fetal monitoring CH14

what are the goals of fetal surveillance?

• maximize uterine & umbilical blood flow

• assess & maximize fetal oxygenation

• detect abnormal changes in FHR/fetal oxygenation

• guide decision making & evaluate effectiveness of interventions

• maintain appropriate uterine activity

• support coping & labor progress

what is intermittent auscultation? what do we use? when is it used? who are the best candiates for this?

• using a fetoscope or doppler to listen to FHR

• IA is used for low risk pregnancies & normal FHR (110-160 bpm w/ regular rhythm)

• auscultate FHR before, after, during a UC

• assess UC pattern by palpation/maternal report

• best candidate:

  • low risk pregnant individuals, full term, spontaneous labor on its own w/o medical inductions, absence of maternal or fetal comorbidities (HTN, diabetes

what are the 2 types of continuous electronic fetal monitoring? where is everything placed (describe steps)? how do they differ from one another?

1. external

• uses EFM & uterine monitors use ultrasound to detect FHR & uterine pressure

• FHR & UC are recorded & displayed on monitor

• steps:

  • place toco transducer (uterine contractions) near fundal area b/c strongest contractions are there → button surface looking & placed higher up

  • apply gel to ultrasound (FHR) transducer & place it where the fetus’ back is (locate w/ leopold maneuver) → smoother surface looking → placed on lower abd

  • secure with a belt or faha

• wireless EFM & toco are available → allows pt freedom of movement while in labor

2. internal

• invasive devices

• fetal scalp electrode (FSE) on fetal head or presenting part of the fetus to detect FHR

  • ex. applied to buttocks if pt is breech

• IUPC (intrauterine pressure catheter) placed in uterine cavity

  • only used when someone is not progressing & unsure if contractions are inadequate

• IUPC measures intensity of uterine contraction

what are the limitations to external monitoring?

• unable to measure intensity & must be palpated to compare to nose, chin, forehead

• correlated with higher operative deliveries (using tools)

• sores occur if worn for a long time

what conditions need to be met for internal monitoring? what are the risks of internal monitoring? what is it contraindicated in?

• conditions that need to be met:

  • spontaneous or artificial ROM

    • internal equipment can’t bypass or puncture an intact sac

  • cervix must be open enough to all clinician’s fingers & instrument to pass through

    • minimum of 1-2 cm dilation

  • fetal presenting part must be low enough in the pelvis

    • it must attach to a bony surface; avoid face, fontanelles, or genitals

• risks:

  • contraindicated in: chorioamnionitis (infection of fetal membranes & amniotic fluid), active maternal genital herpes, HIV, +GROUPB STREP, placenta previa, undiagnosed vaginal bleeding

  • intrauterina infections (increases risk of chorionamnionitis)

  • injury where it can cause trauma, lacerations, uterine perforation

what can we do if we do not have amniotic fluid?

• infuse NS through intrauterine pressure catheter → amnioinfusion

  • can tx thick meconium → fluid just leaks out of uterus

what is frequency of FHR assessment based on?

risk status, stage of labor, ongoing clinical assessment

for intermittent auscultation, when is it used? how often is it used during the latent, active, and pushing phase?

• used for no risk factors

• Q1 hr latent phase

• Q30 min active phase

• Q15 min pushing phase

• switch to continuous EFM if abnormal FHR

for continuous EFM when is it used? how often is it used during normal tracing, decelerations, 2nd stage of labor?

• used for when risk factors are present

  • ex. chronic HTN, GDM, pain meds, etc

• Q1 hr normal tracing

• Q30 min for decelerations

• Q15 min 2nd stage of labor

what are the components to identify in EFM tracing?

• FHR baseline & variability

• identification of accelerations & decelerations

• interpret uterine contractions

what is the fetal heart rate baseline? what is normal, bradycardia, tachycardia?

• baseline = mean FHR

  • rounded to increments of 5

  • excludes accelerations, decelerations, or marked variability

  • at least 2 mins of identifiable baseline segments (not necessarily continuous) or it is indeterminate

• normal baseline FHR 110-160 bpm

• bradycardia <110 bpm for 10 mins or >

• tachycardia >160 for for 10 mins or >

what is tachycardia? what are the causes? what nursing actions to take?

• baseline above 160 for at least 10 min

• causes:

  • infection, dehydration, certain drugs

• nursing actions:

  • VS, abx, antipyretics, ice packs, IV hydration

what is bradycardia? what are the causes & some example? what nursing actions to take?

• baseline below 110 for at least 10 min

• causes:

  • fetal hypoxia caused by abrupt interruption of oxygenation (ex. maternal hypotension, abruption, cord prolapse, tachysystole)

• nursing actions:

  • fetal resus, move to the OR

what can influence fetal heart rate?

1. uteroplacental unit

• disruption to the intervillious space → decreases amount of O2 to fetus

  • ex. contractions, cord compression problems w/ placenta

• a decrease in oxygen to the fetus results in deceleration of FHR

2. autonomic nervous system

• PNS (vagus nerve) → decrease HR

• SNS → increase HR

3. baroreceptors

• stretch receptors that detect pressure changes → deceases HR, CO, BP

  • incr. BP → baroreceptors trigger vagus nerve → decrease HR

4. CNS

• regulates variability

• meds (ex. mag sulfate & fentanyl) can cross placenta → decrease HR

5. chemoreceptors

• stimulates vagus nerve → decrease HR

6. hormonal regulation

• decrease in oxygenation → hormones are released

  • epinephrine, norepinephrine, vasopressin, catecholamines are released to facilitate hemodynamic changes to maximize blood flow to vital organs

what does baseline variability mean? what is it an important indicator of? what does it reflect?

• variability: small fluctuations in fetal heart rate

  • fluctuation in baseline FHR that are irregular in amplitude & frequency

• shows peak & trough of HR within baseline

• most important predictor of adequate fetal oxygenation & fetal reserve during labor

• reflects intact CNS

describe the fetal heart rate variabilities. how does it look?

1. absent (worrisome)

• little to no fluctuation in FHR

• variability less than 5 bpm or basically 0

• look: straight line

2. minimal (kind of concerning)

• FHR detectable but less fluctuation than 5 bpm

• look: not moving a lot

3. moderate (happy baby)

• fluctuation in FHR ranges from 6 to 25 bpm

4. marked (may be concerning)

• fluctuation in FHR >25 bpm

• look: going crazy

what are some influences on variability?

• fetal wake/sleep cycle

  • fetus less active during sleep

• maternal & fetal oxygenation

  • decreased O2 → reduces variability

• placental function

  • poor blood flow

  • ex. pre-e or pregnancy beyond due date

• umbilical function

  • cord compression disrupts blood flow

• narcotic effects

  • meds can depress CNS

• fetal causes: anomalies, neuro function, cardiac function, prematurity, etc

what are the 2 characteristics of fetal heart rate?

1. acceleration

2. deceleration

• early, late, variable, prolonged

what is acceleration? what could absence of it mean? how long are prolonged accelerations?

• predictive of adequate oxygenation

• absence of accels in intrapartum in fetal acidemia (baby’s blood loss has low pH & high acidity)

• > 32 GA increase in FHR at least 15 beats above baseline for at least 15 secs

• accels may be 10 beats above baseline & lasts 10 secs < 34 wks

• prolonged accels are >2 mins < 10 mins

what is early deceleration? what are the shape & timing characteristics? what are the causes? what is the clinical significance (do they require intervention, what does it indicate)?

• gradual decrease in FHR that start before the peak of a contraction & returns to baseline by end of contraction

• characteristics

  • shape: visually apparent gradual decrease of >30 secs to the nadir (peak), smooth & symmetrical

  • timing: occurs at the same time as contraction, beginning before & returning to baseline with contraction (mirrors contraction)

• causes:

  • head compression, which stimulates vagal nerve & results in decrease in HR

• clinical significane:

  • usually benign & a normal physiological response during labor, do not indicate fetal distress, do not require intervention

what is late deceleration? what are the shape & timing characteristics? what are the causes? what is the clinical significance (do they require intervention, what does it indicate)?

• gradual decreases in FHR that begin after the peak of contraction & return to baseline after the contraction has ended

• characteristics:

  • shape: gradual & smooth, visually apparent symmetrical

    • onset is gradual w/ onset of nadir >30 secs

    • onset, nadir, recovery of decel occurs after onset of UC

  • timing: begin after peak of contraction & return to baseline after contraction ends

• cause:

  • uteroplacental (placental) insufficiency, which reduces blood flow & oxygen to fetus

• clinical significance:

  • indicative of fetal distress & requires prompt evaluation & intervention

  • persistent late decels → need to change maternal positions, increased IV fluids, or even expedited delivery

what are the nursing actions for late deceleration?

• fetal resuscitation

• consider tocolytics (relax uterus from making excessive UC)

• consider delivery

• consider fetal scalp stimulation or VAS

what is variable deceleration? what are the shape & timing characteristics? what are the causes? what is the clinical significance (do they require intervention, what does it indicate)? what are the nursing actions?

• abrupt decrease (periodic or episodic) in FHR that varies in shape, timing, duration, depth

  • often irregular & may or may not coincide w/ contractions

  • recurrent variables that become deeper = fetal acidemia

• characteristics:

  • shape: V, U, or W shaped

    • visually apparent of ABRUPT decrease in FHR of <30 secs from baseline to nadir with drop of >=15 bpm below baseline & lasts for >15 seconds but < 2 mins

  • timing: occur at any time during contraction, often beginning & ending suddenly

• cause:

  • umbilical cord compression, which reduces blood flow & oxygen to fetus

• clinical significance:

  • can be benign but can indicate issues aka cord compression OR severe cases → fetal hypoxia

  • continuous monitoring & assessment are needed

• nursing actions

  • fetal resuscitation

  • consider amnioinfusion

    • oliohydramnios → less cushioning → cord compression → variable decels

what are the characteristics of concerning variable deceleration?

• prolonged

• > 60 bpm lasting for more than 60 secs

• absent variability

what is prolonged deceleration? what is it due to/caused by? what are the nursing actions?

• decrease in FHR below baseline >15 bpm lasting >2 mins but <10 mins

• due to profound change in fetal O2:

  • interruption of placental perfusion

  • tachysystole

    • too many contractions

    • excessive UC reduces time for placental blood flow to recover

  • maternal hypotension

  • abrupted placenta

    • placenta separates → reducing exchange

  • interruption of umbilical blood flow

  • cord compression

  • cord prolapse (cord is between cervix & vagina aka ahead of the baby)

• nursing action:

  • fetal resuscitation

  • consider amnioinfusion

  • consider tocolytics

  • consider delivery

  • turn to the side → reposition

  • anything to promote circulation

what does veal chop stand for?

1. variable → cord compression

2. early → head compression

3. accels → okay (oxygenated)

4. late → placental insufficiency

what are the 4 components to interpret uterine contractions?

1. frequency: time elapsed from the beginning of 1 contraction to the beginning of the next

• assessed on fetal monitor or by palpation to ensure contractions occur at appropriate intervals for the stage of labor

2. duration: time elapsed from the beginning of a contraction & its end, measured in seconds

• important to monitor b/c excessive long contractions → uterine hyperstimulation & potential complications

3. intensity: strength of contraction at its peak palpation (mild, moderate, strong → nose, chin, forehead)

• determines effectiveness of contractions in dilating the cervix

• measured by palpation or IUPC (mmHg)

4. resting tone: baseline pressure of the uterus before contractions begin (soft or firm)

• how relaxed or tense the uterus is when not contracting

• measured using IUPC or palpation (described as soft if relaxed)

  • IUPC normal resting tone is <20 mmHg

• normal resting ensures proper fetal oxygenation & uterine recovery between contractions

• if fetal HR goes down = worry about deceleration

what is the normal uterine contractions? what is tachysystole & what is the worst outcome it can result in?

• normal: <= 5 UCs in 10 mins averaged over 30 minutes

• tachysystole (excessive uterine activity → progressively effects fetus)

  • > 5 UCs in 10 mins over 30 minutes

  • excessive UC → decreased blood flow in the intervillous (where O2 exchange occurs) → decreased O2 to fetus → fetal hypoxemia → abnormal FHR

  • tachysystole may result in abruption or uterine rupture

what are the nursing actions for tachysystole?

• turn off pictocin

• IV fluids → corrects hypotension

• reposition pt to side lying

• administer a tocolytic (terbutaline) → relaxes uterine muscle

how are episodic & periodic changes related to UCs?

• episodic → not associated w/ contractions

  • ex. baby moves causing FHR to increase even though mom does not have contraction

• periodic → ARE associated w/ contractions

how to classify/interpret fetal HR?

by categories 1, 2, 3of the NICHD

what is characteristics of category 1 (baseline HR, variability, accelerations, decelerations)? what is the clinical significance?

• category 1: reassuring/normal

• baseline HR: 110-160 bpm

• baseline variability: moderate (6-25 bpm)

• accelerations:

  • present or absent

  • accelerations are generally reassuring if they occur w/ fetal movement or contractions

• decelerations:

  • no late or variable

  • early decels may be present & considered normal

• clinical significance

  • indicates well oxygenated fetus (normal acid basis status), normal CNS function

  • no immediate concerns

  • continue monitoring & care are generally appropriate

what is characteristics of category 2 (baseline HR, variability, accelerations, decelerations)? what is the clinical significance?

• category 2: indeterminate

• baseline HR:

  • within or outside normal range (ex. less than 110 or more than 160)

• baseline variability:minimal or absent variability

• accelerations:

  • may or may not be present

• decelerations:

  • early: gradual decreases that coincide w contractions

  • late: gradual decreases that begin after the peak of contraction

  • variable: irregular in shape & timing

• clinical significance

  • fetal status is uncertain & requires further eval

  • may require additional monitoring, interventions, or assessment to determine the cause & address potential issues

what is characteristics of category 3 (baseline HR, variability, accelerations, decelerations)? what is the clinical significance?

• category 3: abnormal

• baseline HR:

  • either less than 110 (brady) or more than 160 (tachy) w/ persistent abnormalities

• baseline variability: absent variability accompanied with either recurrent late decels, recurrent variability, or bradycardia

• accelerations:

  • absent, esp in the presence of concerning decels

• decelerations:

  • recurrent late: gradual decreases that begin after the peak of contraction

  • recurrent variable: abrupt decreases that vary in shape & timing, often associated w cord compression

  • prolonged decel: decrease in FHR lasting more than 2 mins but less than 10 min

• clinical significance

  • indicate possible fetal distress or hypoxia

  • immediate intervention is necessary, which includes repositioning mom, increase maternal O2, or preparing for an expedited delivery (c-section), increase fluids

what heart rate pattern is part of category 3? what is it associated with?

• sinusoidal (smooth, repeating waves)

• associated w severe fetal anemia, ominous often premorbid finding

what are the nursing managements and interventions for category 3?

• reposition

  • change mother’s position can alleviate cord compression & improve blood flow

• increase fluids

  • administer fluids can help improve uterine blood flow & oxygen delivery to the fetus

• oxygen admin

  • providing supplemental oxygen to the mother may help improve O2 to the fetus

• assessing uterine activity

  • ensuring that uterine contractions are not too frequent or too strong can help reduce the risk of decelerations

• discontinue or decrease the oxytocin (pitocin) then notify MD

• immediate delivery

  • in cases of persistent or severe late decels or other indications of fetal distress, expedite delivery via c-section may be needed

when should we intervene?

• recurrent late decels

• recurrent variability decels

• minimal variability > 30 min

• fetal tachycardia

• fetal bradycardia

• prolonged decels

where does O2 exchange occur in the umbilical cord? what blood travels to the fetus?

• occurs in intervillous space

• oxygenated blood travels to fetus

what is the umbilical cord acid base balance & what do we do? what does it evaluate? how is it measured?

• objective analysis of the pH blood levels

• after birth, take blood from the umbilical artery & the vein to examine acid base

• evaluates whether a poor neonatal outcome is due to hypoxia as evidenced by an acidic pH

• normal levels are compared to the cord blood sample:

  • acidic pH → fetus moves from aerobic metabolism to anaerobic

normally, can the fetus maintain aerobic metabolism if there is slight decrease in blood flow & how? when does anaerobic respiration occur & what can it cause?

• normally, it can maintain aerobic metabolism even though there is decrease in blood flow to uterus d/t fetal reserve (more O2 in placenta’s intervillious space than the fetus actually needs)

• anaerobic respiration occurs when O2 in intervillious space falls below 50% of normal levels

  • can cause…

    • redistributes blood to vital organs (heart, brain, adrenal glands)

    • chronically altered O2, fetal growth will decelerate & lead it intrauterine growth restriction

    • fetal myocardium changes → changes in HR

what is fetal distress? how do we address this & what does it prevent? what are the nursing interventions?

• an emergency pregnancy, labor, delivery complication where the baby experiences birth asphyxia (O2 deprivation) → changedsin baby’s HR, movement, meconium in amniotic fluid

• address by having c-section to prevent hypoxic ischemic encephalopathy (brain injury d/t lack of O2 & blood)

• interventions:

  • reposition

  • increase fluids

  • o2 admin

  • assess uterine activity

  • d/c or decrease oxytocin & notify MD

  • immediate delivery

what is uterine irritability?

a condition where the uterus experiences frequent or irregular contractions that are not yet strong enough to be considered true labor contractions

what is coupling?

the occurrence of 2 consecutive contractions w/ minimal or brief resting period in between followed by a slightly longer period of relaxation

what is reactive twin strip?

pattern on FHR that indicates a reassuring or normal FHR for both twins → the term is used to describe fetal heart rate patterns & indicative of well being during labor or before (antepartum) monitoring