Venipuncture (Blood drawing)

In medicine, venepuncture,venopuncture or venipuncture is the process of obtaining intravenous access for the purpose of intravenous therapy or obtaining a sample of venousblood. This procedure is performed by medical laboratory scientists , medical practitioners, some EMTs, paramedics, phlebotomists and other nursing staff. Venepuncture is one of the most routinely performed invasive procedures and is carried out for two reasons, to obtain blood for diagnostic purposes or to monitor levels of blood components (Lavery & Ingram 2005). Blood analysis is one of the most important diagnostic tools available to clinicians within healthcare. Its data is relied upon in the clinical setting for interpretation of a myriad of clinical signs and symptoms and developing skills in venepuncture can facilitate holistic and timely treatment.

Blood is most commonly obtained from the median cubital vein, on the anterior forearm (the side within the fold of the elbow). This vein lies close to the surface of the skin, and there is not a large nerve supply.

Minute quantities of blood may be taken by fingersticks sampling and collected from infants by means of a heel stick or from scalp veins with a winged infusion needle.

Phlebotomy (incision into a vein) is also the treatment of certain diseases such as hemochromatosis and primary and secondary polycythemia

Blood Glucose

            blood glucose test measures the amount of a type of sugar, called glucose, in your blood. Glucose comes from carbohydrate foods. It is the main source of energy used by the body. Insulin is a hormone that helps your body's cells use the glucose. Insulin is productiveness and released into the blood when the amount of glucose in the blood rises.

Normally, your blood glucose levels increase slightly after you eat. This increases to release insulin so that your blood glucose levels do not get too high. Blood glucose levels that remain high over time can damage your eyes, kidneys, nerves, and blood vessels.

Several different types of blood glucose tests are used.
Fasting blood sugar (FBS) measures blood glucose after you have not eaten for at least 8 hours. It is often the first test done to check for prediabetes and diabetes.
2-hour postprandial blood sugar measures blood glucose exactly 2 hours after you start eating a meal.
Random blood sugar (RBS) measures blood glucose regardless of when you last ate. Several random measurements may be taken throughout the day. Random testing is useful because glucose levels in healthy people do not vary widely throughout the day. Blood glucose levels thatvary widely may mean a problem. This test is also called a casual bloodglucose test.
Oral glucose tolerance test is used to diagnose prediabetes and diabetes. Anoralglucosetolerance test is a series of blood glucose measurements taken after you drink a sweetliquidthat contains glucose. This test is commonly used to diagnose diabetes thatoccursduringpregnancy (gestational diabetes). For more information, see the medical test Oral Glucose Tolerance Test. This test is not commonly used to diagnose diabetes in a person whoisnotpregnant.
Why It Is Done

Blood glucose tests are done to:
Check for diabetes.
Monitor treatment of diabetes.
Check for diabetes that occurs during pregnancy (gestational diabetes).
Determine if an abnormally low blood sugar level (hypoglycemia) is present. A testtomeasureblood levels of insulin and a protein called C-peptide may be done along with a bloodglucosetest to determine the cause of hypoglycemia. For more information, see themedicaltestC-Peptide.