EMT Chapter 29 - Bleeding and Shock

perfusion

the supply of oxygen to and removal of wastes from the cells and tissues of the body as a result of the flow of blood through the capillaries.

hypoperfusion

inability of the body to circulate adequate blood to the body’s cells to supply them with oxygen and nutrients. A life-threatening condition. Also called shock.

Arteries

carry freshly oxygenated blood away from the heart. They are under a great deal of pressure during the heart’s contractions.

Capillaries

Microscopically small blood vessels that facilitate the exchange of oxygen and nutrients from blood to cells, and allow carbon dioxide and waste products to be taken up by blood.

Veins

Blood vessels that carry oxygen-depleted blood and waste products back to the heart. They have one-way valves to prevent backflow and operate under lower pressure than arteries.

Hypovolemia

occur when blood is lost, or the liquid portion of the blood is removed from the circulatory system

absolute hypovolemia

occurs when blood physically leaves the circulatory system, such as through internal or external hemorrhage.

relative hypovolemia

occurs when the liquid portion of the blood, known as plasma, shifts out of the blood vessels without actual blood loss from the circulatory system

Hypovolemic shock

shock resulting from an insufficient volume in the circulatory system

hemorrhagic shock

a shock resulting specifically from a loss of blood.

cardiogenic shock

shock brought on by the heart’s inadequate pumping action.

distributive shock

hypoperfusion due to a lack of blood vessel tone. Blood vessel dilation leads to decreased pressure within the circulatory system.

Neurogenic shock

hypoperfusion caused by a spinal cord injury that results in systemic vasodilation and nerve paralysis.

Septic shock

a body infection causes a systemic inflammatory response to occur. This inflammatory response causes blood vessels to dilate and capillary membranes to become permeable.

obstructive shock

a term commonly used to describe the different conditions that block the flow of blood and cause hypoperfusion.

compensated shock

period when the patient is developing shock but the body is still able to maintain perfusion for prolonged but limited periods of time.

decompensated shock

period when the body can no longer compensate for low blood volume or lack of perfusion. Late signs such as decreasing blood pressure become evident.

Acidosis

a condition characterized by an excess of acid in the body, leading to a decrease in blood pH.

Coagulopathy

Abnormal blood clotting; can lead to excessive clotting or, more commonly, slow clotting and uncontrolled bleeding.

hemorrhage

bleeding, especially severe bleeding.

Arterial bleeding

bleeding from an artery, which is characterized by bright red blood that is often spurting, profuse, and difficult to control.

venous bleeding

bleeding from a vein, which is characterized by dark red or maroon blood and a steady, easy-to-control flow.

capillary bleeding

bleeding from capillaries, which is characterized by a slow, oozing flow of blood.

pressure dressing

a bulky dressing held in position with a tightly wrapped bandage, which applies pressure to help control bleeding.

Hemostatic agents

substances applied as powders, dressings, gauze, or bandages to open wounds to stop bleeding.