Lecture Exam #1 Flashcards
Lab Testing
1. Hematology
2. Chemistry
3. Microbiology
4. Bronchoalveolar Lavage
5. Pleural fluid examination
6. Histology and cytology
7. Skin testing
- CBC: Complete Blood Count. Blood sample
- BMP: Basic Metabolic Panel.
- Sputum Sample: Check for disease carrying microorganisms
- Bronchoscope: Tissue sample taken through nose
- Needle Biopsy: Done to get fluid from Pleural space
- Tissue Sample: Check cells
- TB testing
Lab Test Parameters
1. Sensitivity
2. Specificity
- Frequency of positive test results in patients with disease
- Frequency of negative test results in patients without disease
Hematology
1. Blood Composition
2. Two major hematology evaluation tests
- Cells (45%): White blood cells (leukocytes), Red blood cells (erythrocytes), and Platelets (Thrombocytes)
Plasma (55%) - (1) CBC: Complete Blood Count
(2) Test of the blood clotting ability of patient’s blood
Complete Blood Count (CBC)
- This test determines the number of circulating red and white blood cells
- The test also determines the number and type of white blood cells present in the circulating blood
- Red blood cells are evaluated for their size and the amount of hemoglobin present
Reference Intervals for CBC
Red Blood Cell Count
Males: 4.20 - 6.00
Females: 3.80 - 5.20
Reference Intervals for CBC
White Blood Cell Count
Both: 4.0 - 11.0
Reference Intervals for CBC
Hemoglobin
Males: 13.5 - 18.0 (135-180)
Females: 12.0 - 15.0 (120-150)
Reference Intervals for CBC
Hematocrit
Males: 40 - 54 (0.40-0.54)
Females: 35 - 49 (0.35-0.49)
Reference Intervals for CBC
Platelet Count
Both: 150 - 450
Reference Intervals for CBC
“Rule of Five” for RBC, Hemoglobin, Hematocrit
Both Sexes
RBC: 5
Hemoglobin: 5 x 3 = 15 (Hb)
Hematocrit: 15 x 3 = 45 (HcT)
White Blood Cell (WBC) Count
- Total number of white blood cells in a known volume of blood; Important to know
- Important to know distribution of white blood cell types: Neutrophils, eosinophils, lymphocytes, basophils, and monocytes
- In healthy people, neutrophils and lymphocytes make up the majority of WBC count
White Blood Cell (WBC)
1. Relative Percentage
2. Absolute Percentage
- The Relative Count is the percentage of a particular cell among all the WBCs counted
- The Absolute Count for the cell type is determined by the CBC analyzer my multiplying its percentage or relative count by the total WBC Count
Reference Intervals for WBC
Segmented Neutrophils
Relative%: 50-70
Absolute%:1.5-7.5
Reference Intervals for WBC
Eosinophils
Relative%: 1-3
Absolute%: 0-0.4
Reference Intervals for WBC
Basophils
Relative%: 0-1
Absolute%: 0-0.1
Reference Intervals for WBC
Lymphocytes
Relative%: 20-45
Absolute%: 1.0-4.0
Reference Intervals for WBC
Monocytes
Relative%: 2-11
Absolute%: 0.1-1.3
Neutrophils (WBC)
- Normally makes up 50% - 70% of the total white blood cell count
- Produced in the bone marrow, where it matures and waits to be called into action
- Once a neutrophil leaves the bone marrow, it enters the circulating blood
- Next, it marginates through the wall of the blood vessel and into the surrounding tissues
- Once the neutrophil marginates into the tissues, it usually participates in phagocytosis and dies (Pneumonia)
- The normal life span of any neutrophil is 10-12 days
Eosinophils (WBC)
- Make up 1% to 3% of the WBCs
- Plays a role in allergic and parasitic infections
Basophils (WBC)
- Make up 0% to 1% of the WBCs
- Also plays a role in allergic reactions
Lymphocytes (WBC)
- Make up 20% to 45% of the circulating WBCs
- Useful in the fight against viral, fungal, and tuberculosis infections
- Two types of lymphocytes: B cells and T cells
(a) 50% to 85% are T Cells. Involved in cell mediated immunity
(b) B Cells and Natural Killer (NK) Cells comprising 5% to 20% each. Develops antibodies
Monocytes (WBC)
- Make up 2% to 11% of the circulating WBCs
- The largest of the different WBCs
- In the lung, the monocyte converts to a macrophage, then plays a key role in clearing the lung of inhaled dusts through phagocytosis
Leukocytosis
An abnormal increase in the circulating WBCs
Leukopenia
An abnormal decrease in the circulating WBCs
Neutrophilia
An increase in leukocytes due to an increase in neutrophils
Neutropenia
- A decrease in leukocytes due to a decrease in neutrophils
- Is a serious medical problem because it represents a reduced ability to fight infection
- Can be caused by bone marrow failure (chemotherapy or leukemia) or when the cells are destroyed rapidly in the tissues when severe infection is present
Eosinophilia
- Occurs with allergic reactions and parasitic infestations
Basophilia
- Occurs with similar disorders that cause eosinophilia
Lymphocytosis (Lymphocytes are increased)
- Occurs with viral infections, especially mononucleosis
Lymphocytopenia (Decrease in Lymphocytes)
- Seen in acquired and congenital immune deficiency states and in various conditions such as acute inflammation, malnutrition, and after treatment with chemotherapy, radiation, or corticosteroids
- An important feature of HIV infection
Monocytosis (Monocytes are increased)
- Seen in chronic infections such as tuberculosis
- May occur in inflammatory conditions and autoimmune states
Blasts
- Are the most immature stage of a cell type, accumulating in the bone marrow and peripheral blood.
Red Blood Cells
- RBCs are produced in the bone marrow
- They have a life span of 120 days
- RBCs do not marginate into the tissues like WBCs
- Main component of RBCs is Hemoglobin
- Primary function of RBC is to carry oxygen to the tissues with the help of hemoglobin
Anemia
- A low RBC count
Microcytic
- RBCs that are smaller than normal
- usually due to a diet deficiency in Iron
Hypochromic
- RBCs that lack adequate hemoglobin
Polycythemia
- An abnormal increase in the number of circulating RBCs
- Occurs when the bone marrow is overstimulated to produce RBCs in the response to a secondary problem
- Chronic hypoxia, living at high elevation, and some heart disease will cause secondary polycythemia
Hemoglobin
- The protein that carries oxygen to the tissues. Major component of RBCs
- Important in maintaining acid-base (PH) balance by acting as a buffer and by carrying CO2 from the tissues to the lungs
- The hemoglobin molecule consists of four heme groups. Each with an iron molecule capable of binding oxygen, and four globin chains
Platelet Count
- Blood platelets are AKA Thrombocytes
- The lower the platelet count, the more likely the patient will have problems with bleeding
- RTs should check patient’s platelet count before performing an arterial puncture
Thrombocytopenia
- Abnormally low platelet count
Hemostasis
- The ability to prevent hemorrhage, form a blood clot, keep blood flowing in circulation.
Coagulation Screening Tests (3 Total)
- Platelet Count: Having a low platelet count could prevent or reduce the body’s ability to form clots
- aPTT: This test assesses the clotting factors in the intrinsic and common pathways by measuring the length of time required for plasma to form a fibrin clot once the intrinsic pathway is activated. The reference interval varies by laboratory, but it is usually 25-35 Seconds
- PT/INR: the PT assesses the clotting factors in the extrinsic and common pathways and is performed similarly, using activation of the extrinsic system as an initiation point. The reference interval for the PT generally falls between 12-15 seconds. An INR is calculated from the PT result using a formula that takes into account the specific reagents and instrument us for the test.
- Monitor anticoagulation therapy. Patients on Heparin and Coumadin
- D-Dimer: Produced as a result of the breakdown of fibrin clots that form in the vasculature
Chemistry
Basic Metabolic Panel (BMP)
- Measures biochemical compounds and external substances administered to patient
- Basic Metabolic Panel includes
(a) Electrolytes
(b) Glucose level
(c) Blood Urea Nitrogen (BUN)
(d) Creatinine
Reference Intervals for BMP
Sodium
Potassium
Chloride
Total CO2
Glucose
BUN
Creatinine
- Sodium (NA+): 135-145 mmol/L
- Potassium (K+): 3.5-5.0 mmol/L
- Chloride (CL-): 98-107 mmol/L
- Total CO2: 22-30 mmol/L
- Glucose (fasting): 70-99 mg/dL
- BUN: 7-20 mg/dL
- Creatinine: 0.7-1.3 mg/dL
Reference Intervals for Renal Panel
BUN
Creatinine
GFR
Urinalysis
- BUN: 7-20 mg/dL
- Creatinine: 0.7-1.3 mg/dL
- GFR: 90-120 mL/min/1.73 m2
- Urinalysis: Multiple tests
Reference Intervals for Hepatic Panel
Albumin
Total Protein
ALP
ALT
AST
Bilirubin
- Albumin: 3.5-5.0 g/dL
- Total Protein: 6.3-8.0 g/dL
- ALP: 38-126 U/L
- ALT: 10-40 U/L
- AST: 5-30 U/L
- Bilirubin (total): 0.3-1.9 mg/dL
Reference Intervals for Lipid Profile
Total Cholesterol
HDL-C
LDL-C
Triglycerides
- Total Cholesterol: <200 mg/dL
- HDL-C: >39 mg/dL
- LDL-C: <100 mg/dL
- Triglycerides: 30-149 mg/dL
Reference Intervals for Cardiac Biomarkers
Total CK
CK-MB
cTnl
Myoglobin
BNP
- Total CK: 50-200 U/L
- CK-MB: <5% total CK
- cTnl: <0.01 ng/ML
- Myoglobin: 19-92 ug/L
- BNP: <20 pg/L
Chemistry: Electrolytes
Sodium
- Sodium is the primary cation
- Normal Values: 135-145 mEq/L
- Sodium concentration regulated by the kidneys
Hypernatremia
- Loss of Water
Hyponatremia
- Caused by excessive water intake or loss of sodium
Chemistry: Electrolytes
Potassium
- Potassium is the primary intercellular cation
- Normal values: 3.5-5.0 mEq/L
- Increase or decrease potassium levels can lead to cardiac dysfunction
Hypokalemia
- Occurs with decreased intake or increased loss of Potassium
Hyperkalemia
- Occurs with Increased intake or decreased loss of Potassium
Chemistry: Electrolytes
Chloride
- The most common extracellular anion
- Normal values: 98-107 mEq/L
Hypochloremia
- Occurs with severe vomiting and chronic metabolic alkalosis
Hyperchloremia
- Occurs with certain kidney diseases and prolonged diarrhea
Blood Chemistry Tests
Bicarb (total CO2)
- Plays a major role in acid-base balance
- Elevation of bicarb occurs with metabolic alkalosis
- A decrease in bicarb occurs with metabolic acidosis
- COPD patients who have chronic CO2 retention will have an elevated total CO2
Glucose
- Normal fasting blood sugar levels range from 70-99 mg/dL
- Blood glucose is needed to create energy
Hypoglycemia
- A reduce blood glucose
Hyperglycemia
- An elevated blood glucose
- Most often occurs from type II diabetes
Renal Panel
- BUN and Creatinine
(a) The two most common tests to check renal function
(b) Normals
BUN: 7-20 mg/dL
Creatinine: 0.7-1.3 mg/dL
(c) Neither test is sensitive to early kidney disease
(d) Heart failure also elevates the BUN - Glomerular Filtration Rate (GFR)
(a) Used to measure kidney function and assess the stage of kidney disease. The higher the number the worse it is. - Urinalysis: Checks for blood, sugar, and protein in the urine
Hepatic Panel
- Measures Proteins
(a) Albumin
(b) Globulin - Liver-associated enzymes
(a) Alkaline phosphatase (ALP)
(b) Alanine aminotransferase (ALT)
(c) Aspartate aminotransferase (AST) - Bilirubin
(a) A byproduct of the spleen’s normal breakdown of hemoglobin
Enzymes
- Found in all body cells
- When organs suffer damage, an enzyme will elevate in the circulating blood
- In some cases, the type of enzyme found to be elevated along with the medical history can help diagnose the problem.
(a) For example, AST elevates with acute hepatitis and following an acute myocardial infarction
Lipid Panel
- Lipids
- Total cholesterol
(a) High-density lipoproteins (HDLs) <40 mg/dL- “Good Cholesterol” because it removes excess cholesterol from the circulation
(b) Low-density lipoproteins (LDLs) <130 mg/dL - “Bad Cholesterol” because it deposits cholesterol on blood vessel walls
- Can then lead to atherosclerosis
- “Good Cholesterol” because it removes excess cholesterol from the circulation
- Triglycerides 30 to 149 mg/dL
(a) The main storage form of fat in humans
Cardiac Biomarkers
- Chemicals that appear in the blood because of either ischemic myocardial damage or stress
- Creatine Kinase (CK) and its heart-specific isoenzyme CK-MB, myoglobin, and TROPONIN
- The current biomarker used to help diagnose congestive heart failure is B-type natriuretic peptide (BNP)
Microbiology
- Medical microbiology involves the isolation and identification of organisms causing disease in the body
- The RT is often asked to obtain a sputum sample from the patient to identify the organism causing the pneumonia
The Sputum Sample
- A legitimate sample from lower airways is needed to identify the offending organism
- Samples from the mouth that contain mostly epithelial cells are of no value
- Samples from the lung have many leukocytes as seen through a microscope
- The sample undergoes Gram stain and culture
Specimen Sampling
- Preanalytical Phase
(a) Specimen Selection
(b) Collection
(c) Transport - Microscopic examination
- Culture and sensitivity
- Examination of pulmonary secretions
Bronchoalveolar Lavage (BAL)
- Performed during bronchoscopy by injecting a large volume of fluid into the lungs and then collecting it after it mixes with cells in the lung
- Lung lavage diagnosis interstitial lung disease and identifies cause of pneumonia
- BAL is contraindicated in the patient who is unstable and hypoxic
Pleural Fluid Examination
- Normal
(a) Clear and Pale
(b) 3 to 20 mL or cc
(c) Few WBC, no RBC - Diagnosis of disease or condition
(a) Exudate- Caused by infections, pulmonary abscess, pulmonary infarction, fungal or viral infection, trauma, various cancers, and pancreatitis
(b) Transudate - Caused by cirrhosis, CHF and chronic renal failure
- Caused by infections, pulmonary abscess, pulmonary infarction, fungal or viral infection, trauma, various cancers, and pancreatitis
Histology and Cytology
- Biopsy of Lung Tissue
- Evaluate tissues to determine if benign or malignant
- cytology studies fluids and secretions
- Used in evaluating lung tumors for cancer
Skin Testing
- Diagnose
(a) Infections
(b) Allergies - Tuberculin skin tests
(a) PPD test
(b) Alternative: interferon-y release assay (IGRA)- QuantiFERON-TB Gold In-Tube test (QFT-GIT)
- T-SPOT TB Test (T-Spot)