Rationale: Evacuated blood collection tubes, or vac tubes, are the most common type of blood transport system in medical facilities today. Vac tubes are color coordinated with specially designed rubber stoppers. The color coding is used to denote specific types of lab work that can be done in each. Certain colors indicate that an additive has been added to the vial for certain specimens. These colors are universal. Before the venipuncture has been secured, the needle is connected to a needle holder (or barrel). The barrel has two purposes. One, the barrel can give a better grip for needle insertion into the vein. Two, it acts as a support system for the vac tube as it is inserted for lab retrieval. Once the lab collection is complete, and the needle is removed, the rubber top self-seals to prevent fluid loss.
Blood Glucose test
Rationale: Blood glucose tests can be given to patients for a number of different reasons. Blood glucose tests are given during well checks once patients enter their mid-40’s to screen for diabetes. These tests can also be given to patients that have exhibited one of more symptoms that are associated with diabetes. Hyperglycemia, or high blood glucose, is demonstrated in patients who have frequent urination, lethargy, general weakness, and complaints of vision blurriness. Hypoglycemia, or low blood glucose, tends to reveal itself in patients who complain of hunger, general weakness, uncontrollable trembling, and sweating. Patients with very low blood sugar can run the risk of syncope, so monitor patients with this lab result closely. This is a relatively non-invasive procedure that requires the patient receive a finger stick to retrieve a small amount of blood that is placed into an electronic reader. These devices typically give instantaneous results.
Routine and Microscopy
Rationale: A urinalysis, also known as Routine and Microscopy, is a lab test performed through the use of a patient’s urine sample. There are a few types of urinalysis tests performed in medical facilities. The most common urine test is performed using a urine test strip. The patient fills a collection cup with urine, and the medical assistant places a urine test strip into the specimen for a predetermined amount of time. Color indicators will change due to the concentrations of various elements in the urine sample. These are recorded based on a provided color coding system, and are given to the physician to interpret. Urine may also be examined microscopically if sent to a lab. This process is used to examine the precise cellular make up of the urine to measure concentrations or abnormalities. Urine can be collected using a specially designed vacuum collection tube and sent to a lab as a culture. Cultures are typically chosen in an attempt to rule out possible urinary tract infections.
Blood Urea Nitrogen
Rationale: If a patient’s kidney function is called into question, a comprehensive metabolic panel is usually ordered for an overview of the patient’s general health. In the event the results point to possible kidney insufficiency, it is likely that a BUN lab will be ordered. BUN stands for Blood Urea Nitrogen. When the liver processes proteins, urea nitrogen is the waste product produced. If the kidney’s are functioning properly and filtering the urea out of the bloodstream into the bladder, then the BUN results should be within normal ranges. If the results return high, this could mean kidney failure, an obstruction in the ureters, or a kidney disease. If the results return too low, this could mean that the liver is damaged or diseased and not processing the proteins sufficiently to produce that wasted urea nitrogen. This could also mean the patient is not eating properly or drinking excessive amounts of fluid. A complete patient history would be needed to rule out the latter.
Rationale: Hematology is the study of all aspects of blood. It pays close attention to the organs that create it, the diseases that can pollute it, and the physiological make-up of the blood itself. Bone marrow is considered to be an aspect of hematology as well. Hematologists typically work indirectly with patients. They study the blood received from lab work taken during extractions in medical facilities. The lab work studied by hematologists can be collected as blood, plasma, or serum. Plasma is the liquid portion of the blood that is known to contain the erythrocytes (red blood cells), leukocytes (white blood cells), and the platelets. Serum is a liquid that can be removed from clotted blood.
Rationale: The tourniquet is a tool used while preparing to select a site for venipuncture. A tourniquet is typically a rubber band, but some facilities choose specifically designed Velcro straps. In the event that there is no tourniquet available, a blood pressure cuff can serve as an acceptable alternative. The tourniquet is generally placed about 3 inches above the chosen venipuncture site. It should be tightened in a way that can be undone with one hand. This allows you to continue securing the needle once it has been placed. It is important to note that once the tourniquet has been tightened, it should never be kept in place for longer than 60 seconds. If the tourniquet is kept in place for extended periods of time, there is a potential for skin trauma, muscle trauma, and nerve damage.
Complete Blood Count Test
Rationale: One of the most common blood tests, used for both well checks and illness, is the Complete Blood Count test (CBC test). The CBC test is used to look for a number of inconsistencies including anemia and infections. The CBC is also used to examine a number of details about the blood itself. These details include but are limited to red blood cell count and quality, white blood cell count and quality, platelet count and quality, and the percentage of hemoglobin in the blood stream. This check is especially useful for well checks because it is a good indicator of overall cellular health. CBC’s offer results of general cellular populations, and gives the physician a good over view of the patient’s general well being. If the patient has been complaining of general weakness or lethargy, and certain cellular populations return with negative results, this could be an indication of a disease or malady.
Comprehensive Metabolic Panel
Rationale: The Complete Metabolic Panel, or CMP, is a specific blood lab test used for yearly well checks and in the case of illness. The CMP is commonly used because of the wide assortment of results given in a single test. A CMP test involves electrolytes, blood glucose, proteins, kidney tests, and liver tests. Because they examine so many different elements in a patient’s blood, this lab can be used to check for a vast array of conditions such as diabetes, kidney and liver disease. The complete metabolic panel is used in well checks because of the labs ability to show inconsistencies in so many different areas. However, because the test is so broad, it isn’t extremely specific in the results. If there is a negative impression left by some results, it would need to be followed up by a more specific regimen of lab tests.
Rationale: The electrocardiogram, or ECG, is a non-invasive test used to measure the electrical activity of a patient’s heart. This is done in routine or trauma situations. The medical examiner is responsible for placing “leads” at various points on the patient. The leads are electrodes that detect electrical impulses on the skin during each heartbeat, and relay that information to the ECG device. These electrodes are available in 3, 5 or 12 electrode combinations. For example, in the 12 –Lead setup, the patient would have 8 leads placed from the sternum, continuing at a downward angle across the area of the heart. The remaining 4 leads are placed on each extremity; one to each upper arm, and one to each lower leg. After the leads are connected to the ECG device, it is important to remind the patient to lie very still, because any movement could throw off the results drastically. After a few moments a graph is printed from the ECG device that visually represents the patient’s heartbeat.
Rationale: Venipuncture is the most commonly used method for blood collection in healthcare. Venipuncture is about gaining access to a vein using a needle for blood work or giving medication. Ultimately, venipuncture is about puncturing the venous system, so there are a lot of options when selecting a site for placing the needle. However, the most common site for selecting a vein is in the antecubital fossa. This is the anterior aspect of the elbow. This is the junction where the Basilic, Cephalic, and the Median Cubital veins converge. After palpation, if you are unsuccessful in selecting an appropriate vein, it is perfectly acceptable to move to different areas of the arm. The back of the hand generally has veins that are much more superficial, and may offer a successful alternative. Keep in mind, that the back of the hand is quite sensitive, and should be used only if the antecubital fossa proves insufficient.