Electronic Fetal Monitoring Flashcards
1
Q
What 2 things will you look at on the fetal monitoring strip?
A
- fetal HEART RATE (baby)
2. UTERINE contractions (mom)
2
Q
What are the 2 types of fetal monitors?
A
- EXTERNAL= little doppler transducers with stretchy straps.
- INTERNAL= fetal scalp electrode (FSE) placed on the baby’s scalp by going in through the mother’s cervix.
3
Q
When do you use internal fetal heart monitors?
A
- if pt is very obese, or you can’t pick up the fetal heart beat using the external monitor.
4
Q
What is a potential risk of placing an internal fetal monitor?
A
- infection
5
Q
What is electronic fetal monitoring (EFM)?
A
- cardiotocography (aka cardiography + uterine contractions (tocodynamometer)
6
Q
Is the top line or bottom line the fetal heart rate?
A
TOP LINE
7
Q
What tells us the variability of the baby’s heart rate on the fetal heart strip?
A
- the “squiggliness” of the line, indicating sympathetic and parasympathetic nervous system activities working together.
- aka you want VARIABILITY
8
Q
*** What is the normal range or fetal heart rate?
A
110-160 BPM
- less than 110= bradycardia.
- greater than 160=tachycardia.
9
Q
Where is the contraction pattern on the fetal monitor strip?
A
- bottom line that looks like mountain peaks.
10
Q
What are the units for contractions?
A
- MONTEVIDEO UNITS= calculated by subtracting the baseline uterine pressure from the peak contraction pressure for each contraction in a 10-min window and adding the pressures generated by each contraction.
Ex. 5 pressure changes of 52, 50, 47, 44, and 49 mm Hg are added together= 242 Montevideo units.
*greater than 200 indicates adequate contractions!
11
Q
Why do we care if the contractions are high enough?
A
- to get her fully dilated so she can start to push.
12
Q
Why do we use electronic fetal heart monitors?
A
- to determine if a fetus is well oxygenated. Hypoxia changes activity of the nervous system, which affects HR and will result in changes on EFM.
13
Q
How is EFM described?
A
- baseline HR
- variability
- presence or absence of accelerations and decelerations.
- frequency of contractions.
14
Q
What actually makes up the irregular horizontal line of the fetal heart rate monitor?
A
- it’s just a series of closely-spaced R to R waves in the fetal EKG.
15
Q
How do you get the mean fetal HR?
A
- round to nearest 5 BPM during a 10 min segment.
16
Q
** What are some causes of fetal BRADYcardia (less than 110 BPM)?
A
- maternal HYPOtension
- umbilical cord prolapse
- rapid fetal descent
- uterine tachysystole
- placental abruption
- uterine rupture
- myocardial conduction defect
17
Q
** What are some causes of fetal TACHYcardia (greater than 160 BPM)?
A
- infection (chorioamnionitis)
- medications (terbutaline, cocaine)
- fetal anemia
- placental abruption
- maternal disorders (HYPERthyroidism)
- fetal tacharrhythmia
18
Q
*** What is variability?
A
- the fluctuation in beat to beat rate (amplitude of peak-to-trough in BPM).
19
Q
*** What is ABSENT variability?
A
- amplitude range undetectable
20
Q
*** What is MINIMAL variability?
A
- amplitude range less than 5 BPM
21
Q
** What is MODERATE variability? (TEST QUESTION)
A
- amplitude range 6-25 BPM
22
Q
*** What is MARKED variability?
A
- amplitude rang greater than 25 BPM
23
Q
Is variability sensitive to fetal acid-base status?
A
YES
24
Q
What does MODERATE variability suggest?
A
adequate oxygenation :)
25
What could cause decreased variability?
- medications (opioids, magnesium sulfate)
- fetal sleep cycle (only 30-40 mins max).
- prematurity
- CNS or cardiac abnormalities
- fetal hypoxia
- fetal acidemia
26
*** What is an ACCELERATION?
- abrupt increase in fetal HR (FHR) with peak of greater than 15 beats above baseline. This is associated with fetal movement, a mature neurocardiac tract, and indicates that the fetus is not acidemic.
- duration of at least 15 sec, up to 2 min.
* aka this reassures fetal well-being
27
** What happens if an acceleration is greater than 2 min?
- this is a prolonged acceleration
| * if over 10 min, it is a CHANGE IN BASELINE.
28
*** What is a DECELERATION?
- decrease in FHR from baseline:
- recurrent= occurs for more than 50% of contractions.
- intermittent= occurs with less than 50% of contractions.
29
**** What are the 3 types of DECELERATIONS? (she said she wants us to know these)
1. EARLY= associated with HEAD COMPRESSION.
2. VARIABLE= associated with CORD COMPRESSION.
3. LATE= associated with UTEROPLACENTAL INSUFFICIENCY; BAD.
* all about timing.
30
What type of deceleration is TIMED WITH THE CONTRACTIONS?
- EARLY (mirror image of the contraction; as the contraction goes up, the HR goes down).
31
What should you do in an EARLY deceleration?
- no treatment necessary, but check pt as head is probably descending.
32
*** What does a VARIABLE deceleration look like?
- ABRUPT decrease in FHR (goes down faster; less than 30 sec).
- decrease in FHR is greater than 15 BPM with a total duration greater than 15 sec.
* V configuration!
33
When do VARIABLE decelerations occur?
- can occur at ANY time; not necessarily associated with contraction.
34
What do we do for VARIABLE decelerations?
- ALLEVIATE CORD COMPRESSION by maternal repositioning, amnioinfusion, or check for prolapsed cord.
35
*** What are LATE decelerations?
- symmetrical gradual decrease in FHR.
- begins at or after peak of contraction and returns to baseline after contraction is over.
- associated with uteroplacental insufficiency from decreased uterine perfusion or decreased placental function.
36
**** What do we do for LATE decelerations? (she wants us to know this)
- maternal repositioning (left or right lateral).
- maternal oxygen administration
- administer IV fluid bolus
- reduce contraction frequency (discontinue oxytocin (pitocin) or cervical ripening agents)
- administer TOCOLYTIC medication.
* goal is to IMPROVE UTEROPLACENTAL BLOOD FLOW
37
What is the ABCD approach?
- Assess oxygen pathway.
- Begin conservative corrective measures.
- Clear obstacles to rapid delivery.
- Determine decision-to-delivery time
38
**** What are the 3 categories of strips and what do they mean?
1. Category I= normal HR, moderate variability, no lates or variables, early decelerations don't matter, accelerations may be present or absent, normal acid-base status (aka everything is GOOD).
2. Category II= everything else.
3. Category III= absent baseline FHR variability, late decelerations, recurrent variable decelerations, bradycardia, sinusoidal pattern, abnormal acid-base status (aka all the BAD stuff).
39
What do we do for category II management?
- continued monitoring and possibly intrauterine resuscitation (maternal repositioning, O2 administration, IVF, reduce contraction frequency, possible amnioinfusion).
40
What is normal uterine activity?
- less than 5 contractions in 10 min averaged over 30 min window.
41
What is tachysystole of uterine activity?
- greater than 5 contractions in 10 min averaged over a 30 min window.
