Intrapartum Flashcards
The fetal heart rate is detected through the maternal abdominal wall using the ultrasound Doppler principle
EXTERNAL (Indirect) electronic fetal heart rate monitoring
The fetal heart rate may be measured by attaching a bipolar spiral electrode directly to the fetus
INTERNAL (Direct) electronic fetal heart rate monitoring
The necessity for membrane rupture and uterine invasion may be avoided by use of external detectors to monitor fetal heart action and uterine activity
EXTERNAL (Indirect) electronic fetal heart rate monitoring
The ultrasonic waves in the external fetal heart rate monitoring undergo shifts in frequency as they reflected from:
Moving fetal heart valves
Pulsatile blood ejected during systole
The mean FHR rounded to increments of __ bpm during a __ minutes segmen
5 bpm
10 minutes
The normal baseline FHR:
110-160 bpm
What is the FHR in bradycardia?
<110 bpm
What is the FHR in Tachycardia?
> 160bpm
This can cause fetal bradycardia:
H - hypoxia A - arrythmias B - beta blockers C - congenital heart blocks M - maternal hypotension
Causes of fetal tachycardia:
M - maternal fever F - fetal infection H - hypoxia B - beta mimetics H - hyperthyroidism A - arrhtyhmia
Baseline FHR Variability:
Amplitude range is undetectable
Absent
Baseline FHR Variability:
Amplitude range is 5 bpm or fewer
Minimal
Baseline FHR Variability:
Amplitude range of 6-25 bpm
Moderate
Baseline FHR Variability:
Amplitude range >25bpm
Marked
Significance of a normal FHR variability
Excellent indicator of good fetal well being
Causes of decreased or absent variability:
AA - asphyxia / fetal acidemia S - fetal sleep P - prematurity D - magnesium sulfate, diazepam, meperidine A - atropine D - defective conduction system
It is generally believed that ________ is the single most reliable sign of fetal compromise
Reduced baseline heart rate variability
A specific fetal heart rate pattern defined as having a visually apparent, smooth, sine-wave undulating pattern in FHR baseline with a cycle frequency of ____ minute that persist for ____ minutes
Sinusoidal fetal heart rate pattern
2-5/minutes persist for >=20 minutes
Fluctuations in the FHR of 2 cycles per minute or greater
Baseline variability
A visually apparent increase (onset to peak in less than 30 seconds) in the FHR from the most recently calculated baseline
Acceleration
Accelerations are always reassuring and always confirming that the fetus is not ___ at that time
Acidemic
In association with a uterine contraction a visually apparent gradual (onset to nadir of __ seconds) decrease in FHR with return to baseline, nadir of the deceleration occurs at the same time as the peak of the contraction
> = 30 seconds
Early deceleration
What is the pathophysiology of early deceleration:
Head compression > Vaal stimulation > affects the FHR
In association with a uterine contraction a visually apparent gradual (onset to nadir of __ seconds) decrease in FHR with return to baseline, onset, nadir and recovery of the deceleration occurs at the beginning, peak, and end of the contraction respectively
Late deceleration
Causes of late decelerations:
U - utero-placental insufficiency
M - maternal hypotension
U - uterine hyperactivity
An abrupt (onset of nadir of < 30 seconds), visually apparent decrease in the FHR below the baseline
Variable deceleration
The decrease in FHR is 15 bpm or more, with a duration of >= 15 seconds but less than 2 minutes
Variable deceleration
The most common deceleration pattern encountered during labor
Variable deceleration
Cause of variable deceleration
Umbilical cord compression
What are the markers of a prolonged deceleration:
Decrease in FHR
>= 15 bpm from baseline, >= 2 minutes but < 10 minutes in duration from onset to return to baseline
Common cause of prolonged deceleration:
C - cervical examination
U - uterine hyperactivity
C - cord entanglement
M - maternal supine hypotension
Other causes of prolonged deceleration:
C - conduction analgesia M - maternal hypothermia A - abruption U - umbilical cord prolapse M - maternal seizure V - Valhalla maneuver
This measurement of the pH in ____ may help identify the fetus in serious distress
Fetal scalp blood sampling
If the pH is greater than 7.25 what will you do?
Labor is observed
If the pH is between 7.20 - 7.25 what will you do?
Measurement is repeated within 30 minutes
If the pH is less than 7.20 what will you do?
Get another scalp blood sample, mother is taken to the OR
If the repeat is pH < 7.20 what will you do?
Deliver
This failure to provoke acceleration was not uniformly predictive of fetal acidemia
Scalp stimulation
If in the scalp stimulation there is a positive fetal heart rate acceleration, this indicates?
Normal pH
The technique that involves the usage of an electronic artificial larynx which is placed directly unto the maternal abdomen
Vibroacoustic stimulation
What is a positive response of a Vibroacoustic stimulation?
Fetal heart rate acceleration
What are the other intrapartum assessment technique?
Fetal pulse oximetry
Fetal echo
Intrapartum Doppler velocimetry
What are the two descriptions used to interpret fetal heart rate patterns:
Reassuring
Non- reassuring
Suggests a restoration of confidence by a particular pattern
Reassuring
Suggest inability to remove doubt
Non-reassuring
What are the three theories associated with Meconium in the amniotic fluid?
- Fetal response to hypoxia
- Maturation of the GIT
- Transient umbilical cord entrapment from Vagal stimulation
Amino infusion uses __ ml bolus of warmed normal saline followed by a continuous infusion of approximately ___
500-800ml
3ml per hour
Translational amnioinfusion may be done in the following:
- Treatment of variable to prolonged variable decelerations
- Prophylactically in cases of oligohydramnios with PROM
- To dilute it wash out thick Meconium
