title: Optimal dose of hyperbaric bupivacaine 0.5% for unilateral spinal anesthesia during diagnostic knee arthroscopy.
abstract: OBJECTIVE
  To determine the dose of hyperbaric bupivacaine 0.5% required for unilateral spinal anesthesia during diagnostic knee arthroscopy.
  
  
  METHODS
  This prospective, randomized, clinical study was performed in 80 patients who were assigned to four groups to receive different doses of intrathecal hyperbaric bupivacaine (5 mg, 7.5 mg, 10 mg and 12.5 mg in Groups 1, 2, 3, and 4 respectively). Onset of sensory and motor block, hemodynamic changes, regression of motor block, and incidence of complications were recorded.
  
  
  RESULTS
  Unilateral sensory block was reported in 90% and 85% of patients in Group 1 and Group 2, respectively, but not in any patient in Group 3 and Group 4. Unilateral motor block (modified Bromage scale 0) was reported in 95% of patients in Group 1, 90% in Group 2, and only 5% in Group 3, while no patient in Group 4 showed unilateral motor block. The time required for regression of motor block (Bromage scale 0) was prolonged with higher doses. The incidence of nausea, vomiting, and urine retention was similar in the study groups.
  
  
  CONCLUSIONS
  Unilateral sensory and motor block can be achieved with doses of 5 mg and 7.5 mg hyperbaric bupivacaine 0.5% with a stable hemodynamic state. However, 7.5 mg of hyperbaric bupivacaine 0.5% was the dose required for adequate unilateral spinal anesthesia.
authors: Department of Anesthesia and Intensive Care, Faculty of Medicine, Suez Canal University, Ismailia, Egypt. hosamatef375@yahoo.com
authors: Hossam
authors: H
authors: Atef
authors: Alaa El-Din
authors: Ael-D
authors: El-Kasaby
authors: Magdy
authors: M
authors: Omera
authors: Mohamed
authors: M
authors: Badr
mesh_terms: D000328:Adult; D000775:Anesthesia, Spinal / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D001182:Arthroscopy / Q000379:methods*; D002045:Bupivacaine / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007719:Knee Joint; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods; D011446:Prospective Studies; D013997:Time Factors; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D002045:Bupivacaine