title: Combined use of hyperbaric and hypobaric ropivacaine significantly improves hemodynamic characteristics in spinal anesthesia for caesarean section: a prospective, double-blind, randomized, controlled study.
abstract: OBJECTIVE
  To observe the hemodynamic changes of parturients in the combined use of hyperbaric (4 mg) and hypobaric (6 mg) ropivacaine during spinal anesthesia for caesarean section in this randomized double-blind study.
  
  
  METHODS
  Parturients (n = 136) undergoing elective cesarean delivery were randomly and equally allocated to receive either combined hyperbaric and hypobaric ropivacaine (Group A) or hyperbaric ropivacaine (Group B). Outcome measures were: hemodynamic characteristics, maximum height of sensory block, time to achieve T8 sensory blockade level, incidence of complications, Apgar scores at 1 and 5 min, and neonatal blood gas analysis.
  
  
  RESULTS
  Group A had a lower level of sensory blockade (T6 [T6-T7]) and longer time to achieve T8 sensory blockade level (8 ± 1.3 min) than did patients in Group B (T3 [T2-T4] and 5 ± 1.0 min, respectively; P < 0.001, both). The incidence rates for hypotension, nausea, and vomiting were significantly lower in Group A (13%, 10%, and 3%, respectively) than Group B (66%, 31%, and 13%; P < 0.001, P = 0.003, P = 0.028).
  
  
  CONCLUSIONS
  Combined use of hyperbaric (4 mg) and hypobaric (6 mg) ropivacaine significantly decreased the incidences of hypotension and complications in spinal anesthesia for caesarean section by extending induction time and decreasing the level of sensory blockade.
  
  
  BACKGROUND
  Chinese Clinical Trial Register ChiCTR-TRC-13004622.
authors.affiliation: Department of Anesthesiology, Beijing You An Hospital, Capital Medical University, Beijing, 100069, China.
authors.forename: ZheFeng
authors.initials: Z
authors.lastname: Quan
authors.affiliation: Department of Anesthesiology, Beijing You An Hospital, Capital Medical University, Beijing, 100069, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Tian
authors.affiliation: Department of Anesthesiology, Beijing You An Hospital, Capital Medical University, Beijing, 100069, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Chi
authors.affiliation: Department of Anesthesiology, Beijing You An Hospital, Capital Medical University, Beijing, 100069, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, Beijing You An Hospital, Capital Medical University, Beijing, 100069, China.
authors.forename: HaiLi
authors.initials: H
authors.lastname: He
authors.affiliation: Department of Anesthesiology, Beijing You An Hospital, Capital Medical University, Beijing, 100069, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Luo
mesh_terms: D000328:Adult; D000577:Amides / Q000008:administration & dosage* / Q000009:adverse effects; D000775:Anesthesia, Spinal / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000009:adverse effects; D002585:Cesarean Section; D004311:Double-Blind Method; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000139:chemically induced / Q000503:physiopathology / Q000517:prevention & control; D007022:Hypotension / Q000139:chemically induced / Q000503:physiopathology / Q000517:prevention & control; D007278:Injections, Spinal; D009325:Nausea / Q000139:chemically induced / Q000503:physiopathology; D009407:Nerve Block / Q000379:methods; D011247:Pregnancy; D011446:Prospective Studies; D000077212:Ropivacaine; D012768:Shivering / Q000187:drug effects; D013116:Spinal Cord; D014839:Vomiting / Q000139:chemically induced / Q000503:physiopathology
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine