Clinical usefulness, safety, and plasma concentration of ropivacaine 0.5% for inguinal hernia repair in regional anesthesia

Background and Objective: The aim of this study was to evaluate the pharmac okinetics, feasibility, and clinical effects of ropivacaine in regional ane sthesia (ilioinguinal-iliohypogastric blocks [IIB], genitofemoral block plu s local infiltration) for inguinal hernia repair. Methods: Following ethics committee approval and informed consent, 21 male adults received 60 mL ropivacaine 0.5% (without vasoconstrictor). In 11 pat ients, further injections of 5 to 10 mL were given while preparing the hern ial sack. Plasma concentration of ropivacaine was determined in venous bloo d after 10, 20, 30, 45, 60, 90, 120, and 300 minutes using reversed-phase h igh pressure liquid chromatography (HPLC). Results: Peak plasma concentrations of ropivacaine were 1.5 +/- 0.6 (0.7 to 2.6) mug/mL (mean +/- SD [range]). These maximum concentrations occurred a fter 45 (30 to 60) minutes (median [range]). No signs of central nervous or cardiovascular toxicity were observed. Twelve of 21 patients did not need any additional analgesics within 24 hours postoperatively. One patient had a femoral motor block lasting 6 hours, 5 patients reported sensory femoral block lasting 5 to 12 hours. Patients, as well as the surgeon, were very sa tisfied with the procedure, and all patients stated that they would like to have it performed again that way in case of an inguinal. hernia on the opp osite side. Conclusion: A ropivacaine dose of 60 to 70 mL of 0.5% appears adequate for regional anesthesia for inguinal hernia repair regarding conditions for sur gery, safety, ambulation, and postoperative pain relief.