Chapter 9 Flashcards
FHR assessment can signal _____
fetal compromise
goal of EFM is to __
interpret and continually assess fetal oxygen to prevent significant fetal acidemia while minimizing unnecessary interventions and promote family-centered care
FHR =
fetal oxygenation
palpating contractions
- subjective
- can cause uterus to become tense and firm
nurses should palpate contractions with __
fingertips
in-between contractions, resting tone is __
soft
mild contractions
- easy indented (tip of nose)
what do moderate contractions feel like when palpated?
- slightly indented (chin)
strong contractions
- can’t indent (forehead)
external electric fetal monitoring measures ____
- FHR
- contractions
external electric fetal monitoring: FHR
- uses ultrasound transducer
- FHR location changes as baby descends
- lose tracing when baby moves
what are contractions noted/read with?
- uses a toco to pick up contractions
- toco is a strain monitor
- doesn’t measure intensity
- doesn’t always pick up contractions
internal fetal and uterine monitoring uses what?
- uses fetal scalp electrode
- membranes need to be ruptured
- very accurate
internal fetal and uterine monitoring cannot be used with
- herpes
- chorioamnionitis
- HIV
- GBS +
- placenta previa
reading FHR strips
- upper graphs is FHR (bpm)
- lower graph is contractions
- 1 small square = 10 seconds
- 6 small squares = 1 minute
FHR interpretation: areas to assess
- FH baseline
- periodic and episodic changes
- uterine activity
normal baseline FHR is
110-160 bpm
- tachycardia = >160 bpm
- bradycardia = <110 bpm
what is baseline variability
- the small up and down bumps (roughness and smoothness) in the road
- defined as the fluctuations in the baseline FHR that are irregular in amplitude and frequency
- flat line 12 is never good
- the bumps show us that the baby is neurologically doing well
- measured in a 10-minute window, excluding decels/accels
- more variability is seen in mature fetus’ because the parasympathetic system exerts itself more as fetus matures
variability is documented as
- absent: undetectable range
- minimal: < 5 bpm
- moderate: 6-25 bpm
- marked: > 25 bpm
accelerations
show the baby is doing well
- want to see these on strip
- an acceleration is a 15 beat rise in HR that lasts at least 15 seconds
VEAL CHOP MINE
Variable decelerations
Early decelerations
Accelerations
Late decelerations
Cord compressions
Head compressions
Oxygen good
Placental insufficiency
Maternal repositioning
Identify labor progress
No interventions
Execute interventions
early decelerations
- OK
- gradual decrease and return to baseline
- gradual decrease is defined as one from the onset to the FHR nadir of 30 seconds
- correspond to the beginning, peak and end of the contraction
- mirror the contraction
cause of early decelerations
head compression
- which causes vaginal stimulation and slowing of the HR
late decelerations
- BAD
- visually apparent usually symmetrical gradual decrease and return of the FHR associated with contraction
- gradual FHR decrease is defined as from the onset to the FHR nadir of >/= 30 seconds
- start after the contraction starts
- peak after the peak of the contraction
- FHR doesn’t return to baseline until contraction is over
cause of late decelerations
placental insufficiency
- provoked by contractions
- any decrease in uterine blood flow or placental dysfunction can cause late decels
- maternal hypotension
- uterine hyperstimulation
- postdate gestation
- preeclampsia
- chronic HTN
- DM
- hypovolemia
treatment of late decelerations
- fix reason
(if on pitocin, may d/c) - turn to left side
- apply oxygen
variable decelerations
- > /=15 beats below for >/= 15 seconds, and <2 minutes in duration
- visually apparent abrupt decrease in FHR
- abrupt FHR decrease is defined as from the onset of the decel to the beginning of the FHR nadir of < 30 seconds
- decrease is calculated from the onset to the nadir of the decel
- not consistent with contractions
- usually in shape of V, U, or W
cause of variable decelerations
cord compression
NICHD category 1+
- normal baseline FHR (110-160)
- moderate variability
- lack of concerning decelerations (no early, late or variable decels)
- accels may be present or absent
*continue monitoring
NICHD category 2+
- indeterminate
- FHR patterns that are concerning enough to warrant increased frequency in monitoring, but that respond to interventions provided
*general measures
consider discontinuing oxytocin
consider potential need to expedite delivery if abnormalities persist or worsen
NICHD category 3+
- abnormal
- absent baseline FHR variability
- recurrent late/variable decelerations
- bradycardia
- sinusoidal pattern
*general measures
discontinue oxytocin (Pitocin)
expedite delivery by operative vaginal or cesarean delivery
how is baseline FHR calculated?
- approximating the mean FHR rounded to increments of 5 bpm during a 10-minute window, excluding accels/decels/periods of marked FHR variability (>25 bpm).
- there has to be at least 2 minutes of identifiable baseline segments (not necessarily contiguous) in any 10-minute window, or the baseline for that period is indeterminate. (refer to previous 10-minute window if this happens)
how can you recognize baseline FHR?
- steady, stable area where most of the FHR is plotted
- mean FHR over 10-minute segment
- a single value in increments of 5 bpm, not a range
tachycardia
baseline FHR is >160 bpm lasting at least 10 minutes
tachycardia: variability
- variability may be minimal because of sympathetic dominance
bradycardia
baseline FHR is < 110 bpm lasting at least 10 minutes
- a term or post-term fetus may have a BL FHR of 100-110 bpm because of parasympathetic maturation
*make sure the HR read is fetus’ and not mom’s
NICHD researchers determined that in practice, LTV and STV are visually assessed as ___
a single unit
preterm fetuses tend to have slightly ____ baselines and ___ variability
- slightly higher baselines (still in normal range)
- decreased variability
cycles per minute
- means that horizontal dimension of variability
- oxygenated fetuses have 2-8 cycles per minute
amplitude
- the vertical dimension of variability
- quantitated in bpm
- measured from the peak to the trough of a single cycle
periodic patterns
those associated with uterine contractions
episodic patterns
those not associated with uterine contractions
periodic changes
- accels
- decels:
-late
-early - variable
episodic changes
- accels
- decels
- variable
- prolonged
a prolonged acceleration is
> 2 minutes but < 10 in duration
what makes an acceleration defined as a baseline change?
if the accel lasts 10 minutes
how are accels defined <32 weeks gestation?
- peak of 10 bpm in a duration of 10 seconds
periodic pattern decels
- early decels
- late decels
- variable decels
episodic pattern decels
- prolonged decels
- variable decels
acme
highest point of the contraction
nadir
lowest point of a decel
what does onset mean (context: decel)?
time from the start of the decel to the nadir
what does offset mean (context: decel)?
time from the nadir of the decel to the return to baseline
abrupt
less than 30 seconds
gradual
at least 30 seconds
recurrent
occurring with >50% of uterine contractions in any 20-minute window
intermittent
occurring with <50% of uterine contractions in any 20-minute window
what is an ominous pattern of late decels?
16 persistent late decels associated with decreased beat-to-beat variability
consistent patterns of variable decels can lead to
acidosis and fetal distress, if not corrected
variable decels occur most frequently in patients who have experienced ___
- PROM
- decreased amniotic fluid
what is the most commonly encountered pattern during labor?
variable decels
uterine muscles contain ___ receptors
adrenergic receptors
estrogen stimulates ___ and increases ___
- stimulates cervical ripening
- increases the concentration of oxytocin receptors
gap junctions
- estrogen and progesterone form gap junctions
- spreads nerve impulses which cause contractions
uterine activity assessment components
frequency
duration
intensity
frequency is
the time from the beginning of one contraction to the beginning of the next
duration is
the time from the beginning to the end of a contraction
intensity is felt by ___ as either __ __ __
felt by palpation
- mild, moderate, strong
normal uterine activity is
</= 5 contractions in 10 minutes, averaged over a 30 minute window
peak IUP
the acme of the contraction in mm HG when an IUPC is in place
interval
the time from the end of one contraction to the beginning of the next
- also called the rest interval
resting tone/baseline tone
the lowest intrauterine pressure found between contractions with IUPC
tachysystole
more than 5 contractions in a 10 minute window averaged over a 30 minute period, regardless of FHR
- always qualified as to the presence or absence of associated FHR decels
- applied to both spontaneous or stimulated labor
hypertonus
abnormally high resting tone
- above 30 mm Hg
uterine tetany
- tetanic contraction
- a uterine contraction that is strong to palpation or > 90 mm Hg and lasts > 90 seconds
hypertonus and uterine tetany are confirmed with ___
palpation
documentation of uterine activity
- method: palpation, toco, IUPC
- frequency
- duration (seconds)
- intensity
- relaxation (soft or resting tone mm Hg)
moderate variability and/or accels exclude the presence of ___
metabolic acidemia
injury requires significant ___
metabolic acidemia
- umbilival artery pH < 7.0 and BE </= -12
__ __ are a protective reflex mechanism in response to transient fetal hypoxia during uterine contractions
late decels
late decels are mediated by ___
chemo and baroreceptors
what happens when late decels continue and are not resolved
- peripheral vasoconstriction fails
- central hypotension
- decreased blood flow to the brain
- hypoxic
- ischemic injury to brain and heart
are late decels clinically significant?
yes- they represent disruption in the oxygen pathway
the intent of intrapartum FHR monitoring is
to assess fetal oxygenation
- but oxygenation is not the only cause of FHR changes
fetal tachycardia: maternal factors/causes
- fever
- infection
- dehydration
- hyperthyroidism
- anxiety (adrenaline)
- medication/illicit drugs
fetal tachycardia: fetal factors/causes
- infection
- supraventricular tachycardia or other tachycardia
- congenital anomalies
fetal bradycardia: maternal factors/causes
- drug response
- prolonged maternal hypoglycemia
- connective tissue disease
fetal bradycardia: fetal factors/causes
- hypothermia
- cardiac defect/arrhythmia
- excessive vagal response (OP, forceps, etc.)
absent variability: causes/factors
- medications (CNS depressants)
- severe fetal anemia
- arrhythmias
- congenital brain anomaly
- cerebral ischemia
minimal variability: causes/factors
- fetus in quiescent phase
- occurs with tachycardia (secondary to dominance of sympathetic nervous system)
- drug effect: CNS depressants
*may be seen in very preterm fetus/baby
marked variability: causes/factors
- fetal activity
- fetal stimulation
- may follow epinephrine administration
- rare in preterm fetuses; more common in post-term fetuses
- may be seen in second stage, especially with vacuum application
nursing actions: FHR abnormalities
- develop a plan of care using terminology and interpretation
- determine physiological goals and interventions using evidence-based guidelines
oxygen pathway
environment
lungs
blood
heart
vasculature
uterus
placenta
umbilical cord
fetus
physiological goals for abnormal FHR
- maximize umbilical cord circulation
- maximize uterine blood flow
- maintain normal uterine activity
- maximize oxygenation
- reduce maternal anxiety
- support mom, coping and comfort
ABCDs of oxygen pathway
A: assess oxygen pathway
B: begin corrective measures, if indicated
C: clear obstacles to rapid delivery
D: determine decision to delivery time
what is assessed when assessing the oxygen pathway
- lungs
- heart
- vasculature
- uterus
- placenta
- cord
- O2 carrying capacity
- kleihauer-betke
oxygen pathway assessment: lungs
airway and breathing
supplemental oxygen
meds prn
oxygen pathway assessment: heart
blood pressure and pulse
treat abnormal BP, arrhythmia
oxygen pathway assessment: vasculature
blood pressure and pulse
volume status
position change
fluid bolus
oxygen pathway assessment: uterus
uterine contractions and tone
exclude uterine rupture: discontinue uterine stimulants
uterine relaxants as needed
oxygen pathway assessment: placenta
exclude abruption, previa, vasa previa
rapid delivery prn
oxygen pathway assessment: cord
exclude cord prolapse: consider amnioinfusion
rapid delivery prn
oxygen pathway assessment: O2 carrying capacity
maternal hemoglobin
MCA
peak systolic velocity
oxygen pathway assessment: Kleihauer-Betke
treat maternal anemia
treat fetal anemia
rapid delivery prn
what are the components of the classic triad of intrauterine resuscitation
oxygen
IV fluids
position changes
hyperoxia can cause ____
free radical production and oxidative stress
avoid supplemental oxygen if there is ___ in the tracing
moderate variability
prior to using oxygen, you should discontinue what medication?
oxytocin
why is a lateral maternal position better?
relieves pressure on the maternal inferior vena cava
improved blood return to the maternal heart
relieves cord compression by altering fetal position
IV fluid bolus: dosage
500-1000 mL of an isotonic solution over 20 minutes resulted in a significant increase in SaO2
IV fluid bolus: physiological changes
increases:
- intravascular volume
- cardiac output
- venous return
-preload even in maternal BP is normal
decreased maternal BP puts the fetus at harm in what way?
significantly reduces perfusion of the intervillous space
how to correct maternal BP
- lateral positioning
- ephedrine
what does ephedrine do?
- increases release of norepinephrine and stimulation of postsynaptic adrenergic receptors, which causes vasoconstriction and increased HR
disruption in the oxygen pathway at the uterine level is most commonly caused by ___
excessive uterine activity
what protocol should you use to reduce uterine activity?
oxytocin-induced tachysystole evidence-based protocol
oxytocin-induced tachysystole evidence-based protocol: category 1 tracing
- maternal repositioning (left or right)
- IV fluid bolus of at least 500 mL lactated Ringer’s solution
- if uterine activity has not returned to normal after 10-15 minutes: reduce oxytocin rate by at least half
- if uterine activity has not returned to normal after 10-15 additional minutes: discontinue oxytocin until uterine activity is no more than 5 contractions in 10 minutes
oxytocin-induced tachysystole evidence-based protocol: category 2/3 tracing
- discontinue oxytocin
- maternal repositioning
- IV fluid bolus of at least 500 mL lactated Ringer’s solution
- oxygen at 10 L/min via non-rebreather facemask (d/c as soon as possible based on fetal response)
- give terbutaline 0.25 mg SQ if: prolonged decel, no response after 10-15 minutes
resuming oxytocin after resolution of tachysystole
*If oxytocin has been discontinued for less than 30 minutes, there is a Category I tracing, and contractions are no more than five in 10 minutes
- Resume oxytocin at no more than half the rate that was being given at the time of tachysystole
- Resume titration as ordered
*If oxytocin has been discontinued for at least 30 minutes, there is a Category I tracing, and contractions are no more than five in 10 minutes:
- Resume oxytocin at initial dose ordered
- Resume titration as ordered
open-glottis pushing technique
- push fewer times with each contraction
- push with every other or every 3rd ctx
-push only with the urge to push have all been shown to improve FHR tracings
amnioinfusion
- replaces amniotic fluid with sterile saline
- think oligohydramnio moms
- relieves intermittent cord compression that may cause variable decels
- has no effect on late decels
nursing actions: maternal anxiety/comfort
include patient/family in planning care
review expectations and interventions
bedside attendance
review and determine labor coping/pain options
use technology only when needed
determining delivery time involves ___
- always involves prediction of unknown future events
- always relies on clinical judgement
- there will NEVER be one universal answer
considerations to clear patient for delivery
- Consider notifying: OB, Surgical Assist, Anesthesia, Neo-peds
- Consider epidural
- Confirm IV access, catheter
- Labs (eg Type & Cross), blood products
- Medications as needed
- CHG skin prep
- Prepare to move rapidly to OR
- Untangle cords/tubes, clear clutter
- Notify charge nurse
- Confirm OR availability & readiness
- Prepare for C/S or operative vag delivery
- Informed Consent
late decels: nursing actions
- degree to which decel is abnormal depends on the status and response of the fetus after the decel
- change maternal position to promote fetal oxygenation
- d/c oxytocin (consider terbutaline) to reduce uterine activity
- assess hydration- give IV bolus to promote fetal oxygenation
- consider fetal scalp stimulation of VAS to assess fetal status
- admin O2 at 10 L/min via non-rebreather mask to improve fetal oxygen status
- consider more invasive monitoring w/ fetal scalp electrode
- support woman and family
- notify the provider/midwife
- plan for delivery and care of the neonate
intrauterine resuscitation: nursing actions
- assess baseline over 10-minute period
- promote fetal oxygenation
- reduce uterine activity
- alleviate umbilical cord compression
- correct maternal hypotension
general plan of action for decelerations
stop drug first
change mom’s position
add O2
variable decels: nursing actions
- decrease or d/c oxytocin
- change maternal position to promote fetal oxygenation
- admin O2 at 10 L/min via non-rebreather mask to improve fetal oxygenation status
- perform a sterile vaginal exam (SVE) to evaluate cord and labor progress and perform fetal scalp stimulation
- perform amnioinfusion if ordered to alleviate umbilical cord compression by increasing the volume of fluid in the uterus and thereby correcting umbilical cord compression
- plan for delivery and care of neonate
- consider the need for tocolytic to reduce contractions
- consider more invasive monitoring with fetal scalp electrode
- modifying pushing
- support woman and family to decrease anxiety/pain
- notify provider/midwife
tetatnic contractions
- type of tachysystole
- very painful
with recurrent decels and minimal/absent variability, _____ can evolve over approximately ___
fetal metabolic acidemia
60 minutes
catastrophic uterine rupture can occur in a time frame of ____
17 minutes
metabolic acidemia will occur more rapidly with what (hint: associated with FHR changes)
- absent variability
- absence of accelerations
- worsening decelerations
normal contraction time length:
2-5 minutes
