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When should doppler use be avoided?
1st trimester
Used for obstetrical doppler are: (5)
1. Maternal vessels
2. Fetal Vessels
3. Fetal ductus venosus
4. Fetal heart
5. Placenta
What are the 2 basic types of doppler us?
CW
PW
With increasing GA there is a __________________ in the S/D ratio.
decline
How do you calculate Resistive Index?
S-D / S
How do you calculate PI?
S-D / mean
As the vascular resistance increases what happens to the:
S/D?
PI?
They both increase
What happens to the PI as the GA increases?
declines
In normal pregnancies, the umbilical vein venous flow is _________________.
____________ velocity.
_____________ during fetal breathing.
constant
low
variation
Some factors related to reduced blood flow to placenta: (4)
smoking
maternal hypertension
various drugs
poor nutrition
What would happen to diastolic velocity if placental resistance increased?
reduce
How is the resistance arrangement when IUGR head sparing occurs?
increased resistance AO & umbilical artery
decreased resistance in fetal middle cerebral artery
Which fetal vessel is studied the most extensively?
Umbilical artery
The umbilical artery has ______________ resistance flow.
low
Increase in fetal HR causes ______________ in pulsatility.
decrease
Umbilical Artery: S/D ratio <3.0 is normal? T/F
True
False
T
Umbilical Artery:
Normal RI=?
<0.7
Risks associated with abnormal S/D ratio include:
preterm delivery
decreased birthweight
decreased amniotic fluid
SGA
Risks associated with admission to NICU
When assessing umbilical artery you should locate a spot close to fetal abdomen/placenta?
fetal abdomen
___________ or ___________ of diastolic flow is a significant finding and indicates placental ____________.
absence or reversal
impedence
Elevated S/D ratios are associated with: (3)
abnormal karyotype
maternal HTN
severe growth restriction
Fetal doppler of MCA is used to detect "________ _______ ______"
brain sparing effect
MCA has _______ cerebral blood flow and little diastolic flow
80%
MCA PI = ?
>1.45
MCA acronym HABS stands for
Heart
Adrenal
Brain
Sleen
Which are the highest velocities found in fetal cardiovascular system?
ductus arteriosus
50-140
Diastolic 6-30cm/sec
Flow Rt to Lt
Maternal uterine artery gives off branches near ?
Runs?
internal os
sup lat along corpus
ant ---> external iliac
When do you sample MUA?
16-22 weeks
After 12 weeks the MUA has a ____________resistance flow pattern
low
What is an abnormal S/D ratio of MUA?
>2.6
above indicates increased vascular resistance and decreased blood supply to uterus
notching on diastolic is bad
MUA normal PI? RI ?
PI = .82
RI = 4.7
What may be one of the earliest signs of IUGR especially if there is maternal HTN?
arcuate artery with reduced flow
Umbilical artery & vein reflect changes in the _______________ vascular bed.
placental
How many weeks before fetus appears to be in trouble may doppler parameters become abnormal?
4 or more
Studies have shown that ___________________ as part of the OB management has resulted in a reduction of emergency c-sections?
doppler
In severe PIH doppler studies correlate well with _______ ______.
fetal distress
You can see doppler changes 24hrs before/after nonstress test?
before
In discordant twins, doppler has/has not proven to be more useful than EFW.
has not
With cardiac anomalies, doppler can gage systolic function by measuring: (3)
aortic volume
systolic velocities
AT
Smoking can increase maternal HR and BP therefore increasing fetal ____________ and _____________blood flow
aortic
umbilical
Doppler of umbilical artery that is suggestive of distress or compromise would be?
absent or reversal of flow
Author
lstaal1
ID
22583
Card Set
OB 510
Description
Obstetrical Doppler
Updated
2010-06-08T19:52:24Z
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