The Effect of L-bupivacaine on BIS Levels in the Maintenance Doses of Propofol and Fentanyl during General Anesthesia in Chinese People

Abstract

Levorotatory forms of amino-amide class of epidural anesthetics are considered to be better than their dextrorotatory counterparts in the way that they are associated with less toxicity and improved absorption and bioavailability.In this study we compared the effect of 2 enantiomers; namely racemic preparation of bupivacaine with pure formulation of its levorotatory form levobupivacaine on the dosage requirements for general anesthesia propofol in a series of 273 patients admitted to hospital of China for nephrectomy. We also compared the effect of epidural anesthetics on intra- and postoperative plasma levels of epinephrine, glucose and cortisol.Our results indicate that levobupivacaine is associated with lower dose requirements of propofol as compared to bupivacaine (3.45±0.5 vs. 4.44±0.5 mg/kg/h). Levo-bupivacaine also attenuated the postoperative stress response as indicated by significant reduction plasma epinephrine levels.Our results suggest that levobupivacaine might be more effective as epidural anesthetic in combined regimen as compared to bupivacaine.

Pharmacokinetics and Placental Transfer of Bupivacaine Enantiomers in HIV‐Infected Parturient Women on Antiretroviral Therapy

“…The administration of epinephrine to local anesthetic prolongs analgesia and motor block by 30 to 60 minutes via a vasoconstrictive effect delaying the bupivacaine absorption from the injection site. [1][2][3][4][5] Bupivacaine is commercialized as a racemic mixture of R-bupivacaine and S-bupivacaine enantiomers. The enantiomers differ in their pharmacokinetic parameters, efficacy, and toxicity.…”

“…The association of epinephrine to bupivacaine decreases the peak plasma concentration but does not prolong the time to peak plasma concentration of the local anesthetic, showing that the absorption of a proportion of bupivacaine dose occurs rapidly before vasoconstriction is complete. The administration of epinephrine to local anesthetic prolongs analgesia and motor block by 30 to 60 minutes via a vasoconstrictive effect delaying the bupivacaine absorption from the injection site …”