Dear Michael
Thanks for your contributions and your very kind comments.
Certainly there is a severe stress effect with catecholamines which can
raise noradrenaline and VMA and possibly metanephrins. Post-operative
stress would certainly do this and the elevated BP and raised
catecholamines usually resolve as the stress lessens.
One of the most interesting cases we had was a 12month old boy who
broke his leg in a fall. He developed hypertension and had raised
catecholamines. He was at the stage of learning to walk and trying to
learn to walk on a broken leg was apparently very stessful. Moving to
upright posture raises catecholamines (a sort of postural stress) and this
combined with his injury evidently caused quite a massive increase in
catecholamines with associated hypertension. Over about three months,
his catecholamines and raised BP returned to normal as his leg healed.
It is probably not necessary to perform catecholamines post surgery
unless the BP is still elevated several days later. What do other people
think about this ?
PS I found Bill Bartlett's comments very interesting and basically agree
with his reference intervals, but was curious as to what "ASTED with
reductive mode ECD" means as mostly we are using oxidative mode ECD.
John Earl
Neurochemistry Laboratory
New Children's Hospital
Sydney, Australia
>>> "Michael Freemantle" <[log in to unmask]> 27/June/1999
07:41pm >>>
Dear Dr John Earl
----------
> From: John Earl <[log in to unmask]>
> To: [log in to unmask]
> Subject: Interference in Urinary Catecholamines
> Date: Friday, June 25, 1999 12:34 PM
>
> As part of our protocol for urinary catecholamine collection we have
> always required that urine should not be collected within 24 hours of
the patient having contrast medium, radioactive gallium for bone scans or
> other nuclear medicine procedures. I must admit I am not entirely sure
of the scientific reasons behind this. Does anyone have any information
?
>
I am are often confronted with this situation and suggest that the
collection be postponed until the next day for no good scientific reason. I
have always used the excuse that the procedure may be stressful to the
patient and thus raise their urine catecholamines - I have not sure that
this would the case. The other problem "hospital patients" are those who
show an episode of increased BP while under anesthesia and a
collection of urine is started as soon as the operation is over - almost all
patients with elevated urine catecholamines levels on day 1 will show a
trend tolevels below the upper reference limit by day three. What advice
do you give to clinicians in regards to the collection of post-op
catecholamines? I know Brett McWhinney has done reference ranges
for his ITU patients which reflect an increased catecholamine excretion
in this patient group as a whole. We never suggest dietary restrictions
for our catecholamine collection preferring that patients collect their
urines while on their normal diet.
Its good to see a bit of activity over this important "needle in the
haystack" , in our neck of the woods aldosterone producing adenomas
are far more common than phaeochromocytomas now-a-days.
Michael Freemantle
Sullivan Nicolaides Pathology
PO Box 344
Indooroopilly Q4068
Brisbane
Australia 4068
ph +61 (0)7 33778638
fax +61 (0)7 38705989
home page http://www.powerup.com.au/~mfreeman
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