ASRA Timing for Neuraxial: A Working Reference
Regional Anesthesia · 8 min read
When can you place a needle? When can you pull a catheter? Memorize the table once, save a spinal hematoma forever.
Why this matters
Spinal/epidural HEMATOMA is rare (1:150,000-1:200,000 in the absence of anticoagulation) but devastating — a delayed diagnosis means permanent paraplegia. Modern practice produces near-zero hematomas not by avoiding regional in patients on anticoagulation, but by following a precise TIMING protocol. ASRA (American Society of Regional Anesthesia) publishes this as the 4th edition Anticoagulation Guidelines, last updated 2018 with periodic addenda. Memorize the timing table; it's a one-time investment with a forever payoff.
ASA + NSAIDs — go ahead
Aspirin alone, even chronic-dose, does NOT contraindicate neuraxial anesthesia per ASRA + per POISE-2 (NEJM 2014). Continue ASA in established CAD perioperatively. NSAIDs alone — same. The combination of ASA + clopidogrel (DAPT) requires the clopidogrel timing below; ASA does not extend the window.
Warfarin
Hold 5 days pre-op; verify INR <1.5 before placement. Restart 24 h post-procedure if uncomplicated. Catheter removal: INR <1.5. Bridge with LMWH if patient is high VTE risk (mechanical mitral valve, recent stroke, recent VTE) — see BRIDGE trial caveats; LMWH then has its own timing.
Heparin (UFH) — by route + dose
SC PROPHYLACTIC (5000 units BID-TID): no time delay required for placement — proceed; remove catheter 4-6 h after last dose. SC INTERMEDIATE (7500-10,000 BID): 12 h before placement. IV THERAPEUTIC: 4-6 h delay + check aPTT in normal range before placement. POST-PLACEMENT heparinization (cardiac surgery): wait 1 h after placement before heparin; if traumatic placement, consider postponing surgery 24 h.
LMWH (enoxaparin, dalteparin) — by dose
PROPHYLACTIC dose (enoxaparin 30 mg q12h or 40 mg q24h): 12 h before placement. THERAPEUTIC dose (1 mg/kg q12h): 24 h before placement. Restart prophylactic 6-8 h post-puncture (if non-traumatic) or 24 h (if traumatic — bloody tap); therapeutic 24 h regardless. Catheter removal: 12 h after last prophylactic dose; 24 h after last therapeutic dose. Next dose: 4 h after catheter removal.
P2Y12 antagonists (clopidogrel + family)
CLOPIDOGREL: 7 days. PRASUGREL: 7 days. TICAGRELOR: 5 days (reversible binding — faster recovery). TICLOPIDINE: 14 days (older agent, longer effect). CANGRELOR (IV): 3 hours. None of these have a routine reversal — platelet transfusion + DDAVP for emergent reversal don't fully restore platelet function while drug is in circulation.
DOACs
RIVAROXABAN, APIXABAN (factor Xa inhibitors), DABIGATRAN (direct thrombin inhibitor): 72 hours for ALL DOACs at normal renal function. Extended with renal impairment, especially DABIGATRAN: CrCl 50-80 → 72 h; CrCl 30-50 → 96-120 h (4-5 days); CrCl <30 → 120 h+ (5+ days, individualized). Restart 24 h post-uncomplicated puncture; longer if traumatic. DEEP peripheral blocks (lumbar plexus, paravertebral, deep cervical): same timing as neuraxial. Reversal: dabigatran → idarucizumab 5 g IV; Xa inhibitors → andexanet alfa or 4F-PCC.
Document + monitor
Document the timing decision in the chart. After placement, monitor for new motor or sensory deficits, severe back pain, sensory level rising — any of these = URGENT MRI + neurosurgical consult; treatment window for spinal hematoma decompression is 6-8 hours from symptom onset. Catheter removal follows same timing rules. After removal: continue neurologic exam for 24 hours.
Pearl — when in doubt, delay
If you can't reach the patient's last anticoagulant dose timing reliably, or if the patient is on a regimen ASRA doesn't address (clinical trials, off-label), default to GA or peripheral nerve block (superficial). The cost of delay is a few extra minutes; the cost of a hematoma is a career-ending complication for the provider and a life-altering disability for the patient.
References
- · ASRA Anticoagulation Guidelines 4e 2018 (Horlocker et al)
- · ASRA 2024 Update on DOAC Reversal
- · POISE-2 NEJM 2014 (perioperative ASA)