Acute and chronic illness can dramatically affect a person's cardiopulmonary function. Body systems (e.g., the cardiovascular system and respiratory system or the musculoskeletal system and the respiratory system) work together, so alterations in one may affect the other. For example, alterations in muscle function contribute to inadequate pulmonary ventilation and respiration, as well as to inadequate functioning of the heart.

Respiratory function varies across the life span. The table below summarizes variations. Age-related variations in pulse rate and blood pressure can be found in Chapter 2, Fundamentals Review 2-1.

Many medications affect the function of the cardiopulmonary system. Patients receiving drugs that affect the central nervous system need to be monitored carefully for respiratory complications. The nurse should monitor rate and depth of respirations in patients who are taking certain medications, such as opioids or sedatives. Other medications decrease heart rate, with associated decreased cardiac output, and the potential to alter the flow of blood to body tissues.

Activity levels and habits can dramatically affect a person's cardiopulmonary status. For example, people who exercise can better respond to stressors to cardiopulmonary health. Regular physical activity provides many health benefits, including increased heart and lung fitness, improved muscle fitness, and reduced risk of heart disease. Cigarette smoking (active or passive) is a major contributor to lung disease and respiratory distress, heart disease, and lung cancer. Cigarette smoking is the most important risk factor for chronic obstructive pulmonary disease (COPD) (NHLBI, 2019). Smoking is one of the key risk factors for heart disease, the leading cause of death in the United States (CDC, 2021).

Research indicates that there is a high correlation between air pollution (Kurt et al., 2016; Turner, Anderson et al., 2020) and occupational exposure to certain chemicals (Johns Hopkins Medicine, 2021) and cancer and lung disease and cardiovascular risk factors (Al-Kindi et al., 2020). In addition, people who have experienced an alteration in respiratory functioning often have difficulty continuing to perform self-care activities in a polluted environment.

The tissues and airways of the respiratory tract (including the alveoli) become less elastic with age. The power of the respiratory and abdominal muscles is reduced, and therefore the diaphragm moves less efficiently. Airways collapse more easily. These alterations increase the risk for disease, especially pneumonia and other chest infections. The normal aging heart can maintain adequate cardiac output under ordinary circumstances but may have a limited ability to respond to situations that cause physical or emotional stress, when the demands on the heart are increased (Eliopoulos, 2018; Hinkle et al., 2022). Decreased physical activity, physical deconditioning, decreased elasticity of the blood vessels, and stiffening of the heart valves can lead to a decrease in the overall function of the heart, leading to decreased oxygenation of body tissues.

Many psychological factors can have an impact on the respiratory system. People responding to stress or anxiety may experience hyperventilation. In addition, patients with respiratory problems often develop some anxiety as a result of the hypoxia caused by the respiratory problem.