Anticoagulation and neuraxial/regional anaesthesia

Model answer

Framework (4). Identify drug, dose intensity, last dose time, renal function; weigh regional benefit vs haematoma risk. ASRA keeps a deliberately conservative antihaemorrhagic stance with set interruption times before blockade — the fifth edition re-labels prophylactic/therapeutic as low/high dose and adds drug-specific assays to guide timing; use the current table for exact hours.^[1][2]

LMWH therapeutic (3). High-dose LMWH needs a longer hold than low-dose before needle or catheter; if the safe window cannot be met, offer alternative analgesia.^[1][2]

Warfarin (3). Check INR and proceed only once acceptably normalised per the table, bridging with the parent team if the thrombotic risk demands it.^[1]

Catheter/haematoma (5). Catheter removal has its own interruption window; run neurological observations after block and after removal. NAP3 (707,455 blocks) put permanent injury at 2.0 to 4.2 per 100,000 and paraplegia-or-death at 0.7 to 1.8 per 100,000 — rare, and two-thirds of initially disabling injuries resolved fully — but a progressive deficit is an emergency MRI and decompression.^[3]