title: Alkalinized lidocaine and bupivacaine with hyaluronidase for sub-tenon's ophthalmic block.
abstract: OBJECTIVE
  Alkalinization of local anesthetics has been shown to decrease the onset and prolong the duration of block for extraconal and intraconal application in ocular surgery. The objective of this study is to determine if alkalinization is also effective in sub-Tenon's block when hyaluronidase is added to the drug mixture.
  
  
  METHODS
  Twenty-nine patients were randomly assigned to 2 groups in a double-blind, prospective fashion to receive 5.125 mL of either a plain mixture LBH (2.5 mL lidocaine 2%, 2.5 mL bupivacaine 0.5%, 5 IU/mL hyaluronidase, and 0.125 mL isotonic saline) or pH-adjusted mixture LBH-PH (2.5 mL lidocaine 2%, 2.5 mL bupivacaine 0.5%, 5 IU/mL hyaluronidase, and 0.125 mL sodium bicarbonate 8.4%) of local anesthetics in a 1-quadrant sub-Tenon's block. Time to onset and time to full akinesia were determined every 30 seconds.
  
  
  RESULTS
  No difference was found between the study groups.
  
  
  CONCLUSIONS
  pH adjustment of the local anesthetic mixture of lidocaine, bupivacaine, and hyaluronidase offered no additional benefit in sub-Tenon's technique in ocular procedures.
authors.affiliation: Department of Anaesthesia/ICU, Sultan Qaboos University Hospital, Muscat, Oman. magdi@omantel.net.om
authors.forename: M M
authors.initials: MM
authors.lastname: Moharib
authors.forename: S
authors.initials: S
authors.lastname: Mitra
mesh_terms: D000328:Adult; D000368:Aged; D002045:Bupivacaine / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006821:Hyaluronoglucosaminidase / Q000008:administration & dosage*; D006863:Hydrogen-Ion Concentration; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009407:Nerve Block; D013508:Ophthalmologic Surgical Procedures; D011446:Prospective Studies
chemical_list: D008012:Lidocaine; D006821:Hyaluronoglucosaminidase; D002045:Bupivacaine