title: Haemodynamic consequences and uterine contractions following 0.5 or 1.0 litre crystalloid infusion before obstetric epidural analgesia.
abstract: OBJECTIVE
  The efficacy of infusion of 0.5 L and 1.0 L Ringer's lactate (LR) to prevent hypotension during induction of obstetric analgesia was studied. The effect of the different fluid boluses on fetal heart rate (FHR) and frequency of uterine contractions were also determined.
  
  
  METHODS
  Ninety-two ASA 1-2 parturients were randomized to receive 0.5 L (Group 1) and 1.0 L (Group 2) LR immediately before incremental epidural injections with lidocaine to achieve T10 sensory block. Systolic blood pressure (SBP) was measured with an automated BP cuff every two minutes for 30 min after infusion of fluid bolus. Fetal heart rate monitoring and tocometry were used continuously. The number of uterine contractions were recorded 30 min before and 60 min after i.v. bolus.
  
  
  RESULTS
  The SBP decreased in both groups, but there was no difference between groups in mean SBP or maternal heart rate. The incidence of hypotension (SBP < 90 mmHg or decrease of 20%) was 4% in both groups. The FHR record of a patient in Group 1 showed a single late deceleration, and a decrease in beat-to-beat variability occurred in one patient in Group 2. A decrease in the frequency of uterine contractions of two or more contractions per 30 min was noted more frequently in Group 2 (P < 0.05). The duration of iv bolus was longer in Group 2 than Group 1 (18.8 +/- 4.3 min vs 12.3 +/- 4.5 min, P < 0.01).
  
  
  CONCLUSIONS
  Administration of 1.0 L LR i.v. does not provide added protection against maternal hypotension, and is associated with delay in providing pain relief and a risk of decreasing uterine contraction frequency.
authors.affiliation: Department of Anaesthesia, Ottawa Civic Hospital, University of Ottawa, Ontario, Canada.
authors.forename: J E
authors.initials: JE
authors.lastname: Zamora
authors.forename: O P
authors.initials: OP
authors.lastname: Rosaeg
authors.forename: M P
authors.initials: MP
authors.lastname: Lindsay
authors.forename: M L
authors.initials: ML
authors.lastname: Crossan
mesh_terms: D000328:Adult; D015360:Analgesia, Epidural; D016362:Analgesia, Obstetrical; D005260:Female; D006340:Heart Rate, Fetal / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007022:Hypotension / Q000517:prevention & control; D007552:Isotonic Solutions / Q000494:pharmacology*; D011247:Pregnancy; D011446:Prospective Studies; D000077325:Ringer's Lactate; D014590:Uterine Contraction / Q000187:drug effects*
chemical_list: D007552:Isotonic Solutions; D000077325:Ringer's Lactate