11.2 Cardiovascular System

The cardiovascular system consists of the heart, blood, and blood vessels. (See Figure 11.1.^[1]) The heart pumps the blood through the blood vessels. Blood can be viewed as the transportation fluid that transports nutrients to cells and carries wastes away from cells.^[2]

The transportation route to all tissues is an intricate blood vessel network composed of arteries, veins, and capillaries. See Figure 11.2^[3] for an illustration of the blood vessel network. The transportation of nutrients begins in the small intestine where they are absorbed and then transported to the liver through the hepatic portal vein. From the liver, nutrients travel in the blood up to the inferior vena cava blood vessel to the heart. The heart pumps the nutrient-rich blood to the lungs to pick up oxygen. The oxygenated blood returns to the heart, where it is pumped out to tissues in the body through the aorta and the arteries. Arteries become smaller and smaller on their way to cells, so that by the time blood reaches a cell, the vessel’s diameter is extremely small, and it is now called a capillary. This reduced diameter of capillaries slows the speed of blood flow and gives cells time to harvest the nutrients and oxygen in the blood and return metabolic wastes to the capillary to be eliminated. Deoxygenated blood containing metabolic wastes is transported back to the heart via veins, and wastes are filtered out by the kidneys and liver.^[4]

As the body ages, the strength and elasticity of the heart and blood vessels decrease, resulting in a decreased ability to regulate blood pressure, distribute oxygen, and remove wastes from the body. These changes can lead to dizziness (and a higher fall risk), fluid retention, edema, fatigue, and decreased stamina to complete daily functions.

In addition to these age-related changes, a diet high in saturated fats causes plaque to be deposited on the walls of the blood vessels, causing further narrowing and decreased blood flow. This decrease in circulation increases the risk for blood clots, heart attacks, and strokes.

Because the cardiovascular system is vital for health, any symptoms related to chest pain, shortness of breath, or lack of oxygenation should be immediately reported to the nurse. Cyanosis is a common cardiovascular symptom that refers to bluish discoloration around the mouth and in the extremities (i.e., feet and hands). It occurs when there is decreased oxygenated blood flow to the tissues and should be immediately reported to the nurse. Common nursing assistant interventions for all cardiovascular conditions include encouraging activity as tolerated; promoting a low fat, low cholesterol diet; motivating individuals to quit smoking; and helping individuals make healthy food choices to maintain a healthy weight. Table 11.2 describes symptoms of common cardiovascular diagnoses and related nursing assistant interventions.

Table 11.2 Common Chronic Cardiovascular Diagnoses and Related Nursing Assistant Interventions^{[5],[6],[7],[8],[9]}