Hi, i don't know where the best place to post this so i thought i would try here:
i was wondering if anyone could help me on some work i have spent the last 24hours trying to find the answer to.

This patient's pattern of results is commonly seen in the lab and are not clinically relevant but have arisen from a number of pre-analytical factors.
What pre-analytical factors could have caused these results with respect to the analytes affected?

Patient 7 also has an IV line, explain the pattern of results:
Analyte Result Ref Range Units
Sodium 119 135 – 145 mmol/L
Potassium 1.8 3.5 – 5.0 mmol/L
Alkaline Phosphatase 70 95 – 320 IU/L
Calcium 1.75 2.12 – 2.62 mmol/L
Magnesium 0.45 0.75 – 1.05 mmol/L
Albumin 20 35 - 50 g/L
Glucose 3.5 3.0 – 5.5 mmol/L

There was another patient, (6) which had the same abnormal results, however his sodium levels were normal and his glucose levels low so i suggested that this patient's sample was taken too close to the IV line which diluted all the analytes except sodium because sodium is present in saline solution. So i can only assume that it is not the case for patient 7, all the work i have looked at appears to be contradictory and i am really struggling.

I initially thought it may have something to do with heparin?

Can anyone shed any light on this? i would be so greatful

Warm regards
Sheila x

It's hard to say, the results seem to indicate a dilution of the sample but without extra information over what happened in the pre-analytical traject that's it.
You could look into the IV-composition, the tube used to collect the patient's sample perhaps a tube tube with liquid heparin and a too smal sample volume.
If I see this kind of result, I would strongly advise to get a new sample and look into the training of the staff.

Let's try of an IV can do the trick.
NaCl or KCL not likely because both Na and K are low
Glucose IV also not likely because level is normal and you would expect a much higher level
Intralid could do the trick but because of none of the parameters shows a sign of interference it should be ruled out.
If the sample was collected in a (not suitable for serum) container with a heparin-solution it could cause this if to little blood was collected for the container.

It is guessing and not very reliable

You should compare these with (1) the patient's clinical picture and (2) previous results for the patient ("delta" check).

In this case, all the values are lower than reference, you suspect dilution due to the IV. Your actions should include liaison with lab staff who performed the analysis : check for short sample, bubbles and correct tube (this needs to be a gel tube). A fluoride tube could have been used for the glucose. Fluoride inhibits glucose metabolism to lactate. That said, since your patient has an IV they are more likely to be an in-patient. A gel tube will suffice here since analysis will be achieved within four hours which most clinical labs accept as the cut-off.

I think these values are clinically significant, though they may well be erroneous. A sodium of 119mmol/l could be Addisons (insufficient cortisol and aldosterone. Aldo acts to retain Na but lose K). A stressed patient with insufficient cortisol would require hydrocortisone cover as a matter of urgency. The low sodium could be due to renal disease, hypothyroidism or SIADH. Similar arguments could be raised for hypomagnesium. The low albumin could be due to chronic hepatic condition. This would also pull down the calcium (you could do a corrected calcium calculation). The lab should have performed a repeat analysis on this sample to rule out a bubble but do check.

Thus far you patient MAY have multi-organ fail. But, you rightly have no confidence in the results. Having checked with the lab staff, you need to liaise with the ward staff about the siting of the IV and the sample collection details. If the IV is saline (150mmol/L NaCl), you should be concerned about the patient's low sodium. This may be a true value. We would prefer sampling from a limb with no IV but it may be that collection WELL BELOW a VEIN with a drip would be unaffected. Whatever was going into the vein (i.e above the sample site) would have to go through systemic circulation and the heart before arriving at the collection site.

The common IVs are saline (expect a RAISED sodium but normal glucose). Dextrose (expect a normal sodium but RAISED glucose). Blood (expect raised values rather than low). Colloids (may well be the culprit in this case. Expect DECREASED values due to the protein exclusion effect).

Come what may, request a repeat sample.

Hope that helps.