title: Effects of baricity of 0.5% or 0.75% levobupivacaine on the onset time of spinal anesthesia: a randomized trial.
abstract: OBJECTIVE
  Levobupivacaine has been extensively evaluated for spinal anesthesia. Its pharmacologic properties are similar to those of bupivacaine, but differences in density between two commercially-available preparations of plain levobupivacaine might lead to different block profiles. We examined the characteristics of spinal anesthesia using the same dose of 0.5% and 0.75% plain levobupivacaine.
  
  
  METHODS
  In this randomized, controlled, double-blind clinical trial, 60 ASA I-III patients, scheduled for hip fracture surgery, were randomly allocated to receive spinal anesthesia with 15 mg of either 0.5% (group Levo-0.5), or 0.75% (group Levo-0.75) plain levobupivacaine. Onset time (primary outcome), sensory block height level by pinprick, motor block using a modified Bromage scale, and hemodynamic variables were recorded.
  
  
  RESULTS
  In group Levo-0.5 (n = 29), surgical anesthesia was obtained within 15 (10-20) min, compared to 12 (7-21) min in group Levo-0.75 (n = 31) (p = 0.409). The highest sensory block level was T11 (T6-T12) in group Levo-0.5, and T10 (T8 - T12) in group Levo-0.75 (p = 0.759). Mean duration of anesthesia was 285 (224-303) min in group Levo-0.5, and 318 (243-375) min in group Levo-0.75 (p = 0.117). The groups were similar in regards to the number of failed blocks requiring general anesthesia, and the number of patients requiring vasopressors.
  
  
  CONCLUSIONS
  In this population of elderly patients, spinal anesthesia with 15 mg of either 0.5% or 0.75% plain levobupiva-caine resulted in similar onset of pharmacological actions, and outcomes. Potential differences in baricity did not appear to be clinically relevant in this setting.
authors.affiliation: Department of Anesthesiology, Critical Care and Pain Medicine, University of Parma, Parma, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Danelli
authors.forename: Marco
authors.initials: M
authors.lastname: Baciarello
authors.forename: Simone
authors.initials: S
authors.lastname: Di Cianni
authors.forename: Michele
authors.initials: M
authors.lastname: Zasa
authors.forename: Giuliana
authors.initials: G
authors.lastname: De Marco
authors.forename: Simonetta
authors.initials: S
authors.lastname: Adamanti
authors.forename: Guido
authors.initials: G
authors.lastname: Fanelli
mesh_terms: D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000737:chemistry; D001794:Blood Pressure / Q000187:drug effects; D002045:Bupivacaine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D000077554:Levobupivacaine; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012677:Sensation / Q000187:drug effects; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000779:Anesthetics, Local; D000077554:Levobupivacaine; D002045:Bupivacaine