Operation Manual

41
While at the lab:
• Make sure that the meter test and the lab test are
performed within 15 minutes of each other.
• Wash your hands before obtaining a blood sample.
• Use only fresh capillary blood.
You may still have a variation between the results because
blood glucose levels can change significantly over short
periods, especially if you have recently eaten, exercised, taken
medication, or experienced stress.
1
In addition, if you have
eaten recently, the blood glucose level from a fingerstick can
be up to 70 mg/dL higher than blood drawn from a vein
(venous sample) used for a lab test.
2
Therefore, it is best to
fast for eight hours before doing comparison tests. Factors
such as the amount of red blood cells in the blood (a high or
low hematocrit) or the loss of body fluid (severe dehydration)
may also cause a meter result to be different from a laboratory
result.
References
1. Surwit, R.S., and Feinglos, M.N.: Diabetes Forecast (1988), April,
49–51.
2. Sacks, D.B.: “Carbohydrates.” Burtis, C.A., and Ashwood, E.R. (ed.),
Tietz Textbook of Clinical Chemistry. Philadelphia: W.B. Saunders
Company (1994), 959.