Should a patient in their late 80s with a right femoral subcapital fracture receive a second dose of dalteparin (Fragmin) 5,000 IU subcutaneously tomorrow if surgery is not performed today?

Should the Patient Receive Fragmin Tomorrow?

Yes, continue dalteparin (Fragmin) 5,000 IU subcutaneously once daily tomorrow and every day until surgery is performed, then continue postoperatively for VTE prophylaxis.

Rationale for Continued Daily Dosing

In hip fracture patients, VTE prophylaxis must be maintained continuously from admission through the perioperative period. The evidence strongly supports this approach:

Pre-operative VTE Prophylaxis

• Hip fracture patients are at extremely high risk for VTE from the moment of injury through the postoperative period 1
• The FDA-approved dosing for hip replacement surgery demonstrates that dalteparin 5,000 IU once daily is the standard prophylactic dose, with treatment continuing for 5-9 days postoperatively 2
• Discontinuing prophylaxis creates a dangerous gap in anticoagulation coverage during a period of maximal thrombotic risk

Timing Considerations

• Your patient may undergo surgery tomorrow, but the exact timing is uncertain
• Daily dosing maintains therapeutic coverage regardless of when surgery occurs
• If surgery happens tomorrow, the patient should receive their dose as scheduled (unless surgery is imminent within 12-24 hours, in which case timing should be coordinated with anesthesia)

Safety in Elderly Patients

• Studies confirm that dalteparin 5,000 IU daily does not cause bioaccumulation even in elderly patients with renal insufficiency 3
• This dose is safe for patients in their late 80s and has been extensively studied in this exact population for hip surgery 2

Practical Management Algorithm

Continue dalteparin 5,000 IU subcutaneously once daily until:

1. Day of surgery arrives:

   • Give the scheduled dose if surgery is >12-24 hours away
   • Hold the dose if surgery is scheduled within 12-24 hours (coordinate with anesthesia, especially if neuraxial anesthesia is planned)
   • Resume 24-48 hours postoperatively at the same dose

2. Surgery is delayed beyond tomorrow:

   • Continue daily dosing without interruption
   • Each day without prophylaxis increases VTE risk in this immobilized, elderly hip fracture patient

3. Postoperative period:

   • Resume dalteparin 5,000 IU once daily starting 24-48 hours after surgery
   • Continue for minimum 5-9 days, though extended prophylaxis for up to 35 days significantly reduces late DVT (incidence reduced from 25.8% to 11.8%) 4

Critical Pitfalls to Avoid

• Do not create gaps in prophylaxis: Every day without anticoagulation in an immobilized hip fracture patient increases VTE risk
• Do not assume surgery will happen tomorrow: Surgical delays are common, and the patient needs continuous protection
• Do not underdose: 5,000 IU once daily is the evidence-based dose for this indication 2
• Coordinate with anesthesia: If neuraxial anesthesia is planned, timing of the last dose matters, but this should not prevent you from giving today's and tomorrow's doses if surgery timing remains uncertain 5

The interdisciplinary care model emphasized in hip fracture guidelines 1 requires clear communication between medicine, orthopedics, and anesthesia regarding anticoagulation management, but the default should always be continued daily prophylaxis until surgery is imminent.