How long should heparin (unfractionated heparin) infusion be held before a lumbar puncture (LP)?

Unfractionated Heparin Discontinuation Before Lumbar Puncture

Unfractionated heparin (UFH) infusion should be stopped at least 4-6 hours before a lumbar puncture to minimize the risk of spinal hematoma. 1

Timing of Heparin Discontinuation

The timing of heparin discontinuation before a lumbar puncture is critical to balance the risk of bleeding complications against thrombotic events:

• Unfractionated Heparin (IV infusion):
  • Stop ≥4-6 hours before lumbar puncture 1, 2
  • This timing is based on UFH's elimination half-life of approximately 90 minutes (can vary from 30-120 minutes depending on anticoagulation level) 2
  • The American College of Chest Physicians provides a conditional recommendation (very low certainty of evidence) for stopping UFH ≥4 hours before procedures 2

Post-Procedure Heparin Resumption

After an uncomplicated lumbar puncture, heparin resumption should follow these guidelines:

• Wait 48-72 hours before restarting full therapeutic UFH dosing 1
• When resuming UFH:
  • Avoid bolus doses
  • Start with a lower-intensity infusion with a lower target aPTT than used for full anticoagulation 2, 1
  • Gradually increase to therapeutic levels if no bleeding complications occur

Risk Considerations

Bleeding Risk

• Therapeutic anticoagulation is a contraindication to lumbar puncture due to significant risk of spinal hematoma 1
• Spinal hematoma, while rare, can cause devastating neurological consequences including permanent paralysis 1
• Monitor for signs of spinal hematoma after the procedure:
  • Back pain
  • Radicular pain
  • Sensory changes
  • Motor weakness

Thrombotic Risk

• For patients at high thrombotic risk (mechanical heart valves, recent thromboembolic events):
  • Consider prophylactic dosing after 24 hours
  • Advance to therapeutic dosing after 48-72 hours if no bleeding complications 1

Special Considerations

• Traumatic Lumbar Puncture: Extend the waiting period before restarting anticoagulation
• Concurrent Antiplatelet Therapy: Aspirin alone does not significantly increase spinal hematoma risk, but combination with heparin increases complication risk 1, 3
• Platelet Count: Should be at least 100 × 10^9/L before performing lumbar puncture in patients who will require anticoagulation 1

Algorithm for Management

1. Pre-procedure:

   • Stop UFH infusion at least 4-6 hours before LP
   • Confirm normal coagulation parameters before procedure
   • Assess patient's thrombotic risk

2. Post-procedure:

   • For standard risk patients: Hold therapeutic heparin for 48-72 hours
   • For high thrombotic risk patients: Consider prophylactic dosing after 24 hours, then advance to therapeutic dosing after 48-72 hours
   • Monitor for signs of spinal hematoma

3. If signs of spinal hematoma develop:

   • Obtain urgent spinal imaging
   • Seek immediate neurosurgical consultation

This approach balances the risk of bleeding complications against thrombotic events while prioritizing patient safety and neurological outcomes.