ABSTRACT
We investigated the cerebrovascular effects of continuous infusion of low-dose oxytocin
in normal pregnant women undergoing induction of labor. In our prospective observational
study, middle cerebral artery velocity was measured with transcranial Doppler ultrasound
in 25 healthy, normotensive, nonsmoking patients undergoing induction of labor. No
vasoactive drugs were used before or during the study period. Measurements were made
at baseline and 15, 30, 60, and 120 minutes after oxytocin initiation. Mean arterial
pressure, cerebral perfusion pressure, resistance index, resistance area product,
and cerebral flow index at different times were calculated and compared using one-way
analysis of variance (ANOVA) for repeated measures or Friedman repeated-measures ANOVA
as appropriate, with p < 0.05 regarded as significant. No significant systemic or cerebrovascular changes
were noted after oxytocin initiation, and there was no correlation between the dosage
administered and any hemodynamic parameter. Induction-dose oxytocin does not significantly
affect selected cerebral hemodynamic parameters in the first 2 hours after initiation.
KEYWORDS
Oxytocin - transcranial Doppler - induction - cerebral hemodynamics - cerebral perfusion
pressure
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Michael Belfort M.D. Ph.D.
1709 Dryden Suite 1100
Houston, TX 77030
Email: belfort@bcm.edu