Blood Collection PDF

Blood Collection Why is blood the most commonly tested type of clinical sample? Accessibility Wealth of information that can be obtained by analyzing its many different constituents Tests performed on blood samples Blood chemistry profiles Kidney function (urea, Na...

Blood Collection Why is blood the most commonly tested type of clinical sample? Accessibility Wealth of information that can be obtained by analyzing its many different constituents Tests performed on blood samples Blood chemistry profiles Kidney function (urea, Na+, K+, creatinine) Liver function tests Hormone concentrations Blood glucose concentrations Blood clotting tests Tests for inflammation Blood lipids and cholesterol Immunology or serology tests to test for antibodies to specific viruses and bacteria Blood grouping  Blood Collection Close attention must be paid to all aspects of sample collection, handling and storage, to ensure the most accurate clinical pathologic results.  Blood Collection How you collect, handle and store the sample before submission to the laboratory?  Clean venipuncture is essential to minimize artefactual changes in the results. Blood should flow freely with minimal interruptions during collection. This is particularly important for hemostasis testing. Blood Collection Vacuntainer system Needle and syringe  Blood Collection – needles You may not have realized it, but there are several different sizes of needles out there.  Blood Collection – needles 18-gauge needle: never use this needle except when taking blood for transfusion purposes because this large needle allows to draw a significant amount of blood quickly. I would still only use this on patients over 60 pounds and only in their jugular vein. Purely because of its size, this needle makes large holes in the vein, so never use it in one of the smaller veins. 20-gauge needle: we can use a 20-gauge needle in larger dogs (over 20 pounds) when doing a jugular collection. It allows rapid filling of the syringe. If we want to collect from the cephalic vein in larger dogs with bigger veins, we can use this needle. 22-gauge needle: For cats and small dogs (under 20 pounds), use a 22-gauge needle on the jugular vein, the biggest vein in their bodies. 25- or 27-gauge needle: If we only need a tiny amount of blood from a patient, or if we have to take blood from a small vein, we can use a 25- or 27-gauge needle for these types of jobs  Blood Collection – needles Not only is the gauge important, but the length of the needle is, too. Blood collection - syringes The needle is attached to a syringe. The one we choose depends on the blood quantity we need to draw. Normally we use a 3-milliliter (3-mL) syringe. However, if we are taking a large blood sample, we will use a 6-mL syringe. To give you an idea of how much that is, it takes 5 mL to make a teaspoon. Blood Collection – collection tubes After we draw the blood, we need to store it in a collection tube. There are many different kinds of tubes, and each one has a unique purpose. Each one is created to hold blood in a certain way and is distinguished by the color of the stopper. Blood Collection – collection tubes  Blood Collection – collection tubes When blood comes out of a vein, it's called whole blood. If it's stored in a plain, red-topped tube with no chemicals, it clumps. This is called clotting, which is caused by clotting proteins. The clot is made up of proteins, but mainly of cells—the red blood cells, white blood cells and platelets.  Blood Collection – collection tubes Sometimes we want the blood to clot so we can remove the serum from it. Many tests are performed with serum, such as determinations of glucose, calcium, liver enzymes, and kidney toxins. Blood Collection – collection tubes Orange tube or SST – (Serum Separator Tube)  Blood Collection – collection tubes They contain a special gel that separates blood cells from serum, as well as particles to cause SERUM blood to clot quickly. The blood sample may then be centrifuged, allowing the clear serum to be removed for testing  Blood Collection – collection tubes Once the blood clots and the serum seeps out of the clot (this takes about 15 minutes or more), the tube is then put into a centrifuge, where it's spun and the layer of serum separates to the top. This process ensures that the serum is not tainted by the chemicals or cells found in the clot. How we distinguish serum from plasma? Serum is that part of blood which is similar in composition with plasma but exclude clotting factors of blood. How we distinguish serum from plasma? Blood Collection – collection tubes What if we don’t want the blood to clot? What do we do? Blood Coagulation Anticoagulant: What is an anticoagulant? Anticoagulants are a class of drugs that work to prevent blood coagulation (clotting).  Blood Coagulation Such substances occur naturally in leeches and blood- sucking insects Blood Coagulation Anticoagulants: EDTA Citrate Heparin Blood Collection – collection tubes This tube contains potassium EDTA, which prevents the clotting proteins from getting together. So no clotting, or no coagulation. EDTA stands for ethylenediaminetetraacetic acid. It works by binding to the calcium in the blood, which is needed for clotting.  Blood Collection – collection tubes If the veterinarian wants to count the cells in the blood to screen for infections, lack of platelets, or anemia, then this is the tube you'll use. Normally when blood clots, the cells are all mashed into a clump, and it's hard for the veterinarian to analyze. But in a lavender-topped tube, they float free.  Blood Collection – collection tubes A gray-topped tube contains sodium fluoride, and we use it for blood sugar determinations. It's especially useful if we want to monitor insulin treatment in a diabetic. The glucose level is more stable with the fluoride tube than with the EDTA tube.  Blood Collection – collection tubes The light blue one contains citrate, and we use it for coagulation tests. If we think that a dog's blood may not be clotting properly (for instance, we see bruises on the gums), this is the tube we use.  Blood Collection – collection tubes Citrate is an anticoagulant. It is in liquid form in the tube and is used for coagulation tests, as well as in blood transfusion bags. It binds the calcium, but not as strongly as EDTA. Correct proportion of this anticoagulant to blood is crucial because of the dilution, and it can be reversed with the addition of calcium  Blood Collection – collection tubes The dark blue stopper tells us the tube has sodium EDTA in it. It is used for trace mineral studies. Used in large animal for diet needs.  Other Anticoagulants: Heparin is a biological substance, usually made from pig intestines. Heparin can be used in vivo (by injection), and also in vitro to prevent blood or plasma clotting in or on medical devices. In venipuncture, Vacutainer brand blood collecting tubes containing heparin usually have a green cap. There are different types of heparin: sodium heparin and lithium heparin. For diagnostic testing, use lithium heparin because the sodium in the sodium heparin will interfere with the sodium measurement in the patient's plasma. Vacutainers  Vacutainers Rather than using a syringe and transferring the blood to a tube, we can fill a tube directly with a Vacutainer. This is a needle and holder that allows you to pierce the skin, enter the vein, and then push the tube onto a needle embedded in the holder to transfer the blood directly to the tube.  Blood Collection Start by wetting the hair with alcohol. Not only to sterilize but it allows to better visualize the vein. Once you've identified the vein, either by feeling it with a finger or seeing it, insert the needle. You will feel the needle enter the vein as you poke through the vein wall, because all resistance disappears. Pull back on the syringe plunger slowly, matching the speed with the supply of blood. If the flow stops, the vein is empty or the needle has slipped out of the vein.  Blood Collection Once you've collected the required volume of blood, withdraw the needle, and get the restrainer to put pressure over the venipuncture site. Blood Collection  Blood Collection Tips Here are a few ideas to keep in mind when taking blood samples (assuming the veterinarian you work with has allowed you to do this). When sliding the needle in, do it so the bevel faces up.  Blood Collection Tips Suck the blood out of the vein slowly. If you go too fast, the vein will collapse. Once you pull the needle out of the vein, put pressure on the puncture site to prevent a hematoma. If the tube is very full once the stopper is in place, stick a needle in, and suck out a little air. This helps ensure that the stopper does not pop out during transport. Blood Collection Tips Remove blood staining on a patient's coat with hydrogen peroxide. Wash the hydrogen peroxide out of the hair with water.  Filling of tubes Avoid positive pressure when filling tubes, forcing the blood into the tube by pressing on the syringe can result in hemolysis. Let the tube fill via vacuum pressure or remove the rubber stopper on the tub Barger, Anne M., Amy MacNeill. Clinical Pathology and Laboratory Techniques for Veterinary Technicians. Wiley-Blackwell, 15/2017. VitalBook file. Where to collect blood from?  Blood Collection Site: The following lists of veins are the most appropriate blood collection sites from different species of veterinary importance Jugular vein- The most commonly used site in the horse, cattle, sheep, goat, camel and large wild mammals: used occasionally in small animals Cephalic vein – Dog and cat Saphenous vein- Big dog  Blood Collection Procedure Placement of the thumb of the left hand in the jugular furrow to occlude and anchor the jugular vein, while manipulating the syringe and needle with the right hand The veins are more clearly out lined when the site is rubbed with alcohol Blood Collection Jugular vein https://www.youtube.com/watch?v=af-hEHWQXvY Jugular Vein Blood to the head passes along the carotid artery and returns to the cranial vena cava via the jugular vein.  Blood Collection Cephalic vein - The most commonly used site for collection of small amount of blood in the dog. By constricting the area on the dorsal aspects of the fore limb at the level of the elbow which can be raised beginning just above the carpal vein. Cephalic Vein https://www.youtube.com/watch?v=ls8BZgUL4do Cephalic vein  Blood Collection: Ear vein Ear vein- can be used in small dog, pig, cat and small lab animals (small dog, rabbit, guinea pig, and monkey). A marginal vein on the dorsal side of the ear is selected Remove the hair by shaving, clipping, or other method Swab the skin with alcohol or other Place the left index finger under the ear at the point of applying stylet or syringe Gentle aspiration is used when using a syringe in small animals like rabbit, to avoid collapse of the vein Blood Collection: Ear vein Blood Collection Toe or Toe nail – can be used in small dog, puppy, guinea pig etc Clip the hair away Disinfect the capillary bed of the nail Cut in to just short of the base of the nail Take 20-40 drops as well as 80 drops (4ml) of blood Blood Collection Tail – can be used in pig, cattle, sheep, rat, and mouse Venipuncture –of the coccygeal vein on the ventral side Blood Collection Tail – can be used in pig, cattle, sheep, rat, and mouse Venipuncture –of the coccygeal vein on the ventral side Blood Collection Tail – can be used in pig, cattle, sheep, rat, and mouse Venipuncture –of the coccygeal vein on the dorsal side  Blood smear A blood film — or peripheral blood smear — is a thin layer of blood smeared on a glass microscope slide and then stained in such a way as to allow the various blood cells to be examined microscopically. The smear shows the number and kinds of white blood cells (differential), abnormally-shaped blood cells, and gives a rough timate of white blood cell and platelet counts Preparing a Blood Smear Illustration by Tim Vojt, Biomedical Media, The Ohio State University College of Veterinary Medicine. Copyright The Ohio State University 59 Blood Smears Dry quickly to prevent RBC artifacts Stain within 48 hours Store at room temperature Ship separately from biopsy specimens exposed to formalin 60 Blood Smear Evaluation Three regions Counting area: between body and feathered edge Illustration by Tim Vojt, Biomedical Media, The Ohio State University College of Veterinary Medicine. Copyright The Ohio State University 61 Blood Smear Blood Smear 800 MyHCT (800 69428) [email protected] www.hct.ac.ae Happiness Center PO Box 25026 Abu Dhabi, UAE HCT_UAE hctuae 64