title: Caesarean delivery vasopressor management.
abstract: OBJECTIVE
  This review assesses the maternal and fetal effects of vasopressor administration during spinal anaesthesia for caesarean delivery, with emphasis on recent findings.
  
  
  RESULTS
  Maternal heart rate is a good surrogate for cardiac output. The initial hypotensive effect of spinal anaesthesia is caused by a rapid decrease in systemic vascular resistance, which makes α-agonists the logical first-line therapy. Effective prophylactic phenylephrine administration can be associated with reduced maternal cardiac output, but this has not been associated with adverse maternal or fetal effects. Prophylactic phenylephrine infusion can cause hypertension if increasing arterial pressure does not trigger a timely reduction in the rate of administration. Phenylephrine has been used safely in mothers with cardiac disease and in pregnancies with suspected fetal compromise. Fetal genotype may increase resistance to ephedrine-induced acidosis. The combination of vagolytics and vasopressors has caused maternal hypertensive crises with serious adverse outcome.
  
  
  CONCLUSIONS
  Phenylephrine is the current vasopressor of choice for the prevention of maternal hypotension and nausea. Phenylephrine regimens need to be developed that can reliably and safely be used with noninvasive blood pressure cycle times less frequent than every minute. Further vasopressor should be used with caution when vagolytic therapy is, quite rightly, used to treat bradycardia associated with hypotension.
authors.affiliation: Department of Anaesthesia, James Cook University Hospital, Middlesbrough, Cleveland, UK. drdavidcooper@aol.com
authors.forename: David W
authors.initials: DW
authors.lastname: Cooper
mesh_terms: D058646:Adrenergic alpha-1 Receptor Agonists / Q000494:pharmacology; D000328:Adult; D000773:Anesthesia, Obstetrical; D000775:Anesthesia, Spinal; D002302:Cardiac Output / Q000502:physiology; D002585:Cesarean Section / Q000379:methods*; D004809:Ephedrine / Q000494:pharmacology; D005260:Female; D005333:Fetus / Q000187:drug effects; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008991:Monitoring, Physiologic; D010656:Phenylephrine / Q000494:pharmacology; D021041:Placental Circulation / Q000187:drug effects; D020250:Postoperative Nausea and Vomiting / Q000453:epidemiology; D011225:Pre-Eclampsia / Q000628:therapy; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D012039:Regional Blood Flow / Q000502:physiology; D013565:Sympatholytics / Q000494:pharmacology / Q000627:therapeutic use; D014662:Vasoconstrictor Agents / Q000627:therapeutic use*
chemical_list: D058646:Adrenergic alpha-1 Receptor Agonists; D013565:Sympatholytics; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D004809:Ephedrine