OB: FHR monitoring Flashcards
Historically labor puts the fetus at increased risk of ____ and _____
morbidity and mortality
Neonatal outcomes have drastically improved in the last ___ ____ in developing countries
40 years
In developing countries intrapartum stillbirths account for as many as ____ % of stillbirths
50
Developed countries ____ ____ are rare, less than 10% of stillbirths
intrapartum stillbirths
The WHO reports that ___ of all deaths in children under 5 are due to intrapartum stillbirth. (Livingston, 2014)
10%
High risk mothers constitute ____% of the pregnant population
20%
(high risk mothers) Their babies represent 50% of the cases of perinatal _____ and _____
morbidity and mortality
High risk pregnancies:
_____ complications
_____ complications
_____ complications
Medical complications (HTN, pre-E, diabetes, autoimmune, hemoglobinopathy)
Fetal complications (IUGR, nonlethal anomalies, prematurity, multiple gestation, post-datism, hydrops)
Intrapartum complications (bleeding, maternal fever, meconium-stained amniotic fluid, oxytocin augmented labor)
Intrapartum Fetal Assessment -
____ ____ ____ ____ Monitoring
Not a specific predictor of fetal wellbeing
No optimal while still practical method has been developed
Electronic Fetal Heart Rate
Intrapartum Fetal Assessment -
Neuronal and humoral factors affect the intrinsic FHR
Fetal parasympathetic outflow → ___________FHR
Fetal sympathetic activity → _________ FHR
decreases
increases
Intrapartum Fetal Assessment -
______ respond to increased BP
Baroreceptors
Intrapartum Fetal Assessment -
Chemoreceptors respond to decreased ____ and increased ____
PaO2
PaCO2
External vs Internal Monitoring -
FHT and uterine contractions are monitored _____
simultaneously
External vs Internal Monitoring -
This allows for a determination of a baseline rate and patterns of FHR compared to _______
contractions
External vs Internal Monitoring -
The external FHR transducer uses ____ _____ to detect changes in ventricular wall motion and blood flow through major vessels
doppler ultrasonography
External vs Internal Monitoring -
Alternatively, a scalp ECG lead measures the ____ interval
R to R
External vs Internal Monitoring -
Both allow for ___ ___ monitoring
continuous FHR
External vs Internal Monitoring -
The external tocodynamometer measures contractions while ____ ____ on the fundus
sitting externally
External vs Internal Monitoring -
An ____ ____ ____ (___) measures exact pressures in the uterus
intrauterine pressure catheter (IUPC)
External vs Internal Monitoring -
IUPC is more accurate regarding the ____ of contractions
strength
Methods to Improve FHR Monitoring -
Continuous FHR monitoring – requires patient to be ____ a ____ ____ of the base
within a few feet
Methods to Improve FHR Monitoring -
_____ – Allows for more movement and ambulation
Telemetry
Methods to Improve FHR Monitoring -
Electronic recording – eliminating the need for ____ ____ (medicolegal implications)
paper record
Uterine Contraction Pattern -
A normal pattern of contractions is ___ ___ ___ in a __-____ period averaged over 30 minutes
5 or less
10-minute
Uterine Contraction Pattern -
_____ is more than 5 contractions in a 10-minute period
Tachysystole
Uterine Contraction Pattern -
The Toco ___________ the onset, duration, and offset of contractions
approximates
Uterine Contraction Pattern -
An IUPC can measure the ____________ of contractions and __________ onset and offset of each contraction
strength
precise
FHR assessment: (4)
- baseline measurements
- variability (long term and beat-to-beat)
- accelerations
- decelerations (and their association with uterine contractions)
Baseline Fetal Heart Rate -
Normal baseline FHR is ___-____
Term fetuses have a ____ baseline FHR than preterm
110-160 bpm
lower
Baseline Fetal Heart Rate -
_____cardia is the initial fetal response to hypoxia
brady
Baseline Fetal Heart Rate -
Prolonged hypoxia may result in fetal _____cardia
Due to catecholamine _____ and SNS ____
tachy
secretion
activity
Baseline Fetal Heart Rate -
Changes in baseline FHR may also be caused by fetal anatomic or functional heart pathology, maternal fever, intrauterine infections, maternally administered medications (____ ____ – terbutaline, or _______ - atropine)
beta agonists
anticholinergic
Fetal heart Rate Variability -
fluctuations in FHR is ______
GOOD
FHR variability -
_____ variability indicates presence of intact fetal cerebral cortex, midbrain, vagus nerve, and cardiac conduction system
Normal
FHR variability -
Variability greatly influenced by _____ tone
parasympathetic
FHR variability -
Hypoxemia fetal myocardial and cerebral blood flow ____ to maintain O2 delivery and a loss of FHR _____ is observed
increase
variability
Accelerations -
____ changes in FHR above baseline
Abrupt
Accelerations -
Defined as at least ____ beats above baseline for at least ____ seconds
15
15
Accelerations -
Prolonged acceleration is >__ ____, but if it persists >__ _____ it is a change in baseline
2 minutes
10 minutes
Accelerations -
______ accelerations correspond with fetal movement, _____ the significance is unclear.
Antepartum
intrapartum
Accelerations -
Accelerations preclude the existence of fetal ___ ____
metabolic acidosis
Decelerations - Early
Occur simultaneously with uterine contractions
Usually less than 20 bpm below baseline
Onset and offset mirrors contraction
Uniform in appearance
Head compression
Decelerations - variable
Vary in depth, shape, duration
Abrupt onset and offset
Vagal activity
Umbilical cord occlusion (partial or complete)
Decelerations - Late
Occur with each uterine contraction
Uniform appearance
Begin 10-30 seconds after contraction begins
End 10-30 seconds after contraction ends
Vary in depth according to the strength of contraction
Placental issues
Ominous when accompanied by lack of variability
Severe if decrease more than 45 bpm
VEAL
CHOP
variable = cord compression
early = head compression
acceleration = okay
late = placental insufficiency
Abnormal FHR patterns -
Saltatory pattern:
_____ alterations in variability
Acute fetal ____
Weak association to ___ Apgar scores
Excessive
hypoxia
low
Abnormal FHR patterns -
_____ pattern:
Fetal anemia
Occasional maternal opioid consumption
Sinusoidal
Anesthesia Implications -
Rule out _____ intervention as the cause
If it is related to anesthetic – correct _____
If epidural level is higher than necessary, let it ____
anesthetic
hypotension
recede
Anesthesia Implications -
If there are ___ _____ FHR tracing during preanesthetic assessment, consider whether anesthetic intervention could worsen fetal status. Discuss with OB
non reassuring
Anesthesia Implications -
When an ____ ____ ____ is called, be prepared (already ready) to move quickly
emergent cesarean delivery
Anesthesia Implications -
If a labor epidural is already in place determine if it can be adequately dosed and utilized for cesarean…. ask yourself what
Is it patchy?
Will the patient/fetus tolerate additional local anesthetic to achieve an adequate level?
How quickly can adequate level be achieved?
What is the probability of block failure?
Would a SAB behoove the situation?
Would it make things worse?
KEY POINTS
A _____ FHR accurately predicts fetal well being
A _____ FHR is not specific in the prediction of fetal compromise (false positive)
_____ prolonged bradycardia or late decelerations with absence of variability
normal
abnormal
Except
