This is an interesting discussion. We had a slightly different need for the
tympanic thermometers in EMS and found a slightly different problem. It is
not uncommon on EMS units for portions of the ambulance to exceed 106 deg F
and in so doing destroy "standard" thermometers. Small handheld electronic
ones seemed to be an ideal solution but you never seemed to know the
accuracy of the device. Along came the tympanic thermometers with their
ASTM "labeling" and storage and operations temperature ranges that matched
the EMS unit.
We noticed a few anecdotal problems though with repeatability and ran a
little test. We had a single "patient" for all "tests". A group of about 5
of us took turns taking the patients' temp in both ears. We noticed as much
as a degree of difference between individuals and a similar amount between
ears for the same person. We also had one person take the "same" temp
several times over a few minutes. Yet again we had almost a degree of
difference. Suddenly, we felt not like a man with two watches but instead
as though we were in a clock store. We had no clue what the actual
temperature was. We could not come up with any reason why the repeated
readings would actually cause a membrane temperature change. This procedure
appears to be VERY operator sensitive because of the need to get a straight
shot down the ear canal at the tympanic membrane. A buildup of wax can also
impede the view the IR sensor has of the membrane.
Now how critical is it for us to know the temperature. Really, in EMS we
probably just need to know "way above normal", "slightly above normal",
about normal" and "below normal". The tympanic unit gave us this but was
an awfully expensive way to go. Clearly the needs of an ED are different.
I would encourage anyone using these to let have their staff try this same
little test for themselves so that they can learn the best positioning
techniques. I think far too often folks just place the speculum in the ear
and press the button without a thought as to whether the sensor can actually
see the membrane.
$0.02 from a Biomedical Engineer who happens to also be a Paramedic.
Chris Counts, MEE, LP
For more information, send mail to [log in to unmask] with the message: info PED-EM-L
The URL for the PED-EM-L Web Page is: