Lecture 6 Hematology, Liver, & GI Laboratory Values Flashcards
(19 cards)
Complete Blood Count (CBC)
provides info on number of each type of blood cell ⇒ platelet count, RBC count, WBC count - this with a differential will also report the different types of WBCs
provides info on RBC morphology (also called RBC indices) - hemoglobin (Hgb), hematocrit (Hct) or packed cell volume (PCV)
When doing a CBC what levels of RBCs are looked at, what different readings are there?
looks at 1. RBC count: reports number of RBCs in cubic mm of whole blood - Ref Range: 4.3-6 x 10^12 cells/L (males) and 3.8-5.2 x 10^12 cells/L (females)
- Hemoglobin (Hgb): reports amount of Hgb/L of whole blood, provides rough estimate of O2 carrying capacity of blood, Ref Range: 135-175 g/L (males) and 120-160 g/L (females)
- Hematocrit (Hct): reports volume of RBCs in whole blood expressed as %, Ref Range: 40-52% (males) and 36-48% (females)
What are RBC indices and what is looked at for them in CBCs?
provides info on size and Hgb content of RBCs, helps classify type of anemia, are calculated from RBC count, Hct, and Hgb
- Mean Corpuscular Volume (MCV): average size of RBCs and classified as normocytic, microcytic, or macrocytic, MCV = Hct/RBC count, Ref Range: 80-100 femtolitres (fL)
- Mean Corpuscular Hemoglobin (MCH): avg weight (or amount) of Hgb in a RBC, MCH = Hgb/RBC count, Ref Range: 28-34 pg/cell
- Mean Corpuscular Hemoglobin Concentration (MCHC): avg conc of Hgb per volume of RBCs, a low one indicates hypochromia, MCHC = Hgb/Hct, Ref Range: 310-360 g/L
- Red cell distribution width (RDW): is a measure of cell size distribution, Ref Range: <16%
What is a ferritin lab test used for, ref range?
this is a stored iron protein complex
it provides a direct measure of how much iron
s stored in the body,, Ref Range: 30-500 micrograms/L (males) and 20-300 micrograms/L (females)
iron deficiency produces a microcytic hypochromic anemia
What is a Vit B12 lab test used for, ref range?
absorbed from GI from meats, eggs, dairy (vegan diet requires supplementation)
low stomach acid (ex. from chronic PPI or antacid use) will increase risk of deficiency, metformin may be linked to deficiency, deficiency produces macrocytic normochromic anemia
Ref range: >160 pmol/L
What is a folic acid lab test used for, ref range?
absorbed from GI from leafy green vegetables
involved in maturation of RBCs, can accompany Vit B12 deficiency
Ref Range: >10 nmol/L
What is a reticulocyte lab test used for?
these are immature RBCs, the count reflects the erythropoietic activity of bone marrow and therefore useful for diagnosis of anemia and monitoring response to med therapy
What is an erythrocyte sedimentation rate (ESR)/Westergren test used for?
measures the rate that erythrocytes (RBCs) fall in a sample of blood placed in a tall, thin vertical tube ⇒ usually process is very slow
What is a C-Reactive Protein test?
it replaces ESR/Westergren test
if 40-100 mg/L - moderate inflammation = viral or bacterial infection
> 100 mg/L - marked inflammation = severe bacterial infection, vasculitis, severe arthritis
What are granular WBCs?
contain granules that are visible in the cytoplasm and have segmented or lobular nuclei
Neutrophils - segmented ones will phagocytose foreign bodies and release proteins and other stuff from granules to destroy, banded ones are immature cells that are present in small numbers and the proportion increases when body has infection
Eosinophils - respond to areas of inflammation, allergic response and parasitic disease, granules in these have histamine
Basophils - can develop into mast cells and have granules with heparin (prevents clotting), histamines, and proteolytic enzymes
What are Agranular WBCs?
Monocytes - mature into macrophages that will migrate into tissue, remove foreign stuff, destroy and clean up old cells and proteins, salvage iron from RBCs and return it to transferrin and develop into foam cells when it is clearing lipid from blood vessel wall
Lymphocytes - T and B cells
What are the categories of liver tests?
A. Liver Fxn - measures ability to synthesize proteins and other stuff, includes albumin, clotting factors
B. Liver Injury - includes aminotransferase (AST and ALT)
C. Identify cholestasis (abnormal flow of bile) - includes alkaline phosphatase, gamma-glutamyl transpeptidase (or transferase) (GGT)
D. Non-specific markers - includes bilirubin, lactic acid dehydrogenase (LDH)
What are the liver tests that are used to assess liver fxn?
A. Albumin - Ref range: 30-45 g/L, major protein in blood, contributes to osmotic pressure in serum, in transport of hormones, meds, anions, etc
with chronic liver disease (ex. cirrhosis) albumin conc will decrease steadily = decline in osmotic pressure = peripheral edema and ascites
B. Clotting factors - Vit K dependent (I, II (PT), V, VII, IX, X) are synthesized in liver, once reserves are depleted clotting abnormalities (excessive bleeding, easy bruising) will occur, monitored by measuring INR
What are the liver tests that are used to assess liver injury?
A. aminotransferases - IC enzymes that assist with protein metabolism, gluconeogenesis and other processes
highest conc in liver but also in other tissue including cardiac and skeletal muscle, kidney, brain, pancreas, lungs, blood cells
includes Alanine aminotransferase (ALT) - more specific for injury, Ref range: <40 U/L (females) and <60 U/L (males)
Aspartate aminotransferase (AST) - Ref range: <35 U/L (females) and <45 U/L (males)
Preview
What is cholestasis, S&S?
substances normally excreted by liver into the bile accumulate, impaired secretion from hepatocytes, obstruction of bile flow through intra or extra hepatic bile ducts
S&S: jaundice, pruritis, xanthomas (lipid deposition in skin), malabsorption of fat soluble vitamins (ADEK), anorexia
Preview
What are the liver tests used to identify cholestasis?
A. Alkaline phosphatase (ALP) - Ref range: 40-120 U/L
enzyme transports metabolites across cell membranes, also found in placenta, bone, GI cells
an increase in this may indicate skeletal disease, extra or intrahepatic biliary obstruction
this condition enhances ALP synthesis and release, concurrent rise in GGT (gamma-glutamyl transpeptidase) would indicate underlying hepatobiliary disease
B. gamma-glutamyl transpeptidase (GGT) - Ref range: <80 U/L (males) and <50 U/L (females)
its a biliary excretory enzyme, also present in kidney, spleen, heart, brain, but NOT bone or placenta
concurrent rise in ALP indicates underlying hepatobiliary disease, often see a rise in GGT associated with alcohol abuse
if ALP 4X ULN ⇒ this condition
if ALP <3X ULN ⇒ non-specific check GGT, if GGT > Ref then hepatic source, if within ref range then non-hepatic source
What are the liver tests which involve non-specific markers?
A. Bilirubin - produced from metabolism of Hgb as liver breaks down RBCs, elevated levels associated with jaundice, total level is sum of unconjugated and conjugated bilirubin (conjugated with glucuronide in liver and secreted through biliary tract into intestine or stored in gall bladder)
Ref Range: total - <20 micromol/L
conjugated - <7.0 micromol/L
Med related causes (hemolytic anemia): antimalarials, benzos, sulfonamides
B. Lactic Acid Dehydrogenase (LDH): metabolic enzyme present in almost every tissue, elevated levels indicate cell damage (liver disease, lung disease, lymphoma), Ref range: 120-250 U/L
What are GI lab values?
A. Amylase - Ref Range: 30-150 U/L
B. Lipase - Ref Range: <80 U/L
digestive enzymes secreted by pancreas and salivary glands
elevation could mean: 1. problems with exocrine fxn of pancreas (pancreatitis), 2. problems with gallbladder or blockade of ducts (ex. gallstones, cholecystitis, appendicitis), 3. inflammation or blockade of salivary gland (ex. mumps), 4. chronic kidney disease (because enzymes in blood are not being cleared properly)
