Laboratory and Diagnostic Testing. Everything you need to know

Transcription

1 Laboratory and Diagnostic Testing Everything you need to know

2 Objectives Discuss the use of common tests and procedures Identify abnormal findings of commonly used tests and procedures Describe nursing care of patients undergoing diagnostic procedures Explain reasons for preparation of patients for tests and procedures

3 Specimen Collection and Diagnostic Exams Explain the rationales for collection of each specimen listed: urine, stool, sputum Discuss guidelines used for obtaining throat and wound cultures State appropriate labeling for a collected specimen List the proper steps for measuring blood glucose levels Discuss the procedure for obtaining a sputum specimen List the proper steps when obtaining urine specimens

4 Before You Start Wash your hands Wear gloves

5 Label all containers with appropriate patient identifiers Date Time Initial Place specimens in proper containers/ biohazard bags Have consents signed for invasive procedures

6 Blood Glucose Monitoring Normal Blood glucose: Monitor glucose levels to manage insulin administration Patient teaching Wash patient s hands Use side of the finger not the pad Wipe off first drop of blood Place large drop of blood on test strip Document procedure

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8 Urine Specimens Test for infection Assess metabolic function Assess kidney function Test for drugs/ alcohol

9 General characteristics and measurements: Color: pale yellow to amber Appearance: clear to slightly hazy Specific Gravity: ph: (average ph between 5 and 6) Volume: 1500cc/24 hours (adult) Chemical determinations: Glucose: negative Ketones: negative Blood: negative Protein: negative Nitrate for bacteria: negative Leukocyte esterase: negative Microscopic exam of sediment: Casts: negative (occasional hyaline casts) Red blood cells (RBCs): negative or rare White blood cells (WBCs): negative or rare Crystals: negative Epithelial cells: few

10 Urine collection technique for women Wash hands with soap and water Spread labia with 1 hand and hold apart for collection Use three povidone-iodine swabs to clean area Wipe down one side, front to back, with one swab Wipe down other side, front to back, with second swab Wipe down center, front to back, with last swab Dry area with sterile gauze Void into toilet for a few seconds and then stop Restart urine stream and collect in sterile container Cap and avoid touching inside of container

11 Urine collection technique for men Wash hands with soap and water Retract foreskin if needed Use povidone-iodine swabs to clean tip of penis Clean glans penis Clean urethral opening Dry area with sterile gauze Void into toilet for a few seconds and then stop Restart urine stream and collect in sterile container Cap and avoid touching inside of container

12 Urine Collection from a catheter Never open the closed system Don t take urine from the collection bag Cleanse collection port with alcohol swab Use sterile needle and syringe Transfer urine to specimen container Dispose of syringe in sharps container

13 Lab requirements At least 10 ml First voided morning urine is more concentrated abnormalities are easier to detect

14 24 Hour Urine Collection Reveals how kidneys adapt to physiologic needs over time Begin test after patient empties bladder Collect all urine over the next 24 hours Collection may need to be chilled

15 Sputum Collection Gather sterile specimen container Explain what is needed to patient Have patient deep breathe and cough Expectorate into container Need sputum NOT saliva

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17 If patient is unable to expectorate, suctioning may be required

18 Stool guaiac test detects the presence of hidden (occult) blood in the stool red meat, any blood-containing food, cantaloupe, uncooked broccoli, turnip, radish, or horseradish eaten 3 days prior to the test may give false positive

19 Colon polyps Colon cancer or other gastrointestinal (GI) tumors Esophagitis Gastritis GI trauma or bleeding from recent GI surgery Hemorrhoids Inflammatory bowel disease Peptic ulcer Angiodysplasia of the GI tract GI infections Esophageal varices and portal hypertensive gastropathy

20 Stool Ova and parasites Culture C. dificil For occult blood only a thin smear is needed

21 Throat Culture Not all bacteria cause illness. Actually the mouth normally contains many types of bacteria which would contaminate the throat culture sample. The swab is taken from the tonsils to isolate primarily infecting bacteria. Even though care is taken not to touch the teeth, roof of the mouth, or tongue when the swab is taken, other bacteria are nevertheless apt to be present in the sample.

22 Throat cultures

23 Wound culture To collect a tissue or fluid sample from a wound, a sterile swab is inserted into the wound. It may be necessary to press around the wound and gently turn the swab to collect as much tissue or fluid as possible. The swab is then placed into either an aerobic or anaerobic culture tube or both, depending on the type of organism suspected

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26 Radiologic Exams The chest x-ray is performed to evaluate the lungs, heart and chest wall. A chest x-ray is typically the first imaging test used to help diagnose symptoms such as: shortness of breath a bad or persistent cough chest pain or injury fever. Physicians use the examination to help diagnose or monitor treatment for conditions such as: pneumonia heart failure and other heart problems emphysema lung cancer Confirm tube placement

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28 CT Scans Becoming the preferred method of diagnosing diseases of bowel and colon May require pt to be NPO or take contrast Know patient allergies to contrast or shellfish Is patient taking metformin or glucophage

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30 Echocardiogram

31 Endoscopy Bronchoscopy Colonoscopy Esophogogastroduodenoscopy (EGD)

32 Colonoscopy Bowel must be empty Used to visualize inside of colon Screen for polyps, colon cancer, lower GI bleeding

33 Nursing Considerations Make sure patient has been NPO Make sure patient has finished bowel prep Patient education Reassurance IV Pain control Follow-up

34 Usually done while patient is sedated but not completely anesthetized. LVN assists MD with procedure, handling equipment, moving patient, etc.

35 EGD NPO after midnight Patient education IV, reassurance Visualize esophagus and stomach Screen for ulcers, esophageal varices Open blocked esophagus

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38 After Care Monitor until patient is awake Gag reflex intact No pain Patient education

39 Thoracentesis Assist with Positioning Reassurance Aftercare

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42 Laboratory Tests Blood tests used to : Diagnose illness Monitor drug levels Monitor disease and healing

43 Common Lab Orders CBC H&H BMP CMP BNP Lytes Mg+ Ca+ Phos Trop CK UA HbA1C ABG s BG LFT Amylase BUN/Creat

44 Amalayse The blood test for amylase is used to diagnose pancreatitis (swelling of the pancreas) and other pancreatic diseases. The near-immediate rise of amylase at the beginning of a pancreatitis attack, and its fall after about 2 days, helps to pinpoint this diagnosis. Amylase is also used (to a lesser extent) in the diagnosis and follow-up of cancer of the pancreas, ovaries, or lungs; gallbladder attack; and mumps.

45 CBC The CBC is used as a broad screening test to check for such disorders as anemia, infection, and many other diseases. It is actually a panel of tests that examines different parts of the blood

46 White blood cell (WBC) count is a count of the actual number of white blood cells per volume of blood. Both increases and decreases can be significant. White blood cell differential looks at the types of white blood cells present. There are five different types of white blood cells, each with its own function in protecting us from infection. The differential classifies a person's white blood cells into each type: neutrophils (also known as segs, PMNs, grans), lymphocytes, monocytes, eosinophils, and basophils Normal: x10 9

47 Red blood cell (RBC) count is a count of the actual number of red blood cells per volume of blood. Both increases and decreases can point to abnormal conditions Decreased with anemia Increased with dehydration or overproduction

48 Hemoglobin measures the amount of oxygen-carrying protein in the blood Normal value: Men: Women: 12 16

49 Hematocrit measures the amount of space red blood cells take up in the blood. It is reported as a percentage. Normal: Men: % Women: 37 47%

50 Platelets The platelet count is the number of platelets in a given volume of blood. Both increases and decreases can point to abnormal conditions of excess bleeding or clotting. Mean platelet volume (MPV) is a machine-calculated measurement of the average size of the platelets. New platelets are larger, and an increased MPV occurs when increased numbers of platelets are being produced. MPV gives the doctor information about platelet production in the bone marrow. Normal: 130, ,000

51 : Erythrocyte Sedimentation rate tests how quickly RBC s settle in a test tube in one hour. Increased ESR indicative of inflammation Males younger than 50:0 15 millimeters per hour (mm/hr) Males 50 and older:0 20 mm/hr Females younger than 50:0 25 mm/hr Females 50 and older:0 30 mm/hr

52 Lytes Electrolytes are salts that conduct electricity and are found in the body fluid, tissue, and blood. Examples are chloride, calcium, magnesium, sodium, and potassium. Sodium (Na+) is concentrated in the extracellular fluid (ECF) and potassium (K+) is concentrated in the intracellular fluid (ICF). Proper balance is essential for muscle coordination, heart function, fluid absorption and excretion, nerve function, and concentration.

53 Magnesium Magnesium is needed for more than 300 biochemical reactions in the body. It helps maintain normal muscle and nerve function, keeps heart rhythm steady, supports a healthy immune system, and keeps bones strong. Magnesium also helps regulate blood sugar levels, promotes normal blood pressure, and is known to be involved in energy metabolism and protein synthesis. There is an increased interest in the role of magnesium in preventing and managing disorders such as hypertension, cardiovascular disease, and diabetes. Dietary magnesium is absorbed in the small intestines. Magnesium is excreted through the kidneys.

54 Magnesium Normal: meq/l 40-60% stored in muscle and bone, 1/3 bound to plasma proteins Hypermangesemia: renal failure, excess intake (usually through antacids), adrenal insufficiency. Excess causes: skeletal smoot muscle contraction, excess nerve function, loss of DTR, N/V, bradycardia, resp. distress

55 Magnesium Hypomagnesemia <1.5 meq/l Malnutrition, malabsorption, renal tubular dysfunction, loop diuretics Causes: Behavioral changes, increased reflexes, muscle cramps, ataxia, nystagmus, convulsions, tachycardia, hypotension

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57 Potassium Normal Kidneys are the most efficient regulator of potassium balance 98% of total body K+ is located in the cells Regulates muscle activity via maintenance of electrical conduction Regulates acid/base balance Required for deposition of glycogen and glucose in liver and skeletal muscle cells

58 Hypokalemia Etiology: Diuretics, diarrhea, vomiting, malnutrition, renal losses associated with glycosuria, ketonuria, hyperaldosteronism. K+ shifts into cells with alkalosis insulin administration S/S: confusion; rapid, weak, irregular pulse; hypotension, anorexia, decreased reflexes, muscle weakness, paresthesia, EKG changes

59 Hyperkalemia Causes: renal failure, cell damage from burns, injuries, chemotherapy, acidosis, DM S/S: Weakness, malaise, nausea, diarrhea, muscle irritability, oliguria,bradycardia, EKG changes

60 Sodium Normal: Sodium is the main cation (positive ion) that circulates in the body fluids outside the cells. It is a critical component in blood pressure maintenance. Sodium is also essential for the proper workings of nerves and muscles.

61 Hyponatremia Burns Vomiting and diarrhea Use of diuretics ("water pills"), especially of the type known as thiazide diuretics Certain kidney diseases Liver cirrhosis Congestive heart failure Syndrome of inappropriate antidiuretic hormone secretion (SIADH, S/S: fatigue, headache, restlessness, nausea, muscle cramps, disorientation, coma, seizures, death

62 Hypernatremia Findings Cognitive dysfunction Dehydration or volume-associated findings Details Lethargy, obtundation, confusion Abnormal speech Irritability Orthostatic blood pressure changes Tachycardia Oliguria High BUN-tocreatinine ratio Dry axillae O

63 Risk factors for hypernatremia Age older than 65 years Mental or physical disability Hospitalization (intubation, impaired cognitive function) Residence in nursing home Inadequate nursing care Urine concentrating defect (diabetes insipidus) Solute diuresis (diabetes mellitus) Diuretic therapy

64 Calcium Normal Function: Promotes and regulates neuromuscular and enzyme activity, coagulation

65 Hypocalcemia Causes: parathyroid insufficiency, hypomagnesemia, hyperphosphatemia, laxatives, malabsorption, malnutrition, diarrhea, vitamin D deficiency S/S: circumoral and peripheral paresthesias, muscle twitching, facial spasm, muscle cramping, seizures, dysrhythmias

66 Hypercalcemia Hypercalcemia is a higher than normal level of calcium in the blood. The most common cause is an overactive parathyroid gland (hyperparathyroidism). The parathyroid glands, which are located below the thyroid gland, regulate calcium in your body. Other causes of hypercalcemia include: Certain medications, such as lithium or thiazide diuretics Certain cancers, including breast, lung and certain blood cancers Sarcoidosis, an inflammatory disorder Excessive intake of calcium or vitamin D supplements Familial hypocalciuric hypercalcemia, a genetic disorder Dialysis for chronic kidney failure Adrenal gland failure Overactive thyroid (hyperthyroidism)

67 Hypercalcemia Nausea/vomiting Excessive thirst Constipation Abdominal pain Muscle weakness Lethargy and fatigue Confusion May cause kidney stones and dysrhythmias

68 Stain urine for stones Send stones to lab for analysis

69 Chloride Normal Functions: Varies inversely with bicarbonate, maintain acid/base balance, associated with low Na+ and low K+ levels

70 Hyperchloremia Occurs when there is too much NA+ or too little bicarbonate No specific symptoms are associated with too much chloride

71 Hypochloremia Causes: Hyponatremia or elevated bicarbonate levels as in metabolic alkalosis. May develop with vomiting and the loss of hydrochloric acid. Cystic fibrosis is characterized by hypochloremia.

72 BUN Normal: 10-20mg/dL Reflects protein intake, liver function, kidney excretory capacity. Elevation without concurrent creatinine elevation is indicative of dehydration Increases: renal disease, inadequate renal blood flow, urinary tract obstruction, protein catabolism as seen in burns and starvation. Decreases: severe liver failure, malnutrition, overhydration,

73 Creatinine Normal: <1.5 mg/dl Excreted by kidneys Increase: Renal disease, DKA, starvation, muscle disease, hyperthyroidism, diuretics, barbiturates

74 BNP Brain Natriuretic peptide Regulates sodium excretion (natriuresis), diuresis, vasodilation leading to large volume of dilute urine BNP levels below 100 pg/ml indicate no heart failure BNP levels of suggest heart failure is present BNP levels above 300 pg/ml indicate mild heart failure BNP levels above 600 pg/ml indicate moderate heart failure. BNP levels above 900 pg/ml indicate severe heart failure.

75 CPK Creatinine phosphokinase An enzyme found in muscle tissue Elevated levels indicate muscle injury CK-MB elevations indicate cardiac muscle injury CK-MM skeletal muscle CK-BB brain tissue

76 Troponin Troponin I: protein released by heart muscle is a specific marker for cardiac injury

77 Specimen Collection

78 Correctly Label Specimens

79 Patient Teaching About the procdure and what to expect Pain control Home care

80 Documentation Understand the significance of the tests Document how patient tolerated tests Document any patient teaching Report and document abnormalities

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