Eduovisual
Perioperative & Surgical Care
DVT prophylaxis in hospitalized patients
— Venous thromboembolism (VTE) — deep vein thrombosis (DVT) and pulmonary embolism (PE) — is among the most common preventable causes of in-hospital death in the United States
— Roughly half of all VTE events are hospital-acquired or develop within 90 days of discharge
— Designated a National Patient Safety Goal by The Joint Commission and a CMS quality measure (VTE bundle, SCIP measures historically)
— Virchow's triad: venous stasis (immobility, anesthesia), endothelial injury (surgery, central lines, trauma), hypercoagulability (malignancy, inflammation, estrogen, inherited thrombophilia)
— Hospitalization itself confers an ~8-fold increase in VTE risk; major orthopedic surgery without prophylaxis carries 40–60% DVT incidence
— Every adult admitted to a medical or surgical service requires a documented VTE risk assessment within 24 hours of admission and at transitions of care (ICU transfer, post-op)
— Acceptable tools: Padua score (medical), Caprini score (surgical), IMPROVE (medical + bleeding)
— Reassess daily — risk evolves with ambulation, bleeding events, procedures, and lines
— Reduce symptomatic DVT/PE and fatal PE while minimizing major bleeding and HIT
— Choice balances thrombosis risk vs bleeding risk vs renal function vs anticipated procedures
Board pearl: On Step 3, the wrong answer is almost always "no prophylaxis" for a hospitalized medical patient with reduced mobility plus one additional risk factor (age >70, cancer, prior VTE, sepsis, CHF, IBD flare). The right answer is risk-stratify, then choose pharmacologic vs mechanical.
CCS pearl: Order "VTE risk assessment" and "DVT prophylaxis" as standing orders at admission — failing to do so is a documented quality lapse the case will penalize.
— Active cancer (3 pts), prior VTE excluding superficial (3), reduced mobility ≥3 days (3), known thrombophilia (3)
— Recent trauma/surgery within 1 month (2)
— Age ≥70, heart/respiratory failure, acute MI/ischemic stroke, acute infection/rheumatologic disorder, BMI ≥30, ongoing hormonal treatment (1 each)
— Low (0–1): early ambulation alone
— Moderate (2): mechanical or pharmacologic prophylaxis
— High (3–4): pharmacologic prophylaxis
— Highest (≥5): pharmacologic + mechanical, consider extended duration
— Bleeding history: recent GI bleed, intracranial hemorrhage, hemorrhagic stroke <3 months, active peptic ulcer, platelets <50K, recent neurosurgery/spine surgery
— Procedure timing: epidural/spinal anesthesia requires careful LMWH timing (hold 12h before, restart 4h after catheter removal)
— Renal function: CrCl <30 alters LMWH and DOAC choice
— Weight extremes: BMI >40 or weight <50 kg may need weight-based or adjusted dosing
— Prior HIT: absolute contraindication to heparin/LMWH — use fondaparinux or argatroban
— Stroke: ischemic stroke with immobility → LMWH/UFH typically started 24–48h after confirming no hemorrhagic transformation; hemorrhagic stroke → mechanical first, pharmacologic delayed 1–4 days
— Trauma/TBI: pharmacologic prophylaxis often delayed 24–72h pending stable imaging
— Pure medical observation <48h with full ambulation: often does not require pharmacologic prophylaxis
Key distinction: Padua is for medical inpatients; Caprini is for surgical patients. Mixing them on a vignette is a classic distractor — match the tool to the setting.
Step 3 management: Document the score, the choice, and the rationale in the chart — Step 3 rewards explicit risk-benefit reasoning over rote prescribing.
— Vital signs: hypotension or tachycardia suggesting occult bleeding shifts toward mechanical-only prophylaxis
— Skin and mucosa: petechiae, ecchymoses, gingival bleeding suggest thrombocytopenia or coagulopathy
— Extremity exam: pre-existing calf asymmetry, varicosities, prior post-thrombotic changes, open wounds (relative SCD contraindication), severe PAD (contraindicates SCDs/compression stockings)
— Neuro exam: baseline deficit documentation matters before any anticoagulant in stroke or post-neurosurgical patient
— Active gastroduodenal ulcer (4.5), bleeding in 3 months prior to admission (4), platelets <50K (4)
— Age ≥85 (3.5), hepatic failure INR >1.5 (2.5), severe renal failure GFR <30 (2.5)
— ICU admission (2.5), central venous catheter (2), rheumatic disease (2), current cancer (2), male sex (1), age 40–84 (1.5)
— Intracranial, spinal, ophthalmic surgery — pharmacologic prophylaxis often deferred 24–48h
— Active surgical site oozing, falling hemoglobin, recent reoperation
— Intermittent pneumatic compression (IPC): severe PAD (ABI <0.5), acute DVT, severe leg edema/CHF, dermatitis, recent skin graft
— Graduated compression stockings (GCS): same plus arterial insufficiency — avoid in stroke (CLOTS-1 trial showed harm)
Board pearl: GCS alone are no longer recommended for stroke patients — CLOTS-1 demonstrated increased skin breakdown without VTE reduction. IPC is preferred mechanical option (CLOTS-3 positive).
CCS pearl: Document a focused bleeding-risk and limb exam before ordering enoxaparin — the case will reward a "PE & exam → risk score → order" sequence over reflexive prescribing.
— CBC with platelets: establishes baseline for HIT monitoring; platelets <50K generally contraindicates pharmacologic prophylaxis
— PT/INR and aPTT: detects unrecognized coagulopathy (liver disease, vitamin K deficiency, occult DIC); INR >1.5 from hepatic failure is a relative contraindication
— Basic metabolic panel with creatinine → calculate CrCl by Cockcroft-Gault (not eGFR) for LMWH/DOAC dosing decisions
— LFTs: severe hepatic dysfunction (Child-Pugh B/C) alters DOAC eligibility — rivaroxaban contraindicated in Child B/C, apixaban cautious in Child B
— Recent heparin exposure within 100 days + new thrombocytopenia → send HIT 4Ts score and PF4 antibody before continuing heparin/LMWH
— Known or suspected antiphospholipid syndrome: confirm baseline aPTT (may be falsely elevated)
— Pregnancy: anti-Xa monitoring may be appropriate for therapeutic LMWH; not routinely needed for prophylactic dosing
— Obesity (BMI >40) or weight <50 kg: consider anti-Xa monitoring with LMWH prophylaxis
— Routine screening duplex ultrasound in asymptomatic high-risk patients is not recommended (low yield, false positives, anticoagulation harms)
— Exception: select trauma/spinal cord injury protocols at some institutions, though guidelines don't mandate
— Recheck platelets every 2–3 days during first 14 days of heparin/LMWH exposure to detect HIT
— Recheck creatinine if clinical status changes (sepsis, contrast, nephrotoxins)
Step 3 management: A 30% drop in platelets between days 5–10 of heparin exposure = stop heparin/LMWH immediately, send HIT workup, start non-heparin anticoagulant (argatroban, bivalirudin, or fondaparinux) — do not wait for the antibody result.
Board pearl: CrCl <30 mL/min → avoid enoxaparin standard dose; use UFH 5000 units SC q8–12h or renally adjusted enoxaparin 30 mg SC daily.
— DVT: unilateral calf/thigh swelling, pain, warmth, Homan sign (low sensitivity), palpable cord
— PE: sudden dyspnea, pleuritic chest pain, tachycardia, hypoxia, syncope, unexplained hypotension
— Wells DVT score: ≥2 = likely → duplex US; <2 = unlikely → D-dimer first
— Wells PE score or Geneva: stratify, then D-dimer (if low/intermediate, hemodynamically stable) vs CT pulmonary angiography (CTPA) directly
— PERC rule: only valid in outpatient/ED low-risk; rarely applies to inpatients
— Elevated nonspecifically by surgery, infection, malignancy, pregnancy, age → low specificity in inpatients
— Use age-adjusted cutoff (age × 10 ng/mL for patients >50) in outpatient settings; many inpatients skip D-dimer and go directly to imaging
— A negative D-dimer with low pretest probability still rules out VTE
— Compression duplex ultrasound: first-line for suspected DVT; non-compressibility of vein = diagnostic
— CTPA: first-line for PE in stable patients with adequate renal function
— V/Q scan: alternative when contrast contraindicated (pregnancy, severe CKD, contrast allergy)
— Echocardiogram: in unstable suspected PE → look for RV strain, McConnell sign; supports bedside diagnosis when CTPA not feasible
— Switch from prophylactic to therapeutic anticoagulation
— Investigate prophylaxis failure: dosing adequacy, missed doses, HIT, occult malignancy
Key distinction: Prophylaxis dosing does NOT reliably treat established VTE — a confirmed DVT on enoxaparin 40 mg daily requires escalation to 1 mg/kg q12h or equivalent.
CCS pearl: Breakthrough VTE on heparin prophylaxis with thrombocytopenia → suspect HIT, send 4Ts and PF4, switch to argatroban immediately.
— Medical: Padua ≥4 = high risk (~11% VTE without prophylaxis)
— Surgical: Caprini ≥3 = moderate; ≥5 = high
— Orthopedic: all total hip/knee arthroplasty and hip fracture patients = high risk by default
— Medical: IMPROVE bleeding score ≥7 = high bleeding risk → mechanical only
— Surgical: procedure-specific (neurosurgery, ophthalmic, spinal — high)
— Low VTE risk: early ambulation only
— Moderate/high VTE risk, low bleeding risk: pharmacologic — LMWH preferred, UFH if CrCl <30
— High VTE risk, high bleeding risk: mechanical (IPC) until bleeding risk resolves, then add pharmacologic
— Highest risk (e.g., hip fracture, major trauma, ICU sepsis): combined mechanical + pharmacologic
— General medical ward, Padua ≥4, no bleeding: enoxaparin 40 mg SC daily OR heparin 5000 units SC q8h
— ICU: nearly all patients qualify — LMWH preferred over UFH (PROTECT trial showed less PE)
— General surgery, moderate risk: enoxaparin 40 mg SC daily starting 12h pre-op or 12–24h post-op
— Orthopedic THA/TKA: enoxaparin 30 mg q12h or 40 mg daily, rivaroxaban 10 mg daily, apixaban 2.5 mg BID, or aspirin 81 mg BID (selected low-risk after initial anticoagulation)
— Hip fracture surgery: prophylaxis for ≥35 days post-op
— Bariatric surgery: weight-adjusted enoxaparin (e.g., 40 mg BID for BMI >40)
— Most medical patients: until discharge or full ambulation
— Extended prophylaxis (post-discharge) for THA (35 days), TKA (10–14 days), abdominal/pelvic cancer surgery (28 days), high-risk medical patients per APEX/MAGELLAN data (selected)
Board pearl: Routine extended prophylaxis after general medical hospitalization is not recommended — trials showed bleeding offset VTE benefit. Reserve for selected high-risk subgroups.
— Enoxaparin 40 mg SC daily (medical, general surgery) or 30 mg SC q12h (orthopedic, trauma)
— Mechanism: anti-Xa > anti-IIa activity; binds antithrombin
— Renal clearance — avoid or reduce if CrCl <30 (use 30 mg daily or switch to UFH)
— Advantages: once-daily, no aPTT monitoring, lower HIT risk than UFH
— Dalteparin 5000 units SC daily is an alternative
— 5000 units SC q8h (high risk) or q12h (moderate risk, lower bleeding tolerance)
— Preferred when CrCl <30, hemodialysis, or imminent procedures (short half-life, easy reversal with protamine)
— Monitor platelets every 2–3 days for HIT
— 2.5 mg SC daily; synthetic pentasaccharide, pure anti-Xa
— No cross-reactivity with HIT antibodies — agent of choice in HIT history (with hematology guidance)
— Avoid if CrCl <30; contraindicated <50 kg in some settings
— Rivaroxaban 10 mg PO daily — THA, TKA
— Apixaban 2.5 mg PO BID — THA, TKA
— Dabigatran 220 mg PO daily — approved internationally; less US use
— Betrixaban: approved for extended medical prophylaxis but limited uptake
— Only after initial LMWH/DOAC course in low-risk TKA/THA patients (ASA 81 mg BID × remainder of 35 days), per AAOS and ACCP
— Not adequate as sole agent for high-VTE-risk patients
— IPC preferred over GCS; sequential calf-thigh devices
— Must be worn ≥18 hours/day to be effective
Step 3 management: Order LMWH at the same time as admission orders, document score, hold for active bleeding/platelets <50K/procedures within 12h. Restart 6–12h after most procedures, 24h after neuraxial/high-bleeding-risk procedures.
Board pearl: Fondaparinux = HIT-safe alternative; argatroban/bivalirudin = active HIT treatment.
— Prophylactic LMWH: last dose ≥12h before neuraxial procedure or catheter removal
— Therapeutic LMWH: ≥24h before
— Restart LMWH ≥4h after catheter removal
— UFH SC 5000 units q8–12h: no significant delay needed for neuraxial, but check platelets if >4 days exposure
— DOACs: hold rivaroxaban/apixaban ≥3 days before neuraxial (longer if renal dysfunction)
— Most general surgery: start LMWH 12h pre-op or 12–24h post-op
— High-bleeding-risk surgery (neuro, spine, ophthalmic, prostate): start post-op only, often 24–48h after hemostasis confirmed
— Trauma: initiate as early as 24–48h after stable imaging in TBI/solid organ injury per modern protocols
— Patients on chronic warfarin admitted for surgery: assess CHA₂DS₂-VASc, mechanical valve status — most AFib patients do not need bridging (BRIDGE trial). Mechanical mitral valves or recent VTE <3 months → bridge with therapeutic LMWH/UFH
— UFH: protamine 1 mg per 100 units heparin given in last 2–3h (max 50 mg)
— LMWH: protamine reverses ~60% (1 mg per 1 mg enoxaparin if <8h); andexanet not indicated for prophylactic doses
— Rivaroxaban/apixaban major bleed: andexanet alfa or 4-factor PCC 50 units/kg
— Dabigatran: idarucizumab 5 g IV
— Warfarin: vitamin K 10 mg IV + 4-factor PCC
— Stop all heparin (including flushes); switch to argatroban (hepatic clearance, preferred in renal failure) or bivalirudin (renal/hepatic clearance, preferred in liver disease)
— Do not start warfarin until platelets recover >150K — risk of venous limb gangrene
CCS pearl: "Hold heparin, send 4Ts and PF4 ELISA, start argatroban, hematology consult, avoid platelet transfusion" — the textbook HIT order set.
— Higher baseline VTE risk AND higher bleeding risk — net benefit usually favors pharmacologic prophylaxis
— Reduced renal function is often unrecognized — always calculate CrCl by Cockcroft-Gault, not just creatinine
— Fall risk alone is not a contraindication to prophylactic anticoagulation — absolute bleed risk from falls is low
— Polypharmacy: review for NSAIDs, SSRIs, antiplatelets that increase bleeding
— CrCl ≥30: standard enoxaparin 40 mg SC daily
— CrCl 15–29: enoxaparin 30 mg SC daily OR UFH 5000 units SC q8–12h (preferred)
— CrCl <15 or dialysis: UFH 5000 units SC q8–12h is standard; LMWH and DOACs generally avoided
— Fondaparinux: avoid if CrCl <30
— Apixaban has the most favorable renal profile among DOACs but is not first-line for prophylaxis in CKD V
— Child-Pugh A: most agents acceptable
— Child-Pugh B: rivaroxaban contraindicated; apixaban use with caution; LMWH preferred
— Child-Pugh C: avoid DOACs; LMWH or UFH with careful monitoring; bleeding risk from varices, thrombocytopenia, coagulopathy may favor mechanical-only
— Cirrhosis is NOT protective against VTE despite elevated INR — these patients have rebalanced hemostasis and still develop DVT/PE
— LMWH historically preferred; apixaban and rivaroxaban now non-inferior per CARAVAGGIO and SELECT-D for treatment
— For prophylaxis in hospitalized cancer patients: LMWH 40 mg daily is standard
— GI/GU cancers — increased bleeding risk on DOACs; LMWH preferred
Board pearl: Cirrhotic with INR 1.8 admitted with cellulitis still needs VTE prophylaxis — the "auto-anticoagulated" myth is a wrong-answer trap. Use LMWH unless platelets <50K or active variceal bleeding.
Step 3 management: Recalculate CrCl whenever creatinine shifts >25% — adjust LMWH dose mid-admission, not just on day 1.
— Pregnancy itself is hypercoagulable; postpartum (especially first 6 weeks) is the highest-risk period
— LMWH is the agent of choice — does not cross placenta; warfarin teratogenic (6–12 weeks); DOACs not recommended (limited data, possible fetal effects)
— Prophylaxis indications: prior VTE, high-risk thrombophilia (antithrombin deficiency, homozygous factor V Leiden, APS), cesarean delivery with additional risk factors
— Cesarean delivery: routine pharmacologic prophylaxis if additional risk factors (obesity, age >35, prolonged labor, infection, prior VTE); mechanical for all
— Postpartum prophylaxis duration: ≥6 weeks for high-risk; longer for known APS or prior VTE
— Anti-Xa monitoring sometimes used in pregnancy for therapeutic dosing; not routine for prophylactic
— VTE rare in healthy children; risk concentrated in adolescents, central venous catheters, malignancy, congenital heart disease, IBD, nephrotic syndrome, trauma
— Routine pharmacologic prophylaxis not standard for most hospitalized children
— Adolescents (≥12–14) with adult-pattern risk factors (post-op, immobility, oral contraceptives, obesity) increasingly receive LMWH 0.5 mg/kg SC q12h prophylaxis at many centers
— Mechanical prophylaxis when device size permits
— Standard fixed-dose enoxaparin underdoses these patients
— Common adjustments: enoxaparin 40 mg SC BID for BMI 40–50; 0.5 mg/kg SC daily weight-based; bariatric surgery patients often get 40 mg BID
— Consider anti-Xa monitoring (target prophylactic peak 0.2–0.5 IU/mL, drawn 4h post-dose)
— Increased bleeding risk; consider enoxaparin 30 mg daily or UFH
Key distinction: Warfarin is contraindicated in pregnancy (except mechanical valves, second trimester only); DOACs are contraindicated throughout pregnancy and lactation; LMWH is the safe default.
Board pearl: Postpartum day 3 with prior unprovoked DVT → restart LMWH for 6 weeks minimum, transition to warfarin or apixaban if not breastfeeding considerations interfere (LMWH and warfarin are lactation-compatible; DOACs are not).
— Major bleeding: defined as fatal, intracranial, intraspinal, intraocular, retroperitoneal, or causing Hb drop ≥2 g/dL or requiring ≥2 units pRBCs
— Risk with prophylactic LMWH ~0.5–1%; higher with UFH and in renal failure
— Management: hold anticoagulant, transfuse as needed, reverse if life-threatening (protamine for heparin), identify source, hold mechanical compression if bleeding into compartment
— Type II HIT: immune-mediated, IgG vs heparin-PF4 complex; typically days 5–10 of exposure (or within hours if re-exposed within 100 days)
— 4Ts score: Thrombocytopenia magnitude, Timing, Thrombosis, oTher causes
— Paradoxical thrombosis in 30–50% — arterial and venous, including limb gangrene, skin necrosis at injection sites
— Risk: UFH (1–5%) >> LMWH (<1%); fondaparinux negligible
— Treatment: stop all heparin, send PF4 immunoassay + functional assay (SRA), start argatroban or bivalirudin, avoid warfarin until platelets >150K, avoid platelet transfusions unless bleeding
— Bruising, hematomas, rarely skin necrosis (consider warfarin-induced or HIT-related)
— Relevant for pregnancy-long therapeutic anticoagulation, less so for short prophylaxis
— IPC: skin breakdown, peroneal nerve compression, false sense of security if poorly applied or not worn ≥18h/day
— GCS: arterial compromise in PAD, skin ulceration, especially in stroke patients (CLOTS-1)
— Breakthrough VTE despite appropriate prophylaxis occurs in 1–3% — investigate dosing, adherence, occult malignancy, antiphospholipid syndrome, HIT
Step 3 management: New thrombocytopenia + new DVT in a patient on heparin = HIT until proven otherwise — empiric switch to argatroban does not wait for lab confirmation.
Board pearl: Warfarin started in active HIT without bridging non-heparin anticoagulant → venous limb gangrene from protein C depletion.
— Suspected or confirmed massive/submassive PE: hypotension (SBP <90 for 15 min), syncope, RV strain on echo, troponin elevation, lactate elevation
— Major bleeding on prophylaxis requiring transfusion ≥2 units or hemodynamic instability
— HIT with thrombosis requiring continuous argatroban infusion
— Confirmed or strongly suspected HIT (4Ts ≥4)
— Antiphospholipid syndrome with thrombosis (triple-positive APS — DOACs contraindicated, warfarin preferred)
— Recurrent VTE despite adequate anticoagulation
— Inherited thrombophilia workup interpretation (rarely changes acute management; usually deferred to outpatient)
— Cancer-associated thrombosis with thrombocytopenia (platelets 25–50K) — modified anticoagulation strategy
— IVC filter considerations: only for acute VTE with absolute contraindication to anticoagulation or recurrent PE despite therapeutic anticoagulation; retrievable filters preferred with documented removal plan
— Not indicated for primary prophylaxis in trauma/bariatric/orthopedic patients per modern evidence (PREPIC-2)
— Catheter-directed thrombolysis for selected iliofemoral DVT with severe limb symptoms
— Weight-based dosing in extreme obesity, anti-Xa monitoring protocols, renal dose adjustments, drug-drug interactions (DOAC + strong CYP3A4/P-gp inhibitors or inducers)
— Many academic centers have multidisciplinary PERT teams for intermediate-high and high-risk PE — single page activates pulmonology, cardiology, CT surgery, IR
— Goals-of-care discussion when prophylaxis decisions intersect with comfort care, bleeding burden, or terminal cancer
CCS pearl: Confirmed massive PE → transfer to ICU, order systemic tPA 100 mg over 2h (or 0.6 mg/kg bolus if arrest), surgical/IR consult for embolectomy if thrombolysis contraindicated, echo at bedside.
Key distinction: IVC filters are not primary prophylaxis tools — selecting one as "prophylaxis" on Step 3 is almost always wrong.
— Superficial thrombophlebitis: palpable, tender cord along great or small saphenous vein; treat with NSAIDs ± fondaparinux 2.5 mg daily for 45 days if >5 cm and near saphenofemoral junction
— Chronic venous insufficiency / post-thrombotic syndrome: bilateral or unilateral, hemosiderin staining, lipodermatosclerosis, ulcers at medial malleolus; compression therapy
— Iliac vein compression (May-Thurner): left leg DVT in young women, left common iliac vein compressed by right common iliac artery; venography + stenting
— Venous obstruction from mass: pelvic malignancy, lymphadenopathy — CT abdomen/pelvis
— Upper extremity DVT (Paget-Schroetter): effort thrombosis in young athletes with thoracic outlet syndrome — duplex US, then thrombolysis + first-rib resection
— Catheter-associated UEDVT: most common cause of UEDVT in hospitalized patients; anticoagulate if line removed or if line remains and is functional
— Cerebral venous sinus thrombosis: headache, seizures, focal deficits, papilledema; MR venography; LMWH/UFH then warfarin
— Splanchnic vein thrombosis: portal, mesenteric, splenic — associated with cirrhosis, JAK2 mutation, pancreatitis; anticoagulate unless contraindicated
— Fat embolism: 24–72h after long-bone fracture; petechiae, hypoxia, altered mental status
— Amniotic fluid embolism: peripartum collapse with DIC
— Air embolism: central line manipulation, neurosurgery, dive injuries
— Tumor embolism: rare, advanced malignancy
Board pearl: Left leg DVT in a young woman without obvious provoking factor → think May-Thurner syndrome; image with CT/MR venography and consider stenting in addition to anticoagulation.
Key distinction: Superficial thrombophlebitis ≠ DVT — but a clot within 3 cm of the deep system or >5 cm in length warrants anticoagulation, not just NSAIDs.
— Cellulitis: warmth, erythema with sharp borders, fever, leukocytosis, often portal of entry; usually unilateral
— DVT: warmth and swelling without sharp erythema, low-grade fever possible
— Both can coexist — when in doubt, duplex US before committing to anticoagulation in suspected cellulitis
— Baker cyst rupture: posterior knee pain, sudden calf swelling mimicking DVT; ultrasound differentiates
— Compartment syndrome: severe pain out of proportion, pain with passive stretch, paresthesias, pulselessness late
— Lymphedema: chronic, non-pitting, pitting early, Stemmer sign positive; often post-surgical or post-radiation
— Hematoma: anticoagulation, trauma, ecchymosis
— Heart failure, cirrhosis, nephrotic syndrome, hypoalbuminemia, severe pulmonary hypertension, medication-induced (CCBs, gabapentin, NSAIDs, pioglitazone), venous insufficiency
— Acute MI / NSTEMI: troponin, ECG
— CHF exacerbation: BNP, CXR, JVD, S3
— Pneumonia: fever, infiltrate, productive cough
— COPD/asthma exacerbation: wheezing, prolonged expiration
— Pneumothorax: post-procedure (central line, thoracentesis), absent breath sounds
— Anxiety/pain: diagnosis of exclusion
— Anemia/hemorrhage: hidden bleed on prophylactic anticoagulation
Step 3 management: Hospitalized patient with new dyspnea + tachycardia → don't lock onto PE; check ECG, troponin, BNP, CXR, and bedside echo concurrently with CTPA decision. Wells score still helps drive imaging logic.
Board pearl: Sudden post-op dyspnea with hypotension in an obese patient who missed two doses of LMWH → PE is high on the list, but always exclude hemorrhage (occult retroperitoneal bleed) before reflexively escalating anticoagulation.
— Total hip arthroplasty: 35 days total (in-hospital + outpatient) — rivaroxaban 10 mg daily, apixaban 2.5 mg BID, enoxaparin 40 mg daily, or aspirin 81 mg BID after initial 5 days of anticoagulant
— Total knee arthroplasty: 10–14 days minimum, up to 35 days
— Hip fracture surgery: 35 days
— Major abdominal/pelvic cancer surgery: 28 days post-op enoxaparin
— Acutely ill medical patients: extended prophylaxis (e.g., betrixaban, rivaroxaban per MARINER) showed modest VTE reduction offset by bleeding — not routinely recommended; consider for highly selected patients (prior VTE, active cancer, severely reduced mobility expected to persist)
— Failing to stop in-hospital prophylactic LMWH at discharge when no longer needed
— Failing to continue extended prophylaxis after orthopedic surgery
— Drug interactions: DOACs + strong CYP3A4/P-gp inhibitors (ketoconazole, ritonavir) or inducers (rifampin, phenytoin) — adjust or switch
— Insurance/coverage: enoxaparin can cost >$400/month uninsured — verify access before discharge; apixaban/rivaroxaban often covered but may require prior auth
— Injection technique for LMWH (rotate sites, abdomen preferred, do not expel air bubble in prefilled syringe)
— Bleeding warning signs: black stools, hematuria, severe headache, falls
— Symptoms of recurrent DVT/PE: unilateral leg swelling, sudden dyspnea, chest pain, syncope
— Avoid NSAIDs, limit alcohol, no contact sports during anticoagulation
— Phone call or visit within 7 days of discharge for high-risk patients
— In-person follow-up in 2–4 weeks for orthopedic patients
— CBC if extended LMWH (HIT surveillance)
Step 3 management: A patient discharged after THA with rivaroxaban 10 mg daily prescription has no need for routine INR or anti-Xa monitoring, but does need follow-up at 2–4 weeks and a clear stop date at day 35.
Board pearl: Extended prophylaxis after general medical hospitalization is the wrong answer unless the vignette specifies active cancer or persistent immobility.
— CBC every 2–3 days for first 14 days of heparin/LMWH (HIT surveillance)
— Creatinine as clinical status warrants — adjust LMWH dosing
— Hemoglobin trend — investigate any drop >1 g/dL
— Injection site assessment daily — bruising, hematoma, necrosis
— Mechanical device compliance — IPC must be worn ≥18 h/day; document on nursing flowsheet
— Prophylactic LMWH does not require anti-Xa levels in most patients
— Exceptions: pregnancy (sometimes), extreme obesity, renal impairment, weight <50 kg → consider peak anti-Xa 4h post-dose (target 0.2–0.5 IU/mL)
— DOACs at prophylactic doses: no routine monitoring
— Most patients: no specific VTE-related follow-up needed
— Orthopedic patients on extended prophylaxis: 2–4 week visit for surgical recovery and prophylaxis adherence
— Patients who experienced HIT: lifelong avoidance of heparin/LMWH, medical alert bracelet, document in chart prominently
— Ambulation is prophylaxis — emphasize early, frequent ambulation as the most underused intervention
— Hydration, leg exercises (ankle pumps), avoidance of prolonged sitting
— Travel post-discharge: hydration, ambulation every 2 hours, consider compression stockings for flights >4h in moderate-risk patients
— CMS VTE-1 and VTE-6 measures track appropriate prophylaxis on admission and hospital-acquired VTE rates
— Hospital-acquired VTE is a non-reimbursable "never event" in some scenarios — institutional protocols increasingly mandate computerized risk assessment with hard stops
CCS pearl: When you discharge a patient, include "ambulate ≥4 times daily, follow-up in 2 weeks, return for unilateral leg swelling or new dyspnea" in your standard discharge instructions — the case rewards proactive transition-of-care planning.
Board pearl: Routine anti-Xa monitoring for prophylactic enoxaparin = wrong answer unless specific population (pregnancy, obesity, renal impairment).
— Pharmacologic prophylaxis carries small but real bleeding risk — discuss with competent patients, especially when bleeding risk is elevated
— Patient refusal of prophylaxis: document discussion of VTE risk, alternatives (mechanical), and patient's specific reasons — refusal of LMWH does not absolve the team of offering IPC or early ambulation
— Computerized clinical decision support (CDS) with admission VTE risk assessment is among the highest-impact patient safety interventions; mandatory at most US hospitals
— Hard stop or default order set drives prophylaxis use from ~50% to >90% in many institutions
— "Hospital-acquired condition" status for some VTE events drives hospital accountability
— Surgery to floor: confirm prophylaxis resumed after procedure
— ICU to floor: re-assess risk; many ICU patients had pharmacologic held — restart appropriately
— Hospital to home: medication reconciliation must include prophylactic anticoagulant if continuing; post-discharge VTE within 90 days is a major liability and quality concern
— Skilled nursing facility transfer: ensure injection administration capability; if patient cannot self-inject and no caregiver, consider DOAC
— Hospital-acquired VTE may be reportable to state quality registries; some institutions require root-cause analysis for any HA-VTE
— End-of-life care: pharmacologic prophylaxis often discontinued when transitioning to comfort care — discuss with family and team
— Jehovah's Witness patients: prophylaxis is permitted; only blood products are refused — but bleeding management options are limited, raising the threshold for pharmacologic prophylaxis in some cases
— Capacity assessments: delirious patient refusing injections — pursue surrogate decision-maker, document capacity assessment
Step 3 management: Patient discharged after THA without rivaroxaban prescription, develops PE on day 20 → root cause: transition-of-care failure. Mitigation: discharge checklist, pharmacy verification, follow-up phone call within 72 hours.
Board pearl: Refusal of LMWH ≠ refusal of all prophylaxis — offer IPC and document the conversation.
— Untreated DVT risk in major orthopedic surgery: 40–60%
— Hospitalization confers ~8× baseline VTE risk
— Padua score ≥4 = high VTE risk; IMPROVE bleed ≥7 = high bleed risk
— Caprini ≥5 = highest risk surgical
— Symptomatic DVT after THA without prophylaxis: ~20%; with prophylaxis: ~2%
— Enoxaparin prophylaxis: 40 mg SC daily (medical) or 30 mg SC q12h (orthopedic)
— UFH: 5000 units SC q8h or q12h
— Fondaparinux: 2.5 mg SC daily — HIT-safe
— Rivaroxaban prophylaxis: 10 mg PO daily
— Apixaban prophylaxis: 2.5 mg PO BID
— Medical patient: until ambulating well or discharge
— TKA: 10–14 days minimum, up to 35
— THA / hip fracture: 35 days
— Cancer abdominal/pelvic surgery: 28 days
— Postpartum high-risk: 6 weeks minimum
— Aspirin alone for high-risk medical or orthopedic prophylaxis in highest-risk patients
— IVC filter as primary prophylaxis
— Routine D-dimer in asymptomatic surveillance
— Warfarin in pregnancy (except mechanical valve, 2nd trimester)
— DOACs in pregnancy, breastfeeding, triple-positive APS
— LMWH in CrCl <15 (use UFH)
— Heparin restart in patient with prior HIT (use fondaparinux)
— Routine extended prophylaxis after general medical hospitalization
— Compression stockings in stroke patients (CLOTS-1 harm)
Board pearl: A vignette mentioning heparin, falling platelets day 7, and new clot = HIT. Switch to argatroban (renal-friendly) or bivalirudin (hepatic-friendly); not fondaparinux acutely if active thrombosis (though acceptable in stable HIT history).
CCS pearl: Memorize: "Padua ≥4 = LMWH, IMPROVE ≥7 = IPC only."
— 72-year-old admitted with CHF exacerbation, BMI 32, prior provoked DVT 5 years ago, now bed-bound x2 days. What's the best next step?
— Answer: Enoxaparin 40 mg SC daily (Padua ≥4, no bleeding contraindication)
— 68-year-old with CKD stage 5 on hemodialysis admitted for pneumonia. Best prophylaxis?
— Answer: UFH 5000 units SC q8h (enoxaparin avoided)
— Day 7 of UFH prophylaxis, platelets drop from 220 to 90, new right leg swelling. Next step?
— Answer: Stop heparin, send PF4 and 4Ts, start argatroban. NOT: continue heparin pending labs; NOT: warfarin; NOT: platelet transfusion.
— Patient discharged day 3 after THA. Discharge prophylaxis duration?
— Answer: 35 days total — rivaroxaban 10 mg daily or equivalent.
— Hospitalized patient with active upper GI bleed, melena, Hb 7.2, on omeprazole drip. VTE prophylaxis?
— Answer: Intermittent pneumatic compression until bleeding resolves, then add pharmacologic.
— 28-year-old G2P1 at 32 weeks, prior unprovoked DVT, admitted for preterm labor. Best agent?
— Answer: LMWH (enoxaparin) — never warfarin or DOAC in pregnancy.
— Cirrhotic with INR 1.7, platelets 80K, admitted for SBP, ambulating minimally. Prophylaxis?
— Answer: Enoxaparin 40 mg SC daily — cirrhosis is not protective; only hold if platelets <50K or active variceal bleed.
— Patient on enoxaparin 40 mg SC daily, scheduled for epidural placement. Timing?
— Answer: Hold ≥12 hours before placement; restart ≥4 hours after catheter removal.
— Trauma patient with multiple injuries, no active VTE, anticoagulation held 48h post-op. Best prophylaxis?
— Answer: IPC ± early LMWH when stable, NOT prophylactic IVC filter.
Step 3 management: Most stems hinge on matching the agent to renal function, bleeding risk, and special population status — read those three data points first.
The Step 3 mandate: Every hospitalized adult requires a documented VTE risk assessment within 24 hours of admission, with prophylaxis (pharmacologic, mechanical, or combined) tailored to thrombosis risk, bleeding risk, renal function, and special population status, continued for an evidence-based duration that may extend beyond discharge.
— Risk-stratify with Padua (medical) or Caprini (surgical); bleeding risk with IMPROVE; document the score, the choice, the rationale
— First-line pharmacologic agent: LMWH (enoxaparin 40 mg SC daily medical; 30 mg q12h orthopedic); switch to UFH 5000 SC q8–12h if CrCl <30; use fondaparinux for HIT history
— Extended prophylaxis durations to memorize: THA 35 days, TKA 10–14 days (up to 35), hip fracture 35 days, abdominal/pelvic cancer surgery 28 days, postpartum high-risk 6 weeks
— High-bleeding-risk patients (active GI bleed, platelets <50K, recent intracranial bleed, IMPROVE ≥7): IPC mechanical-only until bleeding resolves; avoid GCS in stroke (CLOTS-1)
— HIT algorithm: stop all heparin, send 4Ts + PF4 ELISA, start argatroban (or bivalirudin in renal failure), avoid warfarin until platelets recover >150K, no platelet transfusion unless bleeding — and never re-expose to heparin lifelong
— Pregnancy: LMWH only; never warfarin (except mechanical valve, 2nd trimester) or DOACs
— Transitions of care are the highest-yield Step 3 angle: medication reconciliation at admission, post-procedure, ICU transfer, and discharge — failure to continue extended prophylaxis after orthopedic surgery is a classic vignette and a real-world quality event
Board pearl: When in doubt on a Step 3 VTE prophylaxis question, the right answer is rarely "nothing" and rarely "IVC filter" — it is usually the LMWH dose adjusted to that patient's specific physiology, or IPC when bleeding precludes pharmacology.