title: Postural change from lateral to supine is an important mechanism enhancing cephalic spread after injection of intrathecal 0.5% plain bupivacaine for cesarean section.
abstract: BACKGROUND
  Spinal anesthesia is widely used for cesarean section, but the factors that affect the spread of the block in pregnant patients are still not fully explained. This study was designed to investigate the effect of postural changes on sensory block level.
  
  
  METHODS
  Thirty patients scheduled for elective cesarean section under combined spinal-epidural anesthesia were randomly allocated into three groups. After intrathecal injection of 0.5% plain bupivacaine 7.5mg, patients in group S were immediately placed in the supine position with left tilt, patients in group L5 were kept lateral for 5 min and then turned to the supine position with left tilt, and patients in group L10 were kept lateral for 10 min and then turned to the supine position with left tilt.
  
  
  RESULTS
  At 5 min, median cephalad level of sensory block was lower in groups L5 and L10 compared with group S (corrected P<0.001); at 10 min, median cephalad sensory block level was lower in group L10 compared with group S (corrected P<0.001) and group L5 (corrected P<0.001), and lower in group L5 compared with group S (corrected P=0.033); at 15 min, median cephalad level of sensory block was lower in group L10 compared with group S (corrected P=0.003) and group L5 (corrected P=0.015).
  
  
  CONCLUSIONS
  In our population, using 0.5% plain bupivacaine 7.5mg, postural change from the lateral position to the supine position is an important mechanism enhancing cephalic spread of spinal anesthesia during late pregnancy.
authors.affiliation: Department of Anesthesiology, Peking University Third Hospital, Beijing, China.
authors.forename: F
authors.initials: F
authors.lastname: Xu
authors.affiliation: Department of Anesthesiology, Peking University Third Hospital, Beijing, China.
authors.forename: M
authors.initials: M
authors.lastname: Qian
authors.affiliation: Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, Peking University Third Hospital, Beijing, China.
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, Peking University Third Hospital, Beijing, China.
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Anesthesiology, Peking University Third Hospital, Beijing, China. Electronic address: xiangyangguoby@163.com.
authors.forename: X
authors.initials: X
authors.lastname: Guo
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000767:Anesthesia, Epidural; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local; D002045:Bupivacaine; D002585:Cesarean Section; D005260:Female; D006801:Humans; D007278:Injections, Spinal; D056888:Patient Positioning / Q000379:methods*; D011187:Posture; D011247:Pregnancy
chemical_list: D000779:Anesthetics, Local; D002045:Bupivacaine
keywords: Cephalic spread; Cesarean section; Intrathecal anesthesia; Postural change