65 year old man, admitted urgently with rapid atrial fibrillation. Serum
results were

Albumin:		35 g/L	(35 - 49)
Globulins:		34 g/L	(17 - 35)
Uric acid:		652 umol/L	(208 - 506)
Bilirubin:		10 umol/L	(3 - 22)
Alkaline phosphatase:	50 umol/L	(<126)
ALT:			24 IU/L	(<56)
Gamma-GT:		70 IU/L	(<78)
AST			20 IU/L	(<41)
CK:			115 IU/L	(elderly male, <170)
Urea, creatinine, and electrolytes were all within reference limits.

The same patient had visited his Family Doctor 3 months previously.
Clinical information then was 'alcoholism'. Serum results were similar
apart from
Uric acid:		360 umol/L
ALT:			126 IU/L
Gamma-GT:		460 IU/L

This Case attracted 24 participants.

2 would discuss this with the requesting Clinician; [0.6]
4 would not telephone; [0.8]
3 would make no comment. [0]

2 thought it possible that there had been a confusion over samples (same
patient?); [0.6]
3 advised a repeat on a fresh sample (1 prudently adding 'after
Christmas'). [0.8]

5 participants thought it likely that this was a reformed alcoholic; [0.8]
but 4 queried a recent 'binge'; [1.2]
and 2 thought the urate was related to alcohol use. [1.0]

3 thought the urate may be related to diet; [0.5]
4 queried the drug history; [0.8]
	3 mentioning thiazide diuretics. [0.8]

3 queried gout; [0.4]
2 queried malignancy; [0]
1 each queried
	alcoholic heart disease; [0.8]
	ischaemic heart disease; [0]
	multiple myeloma. [-0.8]

8 would check thyroid function tests; [0.3*]
3 would (re)check cardiac markers; [-0.8]
2 would suggest protein electrophoresis; [-0.4]
1 would check fasting lipids. [1.0]

This comparatively nondescript case is comparatively low-scoring; and there
was fundamental disagreement between the assessors on only one point -
checking thyroid function.

Ordinarily, I would not have bothered too much about this case, and
probably would not have commented at all. However, I happened to know this
patient, and was intrigued by the highly significant increase in urate.
Going to talk to him, it transpired that he had not been prescribed any
drugs. For three months he had been highly reformed, and had stayed at home
drinking between one and two litres of 'Diet Coke' each day rather than his
usual tipple. Diet Coke is of course a rich source of caffeine -
unfortunately there was insufficient blood to look at caffeine on his
admission sample, but 36 hours after admission, and on a caffeine free diet
while in hospital, his serum caffeine was around 4 mg/L. Taking an average
half life of 4 hours for caffeine, that put him well into the toxic
caffeine range on admission; and caffeine metabolites cross-react in our
urate assay. One effect of caffeine toxicity is of course rapid atrial
fibrillation. So although I can't be sure, I suspect that his remedy did
him almost as much harm as his original problem. I leave it to you to
decide whether this case has a suitable moral for Christmas.

Best wishes
Gordon Challand



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