title: Preparation of pH-adjusted local anesthetics.
abstract: Characteristics of alkalinized local anesthetics are poorly described with regard to stability and precipitation. Current fixed-volume methods of alkalinization often result in unstable, precipitated solutions of unpredictable pH. We determined a stable, nonprecipitating, anesthetic mixture and used it in a randomized double-blind crossover study of 21 patients to evaluate alkalinized anesthetic solutions in reducing pain on injection. Our solution significantly reduced pain associated with retrobulbar injection (analysis of variance, P = .0362) but not that associated with Nadbath injection. Fixed-volume alkalinization is not recommended because complications can result with the use of precipitated anesthetics.
authors.affiliation: University of Illinois at Chicago 60612, USA.
authors.forename: K D
authors.initials: KD
authors.lastname: Hinshaw
authors.forename: R
authors.initials: R
authors.lastname: Fiscella
authors.forename: J
authors.initials: J
authors.lastname: Sugar
mesh_terms: D000772:Anesthesia, Local / Q000379:methods*; D000779:Anesthetics, Local / Q000737:chemistry* / Q000627:therapeutic use; D002045:Bupivacaine / Q000737:chemistry / Q000627:therapeutic use; D002387:Cataract Extraction; D011232:Chemical Precipitation; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004355:Drug Stability; D004359:Drug Therapy, Combination; D004837:Epinephrine / Q000737:chemistry / Q000627:therapeutic use; D006801:Humans; D006821:Hyaluronoglucosaminidase / Q000737:chemistry / Q000627:therapeutic use; D006863:Hydrogen-Ion Concentration; D008012:Lidocaine / Q000737:chemistry / Q000627:therapeutic use; D010149:Postoperative Pain / Q000517:prevention & control; D010865:Pilot Projects; D017693:Sodium Bicarbonate
chemical_list: D000779:Anesthetics, Local; D017693:Sodium Bicarbonate; D008012:Lidocaine; D006821:Hyaluronoglucosaminidase; D002045:Bupivacaine; D004837:Epinephrine