Fetal Monitoring Flashcards
What are some external monitors?
U/S (ultrasound) for FHR
Toco- to detect contractions
What are some internal monitors?
FSE- fetal scalp electrode which monitors FHR
IUPC- intrauterine pressure catheter which monitors contractions
How is the baseline fetal heart rate determined?
By approximating the mean (average) FHR during a 10 minute period, rounding to increments of 5 bpm like 125,130 etc
What is normal, bradycardia, and tachycardia heart rate for fetus?
Normal- 110-160
Bradycardia- <110 for at least 10 min
Tachycardia- > 160 for at least 10 minutes
What is baseline variability?
A reliable indicator of fetal cardiac and neurologic function and well-being and is defined as fluctuations in the baseline FHR, that are irregular in amplitude, and with a frequency of over two cycles per minute
How is variability classified
Absent FHR variability
Minimal FHR
Moderate FHR
Marked FHR variability
What is absent FHR variability
Amplitude range undetected
0-2 beats- looks like a flatline, non reassuring
What is minimal FHR variability
Amplitude range detectable, but 5 bpm or less
3-5 bpm
What is moderate FHR variability
Normal
Amplitude range of 6 to 25 bpm
Indicates absence of hypoxia, even if decelerations are present, demonstrating the fetus can utilize available oxygen
What is marked FHR variability
Amplitude range greater than 25 bpm
Excessive variability and uncommon. May indicate early hypoxia
What is an acceleration?
Abrupt increase in the baseline FHR with an onset to peak of less than 30 seconds and lasting less than 2 minutes
What is classified as an acceleration?
The peak must be 15 bpm or more, and the acceleration must last 15 seconds or more when the fetus is equal to, or greater than 32 weeks
What are accelerations for less than 32 weeks of gestation
A peak of 10 bpm or more and a duration of 10 seconds or more
Why are accelerations usually benign?
Because they are associated with an intact fetal nervous system, lack of fetal hypoxia, and acidosis
What are decelerations
Often referred to as decels
Generally defined as decreases in the FHR below the baseline
When does acceleration occur?
Fetal movement or stimulation
What is a reactive strip?
15 by 15
Abrupt increase by at least 15 beats above baseline for at least 15 seconds
In other words, increased by 1.5 boxes and across 1.5 boxes
What are the categories for decelerations?
Early
Variable
Late
Prolonged
Which category for deceleration is reassuring?
Early, meaning, no nursing intervention is needed
What are early decelerations and what causes them?
Occurs early with the onset of the contraction
Mirrors the shape and timing of the contraction
Appearance is shallow and cuplike
It is reassuring, caused by vagal stimulation that occurs with pressure on the babies head
What are variable decelerations?
Can occur with or without a contraction
Often abrupt onset with a U, V, or W shape.
Non reassuring, especially if deep and prolonged
What is a variable deceleration the result of
Compression of the umbilical cord
Interventions for variable decelerations
IV open
Pit off
Position change
02 on
May perform vaginal exam
What are late decelerations?
Occurs late, or after the onset of the contraction
Non reassuring, especially if seen with absent or minimal variability
What is late decelerations caused by?
Result of uteroplacental insufficiency (fetus not getting enough oxygen)
Why is the baby not getting enough oxygen during late decelerations?
When you have a contraction, no matter what, during that contraction the placenta is compressed, and during that time period there is no blood flow and therefore no oxygen going to the baby.
Now the problem with lates is that the baby is not tolerating that contraction, so having a late decel is kind of the baby kicking itself while it’s already down because it’s lost oxygen during the time of the contraction, and then furthermore is continuing to not be able to access oxygen during the time.
What is a prolonged deceleration?
A “long late”
A 15 beat drop below baseline lasting more than two minutes, but less than 10 minutes
Non reassuring
What happens if a prolonged deceleration is longer than 10 minutes
You have a new fetal heart rate baseline
What is VEAL CHOP
V- variable deceleration
E- early deceleration
A- acceleration
L- late deceleration
C- cord compression
H- head compression
O- OK
P- placental insufficiency
What is category one?
Reassuring
FHR 110-160 baseline, moderate variability, no variable or late decelerations
What is category II?
Indeterminate, warrants continual assessment
Those that are not either reassuring, or non-reassuring
What is category III?
Non-reassuring, warrants immediate intervention
Absent variability, with recurrent late or variable decelerations and/or bradycardia or sinusoidal patterns
How does changing laboring mothers position help the fetus?
Improves blood flow to baby and relieves possible cord compression
Why does opening an IV help with decelerations?
Increases rate of IV fluids which could be either normal saline or lactated ringers to maintain blood pressure and hydration
How much oxygen would be administer?
10 L/ min via face mask
Why would we do a vaginal exam for decelerations?
It’s to evaluate labor progress, and rule out cord prolapse
What does Pitocin do?
Makes the contractions stronger and longer
Which is why we shut it off
When do we call the doctor?
After we’ve done our nursing interventions
What do we look at when observing contractions?
Frequency
Duration
Intensity
Resting tone
What is the frequency of a contraction?
Measured in minutes
Beginning of one contraction to beginning of the next contraction
What is the duration of a contraction?
Measured in seconds
Beginning to end of each contraction
How do you measure the intensity of a contraction?
External monitor (toco): palpation: mild, moderate, or strong
Internal monitor (IUPC): subtracting resting tone from strongest (tallest contraction) and weakest (shortest) for a range in mmHg
What is resting tone
Pressure of the uterus at rest/between contractions
External: by palpation (we want the fundus soft)
Internal: in mmHg (we want it less than 35)
Example of an intensity with internal monitor?
Resting tone is 20
Weakest UC is 75
Strongest UC is 95
75-20= 55
95-20= 75
UC intensity is 55-75 mmHg
