PATHOPHYSIOLOGY OF THE RESPIRATORY SYSTEM

Pathophysiology of the Respiratory System



Table of Contents

Introduction/Background2

Path physiology and pathology4

Epidemiology of Asthma4

Exercise-Induced Asthma5

Clinical Manifestations7

Classification7

Pre-hospital/Medical Management9

Managing Asthma9

Preventing Asthma Attacks10

Improvement of Indoor Air11

Overcoming Barriers to Asthma Intervention12

Treatment14

Pathophysiology of the Respiratory System

Introduction/Background

Asthma is a pulmonary condition that involves chronic inflammation of the airways, which leads to bronchial hyper reactivity or spasm. Symptoms may include wheezing, cough, chest tightness, and shortness of breath. In the United States, asthma is present in about 6% to 7% of the child population, and an estimated 17 million adults have chronic asthma. The inflammation and spasm of the airways create an obstruction to airflow and thus generate the symptoms of wheezing, cough, and shortness of breath. The degree of airflow obstruction can be measured with a peak flow meter, or spirometry. These instruments can measure the volume and speed of airflow, which can be compared with the standards for age and height to assess any deficits. Patient complaints of symptoms of tightness, wheezing, or cough are important in making the diagnosis of asthma even if these symptoms are not present at the time of examination. The diagnosis of asthma is confirmed when the airflow obstruction can be reversed by bronchodilator medication and repeat spirometry or if peak flow measurements normalize. The severity of asthma is classified on a scale from mild to severe according to the frequency of symptoms, lung function, and the medications needed to maintain control (Ford, 2003, pp. 119).

The causes of asthma are not entirely understood, and there is no known cure for the disease: instead, medical practice focuses on trying to prevent attacks and limit their severity through avoidance of “triggers” (substances that can set off an attack in a particular individual) and the use of medications. Despite being a fairly common disease, asthma is also complex, with much variability in symptoms and risk factors among cases, both of which complicate efforts both to diagnose individual cases and to do epidemiological research regarding the disease (Fireman, 2003, pp. 79). For instance, it is difficult to calculate the rates of occurrence in a single population and even more complex to compare disease rates across different populations because diagnostic criteria differ in different countries, and many cases of asthma remain undiagnosed. Even within an industrialized country such as the United States, significant changes have been made in the past 50 years or so in the process for diagnosing asthma.

There seems to be a genetic component involved in the disease, that is, certain people are born with a predisposition to develop asthma. Clinical studies suggest that a child is at increased risk of asthma if one or both parents have the disease: for one parent, the risk is about 30 percent (versus less than 10 percent in the general population), while a child whose parents both have asthma has a risk of about 50 percent of developing the disease. However, environmental factors, including exposure to certain substances, also appear to play a role, and the influence of genetic and environmental factors ...