Serum bupivacaine levels during laparoscopic sterilization using local anesthesia.

Study Objective: To determine the serum levels of bupivacaine during laparoscopic sterilization when bupivacaine 0.5% without epinephrine is used as the sole local anesthetic agent.

Design: Case series.

Setting: Regional medical center and primary teaching hospital of Ob/Gyn Department of the University of Tennessee, Memphis. PATIENTS; Thirty women undergoing laparoscopic sterilization with bupivacaine for local anesthesia.

Interventions: Venous serum bupivacaine levels were measured, with samples drawn at 45, 60, 90, and 120 minutes after injection in 25 patients. Five additional patients had sampling at 15 and 30 minutes as well as at the above times.

Measurements And Main Results: The highest concentration of bupivacaine was detected at 15 minutes. The mean concentrations at 15, 30, 45, 60, and 120 minutes were 0.86, 0.74, 0.31, 0.27, 0.23, and 0.22 microg/ml, respectively. This is well below the level of serious toxicity. Only four patients received 2.5 mg/kg or greater of bupivacaine. In these patients, mean serum levels were 1.1, 1.0, 0.28, 0.43, 0.9, and 0.29 microg/ml, respectively.

Conclusion: Serum bupivacaine levels during sterilization using bupivacaine 0.5% without epinephrine for local anesthesia are well below the threshold for serious toxicity.