Question

Using the information on the introduction to activity 2, how do conditions such as emphysema and asthma affect a person’s ability to breathe?

Answer 1

The pathophysiological events of emphysema include,

1) Inflammation of the central airways due to the release of the inflammatory mediators, oxidative stress, inflammatory cells like neutrophils, macrophages, lymphocytes.

2) Remodelling of the peripheral airway will occur.

3) Parenchymal destruction occurs due to imbalance between proteinase and ant proteinase.

4) Pulmonary vascular changes like thick vessels, inflammatory cells infiltrate, collagen deposition occurs and destruction of the capillary bed.

Emphysema causes the lungs remain overinflated for chronic periods, so the rib cage expands partially. The loss of elastic recoiling of chest wall, deposition of collagen and overinflation of lungs all contribute to the “barrel chest” configuaration in emphysema.

Due to the decreased surface area of the lungs and central airway inflammation, the patients suffer from dyspnea or shortness of breath. The arterial blood gas values of an emphysema patient generally reveal high carbon dioxide and low oxygen levels. During the progression of the disease, symptoms and dyspnoea interferes with the daily activities of the patient. In late stages dyspnoea is present even at rest. Patient frequently complains about anorexia, weight loss and fatigue. Dyspnoea impairs the food intake and reduces exercise tolerance. The metabolic rate in COPD patients increases, which increases the demand for intake of proteins and other energy sources.

Pathophysiology of asthma:

Asthma occurs due to persistent subacute inflammation of the airways. The clinical features and physiology of the asthma is due to interaction of the infiltrating and resident inflammatory cells, inflammatory mediators and cytokines with the airway surface epithelium. The increased mucus secretion and bronchoconstriction obstruct the respiratory process.