Chapter 4 - Lab Values & Drug Monitoring Flashcards
COMPLETE BLOOD CELL COUNT
- Consists of what?
- What is CBC with differential?
- RBCs average life span:
- Platelets average life span:
CBC:
- WBCs
- Neutrophils
- RBCs
- PLTs
- Hemoglobin (oxygen-carrying protein in RBCs)
- Hematocrit (the level of RBCs in the fluid component of the blood, or plasma).
CBC with differential:
- types of neutrophils are analyzed
RBCs average life span: 120 days
Platelets average life span: 7 -10 days
What are the BASIC METABOLIC PANEL (BMP) & COMPREHENSIVE METABOLIC PANEL (CMP)
- BMP: Electrolytes, glucose, renal function and acid/base (with the HC03, or bicarbonate).
- CMP: BMP + albumin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin and total protein.
– The additional tests are used primarily to assess liver function.
WBC > HGB/HCT< PLTS
Na / Cl / BUN
——————— < Glucose
K /HCO3/ SrCr
BLOOD CELL LINES:
- Stem cells in the bone marrow produce:
- Red blood cells (erythrocytes)
- White blood cells (leukocytes)
- Platelets
– Immature red blood cell: Reticulocyte
inc WBC is called:
Leukocytosis
inc RBC is called:
Polycythemia
inc platelet
Thrombocytosis
dec WBC
Leukopenia
dec RBC
Anemia
dec Platelet
Thrombocytopenia
Myelosuppression is when there’s a:
Decrease in:
- WBC
- RBC
- Platelets
Agranulocytosis
- Drug causes
- dec in what?
Drug causes:
- clozapine (BDZ - Sedative drug used to treat schizophrenia)
- propylthiouracil (Treats hyperthyroidism)
- methimazole (Treats hyperthyroidism)
- procainamide (Antiarrythmic)
- carbamazepine (BDZ - anticonvulsant/ analgesic)
- sulfamethoxazole/ trimethoprim
- isoniazid (Bacteriostatic - treats tuberculosis)
– Dec granulocytes (WBCs that have secretory granules in the cytoplasm);
– includes dec neutrophils, basophils and eosinophils
Calcium, total
- When do you calculate corrected calcium?
- When is it increased?
- When is it Decreased?
- When should u supplement with calcium?
- Calculate corrected calcium if albumin is low.
– Correction is not needed for ionized calcium. - Inc due to calcium supplementation, vitamin D, thiazide diuretics.
- Dec due to long-term heparin, loop diuretics, bisphosphonates, cinacalcet, systemic steroids, calcitonin, foscarnet, topiramate.
- Supplement calcium in pregnancy, osteoporosis/ osteopenia and with certain drugs.
Magnesium (Mg)
- When does it inc?
- When does it dec?
- BMP and Electrolytes
- Inc due to magnesium-containing antacids and laxatives with renal impairment.
- Dec due to PPls, diuretics, amphotericin B, foscarnet, echinocandins, diarrhea, chronic alcohol intake.
Phosphate (PO4)
- BMP and Electrolytes
- Inc in renal failure.
- Dec due to phosphate binders, foscarnet, oral calcium intake.
Potassium (K)
- BMP and Electrolytes
- Inc due to ACE inhibitors, ARBs, aldosterone receptor antagonists (ARAs), aliskiren, canagliflozin, cyclosporine, tacrolimus, mycophenolate, potassium supplements, sulfamethoxazole/trimethoprim, drospirenone- containing oral contraceptives, chronic heparin use, NSAIDs, pentamidine
- Dec due to beta-2 agonists, diuretics, insulin, steroids, conivaptan, mycophenolate (both inc and dec reported)
Sodium (Na)
- BMP and Electrolytes
- Inc due to hypertonic saline, tolvaptan, conivaptan.
- Dec due to carbamazepine, oxcarbazepine, SSRls, diuretics, desmopressin.
Bicarbonate
(HC03 or “bicarb”)
- BMP and Electrolytes
- Used to assess acid-base status
- Inc due to loop diuretics, systemic steroids.
- Dec due to topiramate, zonisamide, salicylate overdose.
Blood Urea Nitrogen (BUN)
- BMP and Electrolytes
- Inc in renal impairment and dehydration.
- Used with SCr (BUN:SCr ratio) to assess fluid status and renal function.
SerumCreatinine (SCr)
- BMP and Electrolytes
- Inc due to many drugs that impair renal function (aminoglycosides, amphotericin B, cisplatin, colistimethate, cyclosporine, loop diuretics, polymyxin, NSAIDs, radiocontrast dye tacrolimus, vancomicin).
- False inc due to sulfamethoxazole/trimethoprim, H2RAs, cobicistat.
- Dec with low muscle mass, amputation, hemodilution.
Anion Gap (AG)
- BMP and Electrolytes
- A calculated value, but often reported on the BMP.
- Presence of inc anion gap suggests metabolic acidosis.
White Blood Cells
- WBC and Differential
- Used to diagnose and monitor infection/inflammation
- Can inc as an acute phase reactant, indicating a systemic reaction to inflammation or stress
(surgery) - Inc due to systemic steroids, colony stimulating factors, epinephrine.
- Dec due to clozapine, chemotherapy that targets the bone marrow, carbamazepine, cephalosporins, immunosuppressants (OMAROs, biologics), procainamide, vancomycin.
Neutrophils & Bands
- WBC and Differential
- Neutrophils and bands are used with clinical s/sx to assess likelihood of acute infection and with WBC in absolute neutrophil count (ANC) calculation
- Neutrophils are also called polymorphonuclear cells (PMNs or polys) and segmented neutrophils (segs).
- Bands are immature neutrophils released from bone marrow to fight infection (called a “Left shift” when elevated).
Eosinophils
- WBC and Differential
- Inc in drug allergy, asthma, inflammation, parasitic infection.
Basophils
- WBC and Differential
- Inc in inflammation, hypersensitivity reaction, leukemia.
Lymphocytes
- WBC and Differential
- Inc in viral infections, lymphoma.
- Dec in bone marrow suppression, HIV or due to systemic steroids.
Anemia:
Red Blood Cells (RBC)
- Inc due to erythropoiesis-stimulating agents (ESAs), smoking and * polycythemia (a condition that causes high RBCs).
- Dec due to chemotherapy that targets the bone marrow, low production, blood loss, deficiency anemias (B12, folate), hemolytic anemia, sickle cell anemia.
Anemia: Hemoglobin
- Hgb is the iron-containing protein that carries oxygen in the RBCs.
- The Hct mirrors the Hgb result (providing the same clinical information}.
- Inc due to ESAs
- Dec in anemias and bleeding (risk with anticoagulants, antiplatelets, ibrinolytics).
Mean Corpuscular Volume (MCV)
- Inc due to B12 or folate deficiency.
- Dec due to iron deficiency.
Folic acid (folate)
B12 and folate are ordered for further workup of macrocytic anemia.
- Dec due to phenytoin/fosphenytoin, phenobarbital, primidone, methotrexate, sulfamethoxazole/ trimethoerim, sulfasalazine.
- Supplement folate in women of childbearing age and alcoholism
Vitamin B12
- Dec due to PPls, metformin, colchicine, chloramphenicol.
Methylmalonate
- Used for further workup of macrocytic anemia when B12 deficiency is suspected.
- Schilling test has also been used.
Reticulocyte count
- Measures the amount of reticulocytes (immature red blood cells) being made by the bone marrow; reticulocyte count is inc in blood loss and dec in untreated anemia due to iron, folate or B12 deficiency and with bone marrow suppression.
CoombsTest, Direct
- Used in the diagnosis of hemolytic anemia, when the cause of hemolysis is unclear (an immune mechanism vs. another cause).
- Drugs that can cause hemolytic anemia include penicillins and cephalosporins (prolonged use/high concentrations), dapsone, isoniazid, levodopa, methyldopa, methylene blue, nitrofurantoin, pegloticase, primaquine, quinidine, quinine, rasburicase, rifampin and sulfonamides.
- If the Coombs test is positive and a drug-induced cause is suspected, discontinue the offending drug.
Glucose-6-phosphate dehydrogenase
(G6PD)
- Used to determine if hemolytic anemia is due to G6PD deficiency (the result will be low).
- The RBC destruction with G6PD deficiency is triggered by stress, foods (fava beans) or these drugs: dapsone, methylene blue, nitrofurantoin, pegloticase, primaquine, rasburicase, sulfonamides