Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: Brian Cesar on 08/09/2011 17:01:03
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Brian Cesar asked the Naked Scientists:
Hello Chris!
My daughter and I are big fans of the show (http://www.thenakedscientists.com/HTML/podcasts/). Thanks for helping me get her interested in science.
Anyway, I have a question. I am an emergency department nurse and have bit of a mystery. The sense of smell is an important tool we use during the rapid triage exam. I cannot seem to be able to recognise the characteristic smell of diabetic ketoacidosis. Many of my peers can tentatively diagnose this condition immediately on speaking with the patient, and they uniformly describe it as "fruity" or similar to acetone. For some reason I cannot smell it. I don't have problems with using my nose to detect for other common diagnostic issues such as various infections, identifying substance abuse, etc.
Is this genetic? I have heard of people with similar issues that can't smell certain specific things. Some kind of issue with the specific receptor for this chemical? I can smell acetone as a pure chemical in a bottle, just not on the breath of a patient.
Thanks again,
Brian Cesar
Atlanta, Georgia
What do you think?
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Acetone and Genes
Robert Matz, Professor-Medicine
Mont Sinai School of Medicine,Neww York,N.Y.
When I was but a callow youth-either in medical school or residency I was told[I have no reference ]that the ability to detect the odor of acetone on a patients breath was genetic.I don't knoww whether it is dominant or recessive.In my experience those who can detect it do so with no training and are able to do so repeatedly with ease.Those who can not detecct it never acquire the ability regardless of training.The important issue clinically is that a practitioner who is unable to detect this aroma should be awware and never in aclinical setting attempt to determine whether a diabetic with a high blood sugar is ketotic by smell alone.
http://www.bmj.com/content/321/7266/970.full/reply#bmj_el_10289
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... I can smell acetone as a pure chemical in a bottle, just not on the breath of a patient.
The breath smell is not pure acetone: there are other related chemicals present which you may not be able to smell while others can ...
ketone body, acetone body (a ketone that is an intermediate product of the breakdown of fats in the body; any of three compounds (acetoacetic acid, acetone, and/or beta-hydroxybutyric acid) found in excess in blood and urine of persons with metabolic disorders)
http://wordnetweb.princeton.edu/perl/webwn?s=ketone%20body
Some people cannot smell acetoacetic acid as such, but can recognise the acetone smell in the breath. If you are able to smell acetoacetic acid it is very distinctive, and not easily mistaken for anything else. The closest other smell resembling that of acetoacetic acid is very ripe apples, but not everyone finds that a useful description.
http://sun025.sun.ac.za/portal/page/portal/Health_Sciences/English/Departments/Biomedical_Sciences/MEDICAL_PHYSIOLOGY/Essays/Post-exercise%20ketosis