956-1050 Flashcards
- STAT for the Latin word statim meaning immediately. Tests that fall into this category include:
Glucose in diabetic ketoacidosis
Some drug levels such as theophylline
Amylase in suspected pancreatitis
CK in suspected MI
Hematocrit
Blood gases
Potassium
- CRITICAL VALUES or PANIC VALUES: list of analytes that truly do have the potential to be lethal if unchecked for a short period.
- SCHILLING TEST: Laboratory determination of vitamin B12 absorption
- Hemostatic mechanisms comprise four (4) main systems: the vascular system, platelets, coagulation system and fibrinolytic system.
- OSMOLALITY
Osmolality = 2Na + ( Glucose/20 ) + ( BUN/3 )
Osmolality = 1.86Na + ( Glucose/18 ) + ( BUN/2.8 ) + 9
- ANION GAP (AG)
AG = Na - (Cl + HCO3)
AG = (Na + K) – (Cl + HCO3)
NORMAL URINARY CRYSTALS
962. Uric acid is alkali soluble
963. Amorphous urates - soluble in alkali and heat
964. CaOx - soluble in dilute HCl
965. Amorphous phosphates - soluble in dilute acetic acid
- Calcium phosphate - soluble in dilute acetic acid
- Triple phosphate - soluble in dilute acetic acid
- Ammonium biurate - soluble in acetic acid with heat
- Calcium carbonate - forms gas from acetic acid
ABNORMAL URINARY CRYSTALS
970. Cystine is soluble in ammonia, dilute HCl
971. Cholesterol is soluble in chloroform
972. Leucine is soluble in hot alkali or alcohol
973. Tyrosine is soluble in alkali or heat
- Bilirubin is soluble in acetic acid, HCl, NaOH, ether and chloroform
- Sulfonamides soluble in acetone
- Radiographic dye soluble in 10% NaOH
- Ampicillin crystals form bundles when refrigerated
- F. tularensis is a very small, strictly aerobic, coccoid to pleomorphic rod-shaped, gram-negative bacillus that requires CYSTINE or CYSTEINE for growth
- Legionella spp. may be isolated on BCYE agar supplemented with growth factors, including L-CYSTINE, FERRIC SALT, AND Α-KETOGLUTARATE.
- Bordetella spp. are strictly aerobic, nonfermentative, catalase-positive, minute coccobacilli requiring NICOTINIC ACID, CYSTEINE, and usually METHIONINE for growth.
- MEDICAL MALPRACTICE is misconduct or lack of skill by a health-care professional that results in injury to the patient.
- NEGLIGENCE, which is defined as failure to give reasonable care by the health-care provider, must be proven in a malpractice suit.
- SERUM or PLASMA is the specimen of choice for the determination of circulating concentrations of most drugs. THERAPEUTIC DRUGS, BISHOP
- Analysis for the presence of ABUSED SUBSTANCES has focused primarily on the use of URINE as the test sample of choice. The urine specimen represents the net load of the drug over a long period, whereas the blood sample provides only a quick picture of the drug level at a specific time. DRUGS OF ABUSE, CALBREATH
- CHAIN OF CUSTODY
Processing steps for such specimens—initial collection, transportation, storage, and analytical testing— must be documented by careful record keeping. Documentation ensures that there has been no tampering with the specimen by any interested parties, that the specimen has been collected from the appropriate person, and that the results reported are accurate.
Each step of the COLLECTION, HANDLING, PROCESSING, TESTING, AND REPORTING PROCESSES must be documented; this is called the chain of custody.
- RICE BODIES are fragments of degenerating proliferative synovial cells or microinfarcted synovium.
- OCHRONOTIC SHARDS, ground pepper appearance from pigmented cartilage fragments may be the result of a metabolic disorder (i.e., ochronosis).
- PROBLEMS: RBCs appear gray, WBCs are too dark, eosinophil granules are gray, not orange.
CAUSES: Stain or buffer too alkaline (most common), inadequate rinsing, prolonged staining, heparinized blood sample. - PROBLEMS: RBCs are too pale or are RED, WBCs are barely visible.
CAUSES: Stain or buffer too acidic (most common), underbuffering (too short), over-rinsing.
- HBeAg indicates HIGH INFECTIVITY.
- CORDOCENTESIS, or percutaneous umbilical blood sampling (PUBS).
SPECIAL URINE PRESERVATIVES
992. Formaldehyde – for Addis count
993. HCl – for epinephrine, norepinephrine, catecholamines, vanillylmandelic acid
994. Glacial acetic acid pH 4.5 – for aldosterone
995. Sodium carbonate – for porphyrins and urobilinogen (to ensure alkalinity)
- Glacial acetic acid pH 2.0 – for serotonin
- Conc. HCl – for steroids, ammonia, urea, total nitrogen
- Chloroform – for aldosterone
- Sulfuric acid – preserves calcium and other inorganic constituents
- Sodium fluoride or benzoic acid – ideal for glucose analysis, prevents glycolysis
- DILUTION is an INDICATION OF RELATIVE CONCENTRATION
- RATIO is an expression of one amount relative to another amount (AMOUNT/AMOUNT)
- CONCENTRATION is the amount of one substance relative to the amounts of other substances in the solution (AMOUNT/SOLUTION)
- MOLARITY is the gram-molecular mass (or weight) of a compound per liter of solution
- SODIUM is the most abundant extracellular cation. It contributes to the osmolality of extracellular fluid and maintains the volume of ECF and cell size and shape. Sodium is essential for transmitting nerve impulses.(Hubbard)
- POTASSIUM is the major intracellular cation that regulates activity at the neuromuscular junction, as well as cardiac muscle contraction and pH. (Hubbard)
- POTASSIUM is an INTEGRAL PART OF NERVE IMPULSE TRANSMISSION. (Calbreath)
- CHLORIDE is the major extracellular anion that acts to maintain osmotic pressure, keeps the body hydrated, and maintains electric neutrality via interaction with sodium or carbon dioxide.
- BICARBONATE is the second most abundant anion in the extracellular fluid. It is a major component of the blood buffering system, accounts for 90% of total blood carbon dioxide, and maintains charge neutrality in the cell.
- Assays for bicarbonate (carbon dioxide)
Assay as carbon dioxide (1) measure carbon dioxide with ion-selective electrode and (2) diffuse carbon dioxide into solution containing PHENOLPHTHALEIN indicator.
Enzymatic assay for bicarbonate.
- Regulation of aldosterone secretion via the renin/angiotensin system is achieved as follows:
Decreased blood volume or blood pressure induces the release of kidney renin, which induces the production of angiotensin I and II.
Angiotensin II affects release of aldosterone from the adrenal gland, which ultimately causes the kidney distal tubule to RETAIN SODIUM, thereby raising blood volume and blood pressure.
- CHYLOMICRONS are large molecules that contain mostly triglyceride.
- VLDLs are smaller than chylomicrons. They contain mostly endogenous triglyceride, are made in the liver, contain equal amounts of phospholipids and cholesterol, and degrade to LDLs in the circulation.
- LDLs contain mostly cholesterol, with equal amounts of phospholipid and protein and some triglyceride.
- HDLs contain mostly protein, some cholesterol, and a little triglyceride.
- Sterile normal saline, containing 9 grams of salt per liter or 1000 mL (0.90% NaCl).
- Pulmonary secretions may be obtained by any of the following methods:
Spontaneously produced or induced sputum, gastric lavage, transtracheal aspiration, bronchoscopy, and laryngeal swabbing.
Most specimens submitted for examination are sputum, aerosol-induced sputum, bronchoscopic aspirations, or gastric lavage samples.
Spontaneously produced sputum is the specimen of choice. (Bailey)