Fetal Monitoring Flashcards
Why do we use fetal monitoring ?
primary mode of intrapartum fetal assessment in the U.S
- useful took for assessing fetal response to labor and uterine activity
What are the goals of intrapartum fetal monitoring ?
- support maternal coping and labor progress
- maximize uterine blood flow
- maximize umbilical circulation
- maximize oxygenation
- maintain appropriate uterine activity
What are the 3 reasons why fetal oxygen supply can decrease ?
- reduction to blood flow
- reduction of oxygen content
- alterations in fetal circulation
What are the reasons of reduction of blood flow to fetus ?
- poor maternal circulation
- poor placental perfusion
What are the reasons for reduction of oxygen content to fetus ?
- maternal hemorrhage
- severe anemia
What are the reasons for alterations in fetal circulation in fetus ?
- cord compression
- head compression
- placental abruption
What are the different types of monitoring techniques ?
- intermittent auscultation
- electronic external and internal
What is intermittent auscultation ?
every 30 mins going to listen with the doppler
What is electronic monitoring ?
- External: intermittent and continuous with the Toco which is placed on the fundus because that is where all the pressure is
- Internal: invasive
How does the Toco work ?
as the mom contract it presses on the button which produces a wave that can be seen on the computer or paper
Where do you place an external fetal monitor ?
you palpate the mom’s abdomen to feel where the baby’s position is with Leopold’ Maneuver
- US transducer should be placed on fetal back and the Toco near the fundus (top) of uterus
- smooth side is baby’s back and pointy parts are arms/legs
Where is the fetal heart rate best heard ?
along the fetal back
What are the 2 internal electronic fetal monitoring devices ?
- fetal scalp electrode (FSE)
- intrauterine pressure catheter (IUPC)
What is the fetal scalp electrode (FSE) ?
direct ECG monitoring of fetal heart where a thin wire is placed under the skin of the fetal head
- mom has to be dilated and water has to be broken
- Contraindications: infection (HIV, Hep B)
What is an intrauterine pressure catheter (IUPC) ?
direct measurement of uterine pressure where a catheter is placed between fetal body and uterus
- in mmHg
- membranes must be ruptured (ROM) & cervix must be dilated
- goal is to be on the side of the fundus
- can poke hole in placenta (if have abnormal placenta placement then not done)
- in IN RN’s can’t do this
What does the fetal heart rate baseline tell you ?
reflects the intrinsic rhythm of fetal heart and central nervous system functioning
- assess q30 min
- if pt is on Pitocin then q15min
- ignore any big peaks or downward beaks when counting the average
What is the normal fetal heart rate baseline ?
110-160 bpm
- baseline rate is the average during a 10 min segment
What is bradycardia in FHR ?
baseline <110 bpm for duration of 10 minutes or longer
What is tachycardia in FHR ?
baseline >160 bpm for duration of 10 mins or longer
What are some causes of bradycardia in FHR ?
- interrupted O2 supply to fetus (occluded umbilical cord, maternal hypotension, hemorrhage)
- medications (Nubain) (any med given to mom affects the baby through placenta)
- post maturity
What are some causes of tachycardia in FHR ?
- maternal fever
- prematurity
- medications (terbutaline)
- abnormal fetal cardiac rhythm
What is FHR variability ?
indirect measurement of fetal oxygenation & CNS functioning
- sympathetic increases the wave and parasympathetic decreases it
What is absent variability ?
undetectable/0 and looks like a straight line
- ominious
- represent fetal hypoxia or metabolic acidosis, and CNS dysfunction
What is minimal variability ?
1-5
- sleep cycle, sedation, sick
- represents hypoxemia, and congenital abnormality
What is moderate variability ?
6-25
- normal
- represents intact CNS and good fetal oxygenation
What is marked variability ?
> 25 and if not corrected it can start to look absent
- unclear significance
What is acceleration ?
increase in FHR of at least 15 bpm above baseline, lasting about 15 secs or more (15x15)
What was acceleration represent ?
reassuring sign of fetal well-being
- oxygenated and intact CNS
- see this when baby is moving around (kicking)
What is early deceleration ?
- benign
- response to fetal head compression
- gradual deceleration that mirrors the contraction
- greater then 30 secs
What causes early deceleration ?
as baby enters the pelvis there is more pressure put on the head
- decrease cerebral circulation/head compression
What is late deceleration ?
response to uteroplacental insufficiency
- gradual deceleration: starts after the contraction begins
- represents not enough bloodflow or O2 to fetus
- takes >30 secs from baseline to acceleration
What is variable deceleration ?
response to cord compression
- abrupt deceleration and return to baseline
- can be with or without contractions
- when increase pressure on cord then the HR drops
- artery constricts so the vein does as well
What is prolonged deceleration ?
response to interrupted oxygen supply
- when is lasts >2 mins but <10 mins
- associated with hypotension or interrupted of the 02 supply
What is VEAL CHOP ?
- Variable ———–> cord compression
- Early ————–> head compression
- Acceleration ———> Okay !
- Late —————-> placental insufficiency
What is required for normal tracings ?
- moderate variability
- baseline rate 110-160
- no late or variable decels
- early decels present or absent
- accels: present or absent
What is required for indeterminate tracings ?
FHR tracings that do not meet the criteria for normal or abnormal
What is required for abnormal tracings ?
absent baseline variability and any of the following:
- recurrent late decels
- recurrent variable decels
- bradycardia or sinusoidal pattern
What is a category 1 tracing ?
strongly associated with normal acid base status
What is a category 2 tracing ?
not predictive of abnormal fetal acid base status but inadequate evidence to classify as normal or abnormal
What is a category 3 tracing ?
predicting of abnormal fetal acid base status
What does frequency mean ?
measure shortest and longest interval between contractions (minutes)
- how often the contractions are coming
What does duration mean ?
measure shortest and longest contraction (seconds)
- how long contractions are lasting
What is intensity ?
measure of strength of contraction
- palpation: mild, moderate, strong (palpate on fundus and press and feel for compression)
- IUPC: mmHg & MVUs
What is resting tone ?
the “tone” of uterus between contractions
- during contractions the uterus becomes taut which means it has increased tone
- palpation: soft or rigid
- IUPC: mmHg
What is tachysystole ?
> 5 contractions in 10 mins
- caused by spontaneous or stimulated contractions
- intervention is necessary to reduce contractions and increase resting tone (can lead to fetal compromise if not corrected)
What does oxytocin do ?
stimulates contractions
What is intrauterine resuscitation ?
interventions used to maximize blood flow and oxygenation in utero when fetus is stressed
- interventions often done simultanously
- intervention is critical to maintain fetal capacity to tolerate labor
What are the goals of intrauterine resuscitation ?
- support maternal coping and labor progress
- maximize uteroplacental blood flow
- maximize oxygenation
- maximize umbilical blood flow
- maximize normal uterine activity
What are the 4 interventions used for intrauterine resuscitation ?
- increase fluid volume (bolus of lactated ringers (LR))
- increase uterine/umbilical perfusion (reposition to L or R side)
- increase oxygenation ( 8-10L O2 with non-rebreather face mask because during labor mouth breathing is common)
- increase uterine resting tone (discontinue oxytocin and admin Terbutaline 0.25 mg SQ)
What is amnioinfusion ?
used to increase “cushion” of fluid volume around umbilical cord in utero
- put IV fluids back into the uterus
- infusion of fluid thought IUPC (LR or NS)
- check pad for fluid return (if not risk of rupturing uterus)
- avoid overdistension of uterus
What is amnioinfusion used for ?
intervention used for recurrent variable decelerations
- decreased amniotic fluid volume after ROM
- umbilical cord compression
