Lab Test-Vmed 1 PDF

Oct. 17, 2024 **ROUTINE LABORATORY TEST** **Hematology -- study of blood** **Hemogram** is the collection of specific measurements that allow evaluation of a patient's erythrocytes, leukocytes, and platelets. - **Erythrogram** -- the portion of the hemogram that contains the parameters tha...

Oct. 17, 2024 **ROUTINE LABORATORY TEST** **Hematology -- study of blood** **Hemogram** is the collection of specific measurements that allow evaluation of a patient's erythrocytes, leukocytes, and platelets. - **Erythrogram** -- the portion of the hemogram that contains the parameters that assess erythrocytes - Platelet parameters are often reported with the erythrogram - **Leukogram** -- the erythrogram and the portion that relates to the leukocytes Components of the hemogram **Components of the Hemogram** **Measurement** **Component Measured** ----------------------------------------------- ----------------------------------------------------------------------------------------------------------------------- **Hematocrit/PCV** Measures the RBC mass as a percentage of blood. The hematocrit is calculated by an instrument and the PCV is measured **Hemoglobin concentration** Measures the amount of hemoglobin contained in the blood **Red cell count** Measures the number of red blood cells/unit volume **Mean cell volume (MCV)** Measures the average volume of the individual red blood cells **Mean cell hemoglobin concentration (MCHC)** Measures the average hemoglobin concentration in individual red blood cells **Mean cell hemoglobin (MCH)** Measures the average amount of hemoglobin in the individual red blood cell **Total white blood cell count** Measures the number of white blood cells/unit volume **Platelet count** Measures the number of platelets/unit volume **Neutrophil count** Measures the absolute number of neutrophils/unit volume **Eosinophil count** Measures the absolute number of eosinophils/unit volume **Monocyte count** Measures the absolute number of monocytes/unit volume **Lymphocyte count** Measures the absolute number of lymphocytes/unit volume **Basophil count** Measures the absolute number of basophils/unit volume **% neutrophils** The percentage of neutrophils in the total white count **% eosinophils** The percentage of eosinophils in the total white count **% monocytes** The percentage of monocytes in the total white count **% lymphocytes** The percentage of lymphocytes in the total white count **% basophils** The percentage of basophils in the total white count **The Five (5) Major Functions** 1. To confirm the diagnosis of the presence or absence of a blood abnormality. 2. To determine the extent of the disease process. 3. To find out why there is a blood abnormality. 4. To serve as a guide in the prognosis of clinical cases. 5. To serve as a guide during therapy in the treatment of clinical disorders. **Vacutainer** **Tube color** **Anticoagulant** **Yield** **Uses** ---------------------- ------------------- ------------- -------------------------------------------------------------------- **Green** heparin plasma blood chem **Orange** *none* serum blood chem **Green with black** heparin plasma blood chem **Red** *none* serum blood chem **Purple** EDTA whole blood hematology, cytology, flow cytometry (PARR), clonality coombs test **Blue** citrate plasma coagulation **COMPLETE BLOOD COUNT (CBC)** - It is a process by which the cellular components of the blood are evaluated. - The components of the CBC provide data that is used to determine whether there are abnormalities in erythrocytes, leukocytes, and platelets. - The packed cell volume (PCV), hematocrit (Hct), hemoglobin concentration, and indices that describe the size of erythrocytes and the concentration of hemoglobin within the erythrocytes are used to evaluate erythrocytes. - The white blood cell count (WBC) and differential leukocyte count are used to evaluate leukocytes. - CBC can be automated or performed manually. - The **blood film evaluation** is an essential part of the CBC and is used to confirm the numbers obtained by the automated or manual CBC and to fully evaluate cell morphology. **Erythrocytes** **Erythron** - Circulating erythrocytes in the blood - RBC transport and protect hemoglobin - Daily production of erythrocytes equals the daily loss in healthy animal **Abnormalities in the erythron may manifest as:** - Anemia - Polycythemia - Hemodilution - Hemoconcentration **A Complete Blood Count (CBC) include:** - Packed Cell Volume (PCV)/Hematocrit (HCT) - Hemoconcentration - RBC - MCV - White cell concentration PCV -- manual Hematocrit -- automatic - Measured directly by centrifuging a blood sample in a microhematocrit tube. - Height of the red cell column after centrifugation represents the PCV. - Examine the color of serum HCT - Using automated hematology analyzers. - [\$HCT(\\frac{MCV\\ \\times RBC\\ count}{10})\$]{.math.inline} - MCV = mean corpuscular volume - RBC = red blood cell count **Examination of the hematocrit tube provide subjective information** - **Color and clarity of the plasma** (icterus, hemolysis, lipemia) **yellow** icterus ----------------------- ------------------------ **cloudy** lipemia **red-tinged** hemolysis **pale to colorless** bone marrow depression - **Size of the buffy coat** -- usually less than 1 mm wide, gray to reddish gray layer (contains WBC and platelet) **uppermost clear layer** thrombocytes --------------------------- -------------------------- **reddish gray** leukocytes **reddish layer** nucleated (immature) RBC - Measurement of the buffy coat can be used to estimate the total leukocyte count. - 1^st^ mm of blood cell is equal to approximately 10,000 leukocyte and each additional 0.1 mm equals 2,000 leukocytes/cm mm. **Causes of Abnormally [High] Level** - Polycythemia due to breed (Dachshund) - Dehydration - Splenic contraction secondary to epinephrine (ex. Horse) - Hypoxemia - Independent erythropoietin -- from the kidney; target organ: bone marrow production (renal lesions) - Polycythemia vera **Next Diagnostic Step** - Assess **hydration status** - Review **clinical history** - Evaluate for **causes of polycythemia** **Causes of Abnormally [Low] Level** - Anemia - Overhydration - Splenic relaxation (anesthetic agents, tranquilizers) **Next Diagnostic Step** - Blood smear evaluation for type of **anemia** and evidence of **regeneration**, **absolute reticulocyte counts** then perform further testing Nov. 15, 2024 **Hemoglobin** - Measures the oxygen carrying capacity of the erythrocytes - Measurement of the quantity of hemoglobin/unit volume express g/dl - Since RBC are approximately 33% hemoglobin - Hemoglobin concentration can be predicted from the PCV in all conditions except **iron deficiency anemia** and during remission phase of **acute blood loss** and **hemolytic anemia** - Value of hemoglobin is approximately equal to 1/3 the PCV - Approximately total erythrocyte count (normocytic, normochromic erythrocyte) can be divided the PCV by 1/6 **[Laser-Based Hemoglobin Analysis]** **BLOOD CHEMISTRY** - Used to [determine the general health status of the animal] - Used to **diagnose disease**, **monitor disease progression**, **response to therapy**, **screen for the presence of underlying disease in apparently healthy-looking animals**. - Chemistry tests can be grouped together on the basis of body system or physiologic process. **Electrolytes** Sodium, Potassium, Chloride ------------------------ -------------------------------------------------------------- **Acid-base** Bicarbonate, Anion gap **Minerals** Calcium, Phosphate, Magnesium **Protein Metabolism** Total Protein, Albumin, Globulin, A/G ratio **Kidney Function** Urea, Nitrogen, Creatinine *-- interpreted along urinalysis* **Liver** - **Injury:** hepatocellular leakage enzymes: alanine aminotransferase (ALT), asparate aminotransferase (AST), sorbitol dehydrogenase (SDH), glutamate dehydrogenase (GLDH), and lactate dehydrogenase (LDH) - **Cholestasis** Cholestatic enzymes: alkaline phosphatase (ALP) and gamma glutamyltransferase (GGT) Bilirubin: total and direct enzyme - **Functionality:** total bilirubin, indirect bilirubin, bile acids, ammonia - [blood flow (shunting)]: bile acids, ammonia "Clinicians brief" -- read **Pancreatic Function**: amylase, lipase (including pancreatic lipase), trypsin-like immunoreactivity (TLI) *\*if high there's something wrong* **Energy Metabolism** - **Carbohydrates:** glucose, fructosamine - **Lipids:** cholesterol, triglycerides, non-esterified fatty acid (NEFA), B-hydroxybutyrate (BHB), transition dairy cow energy metabolite assessment **Muscle Injury:** creatine kinase (CK), AST, ALT, LDH **Iron Metabolism:** iron, total iron binding capacity (TIBC), percentage saturation of transferrin - **Biochemistry test** included in the general health profile - **Proteins** -- Total protein, albumin, globulin - **Albumin** -- Indicate if the animal is [dehydrated], also provide information about the function of the *liver*, *kidneys*, and *digestive system*. - **Globulin** levels reflect underlying [inflammation] and/or [antibody production]. - **Increased** levels of globulins are often associated with *infectious diseases*, *immune-mediated disease*, and *some types of cancer*. - **Liver enzyme** -- Alanine aminotransferase (ALT) and Alkaline phosphatase (ALP) - **Bilirubin** - **Kidney tests** -- Urea and Creatinine - **Pancreatic enzymes** -- Amylase, Lipase, Pancreatic lipase immunoreactivity - **Glucose** - **Calcium and Phosphorus** - **Muscle enzymes** -- Creatinine kinase (CK), Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) - **Cholesterol** - **Electrolytes** -- most important electrolytes are **potassium**, **chloride**, **sodium**, and **bicarbonate** **URINALYSIS** - An essential part of the diagnostic evaluation of sick patients. - Results should be interpreted along with the results of a chemistry panel. - An essential part of a routine workup and aids in diagnosing urinary tract inflammation, renal tubular dysfunction, and glomerular disease. - Since urine is derived through filtration of blood, urine can often provide valuable information about metabolic derangements or disorders of other organ systems, aiding in diagnosis of such conditions as liver disease, muscle disease, endocrine disease, and hemolysis. - Evaluation of urine can be advantageous because urine contains compounds *(**e.g.**, cortisol, bile acids)* filtered from the blood over several hours. This may provide a better reflection of homeostasis and disease than does single random blood sample. - In addition, renal clearance may affect blood levels of some compounds. Rapidly cleared molecules, such as Bence-Jones protein, may be found in urine but be undetectable in a serum sample. - Finally, comparison of the concentration of an analyte, such as creatinine or sodium, in concurrent urine and serum samples may provide significantly more information about renal clearance than that provided by a serum sample alone. - By itself, urine analysis rarely provides a specific diagnosis, but must instead be interpreted in conjunction with physical exam findings, CBC data, serum chemistry test results, and imaging techniques such as ultrasonography or contrast radiographs. **Urinalysis gives information on:** - **Tubular Function** - **Urine Specific Gravity (USG)** gives information on the ability of the loop of Henle to dilute urine and distal tubules to concentrate urine. - **Dipstick analysis** gives information about the ability of proximal tubules to resorb normally filtered low molecular weight substances, including proteins and glucose. - Proteinuria that is excessive for the USG and glucosuria without hyperglycemia can reflect proximal tubular disease. - **Sediment examination** -- helps detect tubular injury via the presence of cellular, granular, waxy casts or other rare casts (hemoglobin, red and white blood cells) - **Glomerular Function:** This is generally assessed more from serum or plasma biochemical tests, i.e. urea, nitrogen, creatinine and SDMA, however proteinuria (particularly albuminuria) reflects glomerular barrier function. In rare cases, hematuria can be glomerular in origin. **Other Conditions:** - **Hemorrhage** via the presence of excess RBCs in the urine, usually accompanied by a positive heme reaction. - **Infection or inflammation in the urinary tract** via the presence of WBC (neutrophils primarily, pyuria) and/or bacteriuria - **Cancer** if tumors exfoliate into the urine. - **Crystalluria** these can be normal, part of an overall metabolic animal condition (cystinuria) or **Steps in Performing Urinalysis** 1. Assessment of **visual property of urine** -- volume, color, turbidity 2. Assessment of **concentrating ability** -- determination of specific gravity; determination of urine osmolality 3. **Dipstick Analysis** - Gives results for pH, protein (mostly albumin), glucose, ketones (primarily acetoacetatic acid), bilirubin (the conjugate or direct form), and proteins containing a heme group (a porphyria ring with iron in its center) - Dipstick can be applied quickly into the use to immerse the pads or a transfer (plastic) can be used to drop urine individually onto the pads 4. **Sediment Examination** - Standard volume of urine is centrifuge in a low speed; centrifuge on thorough gravity sedimentation in a microtube plate - Low Magnification (10X) casts, large crystals, large infectious agents (parasitic ova) and other constituents (debris, mucus, other contaminated serum quantities) - High Magnification (40X) cells (leukocytes, erythrocytes, epithelial cells, sperm, small crystals, small infectious agents (bacteria, fungi) and other constituents (fat droplets, debris, other contaminants on semi-quantified) **Urinalysis: Visual Feature** **Urine Color** -- subjective **Color** **Possible Causes** --------------------- ------------------------------------------------------------------------------------------------------------------------------------------------------------ light-red yellow normal colorless dilute urine (USG \< 1.030) dark yellow USG \> 1.020 in most animals very dark concentrated urine (USG likely \> 1.030), bilirubinuria red-brownish-red hematuria (clear color), hemoglobinuria (remain color after centrifuge), myoglobinuria, pyrocatechol oxidized (agent in horse urine which can turn it red) reddish-brown-brown Myoglobinuria, hemoglobinuria, lacks of calcium carbonate in urine of horse -- (those crystal due brown-tinged crystals will sediment on centrifugation) greenish tint bilirubinuria, biliverdin (birds and reptiles) Pee: All About It! - PetTest by Advocate Nov. 7, 2024 **Urine Turbidity** clear \- ----------------- ----- slightly cloudy \+ cloudy ++ opaque (turbid) +++ **Cellular Constituents** **1) RBC** - Round, slightly red-tinged, smooth textured cells, which may be biconcave in fresh urine may be spiky (crenated) in stored urine - Classified as no. per HPF: none seen, \< 5, 5-20, 20-100, or \> 100 - Normal: up to 5 RBC/HPF generally considered acceptable for "normal" urine - May lyse in very alkaline or dilute (USG \< 1.008) urine - More uniform and red-tinged - Fat droplets are more variable in shape, slightly greenish-tinged (refractile), have a darker edge, more globular shape and usually float to top of coverslip. **2) WBC** - Round, colorless cells with a grainy texture (bacterial rods are also visible in the background) - Classified as no. per HPF: none seen, \< 5, 5-20, 20-100, or \> 100 - Normal: up to 5 WBC/HPF generally considered acceptable for "normal" urine, normally segmented neutrophils - May lyse in very alkaline or dilute (USG \< 1.008) urine - More grainy and larger - Smaller with rounder borders than epithelial cells which vary in size are less grainy **3) Transitional Epithelial Cells** - Variable size and shape (depend on origin) - Round/polygonal, pear-shaped, caudate (pelvis), tailed, spindle, may develop refractile, fatty inclusions with storage - From renal pelvis, ureter, urinary bladder and/or urethra - Compared to WBC: WBC are smaller and more uniformly round - Compared to Squamous Epithelial Cells: Transitional Cells are smaller with rounder (not as angular) borders - Can be seen in normal urine (few in samples collected by midstream catch or cystocentesis more in catheterized specimens due to catheter-induced sloughing) as single cells/small clusters, more may exfoliate with inflammation - Difficult to distinguish from neoplastic cells -- requires urine cytology **4) Squamous Epithelial Cells** - Largest cell in urine, thin, flat cells, with angular borders, anuclear or small central nucleus, present as single cells or in variably-sized sheets - Represent contamination (from skin, genital tract, prepuce in male dogs) in voided urine or may reflect squamous metaplasia of prostate (from exogenous estrogen or an estrogen-secreting Sertoli cell tumor) especially if in large number **5) Neoplastic Cell** - Frequently exfoliate as variably sized irregular clusters - May exfoliate into urine in animals with tumors of the genitourinary tract. Most common type is transitional cell carcinoma (TCC) -- arises in urinary bladder, urethra (including prostate urethra in dogs). Rarely, lymphomas and renal carcinoma can arise be observed in urine sediments - Compared to normal Transitional Epithelial Cells: display cytologic criteria of malignancy such as variation in cell and nuclear size *\*30 mins urine process* **6) Crystals** -- Crystalluria - Urine is supersaturated with the compounds that comprise the crystals, ammonium, magnesium, phosphate for struvite - Identified by characteristics, shape and pH of urine when they occur - Can be seen in clinically healthy animals or in animal with no evidence of urinary disease (obstructions and/or urolithiasis) a. **Ammonium biurate** - Yellow to brown - Spearoids - Like sarcoptic - Have horns - Result of liver disease - Normal in Dalmatian or English Bulldogs (in low number) - High no. pathological -- portal vascular anomaly - Common in alkaline urine b. **Struvite** - Coffin-lid appearance - Known as magnesium ammonium phosphate - Normal in dogs and cats - Variable in size - X-shaped - Common in alkaline urine - Presence in huge no. of animals with urolithiasis c. **Calcium oxalate monohydrate** - Colorless, elongated - Ticket-fence appearance - Spindel-shaped or dumbbell shaped - Seen on dogs that ingests ethylene glycol - Present in acute renal failure d. **Melamine cyanurate** - Yellow to brown with centrally radiating e. **Bilirubin crystals** - Normal in dog urine that's very concentrated - If seen in dog or cat that's not concentrated urine, may be abnormality in metabolism of bilirubin, hemolysis, cholestasis disease f. **Calcium oxalate dihydrate** - Envelop/maltese crisis - Common in acidic urine - Seen on urine store in room temperature or too much refrigeration - Normal if patients eat oxalate high-rich food/plant-based ford - Hyperadrenocorticism - Hypercalcemia, when give acidifier - Appear UTI, urolithiasis - Can be seen in normal animal or not g. **Hemoglobin precipitates** - Polygonal, small - Refractile - Seen when there's overwhelming intravascular hemolysis - Uncommon findings h. **Talc granules** - Urine can be contaminated with Talc from gloves - Not considered crystals - Irregular border i. **Cystine** - Flat, hexagonal, stack together - Uncommon findings in dog, rarely in cats - High concentration of secreted cystine - Cystinuria - Increased risk of development cysteine urolithiasis