title: A comparison of hyperbaric 1% and 3% solutions of small-dose lidocaine in spinal anesthesia.
abstract: We examined whether the concentration of hyperbaric lidocaine affected the regression of motor block when the dose of lidocaine was kept constant at 30 mg. We also examined the spread, duration, and regression of sensory block. Sixty-five patients (ASA physical status I or II), scheduled for elective perineum or lower limb surgery, were enrolled in this study. Patients received spinal anesthesia with 1 mL of 3% lidocaine or 3 mL of 1% lidocaine. Adequate level of block was obtained for surgery in 63 of 65 patients. Whereas the administration of 3 mL of hyperbaric 1% lidocaine solution produced a level of sensory block similar to that produced by the administration of 1 mL of hyperbaric 3% lidocaine solution in spinal anesthesia, the administration of 3 mL of hyperbaric 1% lidocaine solution resulted in shorter times to full motor recovery and to urination and produced less motor block compared with 1 mL of hyperbaric 3% lidocaine solution. Two patients receiving 1% lidocaine and four patients receiving 3% lidocaine required IV ephedrine because of hypotension. Our results showed the clinical advantages of hyperbaric 1% lidocaine spinal anesthesia compared with hyperbaric 3% lidocaine spinal anesthesia for surgery of short duration.
  
  
  CONCLUSIONS
  When the dose of lidocaine was kept constant at 30 mg, hyperbaric 1% lidocaine solution resulted in shorter times for recovery from motor block and to urination than did hyperbaric 3% lidocaine solution. Levels of sensory block were similar. Therefore, the more dilute lidocaine for spinal anesthesia may be suitable for day-care surgery and short duration surgery.
authors.affiliation: Department of Anesthesiology, Sapporo Medical University School of Medicine, Japan.
authors.forename: Yurie Tohdoh
authors.initials: YT
authors.lastname: Kawamata
authors.forename: Koki
authors.initials: K
authors.lastname: Nishikawa
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Kawamata
authors.forename: Keiichi
authors.initials: K
authors.lastname: Omote
authors.forename: Motohiko
authors.initials: M
authors.lastname: Igarashi
authors.forename: Masanori
authors.initials: M
authors.lastname: Yamauchi
authors.forename: Koichi
authors.initials: K
authors.lastname: Sato
authors.forename: Masayasu
authors.initials: M
authors.lastname: Nakayama
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Namiki
mesh_terms: D000368:Aged; D000762:Anesthesia Recovery Period; D000775:Anesthesia, Spinal / Q000009:adverse effects; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000009:adverse effects; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000187:drug effects; D009407:Nerve Block; D009475:Neurons, Afferent / Q000187:drug effects; D010147:Pain Measurement / Q000187:drug effects; D019999:Pharmaceutical Solutions
chemical_list: D000779:Anesthetics, Local; D019999:Pharmaceutical Solutions; D008012:Lidocaine