title: Pulse wave analysis by digital photoplethysmography to record maternal hemodynamic effects of spinal anesthesia, delivery of the baby, and intravenous oxytocin during cesarean section.
abstract: OBJECTIVE
  To investigate changes in maternal ECG ST index, blood pressure (BP), cardiac left ventricular (LV) ejection function and vascular tone/stiffness in large and small arteries occurring during elective cesarean section (CS) in spinal anesthesia.
  
  
  METHODS
  Twenty-six women were monitored with photoplethysmographic digital pulse wave (PW) analysis (DPA) before and after spinal anesthesia, after delivery of the baby, after 5 IU oxytocin bolus IV, and 5 min later. Statistics with Wilcoxon matched-pairs signed-rank and Friedman tests at a p < 0.05 were performed.
  
  
  RESULTS
  Spinal anesthesia resulted in significantly decreased BP, increased ST index and LV ejection time, and small-artery vasodilation. Delivery of the baby resulted in global vasoconstriction and increases in systolic BP and heart rate (HR). Oxytocin lowered BP, HR and ST index, increased LV ejection power and caused both large- and small-artery vasodilation. ST index and BP recovered after 5 min, but low HR and low vascular tone persisted.
  
  
  CONCLUSIONS
  Spinal anesthesia and oxytocin caused arterial vasodilation and cardiac affection. Oxytocin caused a decrease in HR despite a fall in BP, indicating a direct negative chronotropic effect. Delivery of the baby caused momentous cardiovascular changes, possibly due to maternal emotions and auto-transfusion of blood from the uterus.
authors.affiliation: a Department of Anesthesiology and Intensive Care , Skåne University Hospital, Institution of Clinical Sciences Lund, Lund University , Lund , Sweden and.
authors.forename: Sofus
authors.initials: S
authors.lastname: Rabow
authors.affiliation: b Department of Obstetrics and Gynecology , Skåne University Hospital, Institution of Clinical Sciences Malmö, Lund University , Malmö , Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Olofsson
mesh_terms: D000328:Adult; D000773:Anesthesia, Obstetrical / Q000009:adverse effects; D000775:Anesthesia, Spinal / Q000009:adverse effects; D002585:Cesarean Section / Q000379:methods; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007262:Infusions, Intravenous; D008991:Monitoring, Physiologic / Q000379:methods*; D010121:Oxytocin / Q000008:administration & dosage*; D017156:Photoplethysmography; D011247:Pregnancy; D063177:Pulse Wave Analysis / Q000379:methods*; D012815:Signal Processing, Computer-Assisted
chemical_list: D010121:Oxytocin
keywords: Arterial elasticity; arterial stiffness; oxytocin; pregnancy; pulse wave analysis; spinal anesthesia