Your blood performs several amazing functions and you will need to know all about them for the EMT exam. The red blood cells carry most of your oxygen quite efficiently, picking it up only at the alveoli, where it’s most abundant, and dropping it off only at the cells, where the concentration is lowest.
White blood cells come in different types, but they work in concert to combat infection. Platelets are cells that initiate the clotting process. All of these cells, along with proteins, nutrients, and waste, are carried in plasma, the watery part of blood.
There are several disorders of the blood. However, as an EMT, one condition you should know about is sickle cell disease. Found predominately in African Americans, a genetic mutation causes red blood cells to form abnormally. As a result, these misshapen cells (many look crescent-shaped, or sickle) don’t carry oxygen very well.
In addition, they can get “stuck” in the capillary beds, causing moderate to severe pain in areas such as bone joints and the abdomen. Treatment is supportive — providing supplemental oxygen, usually low flow with a nasal cannula if oxygen saturation level is low or the patient is in respiratory distress, and keeping the patient as comfortable as possible.
You should also be familiar with clotting disorders:
Thrombophilia is a tendency for blood clots to form, especially in the lower legs. A condition known as deep vein thrombosis (DVT) is often the source of pulmonary emboli, where parts of the clot break off and travel back to the heart, getting lodged in the pulmonary circulation. DVT can cause pain, tenderness, and swelling in the calf area of the lower leg.
Hemophilia is a genetic disease that makes clotting difficult, occurring primarily in men. In other words, patients with hemophilia may spontaneously begin bleeding or, if they become injured, may experience bleeding that is harder to stop.
In either of these disorders, treatment is focused on making sure the patient is oxygenated and treated for shock. Extra caution is needed to help control bleeding in hemophiliac patients; you may need to apply pressure for a much longer period of time than expected.