> Date: Wed, 26 May 1999 08:36:53 +1000
> Subject: Re: Haemolysis after blood collection
> From: Graham Jones <[log in to unmask]>
> To: [log in to unmask]
> Reply-to: Graham Jones <[log in to unmask]>
> Regarding haemolysed samples from the Emergency Department:
>
> Our response (being unable to get the Ed doctors to change their practice)
> is to provide a "corrected" total CK and potassium for the amount of
> haemolysis ( following the work of Jay and Pravasek, Clin Chem
> 1993;39:1804-10). This suppoted by local experiments showing sufficiently
> constant inter-personal ratios of red cell haemoglobin:potassium and
> haemoglobin:CK. As well we have vaildated the algorithms using haemolysed
> and non-haemolysed samples from the same patients in the ED. While this is
> an approximate correction only, we believe it is better than the delay (and
> annoyance) caused by asking for a recollection in each of these cases.
> CK-MB we found was not affected by haemolysis up to an H of "1000".
>
> Graham Jones
>
> Staff Specialist in Chemical Pathology
> St Vincent's Hospital, Sydney
>From personal experience dealing with haemolysed samples on-call
I would say that in approximately 50% of our visibly haemolysed
samples the potassium is unchanged when an unhaemolysed repeat
sample is sent to the lab.
The highest percentage of haemolysed samples is probably in
blood taken by paramedics before the patient arrives in
casualty. We can identify some of these samples because they
arrive in 10mL heparin tubes instead of our standard 6mL tubes.
Mike Collins
Mike Collins MLSO3
Chemical Pathology & Immunology
The General Infirmary at Leeds,
Old Medical School, Thoresby Place
Leeds LS1 3EX, UK
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44 (0) 113 392 2915
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