Ch. 17 Fetal Assessment During Labor Flashcards
What is electronic fetal monitoring?
A useful tool for visualizing FHR patterns continuously on monitor screen or printed tracing
What are the 2 modes used for electronic fetal monitoring?
External & Internal
What must be maintained during labor to prevent fetal compromise and promote newborn health after birth?
The fetal oxygen supply
How can the fetal oxygen supply decrease?
Maternal hypertension (chronic or gestational); Hypotension (caused by supine maternal position, hemorrhage, epidural analgesia, or anesthesia); Hypovolemia (caused by hemorrhage); Reduction of oxygen content in maternal blood (as a result of hemorrhage or severe anemia); Alterations in fetal circulation (compressed umbilical cord, placental separation or complete abruption, or head compression); & Reduction in blood flow to intervillous space in the placenta
What does UC stand for?
Uterine contraction
Are reassuring FHR patterns good or bad?
Good
What does EFM stand for?
Electronic Fetal Monitoring
What does UA stand for?
Uterine activity
What is normal uterine activity (UA)?
5 or fewer contractions in 10 minutes averaged over a 30-minute window
What is tachysystole uterine activity (UA)?
5 or more contractions in 10 minutes averaged over a 30-minute window
What are some characteristics of UCs?
Tachysystole should always be qualified by presence or absence of associated FHR decelerations. Tachysystole applies to both spontaneous or stimulated labor
What are the goals of intrapartum FHR monitoring?
To identify and differeniate reassuring patterns from nonreassuring patterns, which can indicate fetal compromise.
What is included in a reassuring FHR pattern?
Baseline FHR in normal range of 110-160bpm, with no periodic changes and a moderate baseline variability; Accelerations of FHR with fetal movement; Absence of decelerations
Nonreassuring FHR patterns are associated with what?
Fetal hypoxemia, which is a deficiency of oxygen in the arterial blood
What happens if fetal hypoxemia is not corrected?
Hypoxemia can deteriorate to severe fetal hypoxia, which is an inadequate supply of oxygen at the cellular level
What is the normal range for a baseline FHR?
Normal range is 110 to 160 bpm
What does a nonreassuring FHR include?
A baseline FHR of 160bpm; Decreased in baseline; Absent or persistently minimal variability; Irregular rhythms; Recurrent late or variable decelerations; Decreased FHR during or within 30 seconds after a contraction; Bradycardia
What is the nurse’s role in EFM?
To assess that FHR pattern reflects adequate fetal oxygenation
What does IA stand for?
Intermittent Auscultation
What is intermittent auscultation?
Listening to fetal heart sounds at periodic intervals to assess FHR
What can IA be performed with?
Left scope, DeLess-Hillis fetoscope, Pinard fetoscope, and ultrasound device
What is the goal of electronic FHR monitoring?
To detect fetal hypoxia and metabolic acidosis during labor so that interventions to resolve the problem can be implemented in a manner before permanent damage or death occurs
What are the 2 transducers used to monitor the FHR & UCs?
Ultrasound transducer & Tocotransducer
What instrument is used to assess the FHR through the transmission of Ultrahigh-frequency sound waves reflecting movement of the fetal heart and the conversion of these sounds into an electronic signal that can be counted?
Ultrasound device
What device is used in external monitoring to assess FHR and pattern?
Ultrasound transducer
What device is used in external monitoring to measure uterine activity transabdominally?
Tocotransducer
What does a tocotransducer determine?
The frequency, regularity, and approximately duration of UCs but not their intensity
How does the ultrasound transducer work and where is it placed?
It works by reflecting high-frequency sound waves off a moving interface: in this case the fetal heart and valves. It is placed on the lower abdomen.
How does the tocotransducer work?
The device is placed over the fundus above the umbilicus. UCs or fetal movements depress a pressure sensitive surface on the side next to the abdomen
Do you want variability in the FHR?
Yes. You don’t want a flat line.
What is a spiral electrode?
A device used in internal monitoring that penetrates the presenting part to obtain a continuous true assessment of the FHR and pattern
What device is used in internal monitoring to measure the frequency, duration, and intensity of uterine contractions as well as uterine resting tone?
Intrauterine pressure catheter (IUPC)
What is the interventions initiated when a nonreassuring FHR pattern is detected?
Intrauterine resuscitation
What is involved in intrauterine resuscitations?
These interventions involve providing supplemental oxygen, instituting maternal position changes, and increasing intravenous fluid administration.
What is the assessment method that uses digital pressure or vibroacoustic stimulation to elicit an acceleration of the FHR of 15bpm for at least 15 secs and/or to improve FHR variability?
FHR response to stimulation
What is the method of fetal assessment that involves the placement of a specially designed sensor next to the fetal cheek or temple area to provide a continuous estimation of fetal oxygen saturation?
Fetal pulse oximetry
What is an abnormally small amount of amniotic fluid called?
Oligohyroamnios
What is an absence of amniotic fluid called?
Anhydramnios
What is an absence of amniotic fluid called?
Anhydramnios
What is electronic fetal monitoring?
A useful tool for visualizing FHR patterns continuously on monitor screen or printed tracing
Describe an amnioinfusion.
Instillation of room temperature isotonic fluid into the uterine cavity through a double lumen intrauterine pressure catheter when the volume of amniotic fluid is low for the purpose of adding fluid around the umbilical cord and thus preventing its compression during uterine contractions
Describe tocolytic therapy.
Relaxation of the uterus achieved through the administration of drugs that inhibit UCs.
Define baseline FHR.
Average FHR during a 10-minute segment that excludes accelerations, decelerations, and periods of marked variability and normal range at term 110-160 bpm
When is the baseline FHR assessed?
It is assessed during the absence of UA or between contractions
Define undetected variability.
Absence of the expected irregular fluctuations in the baseline FHR.
Define bradycardia.
Persistent (10 minutes or longer) baseline FHR < 110 bpm.
Define prolonged deceleration.
Visually apparent decrease in the FHR of 15 bpm or more below the baseline, which lasts > 2 minutes but < 10 minutes
Define periodic changes.
Changes from baseline patterns in FHR that occur with UCs
Define tachycardia.
Persistent (10 minutes or longer) baseline FHR > 160 bpm
Define variability.
Expected irregular fluctuations in the baseline FHR as a result of the interaction between the sympathetic and parasympathetic nervous system
Define early deceleration.
Visually apparent gradual decrease in and return to baseline FHR in response to transient fetal head compression during a UC.
Define late deceleration.
Visually apparent gradual decrease in and return to baseline FHR in response to uteroplacental insufficiency resulting in a transient disruption of oxygen transfer to the fetus
Describe late decelerations.
Lowest point occurs after the peak of the contraction and baseline rate is not usually regained until the uterine contraction is over
Define variable decelerations.
Visually abrupt decrease in FHR below baseline of 15 beats or more, lasting 15 seconds and returning to baseline in < 2 minutes from the time of onset, which can occur at any time during a contraction as a result of umbilical cord compression.
Define acceleration.
Visually apparent abrupt increase in the FHR of 15 bpm or greater above the baseline, which lasts 15 seconds or more with return to baseline < 2 minutes from the beginning of the increase
Define episodic changes.
Changes from baseline patterns in FHR that are not associated with UC
What is the period of time in between contractions called?
Resting tones.
Describe what the duration of a contraction means?
Onset of one contraction to the onset of the next contraction
Define minimal variability in a FHR.
FHR < 5 bpm above the baseline
Define moderate variability in a FHR.
FHR 6-25 bpm above the baseline
Define marked variability in a FHR.
> 25 bpm above the baseline
What is an early deceleration in the FHR in response to?
Fetal head compression
What causes a late deceleration in FHR?
Uteroplacental insufficiency
What causes variable decelerations in the FHR?
Umbilical cord compression
Does early or late decelerations in the FHR need interventions?
Late decelerations
What is considered a baseline change?
A deceleration lasting more than 10 minutes
What occurs when the deceleration lasts longer than 1-2 minutes?
A loss of variability with rebound tachycardia usually occurs
What are the 5 components of a FHR tracing must be evaluated?
Baseline rate, baseline variability, accelerations, decelerations, and changes or trends in the FHR pattern over time
Why must a nurse evaluate the 5 components of a FHR tracing?
To determine whether immediate intervention is needed or whether there are indications to expedite birth.
What is tocolytic therapy used for?
Helps to slow down UCs.
What is umbilical cord acid-base determination?
Assessment of the newborn’s immediate condition after birth. Umbilical arterial values reflect fetal condition; umbilical venous blood values reflect placental function. Umbilical cord gas measurements reflect the acid-base status of the newborn at birth (not included in the Apgar)
How is an umbilical cord acid-base determination done?
Generally blood is withdrawn from the umbilical artery and tested for pH, PCO2, and PO2.
What 2 factors must be included in the patient and family teaching?
Maternal positioning (avoid supine position) and discouraging valsalva maneuver (vagal response, pt may pass out)
