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    Nancy Klobassa Davidson, R.N., and Peggy Moreland, R.N.

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  • Living with diabetes blog

  • June 15, 2012

    Testing blood sugar: First or second drop?

    By Nancy Klobassa Davidson, R.N., and Peggy Moreland, R.N.

15 comments posted

Controlling Your Diabetes

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When testing your blood sugar, do you use the first drop of blood or the second?

We teach patients to wash their hands with soap and water, dry them, and then test their blood glucose using the first drop. We advise that if the person isn't able to wash his or her hands with soap and water, then the second drop may be used. However, I've heard some patients tell me that they were instructed to use the second drop of blood, even after washing hands with soap and water.

Monitoring your blood sugar is essential to managing diabetes and helps you to make decisions related to diet, exercise and medication. So, what is the "right way" to test your blood glucose?

A February 2011 article in the American Diabetes Association's journal, "Diabetes Care," details a study that investigated whether capillary glucose concentrations, as measured in the first and second drops of blood, differed by 10 percent or more compared with a control capillary glucose concentration in the following situations:

  • Without washing hands
  • After handling fruit
  • After washing the fruit-exposed fingers
  • During the application of different amounts of external pressure around the finger (squeezing).

The conclusion of this study, which included 123 participants, is: "The first drop of blood can be used for self-monitored glucose testing, but only after washing hands. If washing hands is not possible and they are not visibly soiled or exposed to a sugar-containing product, it is acceptable to use the second drop of blood after wiping away the first drop." The study also found that external pressure (or squeezing) of the finger can lead to unreliable readings, as well.

You can find the article at: http://care.diabetesjournals.org/content/early/2011/02/01/dc10-1694

All in all an interesting study. What are your thoughts?

Peggy

15 comments posted

blog index

  • October 31, 2012 10:32 a.m.

    Insulin pens: Yes, they do require priming. Dialing up 1 or 2 units and then pushing on the plunger until a drop of insulin appears helps get rid of air bubbles and gives a more accurate dose. Point the needle upwards and tap the pen to force bubble to the top before priming. To prevent air from entering the pen, do not leave the needle on the pen between injections. I will try to do an article on DPP inhibitors in the future. Thanks for sharing.

    - Nancy and Peggy

  • October 29, 2012 1:16 p.m.

    Interesting article -- thanks! Have never heard of this b-4. Also, heard for the 1st time this week that I should be "wasting" the 1st 2 units of Novolog b-4 I inject my dosse? Have never heard of this. Is this correct? If so, what is the rationale? Also, please do a column on Victoza and the other new diabetes drugs. Thank you.

    - Linda A

  • October 14, 2012 5:41 a.m.

    Yes new to this, I tested yesterday .5 hr after eating it was 219, hr after that 356, hr after that 256,hr later 241, this morning tested it was 257. When should i test and how often? I am reporting the results to my VA doctor monday but would like advice I believe that I have become a diabetic, and would like to hear from ppl with it if you dont mind.

    - shane

  • July 5, 2012 2:21 p.m.

    I have just started looking at 1st, 2nd drop readings. The other day after excercise I did 3 successive readings starting with the 1st drop. The numbers were 39, 62, 73 within seconds of each other. I chalked it up to the possibility of the liver's work to kick in some glucose?

    - Shar

  • July 3, 2012 5:23 p.m.

    What is excessive squeezing? I use one lancet a day (3-4 tests), and I normally prick and give one slight squeeze on most fingers. Since I am right handed, I use a deeper setting on that hand to get through the thicker, tougher skin.

    - Thomas

  • June 28, 2012 6:30 p.m.

    I never heard anything about "First or Second Drop". Very interesting. I usually use alcholol pads prior to using the needle. I am going to try it as mentioned to check the difference. Interesting article.

    - Naomi

  • June 27, 2012 7:49 p.m.

    Getting a drop of blood without excessive squeezing is important because the squeezing can cause tissue interstitial fluids to be expressed diluting the droplet of blood. I use a new lancet every time I test and most times I get a drop of blood sufficient for testing without squeezing....except when my fingers are cold.

    - Florian

  • June 27, 2012 3:51 p.m.

    I don't get the squeeze comment. If I don't squeeze, I don't get a drop of blood. Does that mean my reading for the past 5 years are all incorrect?

    - Tom

  • June 27, 2012 3:12 p.m.

    Well, without any dairy and meat you would be a vegetarian. Lots of healthy people are vegetarians but that doesn't mean it's a cure for diabetes. And who are "they" that are trying to keep this a secret and what would they have to gain by doing such a thing. There's no conspiracy going on here. The Mayo Clinic website even has the suggestion that eating more fruit, vegetables, and grains will benefit those with diabetes.

    - Cindy

  • June 27, 2012 1:49 p.m.

    I hate to be in a location where I can't wash my hands with soap and warm water. I test so much and it makes it easier and just feel clean. I use the first drop but am home most of the time.

    - Linda

  • June 27, 2012 1:07 p.m.

    Truthfully, I will wash my hands if I've been working with food or lotion, etc., but I go with the first drop. If I don't like the answer ;) I'll wash with soap and make sure all soap residue is rinsed off. I'm usually in a hurry.

    - Carol

  • June 27, 2012 10:01 a.m.

    What is the answer to Jason who claims Type 11 can be cured by not eating dairy or meat? I have never heard such a thing and there are lots of stuff like that going around. If that were true wouldn't the doctors know about it and how healthy can a diet be by leaving out those foods?

    - Ferne

  • June 26, 2012 4:20 p.m.

    Wesley: Good question. Actually, soap and water are all you need to prevent infection. Alcohol can cause skin dryness and skin breakdown, especially for those who need to test often. Also, if you don't let the alcohol completely dry, the blood glucose test can sting. Alcohol may react to the chemical in the test strip and cause a false blood glucose reading which is why we "waste" the first blood glucose drop when we do a fingerstick blood glucose test in the lab.

    - Nancy and Peggy

  • June 23, 2012 3:14 a.m.

    Why not swipe with alcohol on gauze as in lab. phleb.?

    - Wesley

  • June 20, 2012 5:31 p.m.

    Cure type II Diabetes by simply eliminating DAIRY and MEAT for 6 - 8 weeks! They don't want you to know! God Bless!

    - Jason

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