Class 5: Fetal Surveilance Flashcards
what is the goal of intrapartum fetal surveillance (2)
identify potential fetal decompensation to:
- allow for timely and effective intervention
- prevent perinatal morbidity and mortality
fetal surveilance tells us…
- how the fetus is adatping/coping w the stress of labor
FHR surveillance is always assessed in conjunction with…
- uterine activity (contractions) in labour
the heart rate of a healthy, well-oxygenated fetus, with a well oxygenated brain, can…
certain changes in FHR can indicate…
- can cope w the stress of labor
- can indicate that the fetus is experiencing hypoxia and is no longer compensating
describe the fetal lungs role in gas exchange
- they do not engage in gas exchange
how does oxygen get to the fetus?
- from the pregnant person
how does CO2 get removed from the fetus?
- removed by pregnant person’s lungs
what types of factors influence FHR
- intrinsic
- extrinsic
what intrinsic factors impact FHR (4)
- medulla oblongata in the brainstem (CNS)
- autonomic nervous system
- baroreceptors
- chemoreceptors
baroreceptors respond to? what can cause increased/decreased FHR?
- respond to changes in BP
- high BP = decreased FHR
- low BP = increased FHR
what do chemoreceptors respond to?
- respend to changes in O2 and CO2 in blood
ex. hypoxia, acidosis
what impact does the SNS have on the fetal CVS (2)
stimulation produces:
- increase in strength of cardiac contraction
- increase in FHR
what impact does the PSNS have on the fetal CVS? (2)
stimulation of the vagus nerve:
- slows the SA node rate of firing thus producing a decrease in FHR
- vagal tone increases as gestational age increases and produces a downward effect on the baseline FHR
the “slow down” responses of the PSNS and “speed up” influence of the SNS create a relationship with…
- relationship w baseline variability
what are extrinsic factors
- factors in the fetal enviro that affect the availability of oxygen and the ability to transport oxygen to the fetus = impacting FHR
what are 3 extrinsic factors that influence FHR
- maternal factors
- uteroplacental factors
- fetal factors
what maternal factors influence FHR (4)
- decreased maternal arterial oxygen tension
- decreased maternal oxygen carrying capability
- decreased uterine blood flow
- chronic maternal conditions
what can cause decreased maternal arterial O2 tension (6)
- resp disease
- hypoventilation ** (ex. Mg sulphate, morphine & fentanyl)
- seizure ** (ex. eclampsia)
- trauma
- smoking
- obesity
what can cause decreased O2 carrying capability (2)
- signif anemia **
- carboxyhemoglobin
what can cause decreased uterine blood flow (4)
- hypotension
- regional anaesthesia –> hypotension r/t epidural
- maternal positioning –> supine hypotension
- HTN disorders of pregnancy
what type of chronic maternal conditions can impact FHR? what are 3 examples?
vasculopathies:
- systemic lupus erythematosus
- DM1
- chronic HTN
what uteroplacental factors influence FHR (2)
- excessive uterine activity
- uteroplacental dysfunction
what are examples of excessive uterine activity (2)
- tachysystole secondary to oxytocin, prostaglandins, or spontaneous labor
- placental abruption
what can cause uteroplacental dysfunction (4)
- placental abruption
- placental infarction
- chorioamnionitis
- uterine rupture
placental infarction is dysfunction marked by… (4)
- IUGR
- oligohydramnios
- abnormal doppler studies
- lesions on placenta
what impact do uterine contractions have on FHR?
- uterine arteries and veins pass thru the myometrium
- contractions = increased pressure in myometrium = compression of blood vessels = blood flow impeded to fetus due to compression of the blood vessels
during labor, O2/CO2 exchange occurs primarily when?
- between uterine contractions when the blood flow is unimpeded
what impact does tachysystole (excessive uterine contractions) have on the resting period between contractions
- decreases the resting period between
what fetal factors influence FHR (2)
- cord compression
- decreased fetal O2 carrying capacity
what can cause cord compression (2)
- oligohydramnios
- cord prolapse or entanglement = polyhydramnios
what can cause decreased fetal O2 carrying capacity (2)
- signif anemia
- carboxyhemoglobin
what can cause signif anemia in the fetus (3)
- isoimmunization
- maternal-fetal blled
- ruptured vasa previa
what can create carboxyhemoglobin
- if birther is a smoker
what are methods of fetal surveillance in labor (2)
- intermittent auscultation (IA)
- continuous electronic fetal monitoring (EFM)
IA includes… (2)
- monitoring of uterine contractions
- IA of FHR
EFM includes.. (2)
- electronic monitoring of uterine contractions (internal & external)
- electronic monitoring of FHR (internal & external)
is external or internal monitoring w EFM the standard?
- external = standard
- internal = bigger risk of infection
how many fetuses can EFM monitor
- two
what FHR assessments are done w IA? (3)
- baseline
- rhythmn (IA only)
- changes in FHR
what is assessed r/t rhythm w IA (2)
- regular
- irregular
what is assessed r/t changes in FHR with IA (2)
- accelerations
- decelerations (relationships to contractions)
what is assessed r/t uterine contractions when performing IA (4)
- frequency
- duration
- intensity
- resting tone
what FHR assessments are done w continuous EFM (3)
- baseline –> rate
- variability
- changes in FHR
what is assessed r/t changes in FHR w EFM (2)
- accelerations
- decelerations (relationship to contractions)
what is the recommended method of monitoring fetal surveillance for healthy term pregnant persons in spontaneous labor?
- intermittent auscultation
increased use of EFM is linked to?
- rising c-section birth rates
what types of conditions exist that increase the risk of adverse fetal outcomes ? therefore, what type of monitoring is usually recommended in these situation?
- both antepartum (maternal and fetal) and intrapartum (maternal and fetal)
- continuous EFM
what maternal antepartum conditions are associated w increased risk of adverse fetal outcomes (6)
- HTN disorders of pregnancy
- DM
- antepartum hemorrhage
- maternal medical conditions
- maternal MVA/trauma
- birth perception of decreased fetal mvmt
what fetal antepartum conditions are associated w increased risk of adverse fetal outcomes (7)
- IUGR
- prematurity
- oligohyramnios
- abnormal umbilical artery doppler
- isoimmunication
- multiple pregnancy
- breech presentation
what maternal intrapartum conditions are associated w increased risk of adverse fetal outcomes (9)
- vaginal bleeding in labor
- intrauterine infection/chorioamnionitis
- previous c-section
- prolonged membrane rupture (>24 hrs at term)
- induced labor
- augmented labor
- hypertonic uterus
- preterm labour
- postterm labor (>42 weeks)
what fetal intrapartum conditions are associated w increased risk of adverse fetal outcomes (2)
- meconium-stained amniotic fluid
- abnormal FHR on intermittent auscultation
what is included in nursing care with both IA and EFM (6)
- leopold’s maneuver
- assess uterine activity and FHR characteristics
- interpretation/classification of FHR pattern
- interventions as needed
- communication & documentation
- continued supportive care in labour
what is the freq of assessment of FHR and uterine activity in 1st stage of labour; latent vs active
- latent phase: hourly of w signif change
- active labour: q15-30 min
what is the freq of assessment of FHR and uterine activity in 2nd stage of labour; latent vs active
- latent: q15-30 min
- active: q5 min
what might change the freq of assessment of FHR and uterine activity during the 1st and 2nd stage of labour (3)
- rupture of membranes
- admin of meds and anaesthesia
- changes in clinical picture/complications or changes of FHR pattern
we should always assess FHR after… why?
- ROM
- d/t concern of cord compression/prolapse
describe the procedure for leopold’s maneuver (5)
- wash hands
- empty bladder
- supine position, knees slightly flexed (slight R or L tilt)
- 4 maneuvers
- document (based on facility protocol/guideline)
what is intermittent auscultation? what kind of assessment?
- assessing fetal heart sounds at periodic intervals
- auditory only, not visual
what are the 7 steps of intermittent auscultation
- explain
- leopold’s maneuver
- palpate contractions at fundus
- place IA US fetoscope device over area of maximal intensity
- compare to maternal radial pulse
- listen for 60 seconds immediately after uterine contraction
- interpert findings and document
what is include in the palpate step of IA (2)
- uterine activity
- note freq and duration of contractions and palpate resting tone
when should you listen for 60 seconds during IA
- immediately after uterine contractions
what is included in the listening step of IA (3)
- record FHR baseline
- note rhythm of FHR (regular? irregular? must do for 60 sec)
- identify presence of acceleration or decelerations –> relationship to contractions?
what is included in the interpret & document step of IA (4)
- is FHR normal or abnormal?
- communicate
- interventions
- decision making
what are the steps for EFM? (9)
- leopold’s maneuver
- seperate transducers for assessment of FHR & uterine contractions
- cotinuous strip of fetal monitor paper
- record FHR baseline
- note FHR variability
- identify presence of accelerations & decelerations –> relationship to contractions
- interpret findings and document
- is the FHR tracing/pattern normal, atypical, or abnormal?
- communicate, interventions, decision making
for uterine contractions, where is the tocotransducer placed with EFM? what does this monitor?
- on the fundus above the umbilicus
- monitors freq and duration
how is the intensity and resting tone of uterine contractions assedssed w FHR?
- by palpation
what is the FHR transducer placed with EFM? what does it do?
- placed over area of maximal intensity (external)
- continuous printout of fetal heart rate
what does the continuous fetal monitor paper printed from EFM record? this is sometimes called?
- records both FHR and uterine activity (contractions)
- sometimes called FHR tracing
how is uterine activity/contraction freq and duration assessed w IA? EFM?
how is intensity and resting tone of contractions done in both methods?
- manual counting of freq and duration –> IA
- monitor EFM –> freq and duration
- intensity and resting tone –> palpations –> both EFM and IA
what is the freq of normal uterine activity (2)
- contractions not more than q2min
- max of 5 contractions in a 10 min period, averaged over 30-min time period
frequency of uterine contractions is measured in minute from ____ to ____
- from start of 1 contraction to start of another
what is the duration of normal uterine activity? duration is in seconds from __ to ___
- lasting less than 90 sec
- start of 1 contraction to end of same contraction
what is the resting tone of normal uterine activity
- min 30 sec of rest in between
what is the intensity of normal uterine activity (2)
- mod to strong
- allow for uterine relaxation
what is considered tachysystole
> 5 contractions in 10 min, averaged over 30 min time period
what is needed to determine baseline FHR with EFM
- need 10 min of FHr tracting
baseline FHR excludes…
- accelerations
- decelerations
what is normal baseline FHR at term
110-160
what is considered fetal tachycardia
> 160 bpm for >10 min
what can cause fetal tachy
- maternal fever
- maternal infection
what is considered fetal bradycardia
<110 bpm for >10 min
what can cause fetal bradycardia
- late/post term
baseline FHR should be present for..
- at least 2 min in any 10-min segment to be determined
rhythm of FHR can only be assessed with?
- IA
variability of FHR can only be assessed with?
- EFM
define: variability
- fluctuation or range in the baseline FHR
what are 4 categories of variability
- absent
- minimal or decreased
- mod or average, normal
- marked or increased
what range is considered absent variability
0-2 bpm
what range is considered minimal or decreased variability
- < or equal to 5bpm
what range is considered moderate or average/normal variability
- 6-25 bpm
what range is considered marked or increased variability
> 25 bpm
periodic changes in FHR occur with?
- occur w uterie contractions
what are episodic (or non-periodic) changes in FHR
- not associated w uterine contractions
what is an acceleration of FHR
- abrupt increase in FHR above baseline
how many bpm is considered an acceleration? min time? max time?
- at least 15 bpm above baseline
- lasts 15 sec or longer
- less than 2 min
FHR accelerations are an indiciation of ?
- fetal well being
- classified as normal
FHR accelerations are documented as? (2)
- present
- absent
decelerations are described by their relationship with…
- contractions and shape
what are early decelerations?
- gradual decrease and return to baseline of the FHr during a contraction
with early decelerations the lowest point of the deceleration occurs?
- at the same time as the peak of the contraction
describe the relationship between the deceleration and contraction with early decelerations
- mirror each other
early decelerations are associated w?
- head compression
how can head compression cause decreased HFR
- puts pressure on vagus nerve = decreased FHR
early decelerations are generally…
- normal and benign
describe the appearance of late decelerations (3)
- uniform
- repetitive
- shallow
what are the onset of late decelerations
- occur after beginning of the contraction
when does the lowest point of late decelerations occur?
- after peak of contraction
what do late decelerations return to baseline?
- after the contraction ends
what do late decelerations mean?
- ominous sign
late decelerations are classified as…
- atypical or abnormal
late decelerations indicate
- uteroplacental insufficiency
what is a variable deceleration
- abrupt decrease in FHR
what is classified as a variable deceleration
- decrease in FHR > or equal to 15 bpm
- lasting for > or equal to 15 secs
- and < 2 min in duration
how do variable decelerations appear?
- dramatic, rapid response
- appearance of an icicle
- U, V, or W shaped
what do variable decelerations occur
- during or between contractions
variable decelerations often occur with?
- cord compression –> not always dangerous compression (could just be a position change)
how does cord compression cause decreased FHR
= activates SNS = increased HR = HTN = decreased FHR
variable decelerations are either…
- complicated
- uncomplicated
variable decelerations are classified as.. (3)
- normal
- atypical
- abnormal
what makes a variable deceleration considered normal
- if 1 time occurrence
if variable decelerations have a relationship w contractions, what is the concern?
- concern of prolapse
what does it mean if variable decelerations are reoccurring?
- atypical/abnormal, of concern
what are prolonged decelerations
- visually apparent decrease (either gradual or abrupt) of at least 15 bpm below the baseline and lasting more than 2 min but less than 10 min
what is included in normal classification of FHR with IA r/t baseline, rhythm, decelerations, accelerations
- baseline 110-160
- rhythm = regular (no skipped beats)
- no decelerations
- accelerations may be present
what is included in normal classifications of FHR with EFM r/t baseline, variability, decelerations, accelerations
- baseline 110-160
- variability 6-25 bpm or <5 bpm for <40 min
- decelerations = none present OR occasional uncomplicated variables or early decelerations
- accelerations = spontaneous accelerations present OR accelerations present w fetal scapl stimulation
what is intrauterine resuscitation
- is sometimes used to refer to specific interventions initiated when an atypical or abnormal FHR patter is noted
- mngmt of atypical and abnormal FHR with corrective measures
what are the goals of intrauterine resus (4)
- improve umbilical blood flow
- improve umbilical circulation
- improve O2 sat
- reduce uterine activity
what can improve uterine blood flow & decompress umbilical cord
- moving mother side to side
- position changes
what are examples of intrauterine resus interventions (8)
- stop or decrease oxytocin
- change maternal position
- IV fluid bolus
- perform vaginal exam
- consider amniofusion
- reduce maternal anxiety
- coach birther to modify breathing or pushing techniques
- assist physician w fetal scalp sampling
what is amniofusion
- injection of fluid into membranes
fetal scalp sampling is used to?
- guide decision making concerning fetal status
what is collected from a fetal scalp sample?
- collect a capillary fetal blood sample
what is the min gestational age for fetal scalp sampling
- must be >34 weeks gestations
how dilated does the cervix need to be to collect a fetal scalp sample
- 4-5 cm
how is a fetal scalp sampling sample collected? what must have happened for this?
- thru the dilated cervic with small incision to fetal scape
- membranes must be ruptured
when is fetal scalp sampling done?
- when FHR tracing is atypical or abnormal
- AND birth is not imminent
what is assessed w fetal scalp sampling
- pH
what does a pH of <7.20 mean? what is indicated?
- risk of fetal acidemia
- delivery is indicated
what does a pH of >7.20 mean?
- may continue and reassess within 30 min
