Continuous intrathecal anesthesia for total hip arthroplasty in a patient with ankylosing spondylitis

: A 73-year-old man suffering from ankylosing spondylitis with limited motion of the whole spine was scheduled for right total hip arthroplasty. Ten years before, the patient had undergone left total hip arthroplasty under general anesthesia, in which epidural anesthesia impossible, intrathecal anesthesia insufficient, and tracheal intubation difficult. In the present operation, an 18 gauge epidural catheter was inserted into the epidural space at L3-4 using paramedian approach. Six ml of contrast medium was administered via the catheter, with high resistance on injection and the spread of epidural contrast medium was limited to L2 and L3. Therefore, the catheter was removed and reinserted into the intrathecal space at L3-4. Two ml of contrast medium demonstrated good spread in the intrathecal space from T12 to S2. Next injection of 0.5% isobaric bupivacaine 2.4ml produced bilateral cold sensory blockade from T10 to S5. Two hours after this injection, a single bolus of 1 ml followed by a continuous infusion at a rate of 0.5 ml x hr(-1) with 0.5% isobaric bupivacaine was commenced. There was no pain at rest and on movement, and no additional analgesics and hypertensive drugs were used until 4 hours following the discontinuation of the continuous intrathecal anesthesia in the morning after the operation. No adverse events including post-dural puncture headache were observed. Continuous intrathecal anesthesia may be effective for total hip arthroplasty in patients with ankylosing spondylitis.