Diagnostic Methods - Lab Req and other tests

The flashcards below were created by user Pandora320 on FreezingBlue Flashcards.

  1. CBC with diff
    Provides information about 3 types of cells - WBC, RBC and platelets
  2. BMP
    • Blood chemistry tests help evaluate the body’s respiratory & metabolic status
    • Electrolyte levels provide data on body's acid-base balance & fluid balance
    • Essential components for basic body functions
    • Reflects basic kidney function
  3. CMP
    Same as BMP but also includes LFT
  4. Beta hCG
    • Pregnancy test
    • Quantitative hCG, measures the amount of hCG in the blood, yields a number vs. positive/negative result
  5. Culture, blood
    used to detect the presence of bacteria or fungi in the blood, to identify the type present, and to guide treatment. Testing is used to identify a blood infection (septicemia) that can lead to sepsis, a serious and life-threatening complication. Individuals with a suspected blood infection are often treated in intensive care units, so testing is often done in a hospital setting.
  6. PT
    • (Prothrombin time)
    • Marker of Hepatic Synthetic Function
    • (Liver Metabolism)
    • A glycoprotein produced in the liver
    • Necessary for firm fibrin clot formation
    • Measures the time required for a fibrin clot to form
    • Elevation indicates hepatic disease, clotting factor deficiency or anticoagulation
    • Extrinsic pathway
    • Compared with control times
    • Variations with methods
    • Coumadin therapy - INR replaces PT
    • (Partial Thromboplastin Time)
    • Intrinsic pathway
    • Compared with control times
    • Variations with methods
    • Heparin therapy - APTT more sensitive
  8. Bleeding time
    • A test of platelet function
    • Measured as the time it takes for bleeding to stop due to the formation of a platelet plug
    • Provided that fibrinogen levels and platelet count is normal, this procedure will detect defective platelet function
    • A screening test for inherited and acquired platelet defects
  9. Blood grouping, ABO/Rh
    • used to determine an individual's blood group and what type of blood or blood components the person can safely receive. It is important to ensure that there is compatibility between a person who requires a transfusion of blood or blood components and the ABO and Rh type of the unit of blood that will be transfused. A potentially fatal transfusion reaction can occur if a unit of blood containing an ABO antigen to which a person has an antibody is transfused to that person. For example, people with blood group O have both anti-A and anti-B antibodies in their blood. If a unit of blood that is group A, B, or AB is transfused to this person, the antibodies in the person's blood will react with the red cells, destroying them and causing potentially serious complications.
    • If an Rh-negative individual is transfused with Rh-positive blood, it is likely that the person will produce antibodies against Rh-positive blood. Although this does not cause problems for the person during the current transfusion, a future transfusion with Rh-positive blood could result in a serious transfusion reaction.
    • Rh typing is especially important during pregnancy because a mother and her fetus could be incompatible. If the mother is Rh-negative but the father is Rh-positive, the fetus may be positive for the Rh antigen. As a result, the mother’s body could develop antibodies against the Rh antigen. The antibodies may cross the placenta and cause destruction of the baby’s red blood cells, resulting in a condition known as hemolytic disease of the fetus and newborn. To prevent development of Rh antibodies, an Rh-negative mother is treated with an injection of Rh immune globulin during her pregnancy and again after delivery if the baby is Rh-positive. The Rh immune globulin binds to and "masks" any Rh antigen from the fetus that the mother may be exposed to during her pregnancy and delivery and prevents her from becoming sensitized and developing antibodies against the Rh antigen.
    • Blood typing is also used to determine the blood group of potential donors at a collection facility. Units of blood that are collected from donors are blood typed and then appropriately labeled so that they can be used for people that require a specific ABO group and Rh type.
  10. Sed Rate
    • ESR
    • Non-specific test for inflammation
    • No indication of cause/effect relationship
    • What is normal? Esp in elderly females
    • Relatively sensitive sick/not sick gate
    • Other acute phase reactants may be better to follow acute inflammation (CRP)
    • Anemia and macrocytosis increase ESR
    • Not ordered routinely, generally ordered with joint pain or other complaints by pt.
  11. C-reactive Protein
    Used to identify the presence of inflammation and to monitor response to treatment for an inflammatory disorder. Conditions include serious bacterial or fungal infection, or inflammatory disorders such as arthritis, an autoimmune disorder, or inflammatory bowel disease.
  12. EKG
    recording of the electrical activity of the heart
  13. Echocardiogram
    An echocardiogram is a test that uses sound waves to create pictures of the heart. The picture is more detailed than a standard x-ray image. An echocardiogram does not expose you to radiation.
  14. Stress test
    • A stress test, also called an exercise stress test, is used to gather information about how well your heart works during physical activity. Because exercise makes your heart pump harder and faster than it does during most daily activities, an exercise stress test can reveal problems within your heart that might not be noticeable otherwise.
    • An exercise stress test usually involves walking on a treadmill or riding a stationary bike while your heart rhythm, blood pressure and breathing are monitored.
  15. Serial cardiac biomarkers
    • substances that are released into the blood when the heart is damaged or stressed. Measurement of these biomarkers is used to help diagnose, risk stratify, monitor and manage people with suspected acute coronary syndrome (ACS) and cardiac ischemia.
    • Troponin I or T, CK, CK-MB
    • Also myoglobin, BNP, and hs-CRP
  16. BNP
    used to help detect, diagnose, and evaluate the severity of heart failure. Testing may be performed if a person has symptoms such as swelling in the legs (edema), difficulty breathing, shortness of breath, and fatigue. It can be used, along with other cardiac biomarker tests, to detect heart stress and damage and/or along with lung function tests to distinguish between causes of shortness of breath. Chest X-rays and an ultrasound test called echocardiography may also be performed.
  17. Homocysteine
    • to determine if a person has a vitamin B12 or folate deficiency. The homocysteine concentration may be elevated before B12 and folate tests are abnormal. Some health practitioners may recommend homocysteine testing in malnourished individuals, the elderly, who often absorb less vitamin B12 from their diet, and individuals with poor nutrition, such as drug or alcohol addicts.
    • Homocysteine may be ordered as part of a screen for people at high risk for heart attack or stroke. It may be useful in someone who has a family history of coronary artery disease but no other known risk factors, such as smoking, high blood pressure, or obesity. However, the exact role that homocysteine plays in the progression of cardiovascular disease has not been established, so the utility of the screening test continues to be questioned. Routine screening, such as that done for total cholesterol, has not been recommended.
    • Tests for both a urine and blood homocysteine may be used to help diagnose homocystinuria if a health practitioner suspects that an infant or child may have this inherited disorder. In the U.S., all babies are routinely tested for excess methionine, a sign of homocystinuria, as part of their newborn screening. If a baby's test is positive, then urine and blood homocysteine tests are often performed to confirm the findings.
  18. Fasting lipid profile
    used as part of a cardiac risk assessment to help determine an individual's risk of heart disease and to help make decisions about what treatment may be best if there is borderline or high risk. The results of the lipid profile are considered along with other known risk factors of heart disease to develop a plan of treatment and follow-up. Depending on the results and other risk factors, treatment options may involve lifestyle changes such as diet and exercise or lipid-lowering medications such as statins.
  19. Myoglobin
    • ordered as a cardiac biomarker, along with troponin, to help diagnose or rule out a heart attack. Levels of myoglobin start to rise within 2-3 hours of a heart attack or other muscle injury, reach their highest levels within 8-12 hours, and generally fall back to normal within one day. An increase in myoglobin is detectable sooner than troponin, but it is not as specific for heart damage and it will not stay elevated as long as troponin.
    • Although a negative myoglobin result effectively rules out a heart attack, a positive result must be confirmed by testing for troponin.
    • Sometimes, a urine test is ordered to evaluate myoglobin concentrations in those who have had extensive damage to their skeletal muscles (rhabdomyolysis). Blood levels of myoglobin can rise very quickly with severe muscle injury. Urine myoglobin concentrations reflect the degree of muscle injury and, since myoglobin is toxic to the kidneys, reflect the risk of kidney damage.
  20. hs-CRP
    • (High-sensitivity C-reactive Protein)
    • used by itself, in combination with other cardiac risk markers, or in combination with a lipoprotein-associated phospholipase A2 (Lp-PLA2) test that evaluates vascular inflammation. The hs-CRP test accurately detects low concentrations of C-reactive protein to help predict a healthy person's risk of cardiovascular disease (CVD).
    • High-sensitivity CRP is promoted by some as a test for determining a person's risk level for CVD, heart attacks, and strokes. The current thinking is that hs-CRP can play a role in the evaluation process before a person develops one of these health problems. Clinical trials that involve measuring hs-CRP levels are currently underway in an effort to better understand its role in cardiovascular events. These studies may eventually lead to guidelines on its use in screening and treatment decisions.
  21. Metanephrine
    Urine metanephrines testing is primarily used to help detect and rule out pheochromocytomas in symptomatic people. It may also be ordered to help monitor the effectiveness of treatment when a pheochromocytoma is removed to monitor for recurrence. Urine metanephrines testing may be ordered by itself or along with a plasma metanephrines test. Plasma and urine catecholamines testing may also be ordered, either along with urine metanephrines or as follow-up tests. Since catecholamines secretion tends to fluctuate over time, a 24-hour urine test for metanephrines or catecholamines may detect excess production that is missed with the blood test.
  22. VMA
    • (vanillylmandelic acid)
    • used to detect and rule out neuroblastomas in children with an abdominal mass or other symptoms suggestive of the disease.
    • A VMA test was once frequently ordered to detect pheochromocytomas, but the preferred tests are now plasma free metanephrines, urine metanephrines, and urine or plasma catecholamine tests. The VMA test may still be ordered along with one or more of these tests to help detect and rule out a pheochromocytoma.
  23. Cortisol
    • to screen for and help diagnose Cushing syndrome, a group of signs and symptoms associated with excess cortisol. Blood cortisol testing evaluates both protein-bound and free cortisol while urine testing evaluates only free cortisol, which should correlate with the levels of free cortisol in the blood. Sometimes salivary cortisol is also ordered to help detect Cushing syndrome.
    • Blood cortisol is also used to help diagnose adrenal insufficiency and Addison disease, conditions in which the adrenal glands do not function properly.
  24. Aldosterone and Renin
    • Aldosterone and renin tests are used to evaluate whether the adrenal glands are producing appropriate amounts of aldosterone and to distinguish between the potential causes of excess or deficiency. Aldosterone may be measured in the blood or in a 24-hour urine sample, which measures the amount of aldosterone removed in the urine in a day. Renin is always measured in blood.
    • These tests are most useful in testing for primary aldosteronism, also known as Conn syndrome, which causes high blood pressure. If the test is positive, aldosterone production may be further evaluated with stimulation and suppression testing.
    • Both aldosterone and renin levels are highest in the morning and vary throughout the day. They are affected by the body's position, by stress, and by a variety of prescribed medications.
  25. Peak Flow
    measures and displays the highest level of expiratory flow produced by a patient; commonly used to monitor pulmonary function in patients with a reversible disease of the airways.
  26. PFTs
    • (Pulmonary Function Tests)
    • A group of breathing tests combined to give an objective evaluation of lung function in disease.
    • Assess the degree of airway obstruction
    • Measure airway response to allergens
    • Quantify airway hypersensitivity
    • Determine effect of bronchodilators
    • Evaluate effectiveness of long-term treatment of lung disease and progression
  27. ABG
    • Measurement of gases/ions within the blood that help to evaluate lung/metabolic function and identify any acid-base imbalance
    • Components include - pH, O2, CO2, HCO3-
  28. D-dimer
    • to help rule out the presence of a thrombus. Some of the conditions that the d-dimer test is used to help rule out include:
    • Deep vein thrombosis (DVT)
    • Pulmonary embolism (PE)
    • Strokes
    • This test may be used to determine if further testing is necessary to help diagnose diseases and conditions that cause hypercoagulability, a tendency to clot inappropriately.
    • A D-dimer level may be used to help diagnose disseminated intravascular coagulation (DIC) and to monitor the effectiveness of DIC treatment.
  29. Pleural Fluid Analysis
    used to help diagnose the cause of inflammation of the pleurae and/or accumulation of fluid in the pleural space. Collected by thoracentesis.
  30. Rapid beta strep
    used to determine whether a person with a sore throat (pharyngitis) has a group A streptococcal infection.
  31. Culture, throat
    A throat culture should be performed on children or adolescents to confirm the results of a rapid strep test and avoid missing infections that could lead to serious complications, such as rheumatic fever. A throat culture is more sensitive than the rapid strep test, but it may take 24-48 hours for results. According to 2012 guidelines from the Infectious Diseases Society of America (IDSA), confirmatory testing on adults is not recommended since adults have lower rates of strep throat and far lower risk of complications than children.
  32. Culture, sputum
    • used to detect and diagnose bacterial lower respiratory tract infections such as bacterial pneumonia or bronchitis. It is typically performed with a Gram stain to identify the bacteria causing a person's infection.
    • Sometimes lower respiratory tract infections are caused by pathogens that cannot be detected with routine bacterial sputum cultures. This is either because the pathogens require very specific nutrients to grow in culture or because they grow very slowly. When this is suspected to be the case, specialized tests may be done in addition to or instead of a routine culture to help identify the cause of infection. These additional tests include, for example, an AFB smear and culture to detect tuberculosis and non-tuberculous mycobacteria infections, a fungal culture, or a Legionella culture.
  33. Monospot
    • (Mononucleosis Spot Test)
    • used to help determine whether a person with symptoms has infectious mononucleosis (mono). It is frequently ordered along with a complete blood count (CBC). The CBC is used to determine whether the number of white blood cells (WBCs) is elevated and whether a significant number of reactive lymphocytes are present. Mono is characterized by the presence of atypical white blood cells.
  34. Hemoglobin A1C
    Used to monitor a person's diabetes and to aid in treatment decisions; to diagnose diabetes; to help identify those at an increased risk of developing diabetes. Tested 2-4 times a year depending on control of diabetes. Gives an average amount of glucose in the blood over the last ~3 months. Less than 7 is desirable.
  35. Fructosamine
    Used to monitor blood sugar levels over time for diabetes mellitus, especially if unable to use A1C test. Determines effectiveness of changes to diabetic treatment plan that might include changes in diet, exercise, or medication. Average blood glucose levels over the last 2-3 weeks. Best for rapid changes in diabetes treatment, gestational diabetes, shortened RBC lifespan (hemolytic anemia, blood loss), abnormal forms of hemoglobin (sickle cell). Not to be used as a screening test for diabetes.
  36. Fasting Blood Glucose
    • To determine if you blood glucose level is within a healthy range; to screen for, diagnose, and monitor high blood glucose or low blood glucose, diabetes, and pre-diabetes.
    • FBG > 125 on 2 different days is indicative of diabetes
  37. Random Blood Glucose
    • Glucose testing on a non-fasting subject
    • RBG > 200 plus signs of hyperglycemia on 2 different days is indicative of diabetes
  38. OGTT
    • (oral glucose tolerance test)
    • a test of the body's ability to utilize carbohydrates by measuring the plasma glucose level at stated intervals after ingestion or intravenous injection of a large quantity of glucose
    • Not performed if FBG > 125
    • 8-12 hours fasting
    • Test is positive if BG > 200 at 2 hours
    • Risk of ketoacidosis
    • Used for diagnosis of gestational diabetes
  39. Whipple's Triad
    • Hypoglycemia diagnosis - usually from over treatment with insulin
    • - Characteristic s/s of hypoglycemia
    • - Venous BG < 45
    • - Symptoms revers within 15-45 minutes with glucose treatment
  40. TSH
    • Thyroid stimulating hormone
    • To screen for and help diagnose thyroid disorders; to monitor treatment of hypothyroidism and hyperthyroidism
    • TSH is regulated by the negative feedback action of T4 and T3
  41. Free T4
    • FT4
    • Free hormone measurements are the preferred tests measured as they tend to be the most accurate
    • T4 is major secretory product of thyroid & correlates best with TSH
  42. T3, free
    • Triiodothyronine
    • Generally when TSH is abnormal, free T4 is normal, and signs/symptoms of hyperthyroidism.
  43. T3, reverse
    • A conversion product of T4–thyroxine, the level of which reflects the rate of peripheral conversion of thyroid hormones of T4 to T3
    • Normal rT3 levels 0.15-0.77 mmol/L.
    • Euthryoid sick syndrome.
  44. Anti-TPO
    • Thyroid Peroxidase Antibody
    • to diagnose and monitor autoimmune thyroid disease (Hashimoto thyroiditis) and to distinguish these from other forms of thyroid disease, as well as guide treatment decisions.
    • Test performed with presentation of goiter, and results of T3, T4, TSH indicate thyroid dysfunction. A Thyroglobulin test is also performed when anti-tpo is used as a monitoring tool.
    • Used for SLE, RA, pernicious anemia
  45. Anti-TBG
    • Thyroglobulin is a glycoprotein stored in the thyroid follicle where it binds T3 and T4
    • Also present with thyroid autoimmunity, but not typically used for screening
  46. Retic Count
    • reticulocyte count
    • to evaluate the bone marrow's ability to produce RBCs; to help distinguish between various causes of anemia; to help monitor bone marrow response and the return of normal marrow function following chemotherapy, bone marrow transplant, or post-treatment f/u for iron deficiency anemia, vitamin B12 or folate deficiency anemia, or renal failure.
    • Test when RBC, HGB, HCT are low and/or symptoms of anemia.
  47. Ferritin
    • Primary storage form of iron in the body
    • Plasma level correlates well with iron stores
    • “Best” test for iron deficiency anemia
    • If normal – do more work up
    • If low treat with iron supplement/multivitamin
  48. Serum Iron
    Measures the iron bound to transferrin
  49. Transferrin
    • A plasma iron-transport protein
    • In healthy people, about 20-50% of available sites are used to transport iron
    • Iron binding glycoprotein produced in the liver
    • Indirect measure of liver function
  50. TIBC
    • total iron binding capacity
    • Test that measures the blood’s capacity to bind iron with transferrin
    • Indirect measure of transferrin ($$$$)
    • Inverse response with ferritin in iron deficiency
    • Young age, pregnancy and drugs may increase TIBC
    • Very Low TIBC = Anemia of Chronic Disease
    • Normal to low = Sideroblastic Anemia
  51. Vitamin B12 and Folate
    • Not part of initial anemia work-up
    • Usually ordered together to identify nutrient deficiency in macrocytic megaloblastic anemia
    • The most common cause of folate deficiency is EtOH
    • Vitamin B12 Deficiency would have neurological deficiencies – parathesesia, weakness, balance/gait, proprioception
  52. Haptoglobin
    • Haptoglobin
    • Protein produced in the liver
    • Binds free hemoglobin
    • Haptoglobin-hemoglobin complex is removed by the RE system (mostly the spleen) to conserve hemoglobin
    • Decreased or “zero” level noted in the serum with hemolytic anemia
  53. Direct Coombs
    • Direct Coombs Test
    • a test for detecting sensitized erythrocytes in erythroblastosis fetalis and in cases of acquired immune hemolytic anemia - the patient's erythrocytes are washed with saline to remove serum and unattached antibody protein, then incubated with Coombs anti-human globulin (usually serum from a rabbit or goat previously immunized with human globulin); after incubation, the system is centrifuged and examined for agglutination, which indicates the presence of so-called incomplete or univalent antibodies on the surface of the erythrocytes.
  54. G6PD screen
    • (Glucose-6-phosphate dehydrogenase)
    • Used to screen for and help diagnose G6PD deficiencies.  May be be used to screen children who experience persistent jaundice as a newborn that could be not explained by another cause.  Also used for patients of any age who have had one or more unexplained episodes of hemolytic anemia, presence of jaundice, or dark urine.  Recent viral or bacterial illness or exposure to a known trigger (fava beans, a sulfa drug, or naphthalene) followed by a hemolytic episode then G6PD may be considered.
  55. Hgb electrophoresis
    • Hemoglobin Electophoresis
    • Types of Hemoglobin
    • Hgb A, normal, 95-99%
    • Hgb A2, normal variant of A, small %
    • Hgb F, fetal
    • Hgb S, sickle cell
    • Hgb C, found in African Americans
    • Hgb H, Alpha Thalessemia
  56. CEA
    • (Carcinoembryonic Antigen)
    • Useful in monitoring treatment and disease recurrences
    • Can be used to determine stage and extent of disease
    • Originally thought to be colon cancer specific but also seen in lung, breast, pancreas and ovary
    • High levels are GI associated
    • Not all cancers produce CEA so not useful for screening
    • ***Elevated levels also seen in smokers
  57. PSA
    • (Prostate Specific Antigen)
    • Screening tool for prostate cancer
    • DRE can cause PSA elevation so blood test should be done 1st
    • Also useful in monitoring treatment and detecting recurrence
    • If PSA <20 ng/ml, bone mets unlikely
    • ***Levels can rise in benign conditions
  58. CA-125
    • Used monitor treatment of ovarian cancer and its effectiveness (1st do U/S)
    • Also used to detect if cancer returns after treatment is completed
    • Used to follow high risk females with a positive family hx
    • Moderate elevations indicate a high cancer risk
    • High levels are ovarian cancer specific, also breast cancer, lung cancer, pancreatic cancer
    • ***Can be high in normal/benign conditions (pregnancy, menstruation, endometriosis and PID)
  59. CA-15.3
    • Monitors patient’s response to breast cancer tx and assess for recurrence
    • Monitoring begins a few weeks after treatment due to initial levels fluctuating
    • Not seen with CA detected early and 25-30% of breast cancers do not have increased levels
    • May aid in dx of breast ca metastasis
    • Not sensitive or specific enough for screening
    • ***Mild to moderate elevations can be present in benign breast disorders
  60. CA-19.9
    • Used to monitor treatment and to watch for recurrence of PANCREATIC Cancer
    • Not sensitive or specific enough to be used as a screening tool
    • Not initially elevated in all pancreatic cancers and only useful as a marker if so
    • By the time a patient has symptoms and significantly elevated levels, the pancreatic cancer is usually at an advanced stage
  61. CA-27.29
    • Similar to CA-15.3
    • Used in conjunction with other studies to assess for recurrence in women treated for stage II- III breast cancer
    • May be elevated by cancers of the colon, stomach, kidney, lung, ovary, pancreas, uterus, and liver
    • Also elevated in first trimester pregnancy and other noncancerous disease processes
  62. AFP
    • (Alpha-fetoprotein)
    • Used to detect tumors of the liver and testes/ovaries (germ cell)
    • The higher the AFP level, the bigger the tumor
    • Used to monitor response to therapy
    • AFP decreases when body responds to therapy, returning to normal in about 1 month
    • Used in pregnancy to detect neural tube defects & Downs Syndrome in utero
    • ***Slightly increased levels seen in chronic hepatitis or cirrhosis
  63. hCG, quantitative
    • (Human chorionic gonadotropin)
    • Useful in confirming pregnancy
    • Useful in dx and monitoring of tx recurrence of germ cell tumors or trophoblastic disease
    • Levels fall in response to treatment
  64. Rheumatoid Factor
    • Antibodies directed against the Fc portion of IgG
    • A variety of non-rheumatic diseases are associated with a positive RF
    • Elevated in >75% of adults with RA
    • Use as CONFIRMATORY test, not screening
    • Level correlates with disease severity and extra-articular disease
    • Normal aging
    • Not useful to monitor course of RA
  65. CCP IgG
    • (cyclic citrullinated peptide)
    • Similar role as RF with similar sensitivity but more specific (98%)
    • The citrulline antibody appears early in the course of RA - diagnostic early in the disease
    • Presence of CCP antibodies is associated with the development of erosive arthritis
    • Associated with more severe disease
  66. Antinuclear antibody
    • ANA
    • Use indirect immunofluorescence to detect antibodies that bind to various nuclear antigens
    • Characteristic of many autoimmune disorders
    • Immunoflourescent procedure yields four patterns of ANA staining with positive test which are associated with certain diseases though not specific
    • Found in 95% patients with SLE (negative ANA strongly argues against the diagnosis)
  67. ds-DNA
    • Highly specific antibody for SLE 95% but not highly sensitive (70%)
    • Absence of ds-DNA does not exclude the diagnosis
    • Often correlates with disease activity in SLE (lupus nephritis and severe flares)
    • Testing not recommended in pts with a negative ANA
  68. HLA-B27
    • (human leukocyte antigen)
    • Genetic predisposition for developing AS
    • AS and + HLA-B27 - strong association 90%
    • May be seen in 5-8% of normal population
    • Presence correlates with - Ankylosing spondylitis, Reiter’s syndrome, Psoriatic arthritis, Inflammatory bowel disease
  69. Synovial fluid analysis
    • Cell count - RBCs & WBCs
    • Gram stain and culture
    • Crystal content - Found with gout or other types of crystal-induced arthritis
    • Glucose level - Similar to that in plasma, decreased with infection & RA
  70. Urinalysis with microscopy
    typically be done when there are abnormal findings on the physical or chemical examination of urine. It is performed on urine sediment to detect RBCs, WBC, epithelial cells, microorganisms (bacteria, yeast, trichomonads), casts, crystals.
  71. Urine Culture & Sensitivity
    • Ordered when symptoms indicate the possibility of a urinary tract infection, such as pain and burning when urinating and frequent urge to urinate. Antibiotic therapy may be prescribed without requiring a urine culture for symptomatic young women who have an uncomplicated lower urinary tract infection. If there is suspicion of a complicated infection or symptoms do not respond to initial therapy, then a culture of the urine is recommended. Pregnant women without any symptoms may be screened for bacteria in their urine, which could affect the health and development of the fetus.
    • A urine culture may be ordered with a urinalysis or as follow up to abnormal results on a urinalysis.
  72. BUN
    • (Blood Urea Nitrogen)
    • used, along with the creatinine test, to evaluate kidney function in a wide range of circumstances, to help diagnose kidney disease, and to monitor people with acute or chronic kidney dysfunction or failure. It also may be used to evaluate a person's general health status when ordered as part of a basic metabolic panel (BMP) or comprehensive metabolic panel (CMP).
  73. Creatinine
    used along with a BUN (blood urea nitrogen) test to assess kidney function
  74. Creatinine clearance
    • used to help evaluate the rate and efficiency of kidney filtration. It is used to help detect and diagnose kidney dysfunction and/or the presence of decreased blood flow to the kidneys.
    • In people with known chronic kidney disease or congestive heart failure (which decreases the rate of blood flow), the creatinine clearance test may be ordered to help monitor the progress of the disease and evaluate its severity. It may also be used to help determine if and when kidney dialysis may be necessary.
  75. BUN/Creatinine Ratio
    The ratio of BUN to creatinine is usually between 10:1 and 20:1. An increased ratio may be due to a condition that causes a decrease in the flow of blood to the kidneys, such as congestive heart failure or dehydration. It may also be seen with increased protein, from gastrointestinal bleeding, or increased protein in the diet. The ratio may be decreased with liver disease (due to decrease in the formation of urea) and malnutrition.
  76. FeNa
    • (Fractional excretion of sodium)
    • a medical parameter representing the fraction of sodium in urine relative to the fraction of sodium in circulation
    • an assessment of acute renal failure comparing the sodium clearance with the creatinine clearance
  77. Therapeutic drug level
    the measurement of specific drugs at timed intervals in order to maintain a relatively constant concentration of the medication in the bloodstream. Monitored drugs tend to have a narrow "therapeutic index," a ratio between the toxic and therapeutic doses of medications. For some drugs, maintaining this steady state is not as simple as giving a standard dose of medication. Each person will absorb, metabolize, utilize, and eliminate drugs at different rates based upon their age, general state of health, genetic makeup, and the interference of other medications that they are taking. These rates may change over time and vary from day to day. Changes in the rate may also occur in various disease states or through interaction with other medications.
  78. Blood alcohol level
    Measures the amount of alcohol (ethanol) in the blood. 0.08% is considered legally intoxicated in most states
  79. Urine drug screen
    to determine whether a person has illegal or banned substances in his or her body.
  80. Liver Function Panel
    • (LFT)
    • Albumin
    • Total protein (TP)
    • Alkaline phosphatase (ALKP, AP, Alk Phos)
    • Alanine aminotransferase (ALT, (SGPT))
    • Aspartate aminotransferase (AST, (SGOT))
    • Bilirubin (Total; Direct)
  81. 4 categories of liver tests
    • Hepatocellular damage - check AST, ALT
    • Cholestatis - check Alk Phos, GGT
    • Biliary (liver) excretion - check Tbili, Dbili
    • Liver synthetic function (Liver Metabolism) - check Albumin, TP, Protime
  82. AST
    • Aspartate aminotransferase (AST)
    • Serum glutamic-oxaloacetic transaminase (SGOT)
    • Marker of Hepatocellular Damage
    • A catalytic enzyme found primarily in the heart, liver and muscle tissue, also intestine and pancreas
    • Not very specific for liver disease
    • Levels elevated with any serious damage to cells
    • AST very high in acute pancreatitis
    • Ratio of 2:1 for AST to ALT
    • No "L" in cirrhosis (ALT)
  83. ALT
    • Alanine aminotransferase
    • Serum glutamic pyruvic transaminase (SGPT)
    • Marker of Hepatocellular Damage
    • An enzyme primarily produced by the liver
    • Necessary for amino acid production
    • Used to evaluate level of liver damage
    • In early stages of liver injury, ALT surpasses AST levels and is more specific to the liver
    • Found primarily in hepatocytes.
    • Released when cells are damaged or destroyed.
  84. Very high ALT and AST
    • usually only come from a couple of sources:
    • Acute viral hepatitis (A,B,C, HSV)
    • Acetaminophen toxicity/overdose
    • "Shock Liver"; cardiac or surgical event?
    • Most other causes don’t produce such high levels.
  85. Hepatocellular Damage
    • Liver biopsy is gold standard
    • Biopsy is second only to a good history.
    • If a biopsy is obtained, need a sufficiently experienced pathologist to interpret it accurately;
  86. Alkaline phosphatase
    • Marker of Cholestasis
    • Enzyme that assists in the transfer of amino acids
    • Sensitive for cholestasis & liver infiltration
    • Limited specificity
    • Found in liver, bone, intestines, pediatrics, placenta
    • Isoenzyme available to further evaluate elevated level - determine source
    • If elevated with GGT, suggests hepatic origin
    • Ideally should be measured fasting
    • Only alk phos has variable range depending on age/sex
    • Find out if pregnant - found in placenta
  87. GGT
    • Marker of Cholestasis
    • A biliary excretory enzyme that assists in transfer of amino acids and peptides across cell membranes
    • Found in the liver, heart, pancreas, kidneys, etc.
    • Used to evaluate progression of liver disease and hepatic metastasis
    • Progression/regression of carcinoma associated with increasing/decreasing levels
    • Screening tool for ETOH abuse
    • GGT stays elevated longer than AST or ALT in cases of binge drinking
  88. Amylase
    • An enzyme that aids digestion of complex carbs
    • Produced in salivary glands and pancreas
    • Inflammation of pancreas causes release of amylase
    • Acute pancreatitis:
    • Increases in ~2 hrs, peak at ~24 hrs, returns to normal in 2-4 days
    • Excreted in the urine
    • Order with Lipase for suspicion of pancreas dysfunction, trauma to pancreas, alcoholics, gallstones
  89. Lipase
    • A pancreatic enzyme that changes fats & triglycerides into fatty acids and glycerol
    • Rises and falls in tandem with Amylase
    • Highly specific for the pancreas
    • Acute pancreatitis - Increases in 2-6 hrs, peaks in 12-30 hrs, remains elevated but slowly decreases for 2-4 days
    • Order with Amylase
    • Amylase also produced in salivary glands so lipase more specific to pancreas
  90. Albumin
    • Marker of Hepatic Synthetic Function
    • (Liver Metabolism)
    • One of two main proteins in blood (other is globulin)
    • Functions to maintain oncotic pressure and transport substances
    • Synthesized in the liver and correlates with severity of liver disease
    • Decreased in malnutrition
    • Reabsorbed by the kidneys, therefore presence in urine → abnl renal function?
    • Edema can be caused by decrease in albumin level, decrease in oncotic pressure
  91. Bilirubin
    • Marker of liver excretion
    • Produced in the liver, spleen and bone marrow
    • Also a by-product of hemoglobin breakdown
    • Total bilirubin increases with jaundice
    • Total Bilirubin broken down into Direct (Conjugated) & Indirect (Unconjugated, Free)
    • Direct or Indirect rise based on etiology
    • Hemolytic anemia – increased total and indirect bili
  92. Direct Bilirubin
    • Marker of liver excretion
    • Excreted by intestinal tract
    • Increased with obstructive or hepatic jaundice (impaired excretion)
    • Directly measured
  93. Indirect Bilirubin
    • Marker of liver excretion
    • Circulates in blood
    • Increased with RBC breakdown
    • Old RBCs, removed by the spleen, sent to the liver
    • Liver "adds" glucuronic acid, making these cells water soluble for excretion; now called direct (or conjugated)
    • Calculated from Total Bilirubin and Direct Bilirubin
  94. Total protein
    • (TP)
    • Marker of Hepatic Synthetic Function
    • (Liver Metabolism)
    • Total amount of albumin and globulin in the serum
    • Serum proteins are synthesized in the liver and RE system, and constitute >100 different substances
    • Decreased in severe hepatic disease and malnutrition
  95. 5’NT
    • (Five Prime Nucleotidase)
    • A plasma membrane enzyme
    • An isoenzyme of Alk Phos found in hepatic parenchyma and bile duct cells
    • When coupled with elevated Alk Phos, increased levels are indicative of liver metastasis
    • Order for pediatric or pregnant patients
  96. Protime
    • (Prothrombin time)
    • Marker of Hepatic Synthetic Function
    • (Liver Metabolism)
    • A glycoprotein produced in the liver
    • Necessary for firm fibrin clot formation
    • Measures the time required for a fibrin clot to form
    • Elevation indicates hepatic disease, clotting factor deficiency or anticoagulation
    • Extrinsic pathway
    • Compared with control times
    • Variations with methods
    • Coumadin therapy - INR replaces PT
  97. Ammonia
    • (NH3)
    • A waste product of nitrogen breakdown during protein metabolism
    • It is metabolized by the liver (and excreted as urea by the kidneys)
    • Elevated levels may lead to encephalopathy
    • Order for someone in a coma
  98. Hemoccult
    • Stool for occult blood (aka - FOBT)
    • Cannot be used for vomitus due to pH
    • Has its own developer solution
    • Indicates bleeding somewhere in the GI tract
    • Useful for Colon cancer screening
    • 3 days prior to and during the test period - do not eat red meat
    • 7 days prior to and during the test period - avoid NSAIDs (ie- Ibuprofen)
    • If taking Aspirin, limit = 1 adult aspirin per day.
  99. Gastroccult
    • Vomitus for occult blood
    • Cannot be used for stool testing
    • Has its own developer solution
    • Indicates bleeding in the upper GI tract only
    • Not useful for cancer screening
  100. Urease breath test
    • Radioactive labeled urea ingested by patient
    • If urease activity present then radioactive CO2 is exhaled
    • Radioactivity is measured
    • Highly sensitive
  101. Stool Culture, bacterial
    • A stool culture is indicated for:
    • Persistent diarrhea
    • Bloody diarrhea with fever
    • Travel to endemic areas
    • Immunocompromised patient with diarrhea
    • Known exposure to enteric pathogens
    • Recent Antibiotic use (antibiotic-associated diarrhea - AAD)
    • Rules out:
    • Salmonella, Shigella, E.coli, Campylobacter species and yeast. All other pathogens require specific request based upon clinical suspicion
  102. Clostridium difficile
    • a spore-forming, gram-positive anaerobic bacillus, that produces two exotoxins. It is a common cause of antibiotic-associated diarrhea.
    • It accounts for up to 25% of all episodes of AAD (antibiotic associated diarrhea)
  103. Stool for ova & parasite
    • 3 Separate Specimens collected 2-3 days apart
    • Specific clinical information should be provided as preparation differs for different organisms.
  104. Scotch tape prep
    • Scotch Tape Test for Enterobius vermicularis (aka - Pinworm)
    • Presenting complaint is perianal itching
    • Most often seen in small children
    • Day care increases risk
    • Organism is pinworm
    • For tapeworms the whole stool specimen is required.
    • Commercial kits available $$$$
    • Use tongue blade and clear tape
    • Early morning
    • Touch to several places around the anus
    • Attach to glass slide
    • Put in clean container
  105. Acute hepatitis panel
    • used to help detect and/or diagnose acute liver infection and inflammation that is due to one of the three most common hepatitis viruses - hepatitis A virus (HAV), hepatitis B virus (HBV), or hepatitis C virus (HCV).
    • Hepatitis A antibody, IgM
    • Hepatitis B core antibody, IgM
    • Hepatitis B surface Ag
    • Hepatitis C antibody
    • HAV antibody, total
    • HBV core antibody, total
    • HBV surface antibody
  106. Fecal fat
    • Assessment for fat malabsorption
    • A number of diseases of the pancreas & GI tract are characterized by fat malabsorption
    • The Test:
    • A random fecal specimen is submitted to the lab and examined under the microscope after staining with a Sudan dye ("Sudan staining")
    • Visible amounts of fat indicate malabsorption and this is then quantified
  107. Fecal pH
    • A specimen of feces is tested for acidity
    • Human feces is normally alkaline
    • An acidic stool can be indicative of a digestive problem such as lactose intolerance or a contagion such as E. coli or Rotavirus
  108. Fecal leukocytes
    • Normally, there are no WBCs in stool.
    • Large numbers of WBCs in the stool may be seen in chronic bacillary dysentery, chronic ulcerative colitis, colonic abscess
    • Monocytes are seen in Typhoid Fever
    • Neutrophils are seen in invasive E.Coli diarrhea, Salmonella, Shigellosis
  109. Wet mount
    A sample of the vaginal discharge is placed on a glass slide and mixed with a salt solution. The slide is looked at under a microscope for bacteria, yeast cells, trichomoniasis (trichomonads), white blood cells that show an infection, or clue cells that show bacterial vaginosis.
  110. KOH test
    Test for Candida albicans (spaghetti and meatballs), also known as a potassium hydroxide preparation or KOH prep, is a quick, inexpensive fungal test to differentiate between dermatophytes (wavy-branched hyphae) and Candida albicans symptoms from other skin disorders like psoriasis and eczema.
  111. Vaginal pH
    • The normal vaginal pH is 3.8 to 4.5. Bacterial vaginosis, trichomoniasis, and atrophic vaginitis often cause a vaginal pH higher than 4.5.
    • Trichomonas, Bacterial vaginosis have pH > 4.5
    • Candida albicans has pH < 4
  112. GC/Chlamydia screen
    Testing for Chlamydia trachomatis and Neisseria gonorrhoeae (gonorrhea) is generally done simultaneously as the two organisms have similar clinical presentations. A definitive diagnosis is important since the symptoms of chlamydia can resemble those of gonorrhea and the two infections require different antibiotic treatment.
  113. RPR
    • (Rapid Plasma Reagin)
    • A Nontreponemal Test (along with VDRL)
    • RPR is more sensitive than VDRL, considered a screening test.
    • Indirect test for syphilis
  114. Tzanck smear
    • a microscopic examination of cellular material from skin lesions to help diagnose certain vesicular diseases. The tissue is scraped from the base of a vesicle, placed on a slide, and stained with Wright's or Giemsa's stain.
    • Multinucleated giant cells are diagnostic of herpesvirus or varicella. Typical pemphigus (acantholytic cells) and other cells also can be identified.
    • Rapid but not very accurate.
  115. Mineral oil prep
    A mineral oil preparation refers to the specimen-containing glass slide that is to be examined using a microscope when attempting to confirm a clinically suspected diagnosis of scabies.  A skin scraping is the procedure usually used to create a mineral oil preparation.  This procedure is rapid, easy to accomplish, and able to be performed--without anesthesia--in the examination room.
  116. Rapid HIV screen
    Test is rapid but doesn't account for the window where levels are high enough to detect.  A positive result should be confirmed with a Western blot test
  117. CD4 count
    • to monitor progression of HIV/AIDS
    • Symptomatic period - Typically begins when CD4 <350
    • AIDS occurs when CD4 <200 (regardless of sx)
    • Very severe disease when CD4 <50
  118. HIV viral load
    • HIV RNA test
    • Test for acute infection of HIV
    • ELISA won't be positive until a few weeks post exposure so viral load test should be done first
  119. X-ray used to evaluate
    • Chest - Infiltrative processes, infectious processes, pulmonary neoplasms, pulmonary emboli, atelectasis, Heart size and diaphragmatic position.
    • Abdominal - Bowel OBS., perforated viscous ("free air"), organomegally, large abdominal masses or fluid collections/ascites.
    • Skeletal - Bony fractures, dislocation, arthritic processes, bony neoplasms, growth and/or malalignment disorders.
  120. CT used to evaluate
    • Brain
    • Sinuses
    • Organs & tissues of the face & neck
    • Chest
    • Abdomen
    • Pelvis
    • Soft tissues of the extremities
    • Joints (especially following arthrography)
    • Blood vessels or heart using a technique known as CT-angio (CTA)
    • Spinal cord following myelography.
  121. MRI used to evaluate
    • Brain & Spinal Cord
    • Nerves
    • Skeletal System & Joints.
    • Abdomen/Pelvis
    • Chest
    • Soft tissues of the extremities.
    • Blood vessels (MRA)
    • Gallbladder and bile ducts. (MRCP)
    • Breast
    • Prostate
    • Heart
    • Joints post arthrography
  122. Contraindications to MRI
    • Pacemakers
    • AICD's
    • Cerebral aneurysm clips prior to 1990.
    • Neuro-stimulators
    • Metal joint replacements degrade the image greatly making scanning in or around these objects difficult.
    • Any other inplantable and/or non-removable metallic device is suspect. Ask the MRI technologist at the medical imaging center if you have any questions concerning a potentially hazardous foreign body or device.
    • Metformin and contrast - nephrogenic systemic fibrosis (NSF)
  123. Wood's Light
    • long wavelength UV light, need dark room
    • fluorescence seen
    • Tinea capitis - green
    • Erythrasma - coral pink
    • Pseudomonas - green and sweet smell
    • Accentuates subtle disorders of pigmentation (vitiligo)
  124. Diascopy
    • glass slide pressed on a vascular lesion to blanch it and verify redness is caused by vasodilation.
    • Confirms presence of extravasated blood in dermis (petechiae and purpura do not change with pressure)
  125. Dermoscopy
    • 10x hand-held dermatoscope to view structures not visible to the naked eye
    • Use ultrasound gel, mineral oil (scabies), alcohol, or water
    • Key use in distinguishing melanocytic lesions (nevi & melanomas) from non-melanocytic lesions (seborrheic keratoses, angiomas, pigmented BCC)
  126. Skin biopsy
    • surgical removal of piece of skin
    • techniques used - shave, snip, punch, incisional, excision, curettage
    • Use local anesthetic
    • Sample fresh lesion, near lesion's edge
    • Avoid where scar would be obvious, upper trunk and jaw line have risk of keloids, lower legs have slow healing, over bony prominences have issues with wound healing and infection.
    • Avoid crushing tissue, place in fixative (H&E), label appropriately (site, name, age, sex of patient), hx of lesion/condition, ddx
  127. Direct Immunofluorescence
    • Detects antibodies in patient's skin
    • IgG, IgM, IgA, C
  128. Indirect Immunofluorescence
    • Detects antibodies in patient's serum
    • 2 steps; (1) antibodies in the patients serum are made to bind to antigens in a section of normal skin (2) antibody raised against human immunoglobulin, conjugated with a florescent dye can then be used to stain these bound antibodies.
  129. Mohs Micrographic Surgery
    • Fixed tissue
    • Fresh tissue
    • A therapy for broad-based, shallow BCC or SCCs, especially for lesions that are 1–2 cm, recurring or on recurrence-prone sites (nose, eyes, ears), or are aggressive histologic subtypes (e.g., sclerosing (morphoeic) BCC).
  130. Cryotherapy/cryosurgery
    • Destruction of tissue by freezing in a controlled manner, to produce sharply circumscribed necrosis
    • Tissue destruction results from intracellular and extracellular ice formation, denatured liquid protein complexes, and cell dehydration
    • Liquid Nitrogen - LN2 (-195.8° C)
    • Most commonly used on warts, molluscum contagiosum, skin tags, seborrheic keratoses, and actinic keratoses
  131. Patch test
    • to detect allergens responsible for allergic contact dermatitis.
    • Type IV delayed hypersensitivity
    • Applied via Finn chambers, remove at 48 hours, read in 10 minutes.
    • May have delayed reaction 1-2 days later (72-96 hours)
    • Results are read as (-) no reaction, (+/-) minimal erythema, (1+) weak positive - erythema and some papules, (2+) strong reaction - palpable erythema and/or vesicles, (3+) reaction (intense palpable erythema, coalescing vesicles and/or bullae
  132. Nontreponemal Tests
    • for screening
    • VDRL - Venereal Disease Research Laboratory
    • RPR - rapid plasma reagin
  133. Treponemal Tests
    • for confirmation
    • Darkfield exam - view spirochetes
    • Direct fluorescent antibody tests - view spirochetes
    • Fluorescent Treponemal Antibody Absorbed (FTA-ABS)
    • Treponema pallidum particle agglutination assay (TP-PA)
    • also EIA and rapid test
  134. Indications for CSF examination
    Tertiary Syphilis symptoms - neurologic or ophthalmic signs/symptoms, aortitis, gumma, iritis, treatment failure, HIV infection with late latent syphilis or syphilis of unknown duration
  135. Painful chancre
    • H. ducreyi - multiple lesions
    • Chancroid
    • Dx by gram stain
    • negative test for syphilis and HSV
    • common in underdeveloped countries
  136. Chlamydia testing
    • Gold standard - culture, uses swab of urethra in males, endocervical swab in females
    • NAAT - Nucleic acid amplification testing - more specific than culture. Uses urine, liquid pap testing, cervical and urethral swab
  137. Gonorrhea testing
    • Gram stain - gram negative diplococcus
    • NAAT
  138. IgM
    • primary antibody response
    • acute disease testing in CMV, toxoplasmosis, VZV, HSV
    • Four-fold increase in titer is a "positive" (x*2^4)
  139. IgG
    • secondary antibody response
    • may reflect acute process, prior disease, immunizations
  140. Direct examination for viral testing
    • antigen detection - immunofluorescence, ELISA
    • Electron and light microscopy
    • Viral genome detection - PCR
  141. Serology
    • detection of rising titers of antibody between acute and convalescent stages of infection
    • detection of IgM in primary infection
  142. Criteria for diagnosing primary infection
    • Presence of IgM
    • Seroconversion
    • (a single high titer of IgG (or total antibody) is very unreliable)
  143. Criteria for diagnosing reinfection
    • 4 fold or more increase in titer of IgG or total (X*2^4)
    • antibody between acute and convalescent
    • absence or slight increase in IgM
  144. HPV strains that cause cancer
    16 & 18
  145. RAIU
    • radioactive iodine uptake
    • distinguish between causes of hyperthyroidism
    • high uptake = Grave's disease, toxic adenoma and multinodular goiter
    • low uptake = subacute thyroiditis, postpartum thyroiditis, exogenous intake
  146. Thyroid ultrasound
    • diagnostic tool to assess thyroid structure and nodules
    • aids in differentiation of solid vs cystic nodules
    • not a screening test
  147. FNA
    • fine needle aspiration
    • simple office biopsy procedure
    • GOLD STANDARD for assessing larger nodules (>1cm)
  148. Hot thyroid nodule
  149. Cold thyroid nodule
    • first do FNA
    • 15% identified by FNA as malignant
Card Set
Diagnostic Methods - Lab Req and other tests
Diagnostic Methods III - PAP-589, Lab Requisition Tests
Show Answers