Background and Objectives Intrathecal (IT) administration of bupivacaine (BUP) for treatment of “refractory” pain has sometimes been associated with unacceptable side effects. This study was undertaken to determine if IT-ropivacaine (ROP) can reduce the rate and intensity of these side effects e.g., urinary retention, paresthesia, and particularly, paresis with gait impairment. A prospective, crossover, double-blind, randomized study.

Methods Twenty-one patients were enrolled, 9 dropped out of the study, and data were analyzed from 12 patients. Patients were treated by insertion of IT tunneled nylon catheters, continuous infusion of 0.5% ROP followed by 0.5% BUP or 0.5% BUP followed by 0.5% ROP solutions from an external electronic pump. Each local anesthetic was infused for 7 days, and their order of infusion randomized. The comparative efficacy of the ROP and BUP IT infusions was assessed from the daily doses of IT ROP and IT BUP, oral and parenteral opioids, and daily scores of nonopioid analgetic and sedative drug consumption. Self-reported pain intensity (visual analogue scale [VAS] mean scores) and scores of Bromage relaxation, ambulation, nocturnal sleep pattern, rates of side-effects attributable to the IT drugs, the patients' assessment of the IT ROP v the IT BUP periods of the trial, and the comparative daily cost of IT ROP v IT BUP were recorded.

Results The daily doses of the local anesthetics used were 23% higher for ROP than for BUP. Further, the daily cost was ≈3 times higher for ROP than for BUP. No other significant differences between IT ROP and IT BUP were found.

Conclusion The results of this study do not support the hypothesis that IT infusion of 0.5% ROP has advantages over IT infusion of 0.5% BUP when administered for relief of “refractory” pain.