OB Anesthesia Exam 2

  1. Placental implantation begins
    150 hours after ovulation
  2. Placental development is complete by
    10 days after implantation
  3. The umbilical cord is made up of
    2 arteries, 1 vein, surrounded by wharton jelly
  4. Route of blood flow from mom to fetus
    • Maternal blood
    • umbilical vein
    • fetal liver
    • anastomosis
    • fetal sinus venosus
    • atria/ventricles
    • truncus arteriosus
    • aortic sac
    • aortic arches
    • dorsal aorta
    • pair of umbilical arteries
    • maternal blood
  5. Rate of fetal BF
  6. Fetal BF depends on
    fetal cardiac activity, BP, R to L shunt, SVR, PVR
  7. Factors that reduce UBF
    • o Umbilical cord compression
    • o Maternal hypo/hypertension
    • o Aortocaval syndrome
    • o VasoC in uterine vessels (predominantly alpha)
    • o Hypertonic uterine contractions
  8. Fetal oxygenation/gas exchange depend on
    adquate UBF, adequate maternal oxygenation
  9. Normal fetal scalp blood gas
    pH>7.25, pCO2 <50, pO2 >20 (variable)
  10. Critical emergency, fetal ABG
    pH <7.2, HCO3 <20, BE> -6
  11. Main determinant of fetal pO2
    Maternal uterine VENOUS pO2
  12. 100% maternal FIO2 will increase fetal pO2 by
  13. Greatest maternal threats:
    • Severe hypoxia
    • Hypotension
    • Acidosis
  14. Chronic fetal hypoxia secondary to chronically decreased U/P perferusion are d/t:
    • Pre-eclampsia
    • Maternal HTN
    • Maternal diabetes
  15. Primary fetal response to acute hypoxia:
    • Maintain BF and oxygenation to brain, heart, kidneys
    • Brief increased HR, THEN vagally stimulated slowed fetal HR to decrease O2 consumption
  16. Secondary fetal response to acute hypoxia:
    fetal oxy-hgb dissociation curve shifts RIGHT
  17. Fetal asphyxia:
    Loss of cerebral autoregulation, ischemic brain, mental retardation
Card Set
OB Anesthesia Exam 2