Re: AFI
From: DuboseTerryJ@exchange.uams.edu
Fri Sep 17 08:29:52 1999
Dr. Smeltzer, I agree. If it were completely up to me I would use the old
experiential gestalt method... too little, just right, too much fluid.
However, as more and more of us are going to PAC systems, with sonographers
working in outlying clinics, and putting their impressions into computerized
databases, we aren't left with that option. The computer will only accept a
number and anything less than 5 cm gets a red flag... so we are forced to
use the 4 quadrant method.
I am not complaining about that situation, just pointing out facts. I do
believe, as you pointed out here earlier, the 4 quadrant method does compel
one to do a more rigorous search and survey for fluid in the uterus. And,
while the reference I gave using infusion as a test of the methods has shown
the 4 quadrant produces more reliable information. Even if the same authors
also showed that infusion may be contraindicated, then they have given us
good information. First, that one method is more consistent than the other,
and second, that infusion may not be good fetal therapy (which by the way, I
had not seen that article. Thanks).
Someone needed to do it so everyone wouldn't go blindly along filling up
uteri.
Terry J. DuBose, M.S., RDMS
Director, Diagnostic Medical Sonography Program
CHRP, University of Arkansas for Medical Sciences
Little Rock, Arkansas, USA
501-686-6510
http://www.io.com/~dubose/ <http://www.io.com/~dubose/>
http://www.uams.edu/CHRP/dmshome.htm <http://www.uams.edu/CHRP/dmshome.htm>
http://www.obgyn.net/us/panel/panel.htm
<http://www.obgyn.net/us/panel/panel.htm>
-----Original Message-----
From: James S Smeltzer MD [SMTP:gaperina@mindspring.com]
Sent: Thursday, September 16, 1999 5:46 PM
To: Multiple recipients of list ULTRASOUND
Subject: RE: AFI
Terry,
The study I posted, by the same authors, showed that infusion of AF
reduced
uterine blood flow in oligohydramnios. To then infuse fluid in this
setting
is not in the fetal best interest, IMHO.
About fluid, the extremes are associated with bad outcomes. No-one
has
shown that the AFI has a better correlation with outcome, to my
knowledge,
than any other measure, including seat-of-the pants.
Jim:)
At 04:10 PM 9/16/1999 -0500, you wrote:
>Dr. Smeltzer, as I recall (it has been a long time since I read the
original
>article), the article concerned the infusion of fluid when there
was none or
>very little in an attempt to minimize Potter's faces and related
effects
>(hypoplastic lungs, etc.). As a part of that study, they used the
single
>largest pocket and the 4 quadrant method to see which gave the best
estimate
>of the amount of fluid they had actually infused. It seems a very
good way
>to compare the methods to me.
>
>As far as being ethical, they did not infuse the fluids so they
could test
>the measurements, they infused the fluids for other therapeutic
reasons due
>to the oligohydramnios. The comparison of the two methods of
measurement
>was incidental to the infusion.
>
>Whether or not the infusion of fluids is a valid therapy in these
cases is
>another question... and I will leave that to you physicians.
However, if
>the infusion is to be done, I see no ethical problem in trying to
use
>whatever methods are available to determine how much fluid should
be
>infused, has been infused, and to compare the various methods of
measurement
>of that fluid.
>
>Terry J. DuBose, M.S., RDMS
>Director, Diagnostic Medical Sonography Program
>CHRP, University of Arkansas for Medical Sciences
>Little Rock, Arkansas, USA
>501-686-6510
>http://www.io.com/~dubose/ <http://www.io.com/~dubose/>
>http://www.uams.edu/CHRP/dmshome.htm
<http://www.uams.edu/CHRP/dmshome.htm>
>
>http://www.obgyn.net/us/panel/panel.htm
><http://www.obgyn.net/us/panel/panel.htm>
>
> -----Original Message-----
> From: James S Smeltzer MD [SMTP:gaperina@mindspring.com]
> Sent: Thursday, September 16, 1999 3:44 PM
> To: Multiple recipients of list ULTRASOUND
> Subject: Re: AFI
>
> Terry,
>
> What does this article say about clinical outcome?
According to the
> following article, the study you mention is unethical, IMHO:
>
> TITLE: Uterine artery blood flow response to correction of
amniotic
>fluid
> volume.
> AUTHORS:Bower SJ; Flack NJ; Sepulveda W; Talbert DG; Fisk NM
> AUTHOR AFFILIATION: Centre for Fetal Care, Royal
Postgraduate
>Medical
> School, London, United
> Kingdom.
> SOURCE: Am J Obstet Gynecol 1995 Aug;173(2):502-7 CITATION
IDS:
>PMID:
> 7645627 UI: 95373576
> ABSTRACT: OBJECTIVE: Our purpose was to investigate whether
acute
> alterations of amniotic fluid volume affect uteroplacental
>perfusion. STUDY
> DESIGN: Three groups of patients of comparable gestational
age were
>studied
> in a fetal medicine referral unit: (1) eight pregnancies
with severe
> polyhydramnios because of twin-twin transfusion syndrome
undergoing
> therapeutic amnioreduction, (2) seven with severe
oligohydramnios
> undergoing diagnostic amnioinfusion, and (3) six control
women
>having
> invasive procedures of similar duration without manipulation
of
>amniotic
> fluid volume. Color Doppler imaging was used to measure
uterine
>artery
> impedance index values and quantitative blood flow before
and within
>15
> minutes of the end of the procedure. RESULTS: Quantitative
flow
> measurements increased after amnioreduction (74% median
increase of
>volume
> flow, range 22% to 329%, p < 0.01) and decreased after
amnioinfusion
>(33%
> median decrease of volume flow, range 17% to 51%, p < 0.05).
>Impedance
> index values increased after amnioinfusion (25% median
increase in
> pulsatility index, range 4% to 71%, p < 0.05) and did not
alter with
> amnioreduction. There were no significant changes in the
control
>group.
> CONCLUSION: Acute changes in amniotic fluid volume alter
>uteroplacental
> perfusion. In twin-twin transfusion syndrome amelioration in
uterine
>flow
> may improve fetal condition and explain in part the success
of
>serial
> amnioreduction therapy.
>
> :) Jim Smeltzer, MD
>
> At 02:01 PM 9/11/1999 -0500, you wrote:
> >Dr. Smeltzer, I am not sure I agree with your statement
that: "The
> >largest single pocket predates the AFI by decade(s), was
never
>shown to
> >be inferior to it...."
> >
> >The following reference was very convincing to me that the
AFI is
> >superior to the single largest pocket measurement.
> >
> >"Sepulveda, Flack, & Fisk, using an infusion method in
severe
> >oligohydramnios and anhydramnios pregnancies, found that
the AFI
> >(4-quadrant sum) was more accurate than the single pocket
method."
> >
> >Their methods seem to be a unique and elegant approach to
this
>question.
> >
> >Peace, Terry J. DuBose, M.S., RDMS
> >Little Rock, Arkansas USA
> >
> >------------------------
> >
> >------------------------
> >At Wed, 08 Sep 1999, James S Smeltzer MD wrote:
> >------------------------
> >>
> >>Dear Joe,
> >>
> >>The largest single pocket predates the AFI by decade(s),
was never
>shown to
> >>be inferior to it, was shown to agree with expert
subjective (?!)
> >>assessment & with AFI. We grasp at pseudoquantitative
measures to
>provide
> >>a level of truth that lacks, IMHO. There are several
older
>studies that
> >>indicate that AF not relevant until truly oligo (<1cm).
There is
>a recent
> >>study indicating that Doppler is better predictor than AF
in IUGR
>& that AF
> >>measure better than the rest of the BPP for the same
purpose.
> >>
> >>My recommendation is to provide referring physicians with
>information that
> >>they can unambiguously use for patient management. For
this one
>it would
> >>be AFI - which does encourage a systematic search for
fluid. I
>provide a
> >>bottom line clinical impression in all abnormalities of
fluid or
>other
> >>measures of fetal status & their clinical significance in
the
>setting of
> >>the patient's problems & indications (& in normal ones in
which
>measures
> >>are relevant). This is the "interpretation", which
constitutes
>the medical
> >>practice part of sonology, IMHO.
> >>
> >>Jim S
> >>
> >>At 12:37 AM 9/4/1999 -0500, you wrote:
> >>> Is amniotic fluid index an outdated technique?
Referring
>some articles
> >>>on medline- largest single pocket has replaced AFI- is
that
>true? One
> >>>referring doc insisted on AFI-- I have no literature
describing
>the
> >>>method. Do you take the total of all four quadrants in
cms? or
>is the
> >>>average of largest pockets taken-- ie: divided by 4?
Please
>describe
> >>>exactly how to estimate AFI. Regards, DR.JOE ANTONY
> >
> >--
> >Peace, Terry J. DuBose, M.S., RDMS, FAIUM
> >University of Arkansas for Medical Sciences, USA
> >Director, Diagnostic Sonography Program
> >http://www.uams.edu/chrp/dmshome.htm
> >VOICE: 501-686-6510 FAX: 501-686-6513
> >Chair, http://www.obgyn.net/us/us.htm
> >http://www.io.com/~dubose/
> >Now is the time for all good folks to come to the aid of
the Earth.
> >
>
