Seeings as I have now asked the same question three times and had no reply,
I am going to assume that no-one on this list has seen a high quality
multislice CT negative xanthochromia positive patient have a neurosurgery
procedure.
Maybe it's because none of you have multislice CTs. (just joking)
That's pretty interesting, isn't it.
It may also interest you to know that I operate in a fee for service
radiology environment, where the protocol for obtaining a CT to rule out SAH
involves ringing the clerk to book the test. We have CT freely available
from 0800-2300 each day. This makes a big difference compared to having to
justify the ordering of tests to some actively work avoiding PGY5 Radiology
Registrar.....
Where's Rowley when I need him. He's a man of interesting and strongly held
views......
PB
-----Original Message-----
From: Accident and Emergency Academic List
[mailto:[log in to unmask]] On Behalf Of Andrew Webster
Sent: Tuesday, 28 February 2006 4:14 PM
To: [log in to unmask]
Subject: Re: SAH
If we are looking at the best situation of a CT done within 12 hours and
the CT is 98% sensitive then maybe 1:1000 risk is acceptable.
If the test though is only 95% sensitive....then the risk would be 1 in 333
But if for example we are relying on non neuroradiologists or even
radiology registrars and their sensitivity is only 90%. Then the
likelihood ratio is only 0.1 and the post test probability is 1 in 20.
Best case scenarios CT at less than 12 hours then 1:1000 should be a
fair enough risk. What the experts would argue for the rest of us, if we
missed a case that we were not working in the best case and our risk is
much higher. The real truth probably lies in between 1 in 20 to 1in 1000.
Paul I presume you were cycling along the coast to Joondaloop from
Perth. Lovely ride which I did last November before coming home. The
thought of doing it cycling 35 Km in 35 degrees......hope you have good
showers in your department. Though much better cycling in the wind and
rain between traffic over here.
Andy Webster
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