Transient neurological symptoms (TNS) following spinal anaesthesia are most strongly associated with which local anaesthetic agent and patient positioning?

• A Bupivacaine; prone positioning
• B Chloroprocaine; lateral decubitus position
• C Ropivacaine; sitting position
• D Hyperbaric lignocaine; lithotomy position with knee arthroscopy ✓

Explanation

Transient neurological symptoms (burning buttock and leg pain without neurological deficit, resolving within 72 hours) occur most commonly after hyperbaric (5%) intrathecal lignocaine, particularly in the lithotomy position (knee arthroscopy, cystoscopy). The incidence is 10–40% with lignocaine in lithotomy vs. <1% with bupivacaine. Proposed mechanisms include uneven drug distribution, nerve stretch in lithotomy, and lignocaine's direct neurotoxicity at higher intraneural concentrations. Ropivacaine and bupivacaine have much lower TNS rates.

Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.