Plasma concentrations of bupivacaine after wound infiltration of an 0.5% solution after inguinal herniorrhaphy: a preliminary study.

After routine inguinal herniorrhaphy we gave 12 patients a wound infiltration regimen of bolus doses of 20 ml of 0.5% bupivacaine via a catheter within the wound and rectally administered indomethacin (100 mg). Peak venous plasma bupivacaine concentrations ranged from 0.07 mg.l-1 to 1.14 mg.l-1 (mean (SD) 0.47 (0.33) mg.l-1), and occurred at between 0.25 and 2 h after the first dose. Plasma concentrations were well below the toxic threshold of 4 mg.l-1 and there was no accumulation. The regimen provided satisfactory analgesia. There were no wound infections nor signs of toxicity.