Should Lovenox (enoxaparin) be started on a patient post fall with negative imaging?

Should Lovenox Be Started Post-Fall with Negative Imaging?

Yes, Lovenox should be started for VTE prophylaxis in post-fall patients with negative imaging if they meet high-risk criteria (immobility, inability to move lower limbs independently, or prolonged bed rest), but only after excluding intracranial hemorrhage and ensuring hemodynamic stability. 1

Risk Stratification is Critical

The decision hinges on assessing VTE risk factors, not the fall itself:

• High-risk patients include: those unable to move one or both lower limbs, unable to mobilize independently, with previous VTE history, dehydration, or comorbidities like cancer 1
• Immobility is the key driver of VTE risk post-fall, with complications from immobility accounting for up to 51% of deaths in the first 30 days 1
• DVT and pulmonary emboli occur most commonly in the first 3 months, with incidence rates of 2.5% and 1.2% respectively 1

Timing and Contraindications

Start enoxaparin immediately if high-risk criteria are met and no contraindications exist 1:

• Absolute contraindications: systemic or intracranial hemorrhage, active bleeding 1
• Critical caveat: Even with negative initial head CT, delayed subdural hematoma can occur after head trauma in patients receiving enoxaparin 2
• If the fall involved head trauma (even with negative CT), strongly consider mechanical prophylaxis (intermittent pneumatic compression devices) instead of pharmacological prophylaxis for the first 24-48 hours 1

Dosing and Alternatives

Standard prophylactic dose: enoxaparin 40 mg subcutaneously once daily 1, 3:

• For patients with renal failure (CrCl <30 mL/min), use unfractionated heparin 5000 IU twice or three times daily instead 1, 4
• Enoxaparin 40 mg once daily is more effective than unfractionated heparin 5000 IU twice daily for DVT prevention 1

Mechanical Prophylaxis as Alternative or Adjunct

Intermittent pneumatic compression (IPC) devices are equally acceptable as first-line prophylaxis 1:

• Apply IPC within the first 24 hours of admission if selected 1
• IPC should be discontinued when the patient becomes independently mobile, at discharge, if adverse effects develop, or by 30 days (whichever comes first) 1
• If considering IPC after the first 24 hours, obtain venous leg Doppler studies first 1
• Compression stockings alone are NOT recommended and should not be used 1

Duration of Prophylaxis

• Continue prophylaxis until the patient is independently mobile 1
• For patients remaining immobile longer than 30 days, ongoing VTE prophylaxis is recommended 1
• Monitor daily for bleeding complications in patients receiving anticoagulation 1

Essential Concurrent Measures

Early mobilization is mandatory and reduces VTE risk 1:

• Begin mobilization as soon as hemodynamically stable 1
• Frequent, brief out-of-bed activity (sitting, standing, walking) should begin within 24 hours if no contraindications exist 1
• Adequate hydration should be encouraged for all patients 1

Common Pitfall to Avoid

Do not withhold VTE prophylaxis simply because imaging is negative—the fall itself is not the indication for anticoagulation; rather, the resulting immobility and inability to mobilize are the primary risk factors that necessitate prophylaxis 1. However, if head trauma occurred (witnessed or suspected in an unwitnessed fall), consider delaying pharmacological prophylaxis for 24-48 hours and using mechanical prophylaxis first, even with negative initial imaging 2.