GLUCOSE TOLERANCE TESTING GESTATIONAL DIABETIC SCREEN (GDS2) GLUCOSE TOLERANCE (FOR DIABETESMELLITUS)- NON-PREGNANT ADULT/CHILDREN (Under 18 years old) (OGTT) GLUCOSE 2-HR POST-GLUCOSE LOAD (2HGPL)-SCREEN (NON-PREGNANT) GLUCOSE TOLERANCE (ORAL) FOR GESTATIONAL DIABETES (GTT-P) Please refer to the following pages to determine the correct patient preparation and specimen collection for the Glucose Tolerance Testing listed above.
GESTATIONAL DIABETIC SCREEN (GDS2) Principle: To identify patients with latent alteration of glucose tolerance during pregnancy (usually)performed between 24 and 28 weeks of gestation). This may influence the management of prenatal care in high-risk situations and may prevent fetal wastage. Specimen Container: One gray stopper (Sodium Fluoride/Potassium Oxalate) plasma tubes. Dietary Restrictions: Patients should consume normal diet with adequate carbohydrates for 3 days before test. Obtain Glucose solution from Pharmacy. 1. Give patient 50 g glucose solution orally. Chill before serving. Add approximately one (1) inch of crushed ice to the bottom of the cup. Note: No more than 10% of the total volume should be ice. The patient does not need to be fasting. 2. Exactly one (1) hour later, draw a blood specimen in a gray stopper 2.0 ml tube. Label with barcoded collection label. Record the date, time drawn, and phlebotomist s initials on label.. 3. Deliver specimen and requisition to Specimen Processing window. 4. Time stamp request upon delivery. If the one hour glucose level exceeds 130 mg/dl, the patient should be investigated by the Glucose Tolerance test for Gestational Diabetes.
GLUCOSE TOLERANCE (FOR DIABETES MELLITUS)- NON-PREGNANT ADULT/CHILDREN (Under 18 years old) (OGTT) PRINCIPLE: Evaluation of carbohydrate metabolism, especially in the diagnosis of diabetes mellitus. Recommended Glucose Tolerance test for the diagnosis of Diabetes Mellitus in non-pregnant patients. SPECIMEN CONTAINER: Two gray stopper (Sodium Fluoride/Potassium Oxalate) plasma tubes. 1. If possible, the patient should consume a regular mixed diet for three days in order to obtain a true response to the test. 2. Patient must be fasting for at least 8 hours overnight. 3. Water is permitted, but food or coffee is prohibited during test. 4. Patient should remain seated and not smoke during testing period. 1. If an inpatient the order must arrive one day in advance. The phlebotomy dispatcher should call Nursing to remind them to have the glucose ready for the next morning. 2. Draw a fasting blood sugar in a gray stopper (2.0 ml) tube. Label with barcoded collection label. If drawn by M.D., use addressograph label. Record the date, time drawn, and phlebotomist s initials on label. Write or attach "FASTING" label on tube. 3. Give patient (Adults) 75 g glucose solution orally. (Child (Under 18 years old) dosage = 1.75 g/kg of ideal body weight up to 75g). Chill before serving. Add approximately one (1) inch of crushed ice to the bottom of the cup. Note: No more than 10% of the total volume should be ice. (300 ml maximum). Entire dosage should be taken within five minutes. Record the time of drink. 4. Exactly two (2) hours later, draw a second blood specimen in a gray stopper (2.0 ml) tube. Label with barcoded collection label. Record the date, time drawn, and phlebotomist s initials on label. Write or attach "2 hr." label on tube. 5. Deliver specimen and requisition to Specimen Processing window. Time stamp request upon delivery. NOTE: To test specifically for post-prandial hypoglycemia, samples at 3, 4, and 5 hours are acceptable.
REFERENCES: A. Criteria for the diagnosis of Diabetes Mellitus with oral glucose tolerance test (American Diabetic Association, 2007) Symptoms of diabetes plus random glucose (sample drawn any time of the day without regard to time since last meal) concentration 200 mg/dl A fasting glucose concentration of 126 mg/dl on more than one occasion. If the fasting glucose meets this criteria, the oral glucose test is not necessary. The 2-hour post load glucose (administration of 75g of oral glucose) concentration of 200 mg/dl. B. Criteria for impaired glucose tolerance Fasting glucose concentration of 100-125 mg/dl The 2-hour post glucose (administration of 75g oral glucose) concentration of 140-199 mg/dl Diagnosis and Classification of Diabetic Mellitus. Diabetic Care, Vol 30, Supplement, 2007.
GLUCOSE 2-HR POST-GLUCOSE LOAD (2HGPL)-SCREEN (NON-PREGNANT) PRINCIPLE: Evaluation of carbohydrate metabolism, especially in the diagnosis of diabetes mellitus. SPECIMEN CONTAINER: One (4.5 ml) light green stopper plasma separator tube (Lithium Heparin). 1. Patient should consume a normal diet with adequate carbohydrates (at least 150 g carbohydrates daily) for 3 days before the test. 2. Patient may not eat, smoke, or drink coffee during the test. The patient may consume water. 1. Give patient glucose solution orally. Chill before serving. If desired, solution can be offered with ice as long as volume of ice is less than 10% of glucose solution. Entire dose should be consumed within 5 minutes. Begin timing when patient begins to drink glucose solution. Recommended Dosage: Adults: 75 g Children: 1.75 g/kg ideal body weight (up to 75 g) 2. Draw blood specimen 120 min.(2 hr.) after administration of glucose solution. LABEL the specimen with computer or Addressograph label. Record date, time drawn and initials phlebotomist s initials on label. Write or attach "2 hr." label on tube on label. 3. Centrifuge the specimen to avoid glucose utilization by the blood cells. (Outpatient Specimens) 4. Deliver specimen and requisition to Specimen Processing window. Time stamp request upon delivery. Normal Impaired Glucose Metabolism Provisional Diagnosis of Diabetes 2-Hour Post- Glucose Load < 140 mg/dl 140-199 mg/dl 200 mg/dl REFERENCE: Diagnosis and Classification of Diabetic Mellitus. Diabetic Care, Vol 30, Supplement, 2007.
GLUCOSE TOLERANCE (ORAL) FOR GESTATIONAL DIABETES (GTT-P) PRINCIPLE: Evaluation of carbohydrate metabolism, especially in the diagnosis of gestational diabetes. SPECIMEN CONTAINER: Four (4) gray stopper (Sodium Fluoride/Potassium Oxalate) plasma tubes. 1. If possible, the test should be done after the patient has been on a regular mixed diet for three days in order to obtain a true response to the test. 2. Patient must be fasting 12-14 hours overnight. 3. Water is permitted, but food or coffee is prohibited during the test. 4. Patient should remain seated and not smoke during the testing period. 1. If an inpatient the order must arrive one day in advance. The phlebotomy dispatcher should call Nursing to remind them to have the glucose ready for the next morning. 2. Draw a fasting blood sugar in a gray stopper (2.0 ml) tube. 3. Label with barcode collection label. If drawn by M.D., use addressograph label. Record the date, time drawn, and phlebotomist s initials on label. Write or attach "FASTING" label on tube. 4. Give patient (Adults) 100 g glucose solution orally. (Adults) Chill before serving. 5. Add approximately one (1) inch of crushed ice to the bottom of the cup. Note: No more than 10% of the total volume should be ice. (300 ml maximum). 6. Entire dosage should be taken within five minutes. Record the time of drink. 7. Draw three (3) blood specimens (one hour apart) at 60, 120, 180 minutes (1 hr., 2 hrs., 3 hrs.) after beginning of the drink. 8. Label each tube collected with the barcoded collection label. Record the date, time drawn, and phlebotomist s initials on label. Write or attach a label indicating "1-hr.," "2-hr.," or "3-hr." specimen. 9. Deliver specimen and requisition to Specimen Processing window. 10. Time stamp request upon delivery For gestational diabetes -- two or more of the following values after a 100g oral glucose challenge must be met or exceeded. Fasting 95 mg/dl 1-hr. 180 mg/dl 2-hr. 155 mg/dl 3-hr. 140 mg/dl If results are normal in a clinically suspect situation, repeat during the third trimester. REFERENCES: Diagnosis and Classification of Diabetic Mellitus. Diabetic Care, Vol 30, Supplement, 2007.
GLUCOSE 2-HR POST-GLUCOSE LOAD (2HGPL)-SCREEN (NON-PREGNANT) PRINCIPLE: Evaluation of carbohydrate metabolism, especially in the diagnosis of diabetes mellitus. SPECIMEN CONTAINER: One (4.5 ml) light green stopper plasma separator tube (Lithium Heparin). 1. Patient should consume a normal diet with adequate carbohydrates (at least 150 g carbohydrates daily) for 3 days before the test. 2. Patient may not eat, smoke, or drink coffee during the test. The patient may consume water. 1. Give patient glucose solution orally. Chill before serving. If desired, solution can be offered with ice as long as volume of ice is less than 10% of glucose solution. Entire dose should be consumed within 5 minutes. Begin timing when patient begins to drink glucose solution. Recommended Dosage: Adults: 75 g Children: 1.75 g/kg ideal body weight (up to 75 g) 2. Draw blood specimen 120 min.(2 hr.) after administration of glucose solution. LABEL the specimen with computer or Addressograph label. Record date, time drawn and initials phlebotomist s initials on label. Write or attach "2 hr." label on tube on label. 3. Centrifuge the specimen to avoid glucose utilization by the blood cells. (Outpatient Specimens) 4. Deliver specimen and requisition to Specimen Processing window. Time stamp request upon delivery. Normal Impaired Glucose Metabolism Provisional Diagnosis of Diabetes 2-Hour Post- Glucose Load < 140 mg/dl 140-199 mg/dl 200 mg/dl REFERENCE: Diagnosis and Classification of Diabetic Mellitus. Diabetic Care, Vol 30, Supplement, 2007.
GLUCOSE TOLERANCE (ORAL) FOR GESTATIONAL DIABETES (GTT-P) PRINCIPLE: Evaluation of carbohydrate metabolism, especially in the diagnosis of gestational diabetes. SPECIMEN CONTAINER: Four (4) gray stopper (Sodium Fluoride/Potassium Oxalate) plasma tubes. 1. If possible, the test should be done after the patient has been on a regular mixed diet for three days in order to obtain a true response to the test. 2. Patient must be fasting 12-14 hours overnight. 3. Water is permitted, but food or coffee is prohibited during the test. 4. Patient should remain seated and not smoke during the testing period. 1. If an inpatient, the order must arrive one day in advance. The phlebotomy dispatcher should call Nursing to remind them to have the glucose ready for the next morning. 2. Draw a fasting blood sugar in a gray stopper (2.0 ml) tube. 3. Label with barcoded collection label. If drawn by M.D., use addressograph label. Record the date, time drawn, and phlebotomist s initials on label. Write or attach "FASTING" label on tube. 4. Give patient (Adults) 100 g glucose solution orally. (Adults) Chill before serving. 5. Add approximately one (1) inch of crushed ice to the bottom of the cup. Note: No more than 10% of the total volume should be ice. (300 ml maximum). 6. Entire dosage should be taken within five minutes. Record the time of drink. 7. Draw three (3) blood specimens (one hour apart) at 60, 120, 180 minutes (1 hr., 2 hrs., 3hrs.) after beginning of the drink. Label each tube collected with the barcoded collection label. Record the date, time drawn, and phlebotomist s initials on label. Write or attach a label indicating "1-hr.," "2-hr.," or "3-hr." specimen. 8. Deliver specimen and requisition to Specimen Processing window. 9. Time stamp request upon delivery For gestational diabetes -- two or more of the following values after a 100g oral glucose challenge must be met or exceeded. Fasting 95 mg/dl 1-hr. 180 mg/dl 2-hr. 155 mg/dl 3-hr. 140 mg/dl If results are normal in a clinically suspect situation, repeat during the third trimester. REFERENCES: Diagnosis and Classification of Diabetic Mellitus. Diabetic Care, Vol 30, Supplement, 2007.