Electronic Fetal Monitoring & Fetal Adaptation to Labor (exam 2) Flashcards
fetal monitoring allows for
ongoing assessment of fetal oxygenation
the fetal heart circulates _______ from the placenta throughout the body and returns _________ to the placenta
oxygenated blood
deoxygenated blood
(opposite from adult - switches when born)
carries deoxygenated blood from the fetus to the placenta
2 arteries
carries oxygenated blood to the fetus
1 vein
adequate oxygenation promotes
normal function of the autonomic nervous system, enabling the fetus to adapt to the stress of labor
types of monitoring
- auscultation/intermittent auscultation
- external fetal monitoring
- internal fetal monitoring
advantages of auscultation
- non-invasive
- fetoscope detects actual fetal heart sounds, therefore you can hear dysrhythmias (rarely used anymore)
- no straps to hold mother down
- no “machine error”
disadvantages of auscultation
- requires skill and practice
- can be disrupted by contractions
- unable to review or archive the information
FHR is obtained by
- doppler
- fetoscope (rarely used)
external monitoring of FHR
- tocotransducer (maternal monitoring)
- ultrasound (fetal monitoring)
uterine activity is measured in
mmHg
internal monitoring
- internal scalp electrode (ISE) for fetal
- intrauterine pressure catheter (IUPC) for maternal
internal EFM advantages
- true reading of FHR
- can detect arrhythmias
- helpful with obese patients
internal EFM disadvantages
- BOW must be ruptured
- cervix must be dilated
- invasive - can lead to infection
external EFM advantages
- continuous
- captures/archives data that can be retrieved later if necessary
- becomes a permanent part of the patient’s chart
- able to visualize fetal responses before, during, and after a contraction
- allows staff to watch more than 1 mother at a time
- can be used whether or not water is ruptured
external EFM disadvantages
- restricts movement
- can lose contact with maternal or fetal movement
- can half or double the rate?
- difficulty with obese pts
- contractions must be palpated
monitoring strip top = bottom = each vertical dark read line = each small square = 6 columns of squares =
top = FHR bottom = uterine activity each vertical dark read line = 1 minute each small square = 10 sec 6 columns of 10 sec squares = 1 min
top of the contraction
acme or peak
baseline FHR
110-160 bpm
average HR measured on EFM strip
measured for 2 “clear” minutes and rounded to 5 bpm
- uterus must be at rest
FHR >160 lasting more than 10 min
tachycardia
FHR <110 lasting more than 10 min
bradycardia
must watch closely to differentiate between bradycardia and prolonged decelerations
fetal tachycardia causes
- early fetal hypoxemia
- maternal fever
- maternal dehydration
- drug induced
- intraamniotic infection
- maternal hyperthyroidism
- fetal anemia
- fetal HF
- fetal cardiac dysrhythmias
drugs that can cause fetal tachycardia
- atropine
- hydroxyzine (Vistaril)
- terbutaline (brethine)
- ritodrine
- cocaine
- methamphetamines