The pill conversation

The COCP must stop; plan alternative contraception sensitively (progestogen-only/non-hormonal), as this affects her life.

"If this is a clot, the combined pill needs to stop because the oestrogen adds to the risk. Let's sort a different method that's safe — there are good options that don't carry the same risk."

💉 Living with anticoagulation

Explain duration, bleeding precautions and what to watch for, framed as manageable.

"If confirmed, you'd take a blood-thinning tablet for at least three months. Most people get on with life normally — I'll go through the things to be careful about and the signs of bleeding to look out for."

🔎 The weight-loss thread

If the event is unprovoked or there are warning features, explain the cancer review without alarm.

"You mentioned losing some weight — because a clot can occasionally be the body's first warning sign, I'd like to do a few routine checks to be thorough. It's precautionary, not because I'm expecting to find anything."

1E — PMH · FH · Drug history · Social history: what changes the anticoagulation plan

🧬 PMH / FH — changes management

Factor	Why it matters	Management impact
Previous DVT or PE	A previous VTE is a Wells criterion and the strongest single predictor of another. A second unprovoked event changes the duration conversation completely. Ask what happened last time — provoked or not, how long treated, any bleeding.	Recurrent VTE → usually long-term anticoagulation after haematology advice. Recurrence while anticoagulated → check adherence and dose, and think antiphospholipid syndrome or occult cancer before switching agent.
Active cancer or cancer treatment	Active cancer (treatment within 6 months or palliative) scores on Wells, raises recurrence risk and changes drug choice because of tumour site, bleeding risk and interactions with anticancer drugs.	NICE NG158: offer a DOAC where suitable; if not, LMWH alone or LMWH with a VKA. Treat 3–6 months, then review. Involve the oncology team.
Kidney or liver disease	All DOACs are partly renally cleared (dabigatran most, apixaban least); apixaban and rivaroxaban are also hepatically metabolised. Creatinine clearance (Cockcroft–Gault, actual body weight) is what the product literature uses for dosing — not eGFR alone.	Severe renal impairment (CrCl <15 ml/min) → DOACs not licensed; LMWH/UFH-based or warfarin plan via the anticoagulation or renal team. Significant liver disease with coagulopathy → specialist advice.
Bleeding history — GI bleed, peptic ulcer, heavy periods, recent stroke	The main harm of treatment is bleeding. Heavy menstrual bleeding is common in women of Grace's age and often gets worse on a DOAC.	Document bleeding risk; consider PPI if prior GI bleed; plan heavy-period management early (an LNG-IUS helps with both contraception and bleeding).
Autoimmune disease, recurrent miscarriage, arterial events at a young age	These point towards antiphospholipid syndrome. MHRA Drug Safety Update (June 2019): DOACs are not recommended in antiphospholipid syndrome, especially triple-positive patients.	Suspected APS → haematology advice; warfarin rather than a DOAC if confirmed. Antibody testing is best timed with the specialist (NG158: consider when planning to stop anticoagulation after unprovoked VTE).
Family history of VTE	A first-degree relative with VTE raises the chance of a heritable thrombophilia. It matters most after an unprovoked event.	NICE NG158: consider hereditary thrombophilia testing only after unprovoked VTE with a first-degree relative affected, and only if planning to stop anticoagulation. Do not routinely test relatives.
Pregnancy, or pregnant in the last 6 weeks	Pregnancy and the puerperium are powerful provoking states. Wells and D-dimer are not validated in pregnancy, and DOACs and warfarin are avoided.	Go straight to ultrasound; LMWH; same-day obstetric/maternity input (RCOG Green-top Guideline 37b).

💊 Drug history · Social history — clinical impact

Factor	Why it matters	Management impact
Oestrogen: combined pill, patch or ring; oral HRT; tamoxifen/raloxifene	Oestrogen raises clotting factor levels. Grace's combined pill is one of three provoking factors. The combined pill is UKMEC 4 (unacceptable risk) with current or previous VTE (CoSRH UKMEC 2025).	Stop the combined method and bridge to a safe method the same day (7G/7F). HRT → specialist menopause advice; transdermal is preferred when VTE risk is raised (NICE NG23).
Antiplatelets, NSAIDs, SSRIs/SNRIs	Each one adds to bleeding risk on an anticoagulant. Over-the-counter ibuprofen for the calf pain is a common, unrecorded example.	Review whether aspirin/clopidogrel is still needed (cardiology/stroke advice). Use paracetamol, not NSAIDs, for the leg pain. Tell the patient to check with a pharmacist before buying any medicine.
Strong CYP3A4/P-gp inducers or inhibitors	Rifampicin, carbamazepine, phenytoin, phenobarbital and St John's wort lower apixaban/rivaroxaban levels. Azole antifungals (itraconazole, ketoconazole) and HIV protease inhibitors raise them.	Check the SPC interactions for the chosen DOAC; an alternative anticoagulant may be needed. Ask specifically about herbal remedies.
Travel, occupation and immobility	An 8-hour flight two weeks ago plus reduced mobility after an ankle sprain. Long-haul travel (roughly 4 hours or more) is a recognised transient risk factor. Her job may involve travel or sitting for long periods.	Classifies the event as provoked. Shapes the future travel advice (7C) and fit-note discussion.
Smoking, obesity, alcohol	Smoking and obesity raise VTE risk; heavy alcohol use raises bleeding risk, falls and liver dysfunction, and affects adherence.	Smoking cessation and weight support; AUDIT-C; factor into the bleeding-risk assessment and the duration decision.
Contact sports, falls risk, occupational injury risk	Head injury on an anticoagulant can cause delayed intracranial bleeding. Some jobs (working at height, heavy machinery) carry more trauma risk.	Specific counselling: any head injury → same-day A&E. Discuss pausing contact sport during treatment.
Planning pregnancy, or chance of pregnancy	DOACs and warfarin carry fetal risk. Stopping the combined pill without a bridging method risks an unplanned pregnancy while she is on a DOAC.	Pregnancy test if any doubt; reliable non-oestrogen contraception from day one; "if you become pregnant, contact us the same day — don't just stop the tablet."

🎓 SCA Checkpoint — Step 1TasksRelating to OthersGlobal Skills

Key phrases that score

"Any breathlessness, chest pain on breathing in, or coughing up blood?" — the PE screen, every time.

"There's a scoring system that tells us whether to go straight to a scan or do a blood test first." — explains the Wells pathway.

"If it is a clot, the combined pill needs to stop and we'll switch you to a safe alternative." — addresses the provoking factor.

Deductions

Not screening for PE
Not applying/realising the Wells pathway (USS vs D-dimer)
Forgetting to stop the COCP / arrange alternative contraception
Missing the unprovoked-VTE cancer consideration

🔴 Red

PE not screened; Wells/pathway not used; COCP not stopped; D-dimer used to "rule in"; no safety-net

🟠 Amber

DVT suspected; some Wells factors; pathway partly correct; COCP addressed; cancer/thrombophilia not considered; ICE partial

🟢 Green

Wells applied correctly → correct pathway (USS/D-dimer ± interim anticoag); PE screened; COCP stopped + contraception switched; provoked/unprovoked addressed with cancer review where relevant; ICE all three; safety-net

Step 2

Triage — Emergency (PE / Phlegmasia) · Urgent (Wells Pathway) · Routine

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DVT itself is urgent, not routine — the triage task is to catch the embolic and limb-threatening emergencies, and otherwise to start the timed Wells-based diagnostic pathway promptly (with interim anticoagulation if scanning is delayed).

🔴 Emergency

Same day / 999

Immediate action

Haemodynamically unstable PEHypotension/collapse/hypoxia → 999/immediate admission
Phlegmasia / threatened limbMassively swollen, discoloured, compromised limb → emergency vascular
Suspected PE (stable)PE Wells + urgent pathway/assessment

🟠 Urgent

Hours (timed pathway)

NG158 pathway

DVT likely (Wells ≥2)Proximal USS ≤4h; if delayed → D-dimer + interim anticoag, scan ≤24h
DVT unlikely (Wells ≤1)D-dimer; if positive → USS ≤4h; interim anticoag if delayed
PregnancyProceed to USS; LMWH; obstetric input

🟢 Routine

After diagnosis

Ongoing care

Confirmed DVTDOAC ≥3 months; address provoking factors
Excluded DVTConsider alternative diagnosis; safety-net
Unprovoked reviewCancer review; duration decision; ?thrombophilia

🎓 SCA Checkpoint — Step 2Tasks

Triage rationale

"Your breathing is fine and the leg, while painful, isn't threatened — so this is the urgent clot-pathway: a score, and a scan today (with a blood-thinner in the meantime if the scan can't happen within a few hours)."

Deductions

Treating a possible DVT as routine / next-week
Not arranging interim anticoagulation when the scan is delayed

Step 3

Examination — The Leg · Wells Signs · Chest · Exclude Mimics

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Examination quantifies the Wells signs, screens the chest for PE, and looks for the mimics — because cellulitis, a ruptured Baker's cyst and a calf tear all masquerade as DVT.

🦵 The leg

Sign	Why
Calf circumference (measure both, >3cm difference)	A Wells criterion; objective swelling.
Tenderness along deep veins, warmth, erythema, pitting oedema	Wells features; warmth/erythema also seen in cellulitis.
Dilated superficial (collateral) veins	A Wells criterion.
Whole-leg swelling vs calf only; bilateral?	Bilateral → systemic/obstructive cause.

🌬️ Chest & mimics

Check	Why
Observations (HR, RR, SpO2, BP)	Tachycardia/hypoxia/hypotension → PE.
Cellulitis features	Spreading erythema, fever, portal of entry → cellulitis (can coexist).
Ruptured Baker's cyst / calf tear	Sudden onset, bruising, popliteal fullness; recent exertion.
Skin / chronic changes	Venous insufficiency, lymphoedema.

🎓 SCA Checkpoint — Step 3TasksGlobal Skills

Narration that scores

"I'll measure both calves, feel along the deep veins, check for warmth and swelling, and check your pulse, breathing and oxygen — to score the likelihood and make sure your chest is fine."

Deductions

Not measuring calf circumference / objective Wells signs
Not checking observations for PE; missing cellulitis

Step 4

Investigations — Wells → D-dimer / USS · Baseline & Cancer Bloods

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Investigation in DVT is a protocol, not a free-for-all: the Wells score selects the next test, D-dimer rules out only in the "unlikely" group, proximal ultrasound confirms, and baseline bloods plus a cancer review accompany an unprovoked event.

🧭 The diagnostic protocol

Step	Action
Two-level Wells	≥2 = DVT likely; ≤1 = DVT unlikely.
Likely (≥2)	Proximal leg vein USS within 4 hours; if not possible → D-dimer + interim anticoagulation, USS within 24 hours.
Unlikely (≤1)	D-dimer (results within 4h, or interim anticoagulation). Negative → DVT excluded. Positive → USS within 4 hours.
Negative USS but positive D-dimer (likely)	Stop interim anticoagulation; repeat USS in 6–8 days.

🧪 Baseline & cancer review

Test	Why
FBC, U&E, LFTs, coagulation	Baseline before anticoagulation; renal/hepatic function guides DOAC.
Occult-cancer review (unprovoked VTE)	NICE NG158: review the history, the baseline bloods above and a physical examination. The older CG144 routine "calcium, urinalysis and chest X-ray for everyone" screen was replaced in 2020 — add tests only where symptoms or signs point to them.
Targeted cancer investigation	Only if clinically indicated by history, examination or initial results — symptom-directed urgent referral per NICE NG12; encourage uptake of national screening programmes. No routine CT or tumour markers.
Thrombophilia testing	NICE NG158: not for provoked VTE or anyone continuing anticoagulation. Consider antiphospholipid antibodies after unprovoked VTE if planning to stop anticoagulation; consider hereditary thrombophilia testing after unprovoked VTE with a first-degree relative with VTE, if planning to stop. Usually specialist-led.

💬 "Can't you just do a D-dimer and tell me?"

"The D-dimer is a useful blood test, but it's only good at ruling a clot OUT, and only when the clinical likelihood is low. Lots of things raise it — even being a bit older or having an infection — so a positive result doesn't confirm a clot. Because your score makes a clot quite likely, the right next step for you is a scan rather than relying on the blood test."

🎓 SCA Checkpoint — Step 4Tasks

Key reasoning

"Your score puts you in the 'likely' group, so you go straight to a scan. If the scan can't happen within four hours, I'll give a blood-thinner to cover you until it does."

Deductions

Using D-dimer to "rule in", or in a "likely" patient to exclude DVT
Not arranging interim anticoagulation for delays
Ignoring baseline bloods / unprovoked cancer review

Step 5

Diagnosis — Confirmed DVT · Provoked vs Unprovoked · The Mimics

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Confirm or exclude DVT on ultrasound, classify it provoked or unprovoked (which drives duration and the cancer question), and name the mimic if DVT is excluded.

Diagnosis	Discriminating features
Proximal DVT	USS-confirmed thrombus in popliteal/femoral veins — anticoagulate.
Distal (calf) DVT	Confined to calf veins; manage per local policy (anticoagulate or surveillance scan).
Provoked DVT	Identifiable transient factor (surgery, immobility, flight, oestrogen, pregnancy) — Grace; usually ≥3 months.
Unprovoked DVT	No factor; consider extended anticoagulation + cancer/thrombophilia review.
Cellulitis	Spreading erythema, fever, portal of entry; can coexist with DVT.
Other mimics	Ruptured Baker's cyst, calf muscle tear/haematoma, venous insufficiency, lymphoedema, superficial thrombophlebitis.

🚩 The discipline — classify the event, don't just treat it

Confirming a DVT is only half the job. Whether it is provoked or unprovoked changes how long anticoagulation continues and whether you must consider occult cancer and thrombophilia. For Grace, the flight, immobility and oestrogen pill make this a provoked DVT — at least 3 months of anticoagulation, stop the COCP, address mobility — but the unintentional weight loss still earns a basic cancer review to be safe.

🎓 SCA Checkpoint — Step 5Tasks

Explaining it plainly

"The scan shows a clot in the deep vein of your leg. It was almost certainly triggered by the flight, being less active, and the pill — so we treat it for at least three months, stop the combined pill, and get you moving."

Deductions

Not classifying provoked vs unprovoked
Missing the cancer/thrombophilia review when unprovoked

Step 6

Referral — Emergency · Anticoagulation Service · Haematology · Cancer Pathway

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Confirmed uncomplicated DVT is largely managed via the local DVT/anticoagulation pathway. Referral is for the emergencies, the complex anticoagulation decisions, pregnancy, and the cancer pathway where the review raises concern.

Referral	Who / when	Urgency
🔴 Emergency admission	Unstable PE, phlegmasia/threatened limb.	Same day / 999
DVT / ambulatory pathway	Suspected/confirmed DVT — local same-day USS and anticoagulation service.	Same day
Haematology	Recurrent VTE or recurrence on anticoagulation, unusual-site thrombosis, isolated distal DVT (local VTE pathway), severe renal impairment or high bleeding risk, thrombophilia questions where results would change the decision to stop, difficult duration decisions, antiphospholipid syndrome.	Soon
Obstetrics + haematology	DVT in pregnancy (LMWH).	Urgent
🟣 Cancer pathway	Where the unprovoked-VTE review or symptoms raise suspicion of malignancy → symptom-directed urgent (suspected cancer pathway) investigation.	Suspected cancer pathway referral if indicated · NG12

🎓 SCA Checkpoint — Step 6Tasks

Pathway awareness

"I'll send you straight into our same-day clot pathway for the scan and to start treatment. If anything in your routine checks needs following up, we'll arrange that too."

Deductions

Not using the same-day DVT pathway
Prescribing a DOAC in pregnancy

Step 7

Management — Expectation · Goals · Lifestyle · Prescribing · Drug Cards · Psychosocial · Follow-Up · Monitoring · Safety-Netting

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Management is anticoagulation (DOAC first-line) for an appropriate duration, addressing the provoking factor (stop the COCP, switch contraception), advice and a clear safety-net for PE and bleeding, and the unprovoked-VTE review where relevant.

Plan at a glance

💊 Anticoagulation

Element	Detail
First-line	Apixaban or rivaroxaban (DOAC) — NICE NG158; no bridging; choose by renal function, bleeding risk, adherence.
Alternatives	LMWH then dabigatran/edoxaban; LMWH + warfarin if DOAC unsuitable; LMWH in pregnancy; consider DOAC/LMWH in active cancer.
Duration	At least 3 months; provoked with a transient factor → usually stop at 3 months; unprovoked / ongoing risk / cancer → consider extended anticoagulation after risk/benefit review.
Renal/bleeding	Dose by renal function; assess bleeding risk; review interacting drugs.

🛡️ Beyond the drug

Element	Detail
Stop COCP/HRT, switch contraception	Oestrogen is a provoking factor; switch to progestogen-only or non-hormonal method.
Mobilise & advise	Encourage mobility; travel advice for future flights; manage pain.
Safety-net (PE & bleeding)	"Seek urgent help if you become breathless, get chest pain, cough blood, or have significant bleeding."
Unprovoked review	Cancer review (history, examination, baseline bloods — further tests only if symptoms/signs, NG158); duration and thrombophilia decision.
Follow-up	Review at ~3 months for duration decision; monitor adherence and bleeding; consider post-thrombotic syndrome.

7A — Address the patient's expectation first: validate → explain → negotiate

🤝

Grace wants an answer today and wants to know whether the clot will reach her lungs. Name both, then explain the plan.

Validate — name the expectation and the fear

Grace expects one of two things: a quick blood test that says yes or no, or reassurance that it is "just a strain". Behind both is her colleague's PE. Name the fear before you explain anything. A patient who is still frightened will not take in the information about the pathway.

"I can see you were hoping for a quick blood test to settle it today, and I can hear how worried you are after what happened to your colleague. Both make complete sense. Let me explain exactly how we'll get you an answer, and how we protect your lungs in the meantime."

Explain — share the reasoning

If examination confirms, for example, localised deep-vein tenderness, pitting oedema in the symptomatic leg and calf swelling >3 cm (1 point each), and no alternative diagnosis is at least as likely, her Wells score is 2 or more, so NICE NG158 says the next step is a proximal leg vein ultrasound within 4 hours, not a D-dimer alone. A D-dimer can only rule a clot out when the score is low. If the scan can't be done within 4 hours, she gets a D-dimer and interim anticoagulation, and a scan within 24 hours.

"Your score puts you in the group where a scan is the right test, because the blood test can't rule a clot out on its own for you. If we can't get the scan in the next few hours, I'll start a blood-thinning tablet today so you're protected until the scan is done. That tablet is also the treatment if the scan shows a clot."

Negotiate — agree what happens next

She leaves with a same-day DVT-pathway referral (or an interim DOAC and a booked scan time), bloods taken, the combined pill stopped with a safe alternative arranged, and the PE safety-net said out loud and written down. Then the three-month review is set up.

"So today: I'm referring you to the clot clinic for a scan, I'm taking some blood tests, and we'll stop the combined pill and sort out a safer contraceptive. If you get sudden breathlessness, chest pain or cough up blood before then, call 999. Does that feel like a plan you can work with?"

Key principle: In DVT the evidence-based answer is faster than the patient expects, not slower. A same-day scan, or treatment started today while waiting, is the NICE NG158 pathway. The communication task is to keep the timeline clear and to separate the leg (a scan will tell us) from the lungs (warning signs she must act on immediately).

7B — Why treatment matters: goals tailored to Grace

≤ 4 hours

Proximal leg vein USS result if Wells ≥2 — otherwise interim anticoagulation and a scan within 24 h (NICE NG158)

≥ 3 months

Minimum anticoagulation for confirmed proximal DVT; provoked DVT with the factor gone → usually stop then (NICE NG158)

6–8 days

Repeat proximal USS if the first scan is negative but D-dimer positive in a "likely" patient (NICE NG158)

10% → 36%

Recurrence after stopping treatment for a first unprovoked VTE: 10% at 1 year, 25% at 5, 36% at 10 (Khan et al., BMJ 2019 meta-analysis)

3–6 months

Anticoagulation for proximal DVT with active cancer, then review by clinical need (NICE NG158)

<50 or >120 kg

Extremes of weight: NICE NG158 advises considering anticoagulation with regular monitoring of therapeutic levels — agree the agent and monitoring with the anticoagulation service

UKMEC 4

Combined hormonal contraception with current or past VTE: unacceptable health risk (CoSRH UKMEC 2025)

≥ 5 days

LMWH lead-in before dabigatran or edoxaban, or overlap with warfarin, when those are chosen (NICE NG158)

~4%

Cancer found within a year of unprovoked VTE; adding routine CT abdomen/pelvis did not significantly increase cancers detected (SOME trial, NEJM 2015)

Treatment goals

Diagnosis confirmed or excluded today, or covered by interim anticoagulationNo PE, no clot extension: therapeutic DOAC from day one, correct loading phase Provoking factors removed: combined pill stopped, mobility restoredSafe contraception in place with no gap (no unplanned pregnancy on a DOAC) No major bleeding: interactions reviewed, NSAIDs avoided, heavy periods managedWeight loss explained, or investigated if genuinely unexplained Informed 3-month decision to stop, based on a provoked event and a resolved factorFuture risk planned: travel, surgery, pregnancy, HRT

Motivational language — tailored to Grace

"The tablet doesn't dissolve the clot straight away. It stops it growing and stops new clot forming, while your body clears the existing one. That's what protects your lungs, so taking it every day, at the right times, is the single most important thing you can do."

"Because we can point to clear triggers (the long flight, the sprained ankle and the pill), this kind of clot is usually treated for three months and then stopped. We'll make that decision together at the review."

7C — Non-medication management: mechanism + evidence + tailored advice

Anticoagulation treats the clot, but what the patient does alongside it reduces symptoms, removes the triggers and prevents the next clot. The protocol message is to mobilise, not rest. Stockings are for symptoms, not for routine prevention (NICE NG158). Remove the oestrogen, and plan ahead for future high-risk situations.

🚶

Early Mobilisation

Target: normal walking as pain allows from day one

Mechanism

The calf muscle pump drives venous return. Once therapeutic anticoagulation has started, walking does not "dislodge" the clot. Immobility slows flow and adds to the stasis that caused the clot.

Practical

Many patients assume they should rest, and some relatives insist on it. Say explicitly that bed rest is unnecessary. Elevate the leg when sitting. Short, frequent walks. Ankle-pump exercises while seated, which also helps the sprain rehab.

Early walking on anticoagulation is safe and eases pain and swelling faster than rest

💊

Stop the Oestrogen

Target: combined pill stopped today, safe method started today

Mechanism

Ethinylestradiol raises hepatic production of clotting factors and lowers natural anticoagulants. Carrying on with it keeps a provoking factor in place while you are trying to treat the clot.

Practical

Combined pill, patch and ring are all UKMEC 4 with current or past VTE (CoSRH UKMEC 2025). Offer a progestogen-only pill, implant, LNG-IUS or copper IUD. Condoms until the new method is effective. The LNG-IUS also helps DOAC-related heavy periods.

Removes a modifiable cause; supports stopping at 3 months

🧦

Compression — Symptoms Only

Target: stockings only for persistent post-thrombotic symptoms

Mechanism

Graduated compression reduces venous hypertension and oedema. A large placebo-controlled trial (SOX) found it did not prevent post-thrombotic syndrome.

Practical

NICE NG158: do not offer elastic graduated compression stockings to prevent post-thrombotic syndrome or VTE recurrence after proximal DVT. They can be used for persistent leg symptoms such as aching or swelling. Check ABPI or pulses first if arterial disease is possible.

Stops a common outdated prescription; targets stockings at symptoms

✈️

Travel Advice

Target: a plan for every journey over about 4 hours

Mechanism

Prolonged seated immobility, cabin conditions and dehydration all add to venous stasis. After one VTE, the risk from future long journeys is higher than for the general population.

Practical

While anticoagulated she is already protected. Wait until she is stable on treatment and symptoms have settled before flying, and ask the anticoagulation service if travel is planned soon. After stopping, plan long-haul trips: aisle seat, walk regularly, calf exercises, hydrate, avoid alcohol and sedatives, and consider properly fitted flight stockings. Specialist advice on prophylaxis for very long or high-risk journeys. Declare the VTE for travel insurance.

She flies to Lagos regularly, so this advice is essential for her

🏥

Future High-Risk Situations

Target: "I've had a clot" said at every surgery, admission and pregnancy

Mechanism

A previous VTE is one of the strongest predictors of another in surgery, hospital admission, plaster immobilisation and pregnancy. In those situations, thromboprophylaxis can be offered.

Practical

Code the VTE clearly in the record. Tell her to mention it at any pre-operative assessment, fracture clinic or antenatal booking. In a future pregnancy she will need early antenatal VTE risk assessment and is likely to need LMWH prophylaxis (RCOG Green-top Guideline 37a). HRT later in life needs specialist input.

Prevention by prophylaxis in future risk windows

⚖️

Weight, Smoking & Activity

Target: healthy BMI; non-smoker; regular activity

Mechanism

Obesity raises baseline VTE risk and intra-abdominal pressure on the iliac veins. Smoking promotes a prothrombotic state. Regular activity improves venous return and fitness.

Practical

Grace is a non-smoker. Her diet is fine to continue, but explore it: how much weight, over what time, deliberate or not? If it is genuinely unexplained, it is a symptom to investigate under NICE NG12, not a lifestyle success.

Modifiable background risk; the weight-loss question is also a safety check

7D — Prescribing guide: NICE NG158 anticoagulant pathway

NICE NG158 (2020, last updated August 2023) sets the anticoagulant choice for confirmed proximal DVT. Apixaban or rivaroxaban first-line. If neither is suitable: LMWH for at least 5 days followed by dabigatran or edoxaban, or LMWH with a vitamin K antagonist (warfarin). Choose by renal function, comorbidity, interactions, adherence and patient preference. There are four situations where the default changes: pregnancy, antiphospholipid syndrome, severe renal impairment and extremes of weight. Doses: always per current SPC. Both first-line DOACs start with a higher-dose loading phase that must be stepped down on time.

Step 1 — First-line: apixaban or rivaroxaban

Apixaban or rivaroxaban — dose per SPC (loading phase then maintenance)

No LMWH lead-in needed. Can be started as interim anticoagulation while waiting for the scan and continued if the scan confirms DVT (NICE NG158)
Apixaban loading phase lasts 7 days; rivaroxaban's lasts 21 days. Put the step-down date on the prescription and tell the patient
Rivaroxaban treatment doses must be taken with food; apixaban can be taken with or without food
Baseline FBC, U&E with creatinine clearance, LFTs, PT/APTT. Start without waiting for the results

Grace: apixaban (twice daily, no food requirement) or rivaroxaban (once daily after loading, with food). Choose by her preference and by heavy-period history.

Step 2 — DOAC first-line unsuitable

LMWH ≥5 days → dabigatran or edoxaban; or LMWH + warfarin

Dabigatran and edoxaban are licensed for VTE only after at least 5 days of parenteral anticoagulation (NICE NG158)
Warfarin: overlap with LMWH for at least 5 days and until the INR is in range (usual target 2.5, range 2.0–3.0) — run by the anticoagulation clinic
Warfarin is preferred in antiphospholipid syndrome, and is an option where DOAC interactions or renal function rule a DOAC out
LMWH dose is weight-based, per SPC and the local protocol

Dabigatran is the most renally cleared DOAC and is not licensed below CrCl 30 ml/min. Check the SPC before choosing it in CKD.

Step 3 — Duration decision at 3 months

Provoked → usually stop · Unprovoked → consider continuing

All confirmed proximal DVT: at least 3 months (NICE NG158)
Provoked, with the factor resolved: usually stop at 3 months. This fits Grace if the combined pill has been stopped and she is fully mobile
Unprovoked: consider continuing beyond 3 months (active cancer: 3–6 months, then review), balancing recurrence risk against bleeding risk, and discuss it with the patient. NG158 suggests considering the HAS-BLED score for bleeding risk, but not relying on risk tools alone (NICE NG158)
Some DOACs have a lower-dose regimen for extended prevention. Check the SPC and haematology advice

Don't let the 3-month review drift. Patients left on a DOAC "by default", with no decision recorded, are a common audit finding and a bleeding risk.

Situation	Agent (source)	Key points
Most adults, including Grace	Apixaban or rivaroxaban (NICE NG158)	Dose per SPC and local formulary; loading phase then maintenance; baseline bloods; no bridging.
Active cancer	A DOAC where suitable; otherwise LMWH alone or LMWH with a VKA (NICE NG158)	Take account of tumour site (e.g. GI or urothelial tumours carry higher bleeding risk), interactions with anticancer drugs, and bleeding risk. Treat 3–6 months, then review. Oncology involvement.
Pregnancy / postpartum	LMWH (RCOG Green-top Guideline 37b)	DOACs and warfarin avoided in pregnancy. Continue for the rest of pregnancy and at least 6 weeks postnatally, with a minimum total of 3 months. Breastfeeding: LMWH or warfarin; DOACs not recommended. Obstetric and haematology care.
Antiphospholipid syndrome	Warfarin, not a DOAC (MHRA Drug Safety Update, June 2019)	Rivaroxaban was associated with more recurrent thrombosis than warfarin in high-risk (triple-positive) APS. Review anyone with APS who is on a DOAC.
Severe renal impairment	Specialist-led: LMWH/UFH-based or warfarin (NICE NG158; SPC)	No DOAC is licensed for VTE treatment at CrCl <15 ml/min or on dialysis. At CrCl 15–29, use with caution and check the SPC for each drug.
Body weight <50 kg or >120 kg	Specialist advice (NICE NG158)	Trial evidence at extremes of weight is limited. Agree the agent and any monitoring of therapeutic levels with the anticoagulation service.
Anticoagulation contraindicated	Specialist decision (e.g. IVC filter)	Rare in primary care. Seek same-day specialist advice.

💬 "Why can't I have aspirin instead? It's just a blood thinner too."

"Aspirin works on platelets, the cells that plug a cut artery. Clots in leg veins are made mostly of a different clotting system, so aspirin isn't strong enough to treat them. The tablet I'm recommending is designed for exactly this kind of clot."

7F — Drug reference cards: anticoagulants for DVT

Apixaban (DOAC — factor Xa inhibitor)

Eliquis · 2.5 mg / 5 mg tablets

✓ First-line

First-line (NICE NG158)Dose per SPC and local formulary — 7-day loading phase, then maintenance, twice daily

✓ Prefer when

Most adults with confirmed proximal DVT, and as interim anticoagulation while waiting for a scan

Irregular mealtimes: no food requirement. Least renally cleared of the DOACs

Concern about heavy menstrual bleeding: observational and trial data suggest less abnormal uterine bleeding than with rivaroxaban

✗ Avoid / caution

Pregnancy and breastfeeding; active major bleeding; CrCl <15 ml/min; antiphospholipid syndrome (MHRA 2019)

Strong CYP3A4 and P-gp inhibitors (azoles, HIV protease inhibitors) or inducers (rifampicin, carbamazepine, phenytoin, St John's wort)

CrCl 15–29 ml/min, significant hepatic impairment, recent GI bleed, concurrent antiplatelets/NSAIDs/SSRIs, weight <50 or >120 kg: specialist advice

⚠ Side effects

Bleeding (bruising, nosebleeds, heavier periods, GI or urinary bleeding); anaemia; nausea

🔬 Monitor

Baseline FBC, U&E/CrCl, LFTs, clotting. Check at the first review that the loading phase has stepped down. Renal function and FBC at least annually, and more often if CrCl is reduced, the patient is older or frail, or they have an intercurrent illness.

💬 Counselling

"Take it twice a day, about 12 hours apart. For the first week the dose is higher. After seven days it drops, and the pack or label will show that, so please check you've switched. If you miss a dose, take it as soon as you remember that day, but never double up. Carry the alert card, and tell any dentist, pharmacist or doctor that you're on it."

Naming the loading phase and step-down date shows prescribing safety. Continuing the loading dose past day 7 is a recognised incident. Say "check with a pharmacist before buying any medicine, especially ibuprofen".

Rivaroxaban (DOAC — factor Xa inhibitor)

Xarelto and generics · 10 / 15 / 20 mg tablets

✓ First-line

First-line (NICE NG158)Dose per SPC and local formulary — 21-day twice-daily loading phase, then once daily, with food

✓ Prefer when

Once-daily maintenance suits the patient's routine and adherence

Interim anticoagulation that can simply be continued if the scan confirms DVT

✗ Avoid / caution

Pregnancy and breastfeeding; active major bleeding; CrCl <15 ml/min; antiphospholipid syndrome (the MHRA June 2019 advice came from a rivaroxaban trial)

Same CYP3A4/P-gp interaction list as apixaban

CrCl 15–49 ml/min: the SPC allows a maintenance dose reduction in some patients whose bleeding risk outweighs their recurrence risk. Check the current SPC. Heavy menstrual bleeding: consider apixaban or plan an LNG-IUS.

⚠ Side effects

Bleeding, including abnormal uterine bleeding (a frequent reason women stop); anaemia; GI upset

🔬 Monitor

As for apixaban. Confirm the switch from twice daily to once daily at day 22, and that it is being taken with a meal (absorption falls when taken fasting).

💬 Counselling

"For the first three weeks you take it twice a day. After that it's once a day. Always take it with food, because it isn't absorbed properly on an empty stomach. Keep the alert card with you. If your periods become much heavier, tell us. We can help with that without stopping your treatment."

The "with food" instruction and the day-22 step-down are the two most specific counselling points. Examiners reward them because they show the prescriber understands the drug.

Low-molecular-weight heparin

Enoxaparin · dalteparin · tinzaparin (subcutaneous)

Special situations

Pregnancy · lead-in · selected cancerWeight-based dose per SPC / local protocol

✓ Prefer when

Pregnancy and postpartum: treatment of choice (RCOG Green-top Guideline 37b)

Lead-in of at least 5 days before dabigatran or edoxaban, or overlap with warfarin (NICE NG158)

Active cancer where a DOAC is unsuitable (e.g. interactions, some GI tumours, poor oral intake)

✗ Avoid / caution

History of heparin-induced thrombocytopenia; active major bleeding

Renal impairment (accumulation: dose adjust or use UFH per specialist); extremes of weight (specialist advice; in pregnancy, anti-Xa monitoring may be used at extremes of weight)

⚠ Side effects

Injection-site bruising, bleeding, rarely heparin-induced thrombocytopenia, hyperkalaemia with prolonged use, and osteoporosis with very long use

🔬 Monitor

Baseline FBC, U&E, weight. Platelet monitoring per local protocol (depends on the clinical setting and previous heparin exposure). Injection technique and sharps disposal.

💬 Counselling

"This is a small injection under the skin of your tummy once or twice a day. The nurse will show you how to do it. Bruising at the injection site is normal. It's the safest blood thinner for your baby, because it doesn't cross the placenta."

In an SCA pregnancy variant, prescribing a DOAC is a clear safety failure. LMWH plus same-day maternity input is the expected answer.

Warfarin (vitamin K antagonist)

0.5 / 1 / 3 / 5 mg tablets

Alternative

APS · DOAC unsuitableINR-guided dosing by the anticoagulation service; usual target INR 2.5

✓ Prefer when

Antiphospholipid syndrome, especially triple-positive (MHRA Drug Safety Update, June 2019)

DOAC contraindicated by interactions, severe renal impairment (specialist-led) or patient choice. Safe in breastfeeding

✗ Avoid / caution

Pregnancy (teratogenic, particularly in the first trimester)

Many drug and food interactions (antibiotics, azoles, amiodarone, alcohol, vitamin K intake); unstable INR; poor access to monitoring

⚠ Side effects

Bleeding (risk higher when INR is unstable); rarely skin necrosis

🔬 Monitor

INR frequently at the start, then per the anticoagulation clinic. Recheck INR whenever interacting drugs are started or stopped. LMWH overlap for at least 5 days and until the INR is in range.

💬 Counselling

"Warfarin needs regular blood tests to keep your level in the right range. Lots of medicines, including antibiotics, and alcohol can change it. So tell the clinic about any new medicine, and keep your yellow book with you."

Knowing that APS means warfarin, not a DOAC, is a high-value point, especially in a young patient with an unprovoked or recurrent clot.

Contraception after VTE (CoSRH UKMEC 2025)

Progestogen-only pill · implant · LNG-IUS · copper IUD

Replace the combined pill

Start the same dayPer CoSRH guidance and SPC

✓ Prefer

Progestogen-only methods (desogestrel POP, etonogestrel implant, LNG-IUS) and the copper IUD are the usual options after VTE. Check the current UKMEC 2025 table for each method's category

LNG-IUS: effective contraception and reduces DOAC-associated heavy menstrual bleeding

✗ Avoid

Combined pill, patch and ring: UKMEC 4 with current or past VTE

Injectable DMPA: generally used with more caution than other progestogen-only methods in people with VTE. Check UKMEC and discuss with SRH services

⚠ Why it matters now

Stopping the combined pill without starting another method risks pregnancy while she is on a DOAC, which carries potential fetal risk

🔬 Check

Pregnancy test if there has been any unprotected sex. Condoms until the new method is effective. Record UKMEC 4 for CHC permanently in the notes.

💬 Counselling

"The oestrogen in your pill adds to clot risk, so after a clot it's not safe to go back to it, now or later. The good news is that the progesterone-only options, like the mini-pill, the implant or the hormonal coil, don't carry the same risk. The coil can also help if the blood thinner makes your periods heavier."

"Stop the pill" is only half the task. Examiners look for a named, safe alternative and no gap in cover.

7G — Psychosocial impact of the diagnosis: work, travel, family, identity

🤝

DVT — the fear of the lungs, three months of tablets, and a life that involves long flights

😟

Health Anxiety after VTE

After a colleague's PE, a clot can feel like a near-death event. Some patients become hypervigilant: every twinge in the chest or calf becomes "another clot", which leads to repeat attendances and poor sleep. Clear, specific safety-netting (what is and isn't an emergency) reduces this more than general reassurance does.

"It's very normal to feel on edge after a clot. The warning signs I've given you are specific. Sudden breathlessness, chest pain or coughing blood means call 999. Ordinary aches in the healing leg are expected and will settle over weeks."

💼

Work & Fit Notes

Most people with uncomplicated DVT can work, and staying active helps. Jobs involving long periods of standing, sitting or driving may need short-term adjustments: regular walking breaks, and leg elevation where possible. Frequent business travel needs a plan (7C).

"You don't need to be off work because of the clot itself. If the leg is too painful for your job for a few days, I can give you a fit note with adjustments, such as regular breaks to walk about."

🚗

Driving

DVT on its own is not generally something that needs reporting to the DVLA. The practical question is whether leg pain or swelling stops her doing an emergency stop safely. Long drives count as immobility: take breaks every couple of hours. A PE with collapse or syncope is a different conversation, so check DVLA guidance if that happens.

"You can drive as long as the leg lets you brake hard safely. On long journeys, stop every couple of hours and walk around."

✈️

Family, Travel & Culture

Grace travels to Lagos to see family. A fear of flying again, or of being unable to visit elderly relatives, can be a real loss. Travel insurance must declare the VTE. Family members may ask about "blood tests for clotting genes". Routine testing of relatives is not recommended (NICE NG158).

"You'll be able to fly again. We'll plan the next long trip together. Your family don't need routine clotting tests, but anyone who's worried can talk to their own GP."

💉

Living with a Blood Thinner

Anticoagulation changes small everyday things: shaving cuts, gardening, contact sport, dental work, heavier periods and buying painkillers. Framing it as time-limited (three months for a provoked clot) and giving practical rules reduces anxiety and improves adherence.

"Most people carry on normally. Use an electric razor if you like, tell your dentist, avoid ibuprofen, and if you bang your head, get checked the same day even if you feel fine."

👤

Identity, Body Image & Contraception

Losing a contraceptive method that worked well for her cycle, skin or periods can feel like a real loss. The weight-loss discussion can be sensitive: she may be proud of dieting and not want it "medicalised". Respectful curiosity avoids both false alarm and a missed cancer.

"Well done on the weight you've lost. Can I ask a couple of questions about it, just so I'm sure it's all from the diet? It's a routine check after a clot."

7H — Follow-up schedule

Day 0 — Same-day pathway

Wells documented. Proximal USS within 4 hours via the DVT service, or D-dimer plus interim DOAC and a scan within 24 hours (NICE NG158). Baseline FBC, U&E/CrCl, LFTs, PT/APTT. Combined pill stopped and safe contraception started. PE and bleeding safety-net given verbally and in writing. If the scan is negative with a positive D-dimer: stop the interim anticoagulant and repeat the scan at 6–8 days.

Scan ≤4 h or interim anticoagStop the COCP

1–3 Weeks — Early review (phone or face to face)

Correct DOAC and dose; loading phase stepped down on time (day 8 for apixaban, day 22 for rivaroxaban); adherence; bleeding; leg symptoms improving; any chest symptoms. Blood results reviewed. Weight-loss history clarified. If genuinely unexplained, examine and follow NICE NG12 criteria. Contraception in place.

Loading dose stepped down?Weight loss clarified

~3 Months — Duration decision

Provoked, factor resolved (combined pill stopped, fully mobile): usually stop (NICE NG158). Unprovoked: discuss continuing, weighing recurrence and bleeding risk, and consider APS or thrombophilia testing only in the NG158 groups before stopping. Assess post-thrombotic symptoms; offer stockings only for symptoms. Plan future travel and risk-period prophylaxis.

Stop or continue — record the decisionPost-thrombotic symptoms

After stopping — Planning ahead

VTE coded prominently; UKMEC 4 for oestrogen contraception recorded. Advice for pregnancy (early booking and VTE risk assessment), surgery and long-haul travel. Safety-net for recurrence (new leg swelling or breathlessness means the same-day pathway or 999).

Record and alertFuture prophylaxis plan

If continued long term — At least annually

Renal function (re-dose or switch the DOAC as CrCl changes), FBC (unexplained anaemia means investigating for a bleed, not blaming the drug), LFTs, bleeding events, interacting drugs, weight, adherence, and whether anticoagulation is still needed. Review more often if CrCl is reduced, in older or frail patients, or during intercurrent illness.

Renal functionStill indicated?

7I — Monitoring: the anticoagulated patient

Memory rule — "Dose · Bleed · Kidney · Decide"

At every review: Dose (right drug, right phase, right for current CrCl and weight); Bleed (any bleeding, heavy periods, Hb, new interacting drugs such as NSAIDs or antiplatelets); Kidney (CrCl, the commonest reason a dose becomes wrong over time); Decide (is there a documented duration plan, and is it still right?).

What	When	Why / action threshold
FBC, U&E with CrCl, LFTs, PT/APTT	Baseline, before the first dose (don't delay treatment for results)	Sets the DOAC choice and dose; flags thrombocytopenia, renal or hepatic impairment, or an unexpected coagulopathy that changes the plan
Loading phase step-down	Day 8 (apixaban) / day 22 (rivaroxaban)	Continuing the loading dose raises bleeding risk. Check the patient's understanding and the prescription
Renal function (CrCl)	Baseline, then at least annually; more often if CrCl reduced, older age, frailty or acute illness	Falling CrCl → re-dose or switch per SPC. CrCl <15 ml/min → DOACs not licensed; specialist plan
FBC / haemoglobin	Baseline; at review if symptomatic; at least annually on long-term treatment	New anaemia → look for occult GI, uterine or urinary bleeding; don't just put it down to the drug
Bleeding history	Every contact	Major bleed → urgent assessment. Heavy periods → LNG-IUS or a switch of agent; tranexamic acid is generally avoided with active VTE, so get specialist advice
Interacting medicines	Every new prescription or OTC purchase	NSAIDs, antiplatelets, SSRIs (bleeding); CYP3A4/P-gp inducers or inhibitors (DOAC levels)
Weight	Baseline and if it changes markedly	<50 kg or >120 kg → specialist advice (NICE NG158). Continued unexplained weight loss → investigate (NICE NG12)
Leg symptoms / post-thrombotic syndrome	Early review, 3 months and after	Worsening despite treatment → check adherence and dose, re-image, seek specialist advice. Persistent aching or swelling → stockings for symptoms
INR (if on warfarin)	Per anticoagulation clinic	Usual target 2.5 (range 2.0–3.0). Recheck with any interacting drug change
Duration decision	~3 months, then at least annually if continuing	Provoked with factor resolved → stop; unprovoked → balance recurrence against bleeding; record the decision

7J — Safety-netting: exact phrases, marking rows and danger zones

⚠ Scenario-specific phrases — use these verbatim

Why safety-netting matters beyond clinical care — document it

Wells score and category documented, with the pathway chosen (USS ≤4 h, or D-dimer + interim anticoagulation + USS ≤24 h) and who is responsible for the result

PE safety-net: "advised to call 999 for sudden breathlessness, pleuritic chest pain, haemoptysis, palpitations or collapse" — verbal and written

Anticoagulant, dose, loading-phase end date, indication and planned review date recorded; alert card given

Combined pill stopped; UKMEC 4 recorded; replacement method and interim condom advice documented

Weight-loss history documented, with the reason it is or is not considered unexplained, and the plan

Duration decision at 3 months recorded with the reasoning (provoked or unprovoked; bleeding risk; patient preference)

TodayScan ≤4 h or interim DOAC; bloods; stop COCP; safety-net

1–3 WeeksDose step-down; bleeding; bloods; weight-loss clarified

3 MonthsStop or continue; post-thrombotic symptoms; future-risk plan

💬 Key phrases

💭 Connecting her idea

"You've put the pieces together well: the long flight, being less mobile with your ankle, and the pill can all make a clot more likely. That's exactly why we're taking this seriously today."

😟 Fear of PE

"Your breathing, pulse and oxygen are all normal, so there's no sign it has reached your lungs. Starting treatment quickly is what makes that much less likely."

🎯 Why a scan, not just a blood test

"The blood test can only rule a clot out when the chances are low. Yours aren't low, so a scan is the right test, and I'll cover you with treatment if the scan can't happen in the next few hours."

💊 The pill

"The combined pill has to stop because its oestrogen adds to clot risk. Let's choose a safe alternative today so you're never without contraception."

⏳ How long

"Because there were clear triggers, we usually treat for three months and then stop, once the triggers have gone. We'll decide that together at the review."

🚨 Safety-net

"Sudden breathlessness, chest pain, coughing blood or fainting: call 999. Black stools, vomiting blood, or any head injury: A&E the same day, and say you're on a blood thinner."

🔴🟠🟢 RAG marking — all 3 domains

Tasks

🟢

Wells applied → USS ≤4 h or interim DOAC + D-dimer + USS ≤24 h; PE screened; DOAC first-line with the correct loading phase; baseline bloods; COCP stopped with a UKMEC-safe alternative; provoked classification → 3-month plan; weight loss explored

🟠

Correct pathway but no interim-anticoagulation plan for delay; DOAC named without phase or step-down; COCP stopped without an alternative; duration vague

🔴

D-dimer used to rule in, or to exclude DVT in a "likely" patient; routine next-week scan with no cover; no PE screen; combined pill continued; aspirin offered as treatment

Relating to Others

🟢

Colleague's PE fear named and addressed with findings; blood-test expectation negotiated; contraception change framed with options; weight-loss question asked respectfully; understanding checked

🟠

Fear acknowledged in general terms only; pathway explained in jargon ("proximal compression ultrasonography"); cancer mentioned bluntly

🔴

False reassurance ("it's probably just a strain"); fear ignored; patient told to stop the pill with no alternative; cancer raised alarmingly or not at all

Global Skills

🟢

Structured: PE screen early → Wells → pathway → treatment → classification → safety-net; time managed; plan summarised; follow-up loops closed

🟠

Safety-net given but generic ("come back if worse"); review date unclear

🔴

No safety-net; no ownership of the scan result; consultation ends with the patient unsure what happens next

🚫 Danger zones

✗

Negative D-dimer used to exclude DVT in a Wells ≥2 patient→ NICE NG158: "likely" → proximal USS. D-dimer only rules out in the "unlikely" group.

✗

Scan booked for days later with no interim anticoagulation→ If the result isn't available within 4 hours, give interim therapeutic anticoagulation and scan within 24 hours (NG158).

✗

DOAC loading dose continued indefinitely→ Step down at day 8 (apixaban) or day 22 (rivaroxaban); doses per SPC.

✗

DOAC in pregnancy or triple-positive APS→ Pregnancy: LMWH (RCOG GTG 37b). APS: warfarin (MHRA DSU June 2019).

✗

Combined pill stopped with no replacement, or restarted later→ CHC is UKMEC 4 after VTE, permanently. Start a progestogen-only method or copper IUD the same day.

✗

Routine CT or tumour markers for every unprovoked DVT→ NG158: history, examination and baseline bloods; further tests only for relevant symptoms or signs. But a symptom like weight loss must be followed up.

✗

Thrombophilia screen sent while on anticoagulation, or after a provoked clot→ NG158: not in provoked VTE or while continuing anticoagulation. Results are unreliable and rarely change management.

✗

Stockings prescribed "to prevent post-thrombotic syndrome"→ NG158: not for prevention after proximal DVT; symptoms only.

🎓 SCA Checkpoint — Step 7TasksRelating to OthersGlobal Skills

A plan that scores

"Here's the plan: a blood-thinning tablet (apixaban) for at least three months, stop the combined pill and switch to a safe method, keep mobile, and seek urgent help if you get breathless, chest pain, cough blood or notice bad bleeding. We'll review at three months to decide how long to continue."

Deductions

No anticoagulation duration plan; no PE/bleeding safety-net
Failing to stop the COCP / arrange contraception
DOAC in pregnancy; ignoring renal/bleeding risk

"Doctor, my right calf's been swollen and really sore for three days now. I flew back from Lagos a couple of weeks ago and a colleague of mine had a clot that went to her lungs — I'm a bit scared it's the same thing."

Who you are

Grace Adeyemi, 46. Three days of an aching, swollen, warm right calf, no injury. The leg looks bigger than the left. You took an 8-hour flight from Lagos two weeks ago and have been less active since you sprained your ankle. You take the combined contraceptive pill, don't smoke. No breathlessness, no chest pain, no coughing blood. You're frightened because a colleague had a clot reach her lungs. If asked, you've lost a bit of weight recently but you've been dieting deliberately. You want to know if it's a clot and whether it's dangerous.

Hidden concerns (reveal if explored)

Fear of PE (main): you're scared it'll go to your lungs like your colleague's did. Being told the doctor has checked your breathing, and that treatment reduces that risk, reassures you.

The pill: you'll be surprised you have to stop it and will want to know about alternatives.

The scan/wait: you'd like an answer today; reassurance about the same-day pathway helps.

Clinical details if asked

Unilateral right calf swelling/pain, warm, tender; calf looks bigger than left; mild pitting
Onset gradual over 3 days; no trauma; reduced mobility after ankle sprain; 8-hour flight 2 weeks ago
On combined oral contraceptive pill; non-smoker; no previous clots; no family history of clots that you know of
No breathlessness, chest pain, haemoptysis, palpitations; not light-headed
Recent intentional weight loss (dieting); otherwise well; no other symptoms
No bleeding problems; no liver/kidney issues; on no other regular medication

Reactions at key moments

On the PE screen: relieved the doctor is checking your chest specifically.
On stopping the pill: "Oh — I'll need something else then?" → reassured by a clear alternative.
On anticoagulation: a bit daunted by months of tablets; reassured by clear explanation.
Challenge line: "Can't you just do a blood test now and tell me if it's a clot?"

"Is it going to go to my lungs like my colleague's did? And can't you just do a quick blood test to tell me right now if it's a clot?"

Resolution: Grace is reassured if the GP: (1) screens for and excludes PE explicitly and takes her fear seriously; (2) applies the Wells score and explains the correct pathway (likely → scan within 4 hours, with interim anticoagulation if delayed), including why a D-dimer alone isn't enough for her; (3) identifies the provoking factors and stops the COCP, arranging a safe alternative; (4) plans DOAC anticoagulation for ≥3 months with a clear duration review, and gives a PE/bleeding safety-net; (5) does a basic cancer review only if needed and frames it calmly. She's unsettled if PE is not addressed, the pathway is muddled, or the pill issue is missed.

🏥

Clinic Quick Reference

DVT — Clinical Decision Framework

NICE NG158 · Wells → USS/D-dimer · DOAC · Provoked vs unprovoked

▼expand

🚦 1 — The pathway

Suspected DVT → two-level Wells

▼

🔴 Emergency first

Unstable PE → 999
Phlegmasia / threatened limb

Admit

🟠 Likely (≥2)

Proximal USS ≤4h
If delayed → D-dimer + interim anticoag, USS ≤24h

Scan

🟢 Unlikely (≤1)

D-dimer; negative excludes
Positive → USS ≤4h

D-dimer

💊 2 — Treat & classify

Confirmed DVT: DOAC (apixaban/rivaroxaban) first-line ≥3 months; LMWH in pregnancy. Classify: provoked (flight/immobility/oestrogen/surgery) → usually 3 months + address factor (stop COCP, switch contraception); unprovoked → consider extended anticoagulation + occult-cancer review (history, examination, baseline bloods; further tests only if symptoms/signs — NG158) ± thrombophilia in the narrow NG158 groups. Safety-net for PE and bleeding; review at 3 months.

🎓

SCA Quick Reference

DVT — Consultation Playbook

Wells pathway · exclude PE · DOAC · stop the oestrogen

▼expand

🎯 The three pivots that pass this case

1 · Exclude PE

Always screen breathlessness/chest pain/haemoptysis/instability — PE is the lethal complication.

2 · Wells decides

Likely → USS ≤4h (interim anticoag if delayed); unlikely → D-dimer (rule out only). DOAC ≥3 months once confirmed.

3 · Classify & address

Provoked vs unprovoked drives duration + cancer/thrombophilia review. Stop the COCP and switch contraception.

⛔ Don't use D-dimer to "rule in", or to exclude DVT in a "likely" patient · Don't forget interim anticoagulation if the scan is delayed · Don't miss PE · Don't leave the combined pill running · In unprovoked VTE, do the occult-cancer review · No DOAC in pregnancy (LMWH)

DVT · GP Clinical Reasoning Framework v2 · NICE NG158 Venous thromboembolic diseases · NICE NG12 Suspected cancer (updated April 2026; occult malignancy in unprovoked VTE) · CoSRH UKMEC 2025 (contraception & VTE) · RCOG Green-top Guideline 37b (VTE in pregnancy) · MHRA Drug Safety Update June 2019 (DOACs in antiphospholipid syndrome)

Two-level Wells selects the pathway: likely (≥2) → proximal USS ≤4h (interim anticoag + D-dimer if delayed); unlikely (≤1) → D-dimer (rule out only) → USS if positive · DOAC (apixaban/rivaroxaban) first-line ≥3 months; LMWH in pregnancy · Always exclude PE; instability = emergency · Provoked vs unprovoked drives duration and the occult-cancer review (history, examination, baseline bloods; targeted tests only if symptoms/signs) · Stop oestrogen-containing contraception/HRT and switch method · Safety-net for PE and bleeding

Teaching clinicians why each step matters — not just what to do · Always consult current NICE NG158 and NG12 guidance · Clinical judgement takes precedence over any framework

DVT

Red Flags — the dangerous ends of DVT

😟 Fear of PE

💊 The pill conversation

💉 Living with anticoagulation

🔎 The weight-loss thread

Same day / 999

Hours (timed pathway)

After diagnosis

🚩 The discipline — classify the event, don't just treat it

Validate — name the expectation and the fear

Explain — share the reasoning

Negotiate — agree what happens next

Health Anxiety after VTE

Work & Fit Notes

Driving

Family, Travel & Culture

Living with a Blood Thinner

Identity, Body Image & Contraception

Day 0 — Same-day pathway

1–3 Weeks — Early review (phone or face to face)

~3 Months — Duration decision

After stopping — Planning ahead

If continued long term — At least annually

Memory rule — "Dose · Bleed · Kidney · Decide"

⚠ Scenario-specific phrases — use these verbatim

Why safety-netting matters beyond clinical care — document it

🎭 Patient actor brief — click to practise

Who you are

Hidden concerns (reveal if explored)

Clinical details if asked

Reactions at key moments