Epidural Catheter Removal with INR 1.36
Yes, the epidural catheter can be safely removed with an INR of 1.36 and 63% activity, as this falls within the accepted safety threshold of INR ≤1.4 established by current guidelines. 1, 2, 3
Guideline-Based Safety Thresholds
The Association of Anaesthetists of Great Britain & Ireland explicitly states that an INR ≤1.4 is acceptable for epidural catheter removal. 1 This threshold is reinforced by multiple consensus guidelines that establish INR ≤1.5 as the standard for safe neuraxial procedures, including catheter removal. 3
Your patient's INR of 1.36 with 63% activity is below the 1.4 threshold and therefore meets safety criteria. 1, 2
Critical Assessment Points Before Removal
Verify the following before proceeding:
No concurrent anticoagulation: Ensure the patient is not receiving therapeutic doses of heparin, low molecular weight heparin, or other anticoagulants while the catheter is in place. 1
Platelet count ≥50 × 10⁹/L: Concurrent thrombocytopenia with elevated INR requires hematology consultation before removal. 2
Normal APTT: The elevated APTT mentioned in your question is concerning—if significantly prolonged, this suggests additional coagulation abnormalities beyond warfarin effect and warrants investigation before catheter removal. 1, 4
No antiplatelet agents: Clopidogrel, prasugrel, or ticagrelor should be discontinued 7 days before removal; aspirin and NSAIDs require no additional precautions. 1
Timing Considerations
Post-removal anticoagulation timing:
- Wait at least 1 hour after catheter removal before administering prophylactic unfractionated heparin. 1
- Wait 4 hours after removal before administering prophylactic low molecular weight heparin. 1
- Warfarin can be resumed after catheter removal once adequate hemostasis is confirmed. 1, 3
Supporting Evidence and Controversy
A large observational study of 4,365 patients demonstrated uncomplicated epidural catheter removal with INRs ranging from 1.5 to 7.1 during warfarin initiation, with zero incidence of spinal hematoma. 5 However, this was specifically during warfarin initiation (within 50 hours of starting warfarin) when other vitamin K-dependent factors remain adequate for hemostasis. 5
Critical distinction: If your patient is on chronic warfarin therapy (not initiation phase), the 1.4 threshold becomes more stringent, as other coagulation factors may be depleted. 5
Mandatory Post-Removal Monitoring
Neurologic assessment protocol:
- Test straight-leg raising at 4 hours after catheter removal. 2
- Document motor function using the Bromage scale. 2
- Inability to straight-leg raise at 4 hours requires immediate anesthesiologist assessment for possible epidural hematoma. 2
- Continue neurologic checks for 24 hours after removal. 5
Red Flags Requiring Delay
Do NOT remove the catheter if:
- APTT is significantly elevated beyond what warfarin alone would cause (suggests additional coagulopathy). 4
- Patient is receiving concurrent therapeutic anticoagulation with heparin or LMWH. 6, 7
- Platelet count is <50 × 10⁹/L. 2
- Patient has received clopidogrel, prasugrel, or ticagrelor within 7 days. 1
Common Pitfalls
Avoid these errors:
- Removing the catheter while therapeutic anticoagulation is active—even with acceptable INR, concurrent heparin dramatically increases bleeding risk. 6, 4
- Failing to investigate elevated APTT—this may indicate additional coagulation defects beyond warfarin effect. 4
- Resuming full-dose anticoagulation too soon after removal—wait the specified intervals based on the agent used. 1
- Inadequate post-removal neurologic monitoring—epidural hematoma can develop hours after removal and requires emergency decompression within 8-12 hours to prevent permanent paralysis. 2, 6