title: Fetal bradycardia and uterine hyperactivity following subarachnoid administration of fentanyl during labor.
abstract: OBJECTIVE
  Changes in uterine tone have been postulated as the cause of fetal bradycardia following subarachnoid administration of fentanyl for labor analgesia. Such a case occurred in a 20-year-old parturient with an intrauterine pressure catheter in place.
  
  
  METHODS
  The patient was given intravenous terbutaline, after which contractions ceased for 20-30 minutes and then resumed.
  
  
  RESULTS
  The patient underwent successful cesarean delivery. Retrospective analysis of the data revealed a significant increase in uterine tone and contractions following fentanyl administration.
  
  
  CONCLUSIONS
  This case supports the view that changes in uterine tone, producing a hyperdynamic contractile state and a resulting decrease in uteroplacental perfusion, may explain the fetal bradycardia following subarachnoid opioid administration. Cases that do not resolve spontaneously may respond to intravenous terbutaline.
authors.affiliation: Department of Anesthesiology, College of Physicians & Surgeons of Columbia University, New York, New York 10032, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Friedlander
authors.forename: H E
authors.initials: HE
authors.lastname: Fox
authors.forename: C F
authors.initials: CF
authors.lastname: Cain
authors.forename: C L
authors.initials: CL
authors.lastname: Dominguez
authors.forename: R M
authors.initials: RM
authors.lastname: Smiley
mesh_terms: D000328:Adult; D016362:Analgesia, Obstetrical / Q000009:adverse effects*; D000701:Analgesics, Opioid / Q000009:adverse effects*; D001919:Bradycardia / Q000139:chemically induced*; D005260:Female; D005283:Fentanyl / Q000009:adverse effects*; D006340:Heart Rate, Fetal / Q000187:drug effects*; D006801:Humans; D011247:Pregnancy; D013346:Subarachnoid Space; D014599:Uterus / Q000187:drug effects*
chemical_list: D000701:Analgesics, Opioid; D005283:Fentanyl