Age and bupivacaine plasma concentrations following radical cystectomy

Continuous epidural analgesia with bupivacaine for postoperative analgesia can increase its plasma concentrations. Whether this effect can be aggravated with increasing age is unknown. Therefore, bupivacaine concentrations were prospectively monitored in patients undergoing radical cystectomies.

We analyzed plasma concentrations of bupivacaine in 38 consecutive patients scheduled for radical cystectomy. All patients received general and epidural anesthesia (10 ml bupivacaine 0.5% followed by bupivacaine 0.375% every 90 min) and postoperative continuous epidural analgesia (bupivacaine 0.25% with sufentanil 0.5 μg/ml). For 4 subsequent days, bupivacaine plasma concentrations were measured and the correlation of bupivacaine plasma concentrations with the patient's age were analyzed. Data (mean ± SD) were analyzed by 2-way ANOVA with post hoc analysis or regression analysis.

The median age of the patients was 70 years (range 41-86). Postoperatively, bupivacaine plasma concentrations increased significantly. No correlation of plasma concentrations and age could be found. Maximal bupivacaine concentrations of the younger patients were not different from the older patients. No neurological or cardiovascular symptoms of bupivacaine intoxication were found.

In conclusion, continuous epidural administration of bupivacaine leads to increasing plasma concentrations. No age dependent differences in bupivacaine plasma concentrations could be found. Therefore, in our patients with intact liver function, we did not find a reason for an age-related restriction in the use of continuous epidural analgesia.