title: Epidural mepivacaine for cesarean section: effects of a pH-adjusted solution.
abstract: OBJECTIVE
  To determine the clinical effects of the alkalinization of 2% mepivacaine with epinephrine used for epidural block during cesarean section.
  
  
  METHODS
  Randomized, double-blind, placebo-controlled (standard commercial preparation of 2% mepivacaine with epinephrine) study.
  
  
  METHODS
  Inpatient obstetric department at a general hospital.
  
  
  METHODS
  Seventy patients scheduled for elective cesarean section under epidural anesthesia.
  
  
  METHODS
  Two groups of 35 patients each receiving either the standard commercial preparation of mepivacaine or the pH-adjusted solution (prepared with the addition of 0.1 meq/ml of sodium bicarbonate to the standard commercial solution).
  
  
  RESULTS
  Measurements of sensory (pinprick) and motor (Bromage's criteria) block were taken at 1- to 2-minute intervals beginning after the completion of the epidural injection. Increasing the pH of the mepivacaine resulted in a significant shortening of the time of analgesia onset (9.3 minutes compared with 16.01 minutes, p less than 0.01) and of peak effect (11.1 minutes compared with 21.2 minutes, p less than 0.01). The alkalinization did not affect duration of the block, intensity of motor block, or mean dose of local anesthetic used.
  
  
  CONCLUSIONS
  The alkalinization allowed the surgery to proceed more rapidly, significantly decreasing the time interval between epidural block and delivery of the infant.
authors.affiliation: Department of Anesthesiology, Fatebenefratelli Isola Tiberina General Hospital, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Capogna
authors.forename: D
authors.initials: D
authors.lastname: Celleno
authors.forename: G
authors.initials: G
authors.lastname: Varrassi
authors.forename: M
authors.initials: M
authors.lastname: Emanuelli
authors.forename: M
authors.initials: M
authors.lastname: Sebastiani
authors.forename: F
authors.initials: F
authors.lastname: Muratori
authors.forename: G
authors.initials: G
authors.lastname: Cipriani
authors.forename: M
authors.initials: M
authors.lastname: Tomassetti
mesh_terms: D000328:Adult; D000767:Anesthesia, Epidural; D000773:Anesthesia, Obstetrical; D001639:Bicarbonates / Q000008:administration & dosage; D002585:Cesarean Section; D036861:Delivery, Obstetric; D004311:Double-Blind Method; D004837:Epinephrine / Q000008:administration & dosage; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008619:Mepivacaine / Q000008:administration & dosage*; D009046:Motor Neurons / Q000187:drug effects; D009407:Nerve Block; D009475:Neurons, Afferent / Q000187:drug effects; D011247:Pregnancy; D012964:Sodium / Q000008:administration & dosage; D017693:Sodium Bicarbonate; D013997:Time Factors
chemical_list: D001639:Bicarbonates; D017693:Sodium Bicarbonate; D012964:Sodium; D008619:Mepivacaine; D004837:Epinephrine