When we added beta hCG to the repertoire of our ELECSYS some time back, we
noted that values with more than 5 digits were not transferred correctly
from the analyser to our Berkeley MasterLab system. Our standard operating
procedure therefore was that six digit results be entered manually.
Recently we had a specimen, assayed late in the afternoon, which gave an
hCG "greater than 10,000" The following day the specimen was re-assayed
on dilution and a value of greater than 100,000 was obtained. It was
rediluted and a final value of 180 056 was obtained.
On this occasion, the result was transferred through the LDS interface which
removed the final digit and a result of 18 005 was reported electronically
to Fountain (a file server system which may be interrogated by ward staff).
An hour later, the MLSO in charge of the section returned from lunch and
found this had occurred and the correct result was entered. Although no
written report had left the department, the duty clinical scientist
contacted a member of the medical staff in case the wrong result had been
accessed from Fountain. She was assured that this had not happened but was
told that an adverse clinical incident could have arisen if the wrong result
had been accessed and acted upon.
When we first became aware of this problem, we contacted the distributors of
both the analyser and the main frame computer and both investigated the
problem and stated it was not due to their equipment. Realising the
potential for a clinical incident, we have chased this up more thoroughly on
this occasion and have identified that the error arose within the LDS
interface. The engineer was called and it appears that there is a simple
"fix" which allows the transfer of up to 9 digit values and this has been
installed. According to the hazard note issued by Berkeley as a result of
this incident, "the potential for this size of result is normally checked at
installation time". However, at the time we installed the ELECSYS, we were
not assaying beta hCG. So, if you are using an LDS interface between your
analyser (any analyser) and lab information system and have added beta hCG
to your lists of assays (we can't think of any other assay which has such a
large number of digits), check your LDS can handle the results.
Elliott Simpson
Consultant Clinical Scientist
Clinical Director, Labs & Pharmacy
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
