L7 and L8 - Lab Medicine 1 and 2 Flashcards
What is the purpose of lab testing?
Augments or supports information obtained from the history and physical
Confirms or rejects differential considerations (DDx)
Informs medical decision making
Allows for monitoring therapy
What are the components of a CBC?
WBCs, hemoglobin, platelets, hematocrit
What causes an increased WBC count?
Infections, inflammatory diseases, auto immune diseases, leukemia, emotional and physical stress
What can cause the WBC count to be low?
Bone marrow failure (sepsis, malignancy)
Collagen vascular disease
Medications such as anti metabolites, barbiturates, anticonvulsants, anti thyroid
When is hemoglobin increased?
Increased in severe dehydration, COPD, polycythemia, erythrocytosis, shock, CHF and high altitudes
When is hemoglobin decreased?
In hemolytic reactions, acute or chronic blood loss, pregnancy, leukemia, drugs, hyperthyroidism
Hemoglobin will typically be what?
Hematocrit/3
What causes platelets to increase?
Essential thrombocytosis, myeloproliferative states, hemolysis, acute inflammatory states as an acute phase reactant
When is the platelet count decreased?
ITP, HIT, aplastic anmeia, uremia, hypersplenism, bone marrow failure related to infection (sepsis)
What are the signs and sx of low platelets?
Easy bruising, epistaxis, hematuria, menorrhagia
What is included in a basic BMP?
Na, K, Cl, total CO2, BUN, Cr, Glucose, anion gap
What is included in a complete/comprehensive BMP?
BMP + AST/ALT, bilirubin, alkaline phosphatase, Ca, albumin, total protein
What causes hyponatremia?
Diarrhea, vomiting, HF, liver failure, SIADH
What causes hypernatremia?
Dehydration (loss of water), Cushing’s syndrome, hyperaldosteronis, advanced age, pregnancy
What causes high K?
AKI, CKD, metabolic acidosis, drugs like ACEI and ARBS
What causes low K?
Vomiting, diarrhea, metabolic acidosis, diuretics, decreased intake, renal dysfunction
What can cause high Cl?
Diarrhea, ATN, mineralocorticoid deficiency, drugs
What can cause low Cl?
Vomiting, excess sweating, SIADH, mineralocorticoid excess
What can cause a high BUN?
Acute GN, PCKD, GI bleeding (breakdown of Hb in gut), chronic nephritis, CKD
What can cause low BUN?
Malnutrition, malabsorption, nephrotic syndrome, overhydration
What causes high creatinine?
Renal dysfunction, shock, dehydration, HF, increased body mass
What can cause low Creatinine?
Muscle wasting
What is an anion gap?
Refers to concentration of unmeasured anions in blood such a protein, phosphate, sulphate, organic acids
AG = Na - (Cl + HCO3)
For HCO3 use the total CO2, can use serum BMP to estimate
What can cause an increased anion gap?
Uremia, lactic acidosis, ketoacidosis, DKA, rhabo, alcohol abuse, drugs
What can cause a low anion gap?
Cirrhosis, nephrotic syndrome, hemorrhage, lithium intoxication
What causes hyperglycemia?
DM, Cushing’s syndrome, acromegaly, pheochromocytoma, glucagonoma, somatostatinoma, drugs such as glucocorticoids, pancreatic insufficiency
What causes hypoglycemia?
Livery failure, excess use of insulin, acute alcohol intoxication, renal failure, sepsis, hypopituitarism, adrenal insufficiency, myxedema, insulinoma, drugs, extra pancreatic tumors
What are examples of iron studies?
Serum iron, serum transferrin, transferrin saturation, serum ferritin
