Mike - I believe that a random urine is a vital part of the investigation
of both hyponatraemia and hypokalaemia. The flowcharts in Walmsley and
White's "A Guide to Diagnostic Clinical Chemistry" clearly explain the
rationale. Also in relation to the investigation of "polyuria ? DI", I
have found that a "random" urine osmolality is an essential first
investigation. The osmolality of the last urine passed before drinking
after overnight dehydration obviates the requirement to proceed to a formal
water deprivation test in 95% of patients in our (largely outpatient)
practice. This is because most patients will concentrate this specimen to
greater than 600 mosmol/L, often much greater than this. This very simple
outpatient test saves a lot of inconvenience for the patient and the
laboratory.
Bruce
*************************
Bruce Campbell
Chemical Pathologist
Sullivan Nicolaides Pathology
ph 07 3377 8672
fax 07 3870 5989
*************************
On Thursday, August 31, 2000 1:05 AM, Mike Addison
[SMTP:[log in to unmask]] wrote:
> I would appreciate the views of my colleagues (and any others who
> read this e-mail) on the use of random urine specimens in
> diagnosis and monitoring of electrolyte disturbances. In addition
> are there any views on the value of a random urine osmolality in
> looking at concentration defects. Are random urines ever
> appropriate for these investigations and if so what are the limits of
> their usefulness? I was taught that random urine eletrolytes,
> especially on inpatients, are generally unhelpful especially in those
> on iv therapy or diuretics. Is this really true or should I revise my
> opinions.
>
> Mike Addison
>
>
>
>
>
>
> Dr G.Michael Addison
> Royal Manchester Children's Hospital
> Pendlebury
> Manchester M27 4HA
> United Kingdom
>
> Tel 0161-727-2250(AM)or 0161-220-5342(PM)
> FAX 0161-727-2249
> Email [log in to unmask]
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