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Kate.... i don't know from what state you write...but i would recommend caution using TCD for braindeath "determination"..  First off, different states have varing  rules for the determination of
brain death - but most will require 2 physicians (one of whom must be in the neuro field) to make a clinical/ and or test determined brain death declaration.  You may want to inquire first, if TCD
is necessary for this type of determeination where you reside. Here are a few comments as food for thought:
*  many TCd texts will describe a globally highly resistant, sometimes bi-directional  waveform or systolic blips as "consistent with" cerebral circulatory arrest.  While I have seen this type of
waveform morphology on many ocasions and these waveforms did concide with clinical or other test derrived outcomes of brain death, you can also see globally highly resistant waveforms (i.e.,
with-out diastolic flow) is patients with severe aortic regurg.  Years ago we made a discovery like this in a patient on a ventilator in a drug- induced coma.  We explained the potential
implications of these waveforms to the physician in charge of the patient care and he subsequently brought the patient "up" from this sedation to do a neuro evaluation.  The patient was fine - but
had a completly incompetent aortic valve.  Since this case, I have seen 2 more patients without intracranial arterial diastolic flow who were NOT brain dead or even near brain death- one patient was
up walking the halls.  Now, having said this, the waveforms from the pts with severe aortic regurg while lacking diastolic flow did have a substatial flow content during systole - a widened spectral
complex compared to  the patients with brain death who demonstrated  spindly systolic spikes-a shortened systolic interval and in some cases the signals were reduced to nothing more than a blip that
concided with the pulse wave striking the swollen brain.  The bottom line is that you see these cases infrequently and having physicians or technologists discern these discrete differences can prove
to be a problem.
*  back in the late 1980's when we started performing TCD evals - my medical director and I had this "brain death" conversation about TCD.  We elected to send a letter to the medical staff of our
laboratory and ask that they refrain from reading a TCD  as  "this study shows brain death";   We recommend that our techs and the physicians state that the waveforms are highly abnormal and
consistent with those seen in brain death.  In other words, we refrain from stating a patient is brain dead by TCD.  Hope this helps as you plow forward in this area.
Kathryn,

Kate Holmes wrote:

> While we're on the subject, I was asked yesterday to assess a fellow for brain death .
>  I am in possession of the Aaslid textbook and see that they talk about particular characeristics associated with brain death , does any one have experience in this area, I have a few questions?
>
> >>> [log in to unmask] 10/30/02 12:18pm >>>
> John,
>   At Cedars-Sinai in LA we have been using duplex ( Acuson128 XP-10 /Acuson
> Sequoia/ ATL 5000) for the last 10 years (approx 1500 cases). The color
> allows accurate cursor placement, immediate flow direction assessment and
> has a much shorter learning curve compared to "blind" TCD (you might want to
> check with Don Ridgeway at Grossmont College for that last statement). All
> probes used were in the 2 MHz range. The early comparisons of temporal
> window failure using duplex I feel are inaccurate as the equipment listed
> above have equal penetration success rates with the blind method.
>                                                                  Best
> regards,
>                                            Tom Rosendahl, RN BS RVT
>
> > ----------
> > From:         Needham, Ann[SMTP:[log in to unmask]]
> > Reply To:     UVM Flownet
> > Sent:         Wednesday, October 30, 2002 7:14 AM
> > To:   [log in to unmask]
> > Subject:      Re: Transcranial Doppler
> >
> > John,
> >
> > I don't do TCD any longer but when in Nashville we used duplex on the ATL
> > (3000) with their dedicated TCD probe, 2 MHz small aperture.  It was
> > easier once you identified the window, as the color sensitivity really
> > helped identify the flow and the vessel identification was much more
> > believable.  Prior I had done them "blind" for 3 years in Little Rock and
> > found the duplex method had a shorter learning curve.  Good luck.
> >
> > Ann Needham, RN RVT
> >
> > -----Original Message-----
> > From: John K. Jain [mailto:[log in to unmask]]
> > Sent: Tuesday, October 29, 2002 5:24 PM
> > To: [log in to unmask]
> > Subject: Transcranial Doppler
> >
> >
> > Hello Friends, Colleagues and Fellow Countrymen,
> >
> > I have a technical question for you all. Is there anyone who is doing
> > transcranial with only a duplex scanner? If so what frequency transducer
> > are make/model of equipment are you using.
> > Our old transcranial machine went to the boneyard years ago and without
> > ever having a significant volume of patients to justify replacing it we
> > let
> > the program go. Now of course there are new nuerosurgeons who are banging
> > the TCD drum and I am trying to evaluate our options.
> >
> > Thank you  ahead of time for your help,
> >
> > John K Jain
> >
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