Chapter IV - Respiratory System

PHYSICAL ASSESSMENT

Evaluation of the respiratory system, espe­cially of the lungs, is carried out by the pro­cess of auscultation and percussion. While diagnosing the ailments of the respiratory system, a physician inspects the symmetry, color and movements of the thoracic cavity. He determines the respiratory rate which, in normal case, should range from 16 to 20. The physician also uses a stethoscope and listens for any extra sound like rales, rhon­chi, or wheezes. He palpates the back and checks for the presence of fremitus. Percus­sion of the chest allows the physician to find out if there is any dull sound or edema present. The physician asks the patient if he/she experiences any shortness of breath or dyspnea.

PATHOLOGY
Bronchiectasis
Bronchiectasis is characterized by the dila­tion of the bronchi, especially the lower lungs. Mucopurulent sputum (sputum mixed with mucus and pus) and hemoptysis are the associated symptoms. Treatment includes mucolytics, bronchodilators, antibiot­ics, and postural drainage.

Bronchopneumonia
Bronchopneumonia is an infectious inflam­matory condition of the lungs, caused by a variety of agents. Bronchopneumonia affect­ing only one side of the lung is referred to as lobar pneumonia, while that affecting both sides of the lungs is called bilateral or double pneumonia. Due to the pathological engorgement, the lungs may develop solidi­fication or consolidation. The condition is characterized by chest pain, mucopurulent sputum, and hemoptysis.

Pneumocystis carinii pneumonia (PCP) is an important consideration in this regard. The causative fungus resides in the normal flora and causes no harm as long as the individual remains healthy. However, with the compromise of the immune system, the or­ganism becomes opportunistic. Physicians diagnose the condition with the help of a biopsy and lavage.

COPD
COPD stands for chronic ob­structive pulmonary disease or it can be also termed as COLD (chronic obstructive lung disease) and are also used as synonyms. However, COLD should not be mistaken for common cold that we usually get infect with. Hence, generally, COPD term is used. This is a respiratory disorder characterized by cough and dyspnea due to the obstruction in the air passages. The three major diseases, which come in this category are asthma, chronic bronchitis, and emphysema.

Asthma is characterized by the spasms of the bronchus. These bronchospasms can by paroxysmal (sudden and violent in nature) causing dyspnea. They can also be characterized by productive cough and thickening of the epithelial cells of the bronchial passages. Causes of this disease can be exposure to al­lergens and irritants, stress, cold, and exer­cise. Treatment includes administration of mucolytics and bronchodilators.

Chronic bronchitis, as is evident from the name itself, is the chronic inflammation of the bronchi. It is primarily caused by the smoking and air pollution, though viruses and bacteria can also be the contributing fac­tors. This is characterized by swelling of the mucosa, heavy and productive cough, chest pain, exercise intolerance, wheezing, and shortness of breath. Bronchodilators and ex­pectorants are required to expand the air passages.

Long-term heavy smoking or other dis­ease, such as asthma, tuberculosis, or chronic bronchitis, may cause the alveoli to lose its elasticity. The air sacs expand, but they are unable to contract, and the residual air gets trapped inside. This results in a 'barrel chest' appearance and is referred as emphysema. People afflicted with emphysema often suf­fer from another condition called orthopnea, i.e. they find it easier to breathe while sitting or standing.

CROUP
Croup refers to an acute obstruction of the lungs caused by allergens, infection, foreign body, or new growth. It is characterized by a resonant, barking cough, laryngeal spasms, suffocation or difficulty in breathing, and the formation of a membrane.

Cystic fibrosis
Cystic fibrosis is a hereditary and systemic disorder, which affects the exocrine glands. The condition is characterized by the pro­duction of viscous mucus, which blocks the bronchioles. The treatment includes use of aerosols and postural drainage. This is a very fatal disease and almost results in loss of life.

Lung cancer
Smoking is the leading cause of lung cancer, and the most commonly affected site is the epithelium of the bronchial passage. The lung cancer of the bronchial passage is called bronchogenic carcinoma. This is character­ized by the rapid division of the basal cells located at the base of the epithelium and metastasis to the other areas of the body. Treatment includes surgery, radiation, and chemotherapy.

Pleural effusions
Pleural effusions refer to the excessive accu­mulation of the fluid in the pleural cavity. Congestive heart failure, ascites, and infec­tious lung diseases can be conducive to pleu­ral effusions. Physicians generally diagnose the pleural effusions with the help of what we call auscultation and percussion. Auscul­tation is listening to the sounds of the chest cavity with the help of a stethoscope, while percussion refers to tapping the chest with the fingers to determine the size position, and consistency of the underlying structures. Different types of pleural effusions are:

1. Empyema: Pus in the pleural space
2. Hydrothorax: serum in the pleural space
3. Hemothorax: blood in the pleural space
4. Pneumothorax: air in the pleural space
5. Pyopneumothorax: pus and air in the pleural space

Treatment often includes thoracocentesis or thoracentesis to remove the excess fluid.

Rales, rhonchi, and wheezes:
Rales are abnormal crackling sounds heard on inspiration produced by the passage of air that contains moisture. Rales are noted by a stethoscope and indicate a pneumonia like condition.

Accumulation of fluids in the airways pro­duces this abnormal chest sound, which resembles snoring. These snoring sounds are known as rhonchi.

Partially obstructed airways produce a whistling musical sound during breathing called wheezing. It may be caused by gen­eral obstruction of the airways (as in asthma and COPD) or local obstruction (as in tu­mors).

Respiratory distress syndrome
Lungs require surfactants in order to fill with air and expand, also known as compliance. Surfactants assist in decreasing the surface tension of the alveoli. Deficiency or impairment of the surfactants may cause the col­lapse of the alveoli and inhalation becomes difficult. When this condition is found in the infants, this is known as IROS (infant respi­ratory distress syndrome) or HMO (hyaline membrane disease). IROS or HMO is com­mon among the premature infants or the in­fants born of the diabetic mothers. ARDS (adult respiratory distress syndrome) is caused by the impairment of the surfactants or accidental inhalation of foreign substan­ces, water, smoke, or chemical fumes.

Stridor
Blockages of the throat, voice box, and wind­pipe produce a crowing sound during breathing, especially during inhalation, which is known as stridor. The sound is caused by a turbulent airflow through a narrowed air­way. It may be due to the epiglottitis, tumor, or edema.

Tuberculosis
Aerosol transmission or particles of dry spu­tum containing the tuberculosis (TB) organism, Mycobacterium tuberculosis cause the spread of the disease. These organisms can remain viable and infectious for a period of 6 to 8 months even when they arc outside the body. This disease develops into three stages: primary tuberculosis, formation of granulomas, and the immunocompromised state of full-blown disease. This lung disease can infect even the meninges, bones, genital tract, and the peritoneum.