title: Fluid preload in obstetric patients. How to do it?
abstract: OBJECTIVE
  In has been shown in non-obstetric patients, that a fast acute fluid preload immediately after spinal anesthesia was more effective than a slow preload before regional block to decrease the incidence and severity of arterial hypotension after spinal anesthesia. This study aimed at comparing the incidence of arterial hypotension and vasopressants consumption in parturients submitted to C-section under spinal anesthesia with different fluid preload regimens.
  
  
  METHODS
  Sixty term pregnant women submitted to C-section under spinal anesthesia. Patients were randomly distributed in three groups receiving acute preload (10 ml kg(-1) lactated Ringer's) as follows: Group 1 (n = 20), before spinal anesthesia through 18G catheter; Group 2 (n = 20), after spinal anesthesia through 18G catheter and Group 3 (n = 20), after spinal anesthesia through 16G catheter with pressurizer. Blood pressure (BP) was monitored at 1-minute intervals until delivery and 0.2 mg bolus metaraminol was administered for any BP decrease from baseline values; 0.4 mg was administered for BP decrease >or= 20%. Control blood pressure was defined as the mean of three successive SBP values obtained before acute preload and spinal block. Variables studied were: preload rate, incidence of maternal arterial hypotension, nausea, vomiting, vasopressants consumption, Apgar scores and umbilical artery pH.
  
  
  RESULTS
  Acute preload was faster in Group 3 as compared to Groups 1 and 2 (201 +/- 61 vs 56 +/- 13 and 59 +/- 21 ml min(-1), p < 0.05). Groups were similar regarding the incidence of arterial hypotension, nausea and vomiting, metaraminol consumption, Apgar scores and umbilical artery pH.
  
  
  CONCLUSIONS
  Acute preload before or after spinal anesthesia performance, in a slow or fast rate, does not change vasopressants consumption, the incidence of maternal arterial hypotension, nausea and vomiting, as well as fetal wellbeing.
authors.affiliation: Hospital e Maternidade Santa Joana, São Paulo, SP.
authors.forename: Mônica Maria Siaulys Capel
authors.initials: MM
authors.lastname: Cardoso
authors.forename: Márcio Martines
authors.initials: MM
authors.lastname: Santos
authors.forename: Eduardo Tsuyoshi
authors.initials: ET
authors.lastname: Yamaguchi
authors.forename: Jacqueline Toshiko
authors.initials: JT
authors.lastname: Hirahara
authors.forename: Antonio Rahme
authors.initials: AR
authors.lastname: Amaro