Grandview Medical Center

The following is a listing of laboratory test that can have their results compromised by timing, chemicals, medications, or activity:

1. Glucose tolerance
   1. Testing lasts from 3 to 7 hours with strict and critical collection times
   2. Must have nothing by mouth during the testing period other than a small amount of water
   3. Discourage smoking

1. 24-hour urine collection
   1. Affected by telepaque (If collection cannot be accomplished before telepaque, 48 hours should pass before 24-hour collection

1. Ova and parasites, occult blood, and stool culture
   1. Affected by bowel prep
   2. Affected by the barium

1. Bone marrow studies
   1. Affected by blood transfusion or other blood building substances

1. Serum iron
   1. Affected by blood transfusion and other blood building substances

1. TICB
   1. Affected by blood transfusion and other blood building substances

1. B12
   1. Affected by blood transfusion and other blood building substances
   2. Wait 48 hours after B12 injection

1. Folate level
   1. Affected by blood transfusion and other blood building substances

1. TSH
   1. Affected by radioactive isotope.  Wait 7 days after radioactive isotope

1. Gastrin
   1. Affected by radioactive isotope.  Wait 7 days after radioactive isotope

1. βHCG
   1. Affected by radioactive isotope.  Wait 7 days after radioactive isotope

1. Digoxin
   1. Wait 24 hours after lung scan