----- Original Message -----
Sent: Friday, October 11, 2002 11:31
AM
Subject: Re: D-dimers and DVT
Ray,
OUr protocfol for DVT (which I can send you from
work on Monday, if you like) starts with the Wells risk stratification.
We did not add anything to this as it seems to have the best evidence base at
present.
We then do a benchtop D-dimer (Simplify, result
in ten minutes - positive or negative, no numbers). Again, there's good
evidence for using this, mainly from the people in McMaster University in
Canada, who seem to be world leaders in venous thrombo-embolism.
We discharge all low probability patients with a
negative d-dimer.
All of the others, i.e. mid and high probability
patients, havwe a duplex compression USS. If they have to wait for the
scan for a day or two, we give them daily Clexane. If the scan is
negative and the D-dimer is negative, the patients are
discharged.
If the scan is negative and the patient is
positive, we repeat the scan at one week. This is to rule out
propagation of a calf DVT, not picked up by the first scan. If this
second scan is negative, we discharge the patient.
Anyone with a positive scan, obviously, is
treated - we still admit them, but only because we haven't agreed a system for
outpatient management and investigation for thrombophilia, if indicated, with
our physicians. But, at least, only patients with a proven DVT get into
a bed.
I wrote this protocol after discussion with our
Haematologist, who specialises in thrombosis and with a professor from
McMaster. I believe it is the best there is, in terms of the research
evidence out there.
I think there may well also be a place for
venometry (strain gauge plethysmography) to avoid doing so many
scans. This is currently being investigated in a big study at McMaster
and I think the preliminary results may well be promising.
Our radiologists were initially somewhat unhappy
at having to repeat scans on some patients but now fully accept that this is
necessary and robust.
I hope this is of help.
If any others out there are interested, let me
know and I can put the protocol on the site - it's only two
pages.
Cheers,
Rocky.
----- Original Message -----
Sent: Saturday, October 05, 2002 9:34
PM
Subject: D-dimers and DVT
I had thought that a D-dimer should not be
requested on a patient with a clinical scoring of 3 or more as this was a
high risk group for DVT. The patient should instead have a doppler
etc. A normal D-dimer test in a high risk group would not be a 100%
reassuring.
However a trend has developed locally for all
patients to need a D-dimer before any further investigation. So a Doppler
may be refused even if the patient obviously has a DVT. e.g. drug addict
injecting into groin with leg twice normal size.
What is happening in other
hospitals?
Ray McGlone
A&E Consultant
Royal Lancaster Infirmary
/ Westmorland General Hospital
