Respiratory Infections Respiratory Conditions

Respiratory tract infections are highly infectious diseases that involve the respiratory tract. They are divided into upper (URTI or URI) and lower respiratory tract infections (LRTI or LRI). LRIs include pneumonia, bronchitis and influenza, and they tend to affect patients more seriously that URIs which include the common cold, tonsillitis, sinusitis and laryngitis. This research dwells on four respiratory infections which are bronchitis, bronchial asthma, exercise-induced bronchospasm and influenza and looks at their risk factors, etiology, pathology, differential diagnosis and treatment. Most of these respiratory infections present with similar symptoms and thus can be easily mistaken. This is why it is important to conduct research on the evidence that is present regarding each of these respiratory conditions.

Bronchitis

Bronchitis is an inflammation of the bronchi which are the main passages of air to the lungs. It may present as an acute or a chronic inflammation and has a potential for recurring. Acute bronchitis usually follows a viral infection of the respiratory system. The first signs are that it affects the nose, throat and sinuses before it spreads to the lungs. Bronchitis may also lead to a secondary infection caused by bacteria in the airways. The at risk group of bronchitis include smokers, people with lung and heart disease, the elderly and young children. Chronic bronchitis on the other hand usually starts with a cough which lasts a few months with excessive production of mucus. Chronic bronchitis is one type of COPD (chronic obstructive pulmonary disease) Salameh, Waked, Baldi, Brochard, & Saleh, 2006.

It is worsened by allergies, air pollution, and occupational hazards such as for those who work in coal mining, handling of grains and manufacture of textiles and other respiratory infections.

Etiology

Acute bronchitis usually presents as a single isolated case or a number of recurring illnesses. There is usually hypertrophy and hyperplasia of mucus secreting cells in the bronchus and it typifies chronic bronchitis which occurs in rats that are exposed to a chemical irritant of gaseous nature for 4-6 weeks Melbostad, Wijnand, & Magnus, 1997.

When bacteria colonize the bronchi, the bacteria that are implicated are normally normal flora of the naso-pharynx region. Therefore, the use of antibiotics to treat bronchitis should be done intelligently to prevent harming the normal flora bacteria Gelb, Nix, & Gellman, 1998()

Pathology

The first changes to occur for patients with bronchitis include congestion and edema of the bronchial mucosa. The secretions at this time are few and scanty but increases over time as there is high activity of the mucus producing c and goblet cells. These secretions become more and more purulent depending on the degree of infection and the type of infection. There is also epithelia desquamation which takes place and in more severe cases, there are necrotic changes that are observed which extend down to the bronchioles thus causing the terminal air passages to be obstructed and resulting in patchy atelectasis due to an associated inflammation of the alveoli (alveolitis). In many cases, there is complete recovery of the mucous membrane but there may be some episodes of acute bronchitis that heal by scarring thus causing permanent damage to the mucosa and the related alveoli. This permits a more ready development of more attacks of acute bronchitis that could become chronic Toro et al., 1997()

Most cases of bronchitis are as a result of an infection in the upper respiratory tract which then descends to the bronchi. A chemical or traumatic bronchitis arises from exposure to certain gases or vapors that irritate the bronchi or from certain pollutants of the atmosphere that produce a minor transient damage to the epithelium of the bronchi with ciliary action paralysis and again it permits the bacterial infection from the upper respiratory tract Toro et al., 1997()

Symptoms

Some of the symptoms of acute and chronic bronchitis include discomfort in the chest, a cough that produces mucus, fatigue, fever, shortness of breath that is made worse by exerting pressure on the chest or mild activity and wheezing. Other symptoms for chronic bronchitis include ankle, foot and leg swelling, frequent infections of the respiratory system, and lips that are blue in color as a result...

For acute bronchitis, even after it has cleared, the patient usually experiences a dry, nagging cough that lingers on for several weeks after Toro et al., 1997()
Differential diagnosis

The health care provider first listens to the patient's lungs using a stethoscope. He or she listens for abnormal sounds called rales as well as any other signs of abnormal breathing. The patient may also produce a wheezing sound when breathing. Other tests that are conducted include a chest x-ray, test of lung function in order to provide essential information for the diagnosis of bronchitis. Other tests include sputum samples which are taken to check for any signs of bacterial infection or inflammation. Yellow-green mucus usually indicates a bacterial infection. A pulse oximetry test is also conducted to determine the amount of oxygen in the patient's blood. This is a test that is conducted quickly and is painless. The device is placed at the end of the patient's finger. Another test that can be conducted checks for amount of oxygen in the arteries and is a more accurate measurement of oxygen levels and levels of carbon dioxide. However, this arterial blood gas test requires a needle stick to be pushed into the patient's artery and it is more painful Toro et al., 1997()

It is important to exclude any primary precipitating disored from bronchitis. Therefore, the buccal mucosa should be examined for presence of Koplik's spots. In a patient with mitral stenosis, acute bronchitis may be confused with the onset of failure of the left ventricle. In a patient with chronic renal disease, bronchitis may be difficult to distinguish from early uraemia but if the patient responds rapidly to antibiotics, the difference can be established. Failure of the patient to respond to antibiotics indicates that the infection is caused by either a drug-resistant organism such as a virus which is the cause of bronchitis. Many children who are asthmatic may have long recurrent attacks of coughing and wheezing. This is the case also for children who have no allergic tendencies. Therefore, the presence of changes to the bronchopulmonary system due to mucoviscidosis must be excluded Toro et al., 1997()

Treatment

Since bronchitis is a viral infection, antibiotics cannot be used to treat it. Usually, the infection goes away on its own after about 1 week. However, this requires the patient to steer away of the risk factors of bronchitis. This means that the patient should not smoke or stay close to smokers, they should drink plenty of fluids and should have plenty of rest. In case of a fever, the patient should take aspirin or acetaminophen (tylenol). The patient should also be advised to use a humidifier to keep the room humidified Toro et al., 1997()

In chronic bronchitis, antibiotic treatment should be started at once with the choice of antibiotic depending on the results of the bacteriological investigation of the patient's sputum. The choice of antibiotics includes penicillin, chloramphenicol, streptomycin, erythromycin and tetracycline. Streptomycin should not be used unless tuberculosis is excluded. Ampicillin and tetracycline are given in 500mg doses t.d.s. For 5-6 fays followed by a dose for maintenance of 500mg b.d. For another 7-10 days Toro et al., 1997()

Bronchial asthma

Bronchial asthma is a hypersensitivity disorder which is characterized by obstruction of the passage of air which is reversible. It is produced by a combination of edema of the mucus secreting cells and constriction of the muscles of the bronchi. Additionally, there is excessive secretion of viscid mucus which causes a mucus plug to form. There is a growing list of agents which are encountered in the environment that are risk factors of bronchial asthma. These include wood and metal dust, certain chemicals, allergens such as pollen, dust mites, mold and pet dander, and perfumes and tobacco smoke Wu & Takaro, 2007.

Exercise and excessive anxiety and stress can also lead to bronchial asthma. Other risk factors include Aspirin and non-steroidal anti-inflammatory agents may also cause severe bronchial asthma. Additionally, beta-adrenergic blockers which include propranolol can also lead to constriction of the bronchi as a result of parasympathetic nerve stimulation. Certain infections such as pneumonia, flu and cold as well as food additives such as MSG also are risk factors of bronchial asthma Shavit et al., 2007()

Etiology

Atopic asthma or extrinsic asthma has been thought to result from sensitization of the bronchial mucosa by antibodies that are specific to these tissues. These antibodies lead to the production of IgE type I immunoglobulin and the amount of total serum concentration of IgE is usually elevated. When the patient is exposed to the allergens of inhalation, there is the antigen-antibody reaction that takes place that leads to the release of chemical mediators of vasoactive broncho-constrictive action which causes the characteristic changes in the tissue. More recent studies show that IgG also plays a role similar to IgE in bronchial asthma Redd, 2002()

For intrinsic or non-atopic asthma, the bronchial reaction is…