Fluid Management for Cesarean Section III (FMCS-III)

• Recurrence of hypotension after ephedrine or phenylephrine [ Time Frame: Anesthesia begin (0 min) to 120 min after anesthesia ] [ Designated as safety issue: Yes ]
• Consumption of ephedrine and phenylephrine [ Time Frame: Anesthesia begin (0 min) to 120 min after anesthesia ] [ Designated as safety issue: Yes ]
• Total volume of colloid or crystalloid [ Time Frame: Fifteen minutes before anesthesia to 120 min after anesthesia ] [ Designated as safety issue: Yes ]
• One-min and 5-min Apgar scores [ Time Frame: The first and fifth minute after cesarean successful delivery ] [ Designated as safety issue: Yes ]
• Oxygen saturation during hypotension [ Time Frame: Anesthesia begin (0 min) to 120 min after anesthesia ] [ Designated as safety issue: Yes ]
• Duration of hypotension [ Time Frame: Anesthesia begin (0 min) to 120 min after anesthesia ] [ Designated as safety issue: Yes ]
• Low umbilical cord pH (artery < 7.20) [ Time Frame: At the time of successful delivery (0 min) ] [ Designated as safety issue: Yes ]

Regional anesthesia, including epidural, spinal and combined epidural spinal anesthesia (CSEA), is a pivotal part in modern anesthesiology. Previously, the investigators found that epidural and spinal anesthesia during cesarean section possesses different responsiveness to fluid (including crystalloid and colloid) management given prior or posterior to anesthesia. Although CSEA is also widely used as an alternative of single epidural or spinal anesthesia for its combined effect of fast onset of anesthesia of spinal anesthesia and the property of duration of epidural catheterization, the fluid resuscitation during CSEA is still unknown. The investigators hypothesized that fluid management during CSEA would produce different effect on hemodynamics in cesarean section compared with epidural and spinal anesthesia.

• Drug: Ringer's Lactate
  Ringer's Lactate 8 ml/kg was given intravenously before or after CSEA in cesarean section
  Other Name: Lactated Ringer's solution
• Drug: Six percent hydroxyethyl starch
  Hydroxyethyl starch (6%) was given before or after CSEA in cesarean section
  Other Name: HES/HAES

• Active Comparator: Prior crystalloid
  Crystalloid (Ringer's Lactate) was given before CSEA
  Intervention: Drug: Ringer's Lactate
• Active Comparator: Posterior crystalloid
  Crystalloid (Ringer's Lactate) was given after CSEA
  Intervention: Drug: Ringer's Lactate
• Active Comparator: Prior colloid
  Colloid (6% hydroxyethyl starch) was given before CSEA
  Intervention: Drug: Six percent hydroxyethyl starch
• Active Comparator: Posterior colloid
  Colloid (6% hydroxyethyl starch) was given after CSEA
  Intervention: Drug: Six percent hydroxyethyl starch

Inclusion Criteria:

• 21-40 yr
• First time of delivery
• ASA status I-II
• No premature
• No genetic and infectious diseases
• Chinese

Exclusion Criteria:

• < 21 yr
• > 40 yr
• Subjects with cardiac and pulmonary disorders
• Dislocation of placenta
• Pregnant hypertension
• Allergy to local anesthetics
• Unwilling to cooperation
• Need intraoperative administration of vascular active agents
• With significant delivery side effects