19 December 2014 (Friday) - BBTS Newsletter

The BBTS newsletter came today; again by email. Being “Blood Transfusion” and much narrower in scope than yesterday’s IBMS missive I was expecting this to be more relevant to me.

Was it?

There was an update on the BBTS Specialist Certificate in Transfusion Science Practice; a qualification I should really be taking. There was news of a scientific meeting taking place next year. Will I attend? I should, but I really don’t like going to these things…

18 December 2014 (Thursday) IBMS Newsletter

The IBMS newsletter came today. I say “newsletter”, but in a typical sign of the times it was via email. I perused it; without wishing to sound cynical I didn’t feel there was much of immediate import to myself.

Perhaps I’m wrong….

17 December 2014 (Wednesday) - Chloride


The NICE clinical guideline 'Intravenous fluid therapy in adults in hospital' (CG174) recommends daily serum chloride monitoring in patients receiving intravenous fluids with chloride concentrations greater than 120 mmol/L, including 0.9% ('normal') saline.

To facilitate this, all inpatient requests for serum electrolyte and creatinine measurements will automatically also have a serum chloride measured and reported.

Up until now chloride has been something of an obscure add-on. Generally chloride levels go up and down with sodium levels, so measuring chloride is a good way to spot an “iffy” sample.

Having said that, I really need to bone up on the topic.


6 December 2014 (Saturday) - HCPC in Focus Magazine

The latest missive from the HCPC is now on-line at http://www.hcpc-uk.org/assets/documents/100049D3HCPCInFocus-Issue56.pdf

The headline gave me pause for thought “Registration renewal figures for operating department practitioners and social workers in England at an all-time high”. Clearly I’m missing something here. Those that don’t renew cannot continue practice. Either they’ve obtained alternate employment or retired. Either way is no big deal, so why is this headline news?

I found it very difficult to read the Fitness to Practice annual report with any degree of impartiality. Between 1 April 2013 and 31 March 2014 2 069 new concerns were raised, an increase of twenty five per cent on the previous year. 0.64% of registrants found themselves to be on the receiving end of a complaint. That’s about one in two hundred; I find that a really high number.

Of personal interest I read that revised standards of proficiency for biomedical scientists and clinical scientists have been published.

There was a report of a meeting between HCPC staff and medical managers in Belfast that took place recently. Again I found myself too close to the subject matter; wondering exactly what was discussed when I read that “Participants at the event took part in discussions using real life FTP case studies”. I see that I can go to one of these meetings if I want to by registering at www.hcpc-uk.org/meethcpc - I’m tempted to sign up.

2 December 2014 (Tuesday) - Potassium

Here’s a little something that came up whilst working in clinical chemistry a few days ago. I found this set of results:

                             Specimen Results Entry

COBBLEPOT, Oswald                                A+       20/11/2014 u/k
MRS   23/11/1946 67 yrs  F  123456              
                  Mr Vladimir Freeze
Specimen No   :  AC619028V               Selected Auth Level : S
 NA     136    F000 |ALKP   98     F000 |                   |
 K      8.8    F000 |ALT    6      F000 |                   |
 KBIC   21     F008 |CRP    108    F000 |                   |
 U      13.7   F000 |HINT  ^0.1    F000 |                   |
 CR     131    F000 |IINT  ^6      F000 |                   |
 _GFR   35     F000C|LINT  ^-0.0   F000 |                   |
 PROT   35     F000 |                   |                   |
 ALB    11     F000 |                   |                   |
 GLOB   24     F000 |                   |                   |
 TBIL   8      F000 |                   |                   |
LTG comments : EC,GFR,LFT,RKOD

 1 Auth'd   2 Unauth'd   3 Nomin'd   4 Change   5 Reject  6 Options  7 eXit> U
 Disc: CLIN    Sect: CC            David Styles       SRE/APEX    Overtype

That potassium result is high; seriously high and most interestingly JNOT consistent with previous findings

COBBLEPOT, Oswald                                A+       20/11/2014 u/k
MRS   23/11/1946 67 yrs  F  123456              

  Date|20/11/2014 19/11/2014 18/11/2014 17/11/2014 15/11/2014 14/11/2014      |
  Time|u/k        u/k        16:50      u/k        u/k        01:30           |
  Spec|AC619028V  AC618219L  AC617116S  AC615563X  AC614400T  AC613165N       |
      |BIO        BIO        BIO        BIO        BIO        BIO             |
NA    |136        137        134        131        127        133             |
K     |8.8        3.9        4.5        4.9        4.8        5.0             |
KBIC  |21                                                                     |
U     |13.7                                                   15.4            |
CR    |131        153        139        141        133        135             |
_GFR  |35         30         33         33         35         34              |
PROT  |35                                                                     |
ALB   |11                                                     13              |
GLOB  |24                                                                     |
TBIL  |8                                                                      |
ALKP  |98                                                                     |
ALT   |6                                                                      |
  1 View   2 Graph   3 eXit  X
                            Cursor Down for more                       More >>

There’s something wrong here. That result’s not right. So a little detective work was in order.

The age of the sample was then checked. The sample was only an hour old.
The nature of the sample was checked. The sample was a SST; not EDTA. An EDTA sample would give a much higher potassium result, but it was something that needed checking.

Perhaps there was EDTA contamination, so calcium levels were analysed. Suspecting EDTA contamination we might expect a very low calcium result.
The result was 1.6... low, but not *THAT* low.

COBBLEPOT, Oswald                                A+       20/11/2014 u/k
MRS   23/11/1946 67 yrs  F  123456              
 Specimen No   :  AC619028V               Selected Auth Level : S
 NA     136    F000 |ALKP   98     F000 |                   |
 K      8.8    F000 |ALT    6      F000 |                   |
 KBIC   21     F008 |
CA     1.6    E000 |                   |
 U      13.7   F000 |$CORCA CALUNR E000 |                   |
 CR     131    F000 |CRP    108    F000 |                   |
 _GFR   35     F000C|HINT  ^0.1    F000 |                   |
 PROT   35     F000 |IINT  ^6      F000 |                   |
 ALB    11     F000 |LINT  ^-0.0   F000 |                   |
 GLOB   24     F000 |                   |                   |
 TBIL   8      F000 |                   |                   |
LTG comments : EC,GFR,LFT,RKOD

 1 Auth'd   2 Unauth'd   3 Nomin'd   4 Change   5 Reject  6 Options  7 eXit> U

For completeness the potassium assay was repeated on our other analyser.  The result was identical; a genuine result.

This was rather frustrating… the result was suspect. but EDTA contamination should have given a far higher potassium result and a far lower calcium result. Perhaps there was only a little EDTA contamination in this case?

A comment was added to the result:

Note raised potassium ? due to EDTA contamination. Please send repeat
sample for confirmation. Ward (staff nurse) telephoned.

A couple of days later I reviewed the case:

COBBLEPOT, Oswald                                A+       20/11/2014 u/k
MRS   23/11/1946 67 yrs  F  123456              

NA    |136       137        138        136        137        134
K     |H         4.3        H          8.8        3.9        4.5
KBIC  |                                21
U     |19.9      19.2       17.5       13.7
CR    |185       162        151        131        153        139
_GFR  |24        28         30         35         30         33
PROT  |44        43         45         35
ALB   |12        13         13         11
GLOB  |32        30         32         24
TBIL  |5         6          6          8
ALKP  |112       121        114        98
ALT   |11        9          7          6

Subsequent results were not consistent with that spurious result. I wonder what happened there.
But the bottom line here is that it’s not all about churning out numbers…. 

13 November 2014 (Thursday) - Dur !!!

Is this true?

….. The 44 percent of people who tested positive for the virus performed 7 to 9 points lower on IQ tests…..

Seems somewhat strange… I can’t think of any causative mechanism. But it’s food for thought. If true it makes you wonder what else viruses might do.

And perhaps you *can* fix stupidity…?

4 November 2014 (Tuesday) - Nasal Polypectomy

Nasal polyps are growths of abnormal tissue that form in the nose or deeper sinuses. They are usually benign, but larger polyps can block nasal passages causing breathing difficulty and sleep apnoea. It's quite amazing just how much sinus space one has, and how blocked they can become.   

If conservative treatment for nasal polyps is not successful or if polyps are problematical a consultant may recommend a nasal polypectomy. This is (usually) performed under general anaesthetic and takes about 30 minutes. The surgeon will access polyps through the nostrils so there will be no incision. Polyps will be removed using special suction and instruments.
After surgery the nose is packed with dressing to help control any bleeding.
Nasal polypectomy is usually done as a day case however sometimes an overnight stay is necessary.

There is a world of difference between reading these dull dry words and having one's sinuses surgically ravaged....

1 November 2014 (Saturday) - The Error Budget (?)

Food for thought...

When you set a financial budget, you know that if you spend too much in one place, you run over your budget. The analogy for lab tests is an ‘error budget.’ We know we have certain sources of error like precision and inaccuracy. How much of the budget gets spent by different error sources, and is it possible that we will overrun the budget if a problem occurs?”

Well, we have information on that, in the form of what quality is required for the test. If you define that in your budget, then you can measure the errors for your methods in the laboratory to be sure they fit within the budget. That should be an ongoing part of quality management: keeping track of how big these errors are and how they relate to the amount of error that is allowable.”
An interesting interview with one of the leading lights in the QC analysis world... http://www.captodayonline.com/lab-qc-much-room-improvement/

30 October 2014 (Thursday) - Myeloma Case Study

An interesting article with cross-discipline aspects to be considered. This case illustrates how very high immunoglobulin levels can ccause interferences in many test results including
  • the prozone effect
  • the volume displacement effect
  • precipitation interference.
We need to bear in mind potential sources of discrepant results in patients with high plasma protein concentrations and should take care to prevent the release of erroneous results.
It's not all about just churning out whatever number the analyser produces...

28 October 2014 (Tuesday) - Prednisolone

Prednisolone is a corticosteroid;  the active metabolite of the drug prednisone and it works by preventing or reducing inflammation. It is used to treat a number of conditions that are characterised by excessive inflammation.

Which is why I've been prescribed it to shrink my nasal polyps !

Prednisolone also suppresses the immune system and so can be used to treat autoimmune diseases. Prednisolone can help to prevent and to treat the rejection of transplanted organs. It can also be used in the treatment of certain types of cancers.
Long term treatment leaves patients prone to infections as their immune system can become weak. These infections may be much more severe than they usually would be and the symptoms that would usually be used to identify such infections can be hidden by the condition for which prednisolone has been prescribed.. For this reason people who take Prednisolone must be careful to avoid exposure to infections such as chickenpox and measles whenever possible. 

14 October 2014 (Tuesday) - NEQAS Participants Meeting

Today togethr with two huundred and sixty others I was sent to the 17th annual participant's meeting of NEQAS for general haematology. A day of lectures.... would like to coment on the introduction but I couldn't hear a word. For the rest of the sessions:


Health Education

This was a very inteeresting session in which a speaker froom Health Education England speculated on the future of healthcare; predicting a major move into preventative medicine. I did like the fact that (like me) the chap felt that poor press coverage was not helping NHS recruitment. The chap touched on how difficult it is to plan years in advance, and had one or two ideas.
Incredibly thoght-provoking.... but not really relevent to me...

Pathology Quality Review

I thought that with the word "pathology" in the title this might be interesting. But a droning speaker who could only talk in meaningless acronyms sent me to sleep.
I am told I didn't snore.


Hb Measurement

An interesting insight into the variation of Hb levels between men and women in venous and capilary samples. Apparently it's not just huumans in which this difference happens. I learrned about the Fahreus effect (!)

Cell Counting in Fluids

There would seem to be new guidelines on the matter from the ICSH. The bottom line was that if anyone is going to do anything with an analyser that the manufacturer hasn't specifically built it to do, one has to have evidence to back up the validity of what one is doing.
Rather obvious really..... it was a shame that wwhat could have been useful sent me to sleep.

Red cell Membranopathies

The red cell cytoskeleton (and its malfunctions) ha always been an interest of mine. But devoting so much valuable time to an obscure condition such as hereditary stomatocytosis seemed rather an odd thing to do. I nodded off again.


Devices and Trend Analysis

The MHRA are bringing in software to analyse error reporting as the MHRA fervently hope that the amount of people squealing and tittle-tattling gooes through the roof. Perhaps I am being flippant; there *is* a place for error reporting. But it's getting out of hand.
Having said that, this was one of the day's better talks and I stayed awake.

Automated Counting Update

There would seem to be changes afoot; NEQAS schemes for NRBC and ESR. And "traffic lights" for poor performances.
The speaker then touched on EQA analysis in his home laboratory. Much like what I do aready myself, but with more peope in his team he could do far more.

Haemoglobinopathy Update

Oh dear. This could have been so good, but the focus was on DNA techniques which are used by only nine labs in the country.
More snoring from me...

Mophology Update

Fascinating. A serious consideration of how one error in identification can send one down entirrely the wrong track. I found this especially relevent to me for reasons that anyone wo knows me would sympathise with.

Overall the day was a mixed one. All sessions were interesting, but (in all honesty) few were really relevent to my day-to-day duties. For all that I did find many of the topics thought-provoking, had I known in advance that it was going to be "all talk" rather than "hands-on-useful" I'm not sure I would have gone.

I might suggest that
  • Future events not focus on laboratory techniques used only by a tiny minority,
  • Speakers be more concise and less soporific
  • Whan asking for questions, the staff identify those delegates who only want to hear the sound of their own voces and sto handing the microophone to them

4 October 2014 (Saturday) - Bodies Beginning with "H"

There were Howell-Jolly bodies in the most recent EQA morphology survey. Apparently...

Howell-Jolly bodies are little fragments of the red cell nucleus. They are most commonly seen in patients with splenectomies purely because the spleen gets rid of them. They can be seen them without any special staining. They appear dark, round dots in the red cells.
Interestingly whilst Howell Jolly bodies were fresh in my mind I read this article on Facebook. (Facebook isn't all drivel - it's a useful source of CPD!!)


Because they both begin with the letter "H" there are those who get Howell-Jolly bodies confused with Heinz bodies. (Apparently). I found this odd - you can't see Heinz bodies without doing supravital staining. I'm old enough to remember Heinz bodies being an unwelcome complication of reticulocyte counting, but realistically who counts retics that way these days?

Heinz bodies are most commonly found in G6PD deficiency. They are denatured globin chains formed when the haemoglobin molecule undergoes oxidative attack. When this happens the haem molecules are recycled, but the globin chains adhere to the inside of the red cell membrane forming Heinz bodies. These are present in cases of G6PD deficiency, but cannot actually be seen without performing supravital staining.
It is worth bearing in mind that macrophages in the spleen chop Heinz bodies out of red cells forming the things traditionally called "bite cells", so on seeing bite cells it may well be worth considering performing a supravital stain.

Having said that I perform a G6PD assay (on a patient as opposed to an EQA sample) about once a year, and in thirty years I think I've only once seen a result which hinted at a deficiency, so Heinz bodies are firmly in the "obscure" category whereas Howell-Jolly bodies are seen on a weekly basis (if not more often).

24 September 2014 (Wednesday) - HLA B27 status determination

Human Leukocyte Antigen (HLA) B27 is a class I surface antigen encoded by the B locus in the major histocompatibility complex (MHC) on chromosome 6 and presents antigenic peptides (derived from self and non-self antigens) to T cells. According to Wikipedia (!)

Individuals with ankylosing spondylitis (AS), and other associated inflammatory diseases referred to as "spondyloarthropathies" are far more likely to have this antigen than not. In fact over 95% of sufferers have this antigen compared with a far lower incidence in the general population: about 8% of Caucasians, 4% of North Africans, 2-9% of Chinese, and 0.1-0.5% of persons of Japanese descent.
Hence the antigen is a useful marker when investigating the suspicion of ankylosing spondylitis

When testing for the presence or absence of the HLAB27 antigen two similar assays are run in parallel. In each instance two aliquots of patient (or control sample) are taken and mixed (in separate tubes) with an isotype control and with anti-HLA B27 and incubated.
A lysing agent is added, and after an incubation period the remaining white cells are washed twice with phosphate-buffered saline. It's important to spin gently; white cells are fragile things.

After the final wash the cells are re-suspended in phosphate-buffered saline and analysed on the flow cytometer. The isotype control (first tube) gives a zone on which to target the analyser for the second tube which will then exhibit positivity or negativity. And being performed in duplicate with differing antibodies gives little scope for error.
The result is positive or negative; because one either has or does not have the HLA B27 antigen. 

 Equivocal results are occassionally due to cross-reactivity from other antigens (HLA B7 is the most likely), but most commonly from a compromised sample. Repeating with a fresh sample will give a definitive result. 

I learned a new technique today...

22 September 2014 (Monday) - Cortisol Levels

When I was a lad cortisol samples were only tested if the sample was collected at 9am because of the diurnal variation of the hormone. These days they are tested on samples collected at any time *but* the time of the sample is a "must-have" because of the known and calculable diurnal variation of the hormone.
This made me think. What about shift workers? Is the hormone level related to activity, sleep patterns or to daylight?

I found this article about cortisol leels in astronauts.
It would seem that cortisol levels are related to light, not diurnal rhythms. Question answered.

18 September 2014 (Thursday) - Anti-Fy(a)

A group and save sample came in shortly before the day staff went home this evening. The diagnosis was "abdo pain" which is rather vague. The outcome could be anything from the patient going home following a good fart through to massive blood transfusions following extensive surgery for a myriad of reasons. Such samples shouldn't really wait around.
This one had a positive antibody screen. The antibody identification panel showed anti-Fy(a) by IAT technique and was negative by enzyme technique (as one might expect for anti-Fy(a))

This was a known antibody, there had been several previous encounters. therefore referral to a specialist centre wasn't necessary on this occasion.

Blood wasn't requested on this encounter; had it been required there shouldn't have been too much trouble providing it. With about a third of the population being Fy(a) negative and the patient being O Rh(D) Positive statistically we would expect to have about seven to ten suitable units in the blood bank.
Statistics notwithstanding I had a rummage in the blood bank just to be sure we could provide something in an emergency.
We could...

A couple of references are always good in a little case study: