4900 Exam II to Final Flashcards
Static tests
Measurement of a nutrient or its metabolite in the blood, urine, or body tissue. Nutrient level may not reflect nutrition status of individual, or weather the body as a whole is in excess or depletion.
Functional status
Measurement of a nutrients performance in the body, the failure of the physiologic processes that rely on that nutrient for optimal performance. May only reflect limited info on nutrition status.
Is urinalysis a goo point of care test
Yes, reliable, but could be more sensitive
How does urinalysis work?
Colorimetric reactions
What is the urinalysis point of care used to test for?
A general health screen for renal & metabolic disease. Can monitor disease - infections, kidney, liver, urinary tract. Check status of diabeties.
Normal urinary pH
4.5-8.0
normal urinary specific gravity
1.002-1.035
proteinuria
> 150 mg/24hrs, or 10mg/100 mL
glucosuria
> 50mg/dL
Ketones
anything more than trace indicates high fat oxidation
nitrates in urine
indicate bacterial infection
Microscopic evaluation of the urine
RBCs, WBCs, epithelial cells, casts, bacteria, yeast, crystals. Any of these on the urine are indicate disease.
What is the most common nutrient deficiency in the US?
Iron, and is the most common cause of anemia
What other nutrient deficiency can result in anemia?
B12 and folate.
Anemia
A hemoglobin level below the normal reference range for individuals of the same sex and age.
Stages of iron deficiency
Depleted stores. Early functional iron deficiency (without anemia). Iron deficiency anemia.
Indicators of depleted iron stores?
Serum ferritin concentration have decreses 400µg/dL, TIBC goes up.
Early functional iron deficiency (without anemia)
Transferrin saturation 70 µg/dL. Serum transferrin receptor >8.5mg/L. Adverse physiologic consequences can begin to occur.
Iron deficiency anemia
Hemoglobin concentration < 80 fL. Also, ↓ serum ferritin, transferrin saturation, hemoglobin & MCV, and increases erythrocyte protoporphyrin
Iron deficiency anemia is associated with what type of RBCs?
Microcytic. MCV < 80 fL
Is there a single test that is diagnostic for iron deficiency anemia?
No
Where is iron stored in the body
On hemosiderin in the bone marrow
Total body iron in men and women
Men = 3.6g (3-4). Women = 2.4g (2-3)
Ferritin
40-160 µg/L. Primary storage form of Fe in the body, is also an acute phase protein. Found in the blood and tissues. An early indicator of iron deficiency.
Ferritin as iron status indicator
Most sensitive test available for detecting iron deficiency. Decreases occur before anemia and RBC changes. No longer a good test once serum depletion occurs.
Transferrin
Normal = 200-400 mg/dL. Binds iron in plasma & transports to bone marrow, and areas using Fe. An indicator of protein status.
Serum iron
Is the amount of iron bound to transferrin. Level is a measure of the amount of iron bound to transferrin. Levels fall between depletion of tissue iron stores and anemia. Could be normal in people with early iron deficiency.
Normal serum iron for men, women, infants, child
Men 65-110µg/dL. Women 50-170 µg/dL. Infants 100-250µg/dL. Children 50-120µg/dL
total iron binding capacity
Measures the amount of iron capable of being bound to serum proteins & provides an estimate of serum transferrin. Is increased with depletion of iron stores.
Transferrin saturation %
A ration of TIBC to serum iron. The % of transferrin with bound iron. More sensitive measure of iron status than either TIBC, or serum iron.
Normal transferrin saturation % in males and females
Male 15-50%. Female 12-45%. NHANES < 16% = deficiency.
What is the best laboratory indicator of body iron stores?
Serum ferritin level, which drops substantially in people with iron deficiency.
Functional iron tests
Hemoglobin, hematocrit, Mean corpuscular hemoglobin, mean corpuscular V, MCHC, Iron deficiency, Iron deficiency anemia.
Hemoglobin (Hgb)
Iron-containing molecule found in RBCs. An indicator of late iron deficiency. Most widely used test for iron-deficiency anemia.
What is the most widely used test for iron deficiency anemia?
Hemoglobin (Hgb)
Normal ranges for Hgb in males, females, pregnancy,
Male 14-18 g/dL. Female 12-16 g/dL. Pregnant female > 11 g/dL.
Hgb for newborns, children
Newborn 14-24 g/dL. 2wk - 18yo 12-15.5 g/dL
Critical values for Hgb
< 5 or > 20 g/dL
What is the point of care device for Hgb
HemoCue.
Hematocrit (Hct)
aka packed cell V. The percentage of RBCs making up the entire V of whole blood. Decreased in late stage iron deficiency.
Normal Hct for men and women, pregnancy
Males 40-54%. Females 37-47%. Pregnancy >33%
Factors that may influence Hgb, & Hct
Altitude. Hemodilution/concentration. Dehydration.
What occurs in stage one iron deficiency
Serum ferritin levels decrease. No other effects
What occurs in stage II iron deficiency
Iron stores are depleted. ↓ transferrin saturation % <15%. ↑TIBC. ↑ Erythrocyte protoporphyrin. Hgb shows little decrease at this point, physiological effects begin to be felt. sTfR ↑, shows depletion before anemia occurs.
What occurs in stage III iron deficiency
Is iron-deficiency anemia - microcytic, hypo chromatic anemia. Serum ferritin, transferrin saturation, Hgb, & MCV are decreased. Erythrocyte protoporphyrin is increases >100µg/dL. Hgb is below normal <82
sTfR
is not affected by inflammation, or acute phase proteins. Regarded as a valuable tool in diagnosing iron deficiency and monitoring erythropoiesis.
Three forms of anemia
Microcytic = MCV < 80 fL & decreased Hgb. Macrocytic = MCV >100fL. Hypochromic = abnormally low Hgb, & MCHC < 27pg
Mean Corpuscular Volume (MCV)
The average V of RBCs. Indicates the size of RBCs.
Normal range of MCV
80-100 fL for both men and women.
Increased MCV indicates?
Macrocytosis - deficiency of folate, or B12. Chronic liver disease, chronic alcoholism, cytotoxic chemotherapy
Decreased MCV indicates?
Microcytosis - chronic iron deficiency, lead poisoning, Thalassemia, anemia of chronic diseases.
Mean Corpuscular Hemoglobin (MCH)
The amount of hemoglobin in RBCs.