Fasting Blood Fasting Blood Glucose(FBG) Glucose(FBG)

andand Glycosylated Hemoglobin Glycosylated Hemoglobin

(HbA1C)(HbA1C)Presented by :Presented by :

Geraldine CharlesGeraldine CharlesTracy HerringTracy Herring

Kara ThompsonKara Thompson

Case StudyCase Study

Patient M.V, 51 years old last seen 3 months Patient M.V, 51 years old last seen 3 months agoagoPMH: NIDDM, Hyperlipidemia, Gastritis, PMH: NIDDM, Hyperlipidemia, Gastritis, migrainesmigraines

SHX: Cholecystectomy 1991, Hysterectomy SHX: Cholecystectomy 1991, Hysterectomy 19891989FHX: mother- cervical Ca, father- DM, HTNFHX: mother- cervical Ca, father- DM, HTN

MedicationsMedications• Metformin 500mg BIDMetformin 500mg BID• Omeprazole 20mg dailyOmeprazole 20mg daily• Imitrex 100mg as needed for Imitrex 100mg as needed for

migrainesmigraines• Lisinopril 10 mg dailyLisinopril 10 mg daily

Vital SignsVital Signs

• Temp-98.1, HR- 68, RR-16, BP-132/84Temp-98.1, HR- 68, RR-16, BP-132/84• Wt-176 lbs( baseline 188lbs)Wt-176 lbs( baseline 188lbs)• HT- 5”2HT- 5”2• Allergies- NKDAAllergies- NKDA

Purpose of :Purpose of :

• FBG useful in diagnosing prediabetes FBG useful in diagnosing prediabetes and diabetesand diabetes

• HbA1C gives us an insight into mean HbA1C gives us an insight into mean plasma glucose concentration over 2-plasma glucose concentration over 2-3 months3 months

• Both tests are used to document Both tests are used to document degree of glycemic control at the time degree of glycemic control at the time of diagnosis and as part of continuing of diagnosis and as part of continuing carecare

Uses across the life spanUses across the life span• Test used for all agesTest used for all ages• Normal range of FBG across the age Normal range of FBG across the age

spectrumspectrum• Fasting adults- < or = 110mg/dlFasting adults- < or = 110mg/dl• Fasting children (2-18) – 60-100mg/dlFasting children (2-18) – 60-100mg/dl• Fasting young children ( Fasting young children (

0-2)-60-110mg/dl0-2)-60-110mg/dl• Fasting premature infants- 40-65mg/dlFasting premature infants- 40-65mg/dl

Uses in infantsUses in infants• Infants with tremor, convulsion or Infants with tremor, convulsion or

respiratory distress should have stat respiratory distress should have stat FBG especially with maternal diabetes FBG especially with maternal diabetes or with hemolytic disease of the or with hemolytic disease of the newbornnewborn

• Newborns that are too small or too Newborns that are too small or too large should have FBGlarge should have FBG

• Few diseases related to neonatal Few diseases related to neonatal hypoglycemiahypoglycemia

Screening GuidelinesScreening Guidelines• New NIH guidelines: diabetic testing for all New NIH guidelines: diabetic testing for all

adults 45 and older every 3 yearsadults 45 and older every 3 years• The ADA recommends the following guidelines:The ADA recommends the following guidelines:• Testing be considered for patients 45 and olderTesting be considered for patients 45 and older• Testing is strongly recommended if patients 45 Testing is strongly recommended if patients 45

and older and overweightand older and overweight• Testing should be considered if patient younger Testing should be considered if patient younger

than 45 and overweight with another risk factorthan 45 and overweight with another risk factor

Diagnosis of DiabetesDiagnosis of Diabetes• FBG of over 126mg/dl with classic FBG of over 126mg/dl with classic

symptoms of diabetes – symptoms of diabetes – polyuria,polydipsia,unexplained polyuria,polydipsia,unexplained weight lossweight loss

• Without symptoms these tests Without symptoms these tests should be repeated on a different should be repeated on a different dayday

FASTING BLOOD SUGAR AND HbA1c

• Explain to patient purpose of testExplain to patient purpose of test• Explain the blood drawing procedureExplain the blood drawing procedure• Explain to patient that he must have Explain to patient that he must have

nothing to eat or drink 8 – 12 hours nothing to eat or drink 8 – 12 hours prior to testprior to test

• If patient is diabetic , no insulin or If patient is diabetic , no insulin or oral hyperglycemic agent prior to testoral hyperglycemic agent prior to test

Fasting Blood Sugar-Patient Fasting Blood Sugar-Patient EducationEducation

External factors that can External factors that can cause increased glucosecause increased glucose• Certain drugs can cause elevated glucoseCertain drugs can cause elevated glucose• PregnancyPregnancy• Heavy smokingHeavy smoking• AlcoholAlcohol• IllnessIllness• Emotional stressEmotional stress• CaffeineCaffeine• Eating less than 8 hours priorsEating less than 8 hours priors

• Hematocrit greater than 55%Hematocrit greater than 55%• Intense exerciseIntense exercise• Certain drugs Certain drugs

External factors that can External factors that can decrease glucosedecrease glucose

HbA1CHbA1C• Your doctor may order this test if you have Your doctor may order this test if you have

diabetes. It is used to measure your blood diabetes. It is used to measure your blood sugar control over several months. In sugar control over several months. In general, the higher your HbA1c, the higher general, the higher your HbA1c, the higher the risk that you will develop problems the risk that you will develop problems such as eye disease, kidney disease, nerve such as eye disease, kidney disease, nerve damage, heart disease, and stroke. This is damage, heart disease, and stroke. This is especially true if your HbA1c remains high especially true if your HbA1c remains high for a long period of time.for a long period of time.

Patient education prior to Patient education prior to testtest• Explain the testExplain the test• No preparation is requiredNo preparation is required• Fasting not requiredFasting not required• Explain that this test is not meant for Explain that this test is not meant for

short term diabetes mellitus short term diabetes mellitus management instead it assesses the management instead it assesses the efficacy of long term management of efficacy of long term management of diabetesdiabetes

External External factorsfactors that effect the that effect the results-results-• AnemiaAnemia• Thalessemia- Hb H- falsely elevate Thalessemia- Hb H- falsely elevate

resultsresults• Sickle cell- Hb S- can falsely decrease Sickle cell- Hb S- can falsely decrease

resultsresults

For these patients the use of For these patients the use of fructosamine/40 = HbA1Cfructosamine/40 = HbA1C

THE GLUCOSE CONTINUUM

> OR= 126MG/DL

DIABETES

< 126MG/DL

PRE-DIABETES> OR = 110MG/DL

<110MG/DL

NORMAL

Lab ValuesLab Values• Normal Range:Normal Range:• FBG: 60-100 mg/dlFBG: 60-100 mg/dl• HbgA1C: < 6%HbgA1C: < 6%

• Low RangeLow Range• FBG: < 60 mg/dl (diagnosis of hypoglycemia)FBG: < 60 mg/dl (diagnosis of hypoglycemia)

• High RangeHigh Range: leads to diagnosis of DM: leads to diagnosis of DM• FBG: equal or > 126 mg/dlFBG: equal or > 126 mg/dl• HbgA1C: > or equal to 6%HbgA1C: > or equal to 6%

• HbgA1C FBGHbgA1C FBG• 6% = 135 mg/dl6% = 135 mg/dl• 7% = 170 mg/dl7% = 170 mg/dl• 8% = 205 mg/dl8% = 205 mg/dl• 9% = 240 mg/dl9% = 240 mg/dl• 10% = 275 mg/dl10% = 275 mg/dl• 11% = 310 mg/dl11% = 310 mg/dl• 12% = 345 mg/dl12% = 345 mg/dl

Chart comparing HbA1c vs Chart comparing HbA1c vs FBGFBG

Panic ValuesPanic Values• HypoglycemiaHypoglycemia• FBG<40mg/dl may cause brain damage in FBG<40mg/dl may cause brain damage in

women and childrenwomen and children• FBG<50mg/dl in menFBG<50mg/dl in men• What to do when in panic range?What to do when in panic range?• If person sufficiently conscious orange If person sufficiently conscious orange

juice, sugar containing candyjuice, sugar containing candy• In the acute care setting IV glucose In the acute care setting IV glucose • ( D50%)( D50%)

Panic ValuesPanic Values• HyperglycemiaHyperglycemia• FBG: > 350 mg/dl (diagnosis of DKA)FBG: > 350 mg/dl (diagnosis of DKA)• HbgA1C: > or equal to 11%HbgA1C: > or equal to 11%

What to do when in panic What to do when in panic range?range?• Goals:Goals:• 1) Get patient to medical facility1) Get patient to medical facility• 2) After confirming FBG level will want to2) After confirming FBG level will want to• A) Correct DehydrationA) Correct Dehydration• B) Normalize ElectrolytesB) Normalize Electrolytes• C) Correct AcidosisC) Correct Acidosis• 3) Done by:3) Done by:• - Administration of insulin: continuous low dose- Administration of insulin: continuous low dose• - 1-2 L normal saline or lactated ringer solution- 1-2 L normal saline or lactated ringer solution• - electrolyte balance: most often potassium supplement- electrolyte balance: most often potassium supplement• - Bicarbonate therapy for pH of 7.0 or below- Bicarbonate therapy for pH of 7.0 or below• 4) Following recovery Explore and Educate 4) Following recovery Explore and Educate

Follow up visitFollow up visit• Lab results-Lab results-• HbA1c- 10 HbA1c- 10 • FBG – 284FBG – 284• Recommendations-Recommendations-• Maximize medical therapy for DM Maximize medical therapy for DM

managementmanagement• Follow up FBG in 2 weeksFollow up FBG in 2 weeks• Repeat HbA1C in 6 weeks Repeat HbA1C in 6 weeks

Questions??????Questions??????

ReferencesReferences• American Diabetes Association (ADA). Retrieved American Diabetes Association (ADA). Retrieved

from from http://www.diabetes.org/about-diabetes.jsp

• Dunphy, L., Brown, J., Porter, B.. (2007). Primary Dunphy, L., Brown, J., Porter, B.. (2007). Primary Care – The Art & Science of Advanced Practice Care – The Art & Science of Advanced Practice Nursing. Philadelphia: Davis Company.Nursing. Philadelphia: Davis Company.

• Fischbach, F (2004). A manual of laboratory and Fischbach, F (2004). A manual of laboratory and diagnostic tests. Lippincott Williams and Wilkins. diagnostic tests. Lippincott Williams and Wilkins. ss

ReferencesReferences• Friesen, J (2003). Case Study: Symptoms in a

Diabetes Client: Type 1, Type 2, or Type 1.5? . Retrieved January 18, 2008, from Clinical Diabetes Web site: http://clinical.diabetesjournals.org/cgi/content/full/21/2/93

• Hurd, Robert (08/11/2006). Baylor Health Care System. Retrieved January 18, 2008, Web site: http://www.baylorhealth.com/healthinformation/2/19723.htm

• Uphold, C, & Graham, M (2003). Clinical Guidelines.Florida: Barmarrae Books.