STABILITY OF LOCAL-ANESTHETICS IN HEPARINIZED BLOOD, PLASMA AND SULFURIC-ACID

Background: This study was undertaken to investigate the stability of local anesthetics in different media. Methods: 60 patients with axilla ry plexus block, using prilocaine, mepivacaine or lidocaine 1%, or wit h lumbar epidural catheter-anesthesia, using bupivacaine 0.5%, were in vestigated. Stability was evaluated in heparinized whole blood for 24 h at +4 degrees C, in plasma for 8 weeks at -25 degrees C and in sulfu ric acid for 6 months at -25 degrees C. Results: Mean recovery rates w ere between 96.4% and 102.6% in all local anesthetics and media. No st atistical significance became obvious for differences between recovery rates and initial values. Conclusion: Stability of prilocaine, mepiva caine, lidocaine and bupivacaine can be expected when samples are stor ed as heparinized whole blood for 24 h at +4 degrees C, plasma for 8 w eeks at -25 degrees C, and after preparation into sulfuric acid for 6 months at -25 degrees C.