Flashcards in Chapter 18 - 2 Deck (20):
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three basic FHR measurements
1)Baseline FETAL HEART RATE
2)Baseline VARIABILITY
3)Periodic RATE
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baseline rate
Normal 120-160 bpm (some authors say 110 for normal term infant
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tachycardia
>160 persisting for 10 mins.
-Causes: fetal hypoxia (increase HR to pump more oxygen), maternal tachycardia (mom's HR and temp are reflective of babies), infection, maternal anxiety
-Interventions: monitor closely, identify possible factors and intervene
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bradycardia
<110 persisting for at least 10 mins.
-Causes: congenital heart disease, fetal distress with decreased variability, maternal hypothermia, postmaturity
-Interventions:change position, notify MD, give O2, prepare for immediate delivery
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baseline variability
-The amount of baseline FHR variance from minute to minute
-The interplay of the symphatic/parasympathic central nervous system
-Usually 6-25 bpm variance
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with hypoxic baby you
lose variability; should intervene if you loose variability
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good variability =
good thing, adequate oxygen
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-Short term variability-
beat to beat which is most accurate with scalp electrode
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-Long term variability-
over a 10 minute period
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-No variability:
fetal acidosis, immature CNS, analgesics to mom
-DO: check med times, assess if fetal problems are present, with decelerations intervene as recommended
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-Decreased variability
<6 bpm causes include prematurity, infant sleep, medication, fetal acidosis, fetal cardiac arrhythmias
- DO: estimate fetal age, stimulate fetus(scalp or vibroacoustic stimulation, check med schedule
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Increased Variability-
>25 bpm
causes include maternal hypoxia and anxiety, tetanic contractions, immature CNS of fetus
-DO: check contractions, change positions, evaluate maternal status, notify MD if it persists
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periodic rate -
Shows how the fetal heart rate is affected by uterine contractions
Either Accelerations or Decelerations
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periodic rate accelerations -
-Above the FHR baseline, usually 15+bpm that lasts at least 15 seconds(10 w/<32 wks)
-Can occur at any time but often associated with fetal movement, vaginal exams, etc.
-Due to the stimulation of fetal autonomic nervous system -- GOOD SIGN (baby trying to compensate for HR dropping)
-Seen with variable decelerations as a compensation mechanism
Do: Explain and watch
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periodic rate declarations -
Three Types and causes
1) Early
2) Variable
3) Late
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interventions for non reassuring patterns
-What’s the cause?
-Stop Pitocin
-Reposition
-Increase IV rate of nonadditive fluid
-Give oxygen
-Keep monitoring
-Notify MD/Midwife
-If continues or worsens prepare for c-section
-increase lactated ringers for hypotension
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Ways to clarify fetal monitor data
-Fetal Scalp Stimulation - acceleration of FHR of 15bpm for at least 15 seconds
- Vibroacoustic Stimulation - used in place of scalp stimulation
- PH Fetal Blood sample - < 7.20 (normal 7.25-7.35 in fetus) For evaluation of fetal distress with persistent abnormal FHR patterns
-Cord Blood Samples Same as fetal blood samples- after delivery
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early
-bc of head compression, pressure on the head, and stimulates the vagal nerve, so HR drops
-contaction occurring and correlation of HR dropping (contraction and drop minor each other)
-normal physiological occurance
- fetal HR decrease before peak of contraction (why called early)
-repetitive and usually doesn't drop below 100 bpm
-does not mean fetal distress
-benign - don't intervene
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late
-drops after peak of contraction
-cause is uteroplacental insufficiency** - not adequate blood flow/oxygen to fetus
-doesn't drop below 100 bpm
-maternal hypotension, excessive uterine activity, placental problem, or abdominal blood flow through placenta, IV to mom can cause
-give oxygen (non rebreather mask for 10 min), position change
-if loose variability with late then could be a CNS problem but with opioid variability pos O2
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