When attempting venipuncture on a rolling vein, the vein is likely to move laterally because it is not firmly attached to the tissue. Rolling veins are most common in infants and older adults, but they are not uncommon and can occur in any patient. Veins are more likely to roll if the needle punctures the vein on the side rather than in the middle. Stretching the skin tautly and anchoring the vein well with the thumb can help to prevent the vein from rolling.

If a patient faints during blood collection, discontinue the draw and discard the needle. Pressure should be applied to the site to prevent bleeding and bruising and the patient should be asked to lower his or her head and breathe deeply to allow oxygenated blood to access the brain. Ammonia inhalants may produce side effects, such as respiratory distress in asthmatic patients, and should not be used. After the patient regains consciousness, he or she should remain in the room for at least 15 minutes.

Withdrawing blood from a vascular access device (VAD) for coagulation studies requires flushing the VAD lock with 5-10 mL preservative-free normal saline (NS) and drawing a discard tube, equal to W.ro times the dead space, before drawing the sample. For most central lines, 5 mL is adequate as the discard volume, although this may vary so the discard volume needed should always be verified. For coagulation studies, typically a discard volume of six times the dead space is recommended, although if drawing blood from a saline lock a discard volume of two times the dead space is adequate. After the specimen is obtained, the VAD is again flushed with 5-10 mL of preservative-free NS.

Connective tissue is the most common type of tissue found in the body. Connective tissues protect and support the body's organs and other tissues. Blood, bone, cartilage, and fat are all connective tissues. Muscle tissue is essential for movement. Epithelial tissue protects the internal and external structures of the body. Nerve tissue consists of cells that send and receive information.

The hemoglobin A1c point-of-care (POC) test reflects the average blood glucose level for the previous 2-3 months. Glucose attaches to hemoglobin A in RBCs and remains for the life of the cells. The typical life of an RBC is approximately 120 days. Hemoglobin A1c is a better predictor of glucose control and the possibility of diabetes complications than serum glucose is. The normal value for hemoglobin A1c is less than 5.7%.