Dear Dr. Donohue — I have diabetes and have my
blood sugar tested quarterly. I had been in the habit of testing my
blood with a device provided to me by my doctor. I detected a
difference in the reading I got and the one the lab got. I called
and was told that the home device was accurate within 20 percent of
the lab reading. I consider that to be similar to Amtrak claiming
it is on time 100 percent because it considers anything within 12
hours of the posted time to be on time. I have not used the meter
since then. — J.R.
Answer — Glucometers, small devices that
provide an instant reading of blood sugar so that patients can
monitor what their level is at home, have been a godsend for
diabetics. They’ve been in use for 30 years or more. Diabetics have
used them to make changes in their diet and dose of medication.
The Food and Drug Administration requires that all glucometers
give a reading that is, at maximum, within 20 percent of lab
reading. That doesn’t mean that every reading is going to be off by
20 percent. Most readings are at only a slight variance from the
lab reading, if at any variance. The results are accurate enough to
make good decisions on adjusting the dose of medicine and modifying
If you want to check the validity of your meter, you can test it
using control solutions, liquids with a known glucose (sugar)
content. The manufacturers of meters provide control solutions that
can be bought. You might find them in retail establishments that
sell such meters.
Dear Dr. Donohue — You discussed the importance
of getting immediate attention for a person suspected of having a
stroke. I have some questions.
In addition to calling 911, should a suspected stroke victim be
given aspirin? You say 80 percent of strokes are due to clots, so
aspirin seems appropriate. Do emergency response units give
clot-dissolving drugs, or are they not given until the patient
arrives at the emergency room? — R.H.
Answer — Most strokes are ischemic strokes —
strokes due to obstruction of blood because of a clot in a brain
artery. Twenty percent, however, are due to bleeding in the brain.
It’s difficult to differentiate which kind of stroke a person has
without a brain scan. Giving aspirin to a person who has had a
brain bleed would almost seal the person’s death. Clot-busting
drugs are given in the ER. They don’t prevent the clot from growing
bigger, as aspirin does. They actually dissolve the clot. That’s
why it is so urgent to get a person to the ER as soon as possible.
There’s about a three-hour window for saving brain tissue with
those clot-dissolving drugs.
Write Dr. Donohue at P.O. Box 536475, Orlando, Fla.