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Dear POCT colleagues Jan Still (21 June) quoted a paper in Am J Clin Path about a US study that found problems with interference in the pCO2 results (Jan's email repeated below). There was a response to the paper from Abbott explaining that the problem was caused by an interfering substance in a particular batch of syringes folowing a change in manufacturing process. It's in Am J Clin Pathol (2000) Nov114(5):821-3. (There's no abstract on Medline so I have summarised it.) The problem only occurred with whole blood but could be reproduced predictably when they investigated it in detail. Once identified it was resolved in collaboration with the syringe manufacturer. The letter does not state what the problem was, but I assume all users would be informed if there was a possibility of a recurrence with a different manufacturers. Ironically one potential advantage of i-Stat is that you don't have to use specific blood gas syringes. The problem was picked up at the time by some other US hospitals and solved by changing syringes. As it was a problem with the syringes it would not be detected by the electronic simulator. It's unfortunate that the interference did not show up with QC materials. No substitute for 'reality testing' by humans at the bedside, as always with POCT! Parallel sampling would have picked this up. A case for routine acceptance testing of syringes by POCT teams? Hope this helps Richard Taylor Hi Richard, Thanks for the information. The article is "The rise and fall of i-Stat" Am J Clin Path 114(1):128-38, Jul 2000 The article says that i-Stat was chosen as a cost saving exercise when they wished to close their ITU hot lab. Their use spiralled and costs were huge. The most worrying problem was clinically significant discrepant values for PCO2 which would have resulted in altered patient treatment.The errors were not noted with either QC or QA material or the electronic checks, but were evident with blood samples.As they could not identify a cause, and fearful of litigation or adverse patient event the whole system was scrapped. I also have a paper Clin Chem 47(11):2064-6,2001 Nov which refers to discrepant chloride values with samples with elevated ureas. Regards Jan