RELIAS - FETAL HEART MONITORING
Midterm Exam Questions and Answers Top
Rated A+
base excess and base deficit
- base deficit is expressed as a positive number
- base excess is expressed as a negative number
~ they are equivalent and terms are used interchangeably ~
fetal acidosis
- when O2 is decreased to fetus, tissue hypoxia results in acidosis, which then shows
a drop in pH, a loss of bicarb, and increase in base deficit
acidemia
assoc w/ widespread, deleterious effects on vital organ and body function
fetal hypoxia during birth
assoc w/ neonatal depression, low apgars, neonatal encephalopathy, and cerebral
palsy
respiratory acidosis
low pH (< 7.10), high pCO2 (> 60), normal base deficit ( < 12)
- increase of pCO2 for fetus that lowers pH but doesn't affect base deficit
factors that contribute to resp acidosis
- sudden decrease in placental or cord perfusion
- uterine tachysystole
- maternal hypoventilation
metabolic acidosis
,ph < 7.10 , normal pCO2 (<60), high base deficit (>12)
- a higher base deficit (such as > 12) has been assoc w/higher risk for severe neonatal
complications
- most common cause of metabolic acidosis in fetus is r/t inadequate O2 delivery
- prolonged hypoxic insult to fetus results in depletion of bicarb, which is a base
buffer that normalizes pH levels
mixed acidosis
pH < 7.10 , high pCO2 > 60, and high base deficit >12
- may develop when resp acidosis persists for a prolonged period of time
-outcome for neonates is dependent on degree and severity, but typically the lower
pH and higher base deficit means worse neonatal outcomes
- most often seen in prolonged bradycardia at time of birth
what is used to evaluate fetal acidosis?
arterial umbilical cord blood
artery values (fetus to placenta)
Normal ranges:
pH 7.20-7.28
pCO2 35-70
Base excess -3 to -9
, venous values (placenta to fetus)
Normal ranges:
pH 7.35
pCO2 33-50
base excess -1 to -8
factors for neonatal encephalopathy or cerebral palsy
Data shows that intrapartum hypoxia-ischemia is rarely sole significant contributing
factor for this
Other contributing factors include:
- infection
- prolonged intermittent hypoxia assoc w/subcortical and cortical or preventricular
damage
- acute total or near total hypoxia is assoc w/damage to midbrain and brainstem
low pH in newborns
- no absolute fetal arterial pH threshold assoc w/harm in all newborns
- typically if pH is < 7.10 that is used to determine acidosis and if the pH is < 7 then
that is associated w/ low apgars, early neonatal seizues, and neonatal deaths
prolonged intermittent hypoxia is assoc w/
subcortical and cortical (term) or perventricular (preterm) damage
Midterm Exam Questions and Answers Top
Rated A+
base excess and base deficit
- base deficit is expressed as a positive number
- base excess is expressed as a negative number
~ they are equivalent and terms are used interchangeably ~
fetal acidosis
- when O2 is decreased to fetus, tissue hypoxia results in acidosis, which then shows
a drop in pH, a loss of bicarb, and increase in base deficit
acidemia
assoc w/ widespread, deleterious effects on vital organ and body function
fetal hypoxia during birth
assoc w/ neonatal depression, low apgars, neonatal encephalopathy, and cerebral
palsy
respiratory acidosis
low pH (< 7.10), high pCO2 (> 60), normal base deficit ( < 12)
- increase of pCO2 for fetus that lowers pH but doesn't affect base deficit
factors that contribute to resp acidosis
- sudden decrease in placental or cord perfusion
- uterine tachysystole
- maternal hypoventilation
metabolic acidosis
,ph < 7.10 , normal pCO2 (<60), high base deficit (>12)
- a higher base deficit (such as > 12) has been assoc w/higher risk for severe neonatal
complications
- most common cause of metabolic acidosis in fetus is r/t inadequate O2 delivery
- prolonged hypoxic insult to fetus results in depletion of bicarb, which is a base
buffer that normalizes pH levels
mixed acidosis
pH < 7.10 , high pCO2 > 60, and high base deficit >12
- may develop when resp acidosis persists for a prolonged period of time
-outcome for neonates is dependent on degree and severity, but typically the lower
pH and higher base deficit means worse neonatal outcomes
- most often seen in prolonged bradycardia at time of birth
what is used to evaluate fetal acidosis?
arterial umbilical cord blood
artery values (fetus to placenta)
Normal ranges:
pH 7.20-7.28
pCO2 35-70
Base excess -3 to -9
, venous values (placenta to fetus)
Normal ranges:
pH 7.35
pCO2 33-50
base excess -1 to -8
factors for neonatal encephalopathy or cerebral palsy
Data shows that intrapartum hypoxia-ischemia is rarely sole significant contributing
factor for this
Other contributing factors include:
- infection
- prolonged intermittent hypoxia assoc w/subcortical and cortical or preventricular
damage
- acute total or near total hypoxia is assoc w/damage to midbrain and brainstem
low pH in newborns
- no absolute fetal arterial pH threshold assoc w/harm in all newborns
- typically if pH is < 7.10 that is used to determine acidosis and if the pH is < 7 then
that is associated w/ low apgars, early neonatal seizues, and neonatal deaths
prolonged intermittent hypoxia is assoc w/
subcortical and cortical (term) or perventricular (preterm) damage
