Fetal Monitoring Chap 9 Flashcards
Baseline FHR
mean FHR in increments of 5 bpm during 10 min period w at least 2 identifiable segments
tachycardia
baseline FHR above 160 bpm in 10 mins
bradycardia
baseline FHR under 110 bpm in 10 mins
FHR variability
fluctuations in baseline FHR that are irregular in amplitude/frequency occuring in 10 mins from exertion of PNS
cycles per min
oxygenated fetuses have 2-8 cycles per min
amplitude
bpm measured from peak to trough of single cycle
absent variability
amplitude range undetectable
minimal variability
amplitude range detectable but 5 bpm
mod variability
amplitude range btw 6-25 bpm
marked variability
amplitude range above 25 bpm
periodic patterns
associated w uterine contractions
episodic patterns
not associated w uterine contractions
periodic changes
accel, decel, variable, late, early
episodic changes
accel, decel, variable, prolonged
acceleration
abrupt increase in FHR more than .15 shorter than .30 lasting total 10 mins
periodic decels
early, late, variable
episodic decels
prolonged and variable
acme
highest point of contraction
nadir
lowest point of contraction
onset
time from start of decel to nadir
offset
time from nadir of decel to return of baseline
abrupt
less than 30 seconds
gradual
at least 30 secs
recurrent
occurring with more than 50% of uterine contractions in 20 min window
intermittent
occurring with less that 50% of uterine contractions in 20 min window
early decelerations
symmetrical and gradual decrease/return of FHR associated w contraction
causes of early decels
fetal head compression during contraction causing vagal stimulation and low HR
late decelerations
symmetrical and gradual decrease/return of FHR associated w contraction with delay in timing
late decels are associated with
uteroplacental insufficiency by contractions, decrease in uterine blood flow, placental dysfunction
physiology of late decels
protective reflex mechanism in response to fetal hypoxemia during contractions
causes of late decels
maternal hypotension, uterine hyperstimulation, postdate gestation, preeclampsia, chronic hypertension, diabetes, hypovolemia
during actions for late decels
admin O2 at 10 L/min, fetal spiral electrode, support, plan for delivery, fetal scalp stimulation, IV bolus
if late decels continue
peripheral vasoconstriction fails, decreased blood flow to brain, ischemic injury to brain/heart
variable decels
abrupt decrease in FHR greater than 15 bpm more than 15 sec under 2 mins
characteristics of variable decels
variable in duration, intensity, timing that arent consistent w contractions
variable decels are common in
PROM and decreased amniotic fluid vol
causes of variable decels
compression of umbilical cord
if persistent variable decels occur and not fixed
cause acidosis and fetal distress
nursing actions of variable decels
change position, sterile vaginal exam to eval cord, amnioinfusion, admin O2 at 10 l/min, decrease/discontinue oxytocin
category 1 FHR (normal)
110-160 bpm (baseline), mod variability, no late/variable decels, early or accel may be present
category 2 FHR (indeterminate)
inconclusive and include all tracings not in 1 or 3
category 3 FHR (abnl)
absent baseline FHR variability and recurrent late/variable decels, bradycardia, sinusoidal pattern
uterine activity
contains adrenergic receptors, estrogen stimulate cervical ripening and increase oxytocin receptors, estrogen and prostaglandins cause contractions
frequency
time from beginning of one contraction to beginning of next
duration
time from beginning to end of contraction
intensity
difference btw peak pressure and rest (mild, mod, strong)
norm uterine activity
under 5 contractions in 10 mins over 30 min period
peak IUP
acme of contraction in mmHg when an IUPC in place
interval of uterine activity
time from end of one contraction to beginning of next (rest)
resting tone/baseline tone
lowest intrauterine pressure found btw contractions w IUPC
tachysystole
more than 5 contractions in 10 min over 30 min period regardless of FHR
hypertonus
abnl high resting tone (above 30 mmHg)
uterine tetany
uterine contraction that is strong to palpation or over 90 mmHg more than 90 sec
hypertonus and uterine tetany
need to be confirmed w palpation
documenting uterine activity
method, frequency, duration, intensity, relaxation
if oxygenation changes is not the cause of FHR
interventions to improve O2 will not correct FHR
fetal tachycardia causes
infection, supra-ventricular tachycardia, tachyarrhytmia, congenital anomalies
maternal causes of tachycardia
fever, infection, dehydration, hyperthyroidism, anxiety, meds, illicit drugs
fetal causes of bradycardia
hypothermia, cardiac defect/arrhytmia, excessive vagal response
maternal causes of bradycardia
drug response, prolonged hypoglycemia, CT disease
absent variability causes
medications (CNS depressants), fetal anemia, arrhythmias, congenital brain anomaly, cerebral ischemia
minimal variability causes
fetus in sleep cycle, tachycardia, CNS depressants
marked variability causes
fetal activity/stimulation, ephedrine administration
physiological goals
maximize umbilical cord circulation/blood flow/O2, maintain activity, reduce anxiety
A
assess oxygen pathways
B
begin corrective measures
C
clear obstacles to rapid delivery
D
determine decision to delivery time
assessing lungs
airway and breathing (give O2 and meds)
assessing heart
BP/HR (treat abnls)
assessing vasculature
BP/HR?volume status (position change, IV bolus)
assessing uterus
contractions/tone (discontinue stimulants, use relaxants)
assessing placenta
rapid delivery
assessing cord
amnioinfusion, rapid delivery
assessing O2 carrying capacity
maternal hemoglobin
Kleihauer-betke
treat maternal/fetal anemia and rapid delivery
intrauterine resuscitation
IV fluids, O2, position changes
supplemental O2
discontinue oxytocin before, causes oxidative stress (consider other options first)
lateral positioning
relieves pressure on vena cava, improve blood return, relieve cord compression
IV fluid bolus
increases intravascular vol, CO, venous return and preload
correcting BP
lateral positioning improves venous return/CO, ephedrine increases HR
excessive uterine activity
causes disruption in oxygen pathway
oxytocin induced tachysystole with Category 1
maternal reposition, IV bolus (if not norm: reduce oxytocin by half…10-15mins later: stop all oxytocin)
oxytocin induced tachysystole with Category 2/3
discontinue oxytocin, maternal reposition, IV bolus, O2, terbutaline (prolonged)
If oxytocin has been discontinued for less than 30 min, Category I tracing, and contractions are less than five in 10 mins
resume oxytocin at half original dose and resume titration
If oxytocin has been discontinued for at least 30 mins, Category I tracing, and contractions are less than five in 10 mins
resume oxytocin and titration
2nd stg pushing
open glottis pushing but pushing fewer with every other/3rd contraction and only when need to push improves FHR
amnioinfusion
replaces amniotic fluid, relieves cord compression
maternal anxiety
include fam, support, expectations, coping skills
clearing for delivery
notify providers, epidural, IV, labs, meds, skin prep, prep OR
determine decision to delivery time
dilation, efface, station, uterine activity, past/expected progress rate
fetal metabolic acidemia
with recurrent decels and min/absent variability can happen in 1 hr
be aware of
rising FHR, loss of variability, worsening decels
