Is this reference range recommended by the manufacturer or locally
generated one?
If it is locally generated one did you verify/audit the range after the
introduction, particularly the lower end I am concerned.
Regards
Vivek
Guy's & St.Thomas' Hospitals
London
On Thu, 5 Oct 2000, Neely Dermot (RR9) Biochemistry wrote:
> I'd be interested to hear what reference ranges people quote for corrected
> calcium. We quote 2.15-2.65 mmol/l (Roche 917 with BCG albumin and formula
> as per Peter). We a fair number of slightly low results and ionised calcium
> is almost invariably normal. I think the cut off for correction of 15g/L is
> much to low but I'm not aware of any data which addresses this issue. Any
> offers?
>
> Dermot Neely
>
> *************************************
> Dr RDG Neely
> Department of Clinical Biochemistry
> North Durham Healthcare NHS Trust
> Dryburn Hospital
> Durham DH1 5TW
> Tel. 0191 3332440 Fax. 0191 3332679
> *************************************
>
> -----Original Message-----
> From: Sharpe, Peter Dr [mailto:[log in to unmask]]
> Sent: 05 October 2000 04:14
> To: [log in to unmask]
> Subject: corrected calcium
>
>
> We give corrected calciums on all samples except when albumin<15 g/l. This
> has met with great enthusiasm by both GPs and hospital medics.
>
> We use the following formula:
>
> Corrected calcium (mmol/l) = total calcium + 0.02(40 - albumin)
> i.e. the measured total calcium is corrected upwards by 0.1 mmol/l for every
> 5 g/l that the albumin is less than 40 g/l.
>
> The main reason for giving corrected calciums was that there was a degree of
> ignorance among GPs in particular regarding total calciums and its
> correction using the serum albumin concentration. We also correct our
> calciums downwards for albumins > 40 g/l although this may not be an
> entirely accurate thing to do??
>
> In cases of difficulty we are lucky in having a near patient testing
> instrument in ICU which measures ionized calcium.
>
> All the best
>
> Peter Sharpe
>
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