Cardiovascular · Topic 44 of 48

VTE Prophylaxis in Hospitalized Adults

Cardiovascular · VTE prevention

VTE Prophylaxis in Hospitalized Adults

Score clot and bleeding risk on admission; give enoxaparin 40 mg daily to high-risk patients, and IPC when bleeding risk rules out anticoagulants.

Key numbers

Padua score ≥ 4 means high riskPadua ≥ 4

Enoxaparin 40 mg SC once daily40 mg SC daily

CrCl under 30: enoxaparin 30 mg dailyCrCl < 30 → 30 mg

BMI ≥ 40: enoxaparin 40 mg twice dailyBMI ≥ 40 → 40 mg BID

01 · Defined byPadua score ≥ 4 means high risk

A Padua score of 4 or more marks a medical inpatient as high VTE risk: give pharmacologic prophylaxis unless contraindicated (active bleeding, low platelets); below 4, decide case by case.

02 · GiveEnoxaparin 40 mg SC once daily

Standard prophylaxis for an acutely ill medical inpatient is enoxaparin 40 mg subcutaneously once daily; LMWH is preferred over unfractionated heparin.

03 · GiveCrCl under 30: enoxaparin 30 mg daily

For CrCl below 30 mL/min, reduce prophylactic enoxaparin to 30 mg subcutaneously once daily, or use unfractionated heparin 5000 units subcutaneously, which is not renally cleared.

The rules

Know these

Medical patients: stop prophylaxis at dischargeFor acutely or critically ill medical patients, give prophylaxis only during the hospital stay; extended post-discharge prophylaxis (including a DOAC) adds bleeding without net benefit.

LMWH, not a DOAC, for medical inpatientsASH strongly recommends LMWH over a DOAC for inpatient prophylaxis of acutely ill medical patients.

Critically ill: UFH or LMWH prophylaxisCritically ill patients should receive UFH or LMWH prophylaxis (LMWH suggested over UFH); mechanical and pharmacologic methods are not routinely combined in medical patients.

Surgery: match prophylaxis to Caprini riskLow-risk surgical patients (Caprini 1–2) get IPC; moderate risk (3–4) LMWH, low-dose UFH or IPC; high risk (≥ 5) LMWH or low-dose UFH plus IPC.

Hip or knee replacement: DOAC or LMWH, extendedAfter total hip or knee arthroplasty, DOACs are preferred (LMWH, fondaparinux or aspirin are options), continued about 14 days after knee and 28 days after hip replacement; hip fracture surgery, 14–35 days.

No IVC filter for primary preventionIVC filters are not indicated for primary VTE prevention, and graduated compression stockings alone are of questionable benefit except in low-risk surgical and selected medical patients.

Diagnosis & monitoring

Work-up

Monitor platelets on any heparinCheck platelet counts during heparin or LMWH prophylaxis because of heparin-induced thrombocytopenia, which is more common with unfractionated heparin.

Do right now

In this order

First moves

Score VTE and bleeding risk on admission

→

Padua score ≥ 4 means high riskPadua ≥ 4

→

High bleeding risk: intermittent pneumatic compression instead

→

Enoxaparin 40 mg SC once daily40 mg SC daily

Why each step

Score VTE and bleeding risk on admissionAssess every hospitalized adult with a validated tool for VTE risk (Padua or IMPROVE for medical, Caprini or Rogers for surgical patients) and for bleeding risk (IMPROVE bleeding score) before choosing prophylaxis.

Padua score ≥ 4 means high riskA Padua score of 4 or more marks a medical inpatient as high VTE risk: give pharmacologic prophylaxis unless contraindicated (active bleeding, low platelets); below 4, decide case by case.

High bleeding risk: intermittent pneumatic compression insteadWhen bleeding risk or another contraindication rules out anticoagulants, use mechanical prophylaxis — intermittent pneumatic compression — and switch to an anticoagulant once bleeding risk falls.

Enoxaparin 40 mg SC once dailyStandard prophylaxis for an acutely ill medical inpatient is enoxaparin 40 mg subcutaneously once daily; LMWH is preferred over unfractionated heparin.

Management

Orders

Low-dose UFH 5000 units every 8–12 hoursLow-dose unfractionated heparin is 5000 units subcutaneously every 8–12 hours (every 12 hours for bedbound medical patients); it is the fallback when LMWH is unsuitable.

BMI ≥ 40: enoxaparin 40 mg twice dailyFixed 40-mg dosing underdoses severe obesity: for BMI 40 or higher, use enoxaparin 40 mg subcutaneously twice daily, considering higher doses at BMI 50 or higher; low-weight patients may need only 30 mg daily.

Red flags & don'ts

Avoid harm

Neuraxial catheter: wait 12 hours after prophylactic LMWH avoidLMWH has a boxed warning for spinal/epidural hematoma: place or remove an epidural catheter ≥ 12 hours after a prophylactic enoxaparin dose (≥ 24 hours after treatment doses); redose ≥ 4 hours later.

Medical or surgical inpatient?

Commonly confused

Risk tool	Padua (≥ 4 = high risk) or IMPROVE
Usual agent	LMWH (enoxaparin 40 mg daily) or low-dose UFH
Hip or knee replacement	Not applicable
Duration	Hospital stay only

More detail

Reference

Show 7 reference facts

Padua points: 3 each for active cancer, prior VTE, reduced mobility, thrombophilia; 2 for recent trauma or surgery; 1 each for age ≥ 70, heart/respiratory failure, MI/stroke, infection/rheumatologic disease, BMI ≥ 30, hormones.

Pharmacologic prophylaxis is generally not used for transurethral prostate resection, laparoscopic cholecystectomy or most neurosurgery; elective neurosurgery uses mechanical prophylaxis.

After major abdominal or pelvic cancer surgery, LMWH prophylaxis is extended beyond discharge.

Chronically ill or nursing-home patients and outpatients with minor provoking factors do not need routine prophylaxis; long-haul travelers without risk factors need only ambulation and calf exercises.

Fondaparinux 2.5 mg subcutaneously daily is an alternative to heparins but not first line because of bleeding risk and renal clearance.

Selected high-risk ambulatory cancer patients receiving chemotherapy (eg, advanced pancreatic cancer) may receive primary prophylaxis with LMWH, apixaban or rivaroxaban.

Medical patients at higher VTE risk include those in critical care and those with heart failure, cancer, respiratory failure, immobility ≥ 3 days, hormonal therapy, thrombophilia, prior VTE or age ≥ 70.

Pearl

Every admission gets two scores — clot risk and bleeding risk — and the pair decides: heparin, pneumatic compression, or nothing.

Sources · Merck Manual Professional — Deep Venous Thrombosis (DVT) Prevention · Schünemann HJ et al. American Society of Hematology 2018 guidelines for management of VTE: prophylaxis for hospitalized and nonhospitalized medical patients. Blood Adv 2018;2(22):3198–3225 · Lovenox (enoxaparin sodium) prescribing information — DailyMed · MDCalc — Padua Prediction Score for Risk of VTE · Sebaaly J, Covert K. Enoxaparin dosing at extremes of weight: literature review and dosing recommendations. Ann Pharmacother 2018;52(9):898–909 · Merck Manual Professional — Medications for Deep Venous Thrombosis · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).