title: A comparison of duration of analgesia of intrathecal 2.5 mg of bupivacaine, ropivacaine, and levobupivacaine in combined spinal epidural analgesia for patients in labor.
abstract: We assessed the duration of labor analgesia rendered by intrathecal (IT) local anesthetics as the sole drugs. In this randomized, controlled, and double-blinded study, labor analgesia was induced using combined spinal-epidural technique in 60 ASA physical status I nulliparous parturients with IT bupivacaine 2.5 mg (group B), ropivacaine 2.5 mg (group R), or levobupivacaine 2.5 mg (group L). Pain scores (0-100 visual analog scale) and blood pressure were recorded pre-block and for the first 30 min post-block. The degree of motor block and the highest sensory block were also monitored. The duration of analgesia (our primary outcome) was the longest in group B but was similar between groups R and L (mean +/- SE, 76.3 +/- 5.9 min versus 52.6 +/- 4.0 min and 51.5 +/- 3.4 min, respectively, P < 0.05). Group B had the most frequent incidence of lower limb motor block but there was no difference between groups R and L (5 of 20 parturients versus 2 of 20 and 0 of 20, respectively, P < 0.05). The profile of the other side effects was indistinguishable between the groups. With the current regimen, IT bupivacaine produced the longest duration of labor analgesia.
  
  
  CONCLUSIONS
  Intrathecal 2.5 mg bupivacaine significantly prolongs the duration of analgesia in laboring patients compared with ropivacaine or levobupivacaine. This suggests that, at clinically relevant doses, bupivacaine may have greater potency.
authors.affiliation: From the Department of Anesthesia, KK Women's and Children's Hospital, Singapore.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Lim
authors.forename: Cecilia E
authors.initials: CE
authors.lastname: Ocampo
authors.forename: Alex T
authors.initials: AT
authors.lastname: Sia
mesh_terms: D000328:Adult; D000577:Amides; D015360:Analgesia, Epidural / Q000009:adverse effects; D016362:Analgesia, Obstetrical / Q000009:adverse effects; D000779:Anesthetics, Local; D001794:Blood Pressure / Q000187:drug effects; D002045:Bupivacaine / Q000009:adverse effects / Q000031:analogs & derivatives; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007743:Labor, Obstetric; D000077554:Levobupivacaine; D010120:Oxytocics / Q000008:administration & dosage / Q000627:therapeutic use; D010121:Oxytocin / Q000008:administration & dosage / Q000627:therapeutic use; D010147:Pain Measurement; D017060:Patient Satisfaction; D011247:Pregnancy; D000077212:Ropivacaine; D016896:Treatment Outcome
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D010120:Oxytocics; D010121:Oxytocin; D000077212:Ropivacaine; D000077554:Levobupivacaine; D002045:Bupivacaine