Characteristic	Possible Cause
Thick, tenacious, and “ropey”; difficult to cough up	Chronic bronchitis, emphysema
Scant, sticky, rust colored	Pneumococcal pneumonia
Frothy, pinkish or blood tinged	Pulmonary edema
Yellow, yellow-green, or grayish yellow, with foul odor or taste	Pulmonary infection
Blood tinged, bloody, or blood streaked	Tuberculosis, or ulcerated pulmonary vessel, or bronchogenic carcinoma
Large amounts	Pneumonia or bronchitis
Scanty	Asthma
Very thick and viscous	Inadequate hydration

*Normal sputum is white and slightly viscous and has no odor or taste.

How do the Bones of the Thorax and the Respiratory Muscles Affect the Respiratory Process?

• Inspiration (inhalation) and expiration (exhalation) occur by movement of the diaphragm and the intercostal muscles in the chest wall. During normal breathing, about 500 mL of air moves in and out of the lungs with each breath.

• When the diaphragm contracts, it moves downward; the other chest muscles contract, pulling the rib cage up and out, expanding the lungs and creating a greater area of negative pressure. Air from the atmosphere, which has a positive higher pressure, flows into the lungs.

• When the muscles relax, the lungs are allowed to return to a resting position that has a smaller internal volume and air is pushed out in exhalation.

• If damage to the spinal cord occurs above the level where the respiratory nerves are located (T1), voluntary respiration ceases.

• If the muscles of the diaphragm and chest are paralyzed, apnea (absence of breathing) occurs.

• The thoracic cage—composed of the thoracic vertebrae, the sternum, and the ribs—forms a stable unit that allows the respiratory muscles to function correctly. If any bones of the thorax or chest wall are injured or fractured, breathing becomes harder and dyspnea (difficult breathing) occurs.

• Compliance describes the elasticity of the lungs or how easily the lungs inflate; when compliance is decreased, the lungs are more difficult to inflate. Chronic obstructive pulmonary disease (COPD) and aging alter compliance due to damage in the alveoli.

• Weakness of the respiratory muscles, such as occurs with neuromuscular diseases, also causes decreased lung capacity.

• Kyphosis (inward curvature and collapse) of the spine constricts the thoracic cavity and restricts the capacity of the lungs to expand fully.

What Factors can Affect the Exchange of Oxygen and Carbon Dioxide?

• Alveoli are tiny air sacs covered with a permeable membrane that come into contact with the pulmonary arterioles and venules; oxygen passes into the blood and carbon dioxide passes from the blood into the alveoli.

• Surfactant is secreted by cells in the alveoli; it decreases surface tension on the alveolar wall so that diffusion of O₂ and CO₂ can take place. Surfactant facilitates expansion with inspiration and prevents alveolar collapse on expiration. When surfactant levels are low, alveoli cannot properly expand and O₂ and CO₂ cannot cross the membrane adequately.

• When interstitial edema occurs in the lung tissue, the alveolar membrane is thickened and gases cannot diffuse across the membrane as easily. During inflammation if fluid fills the alveoli, gases cannot diffuse across the membrane. Tumors may create blockage.

• Edema in the lungs occurs with infectious processes such as pneumonia and in disorders such as congestive heart failure.

• The major portion of the O₂ (about 97%) attaches to the heme portion of the hemoglobin molecule carried by the erythrocytes (red blood cells) and forms oxyhemoglobin. The plasma also transports a portion of each gas; about 3% of O₂ is dissolved in the plasma.

• CO₂, a cellular waste product, combines with water in the red blood cell, forming carbonic acid; dissociation (uncombining) occurs, forming hydrogen ions and bicarbonate ions. About 77% of CO₂ is transported in the blood plasma in the form of bicarbonate ions. The remaining 23% of CO₂ combines with hemoglobin and is carried to the lungs. In the lung, the process reverses and the bicarbonate ions reenter the red blood cells and combine with hydrogen ions to form carbonic acid, which then dissociates into water and CO₂. The CO₂ diffuses across the alveolar membrane and is exhaled.

What Age-Related Changes Affect the Respiratory System?

• The decrease in the immune system’s efficiency makes the elderly more susceptible to upper respiratory infections.

• Aging results in a decreased cough reflex and an increased potential for aspiration.

• Osteoporosis may cause kyphosis, which impinges on lung expansion.

• Adults age 70 and older have some degree of change in connective tissue that causes decreased elasticity and affects lung function and ventilation.

• Total body water decreases to 50% after age 70, thus mucous and respiratory membranes are not as moist and mucous becomes much thicker.

• There is some impairment of the ciliary action, which makes it more difficult for the elderly to remove mucus, and retained mucus provides a breeding ground for bacterial infection.

• There is a loss of normal elastic recoil of the lung during expiration, and the patient must use muscle action to complete expiration. This increases the work of breathing.

• Muscle atrophy may affect the respiratory muscles, diminishing their strength.

• Connective tissue changes and loss of elastic tissue in the alveoli cause the alveolar membranes to become thickened. Oxygen saturation decreases for the elderly, with partial pressure of oxygen (PO₂) dropping to 75 to 80 mm Hg from the usual 80 to 100 mm Hg.

• There is a decreased response to hypoxia (oxygen deficit in tissues) and hypercapnia (excessive amounts of carbon dioxide)

Causes of Respiratory Disorders

Trauma or disease can affect structures of the respiratory system, nerves controlling respiration, or diffusion of oxygen or carbon dioxide across the alveolar membranes into the capillaries. Perfusion (blood flow into cellular tissue) is essential because the bloodstream carries the oxygen to the cells of the body. Blood must be pumped past the alveolar membrane for oxygen and carbon dioxide diffusion to take place (Box 13-1). Cardiac disease, emboli, and other disorders of the heart and pulmonary blood vessels eventually cause problems in the respiratory system.

Box 13-1

Terms Commonly Used in Respiratory Care

• Diffusion: The movement of oxygen and carbon dioxide across the alveolar-capillary membrane. It takes place between the gas in the alveolar spaces and the blood in the pulmonary capillaries.

• Elastance: The extent to which the lungs are able to return to their original position after being stretched or distended.

• Hypoxemia: Deficient oxygenation of the blood.

• Hypoxia: A broad term meaning diminished availability of oxygen to the body tissues.

• Lung compliance: The ability of the lungs to distend in response to changes in volume and pressure of inhaled air. Lung compliance first increases and then decreases with age as the lungs become stiffer and the chest wall more rigid.

• Perfusion: The passage of a fluid through the vessels of a specific organ.

• Pulmonary hygiene: Methods used to clear secretions from the airways

• Resistance: The force working against the passage of air. The major determinant is the radius of the airway.

• Respiratory failure: An abnormality of gas exchange with either an excess of carbon dioxide or a deficit of oxygen, or both.

• Shunting: Intrapulmonary shunting is the diverting of blood so that it does not take part in the gas exchange at the alveolar sites. When intrapulmonary shunting occurs, blood enters the left side of the heart without being oxygenated. It is, therefore, a possible cause of hypoxemia.

• Surfactant: A complex lipoprotein produced by cells lining the alveoli, which lowers surface tension within the alveoli. It prevents collapse of the lung by stabilizing the alveoli and decreasing capillary pressures.

• Ventilation: The movement of air from the external environment to the gas exchange units of the lung. It can be spontaneous or done by a mechanical ventilator.

The respiratory system is particularly susceptible to harmful substances in the environment. Inhalation of bacteria and other organisms can quickly produce an infection in either the upper or lower respiratory tract. Tobacco smoke, allergens, poisonous gases, and other toxic substances cause irritation and inflammation of the air passages and can eventually lead to chronic inflammation, obstructive diseases, and tumors. There may be a familial tendency toward allergies, asthma, or other lung problems.

There are two major types of ventilatory diseases: restrictive and obstructive. Restrictive diseases are characterized by decreased lung capacity. They are not necessarily primarily lung disorders, but eventually the expansion of the lung and chest wall will be limited. Examples include scoliosis and kyphosis, both of which decrease the size of the chest cavity. Arthritis increases stiffness of the chest wall and results in a decreased ability of the chest cavity to expand and contract. Pneumothorax (collapsed lung) diminishes lung surface; neuromuscular disorders weaken the strength of the muscles of respiration (e.g., myasthenia gravis); and disorders of the lung (e.g., pneumonia, atelectasis, and fibrosis) increase stiffness and decrease lung volume.

Obstructive pulmonary diseases are characterized by problems moving air into and out of the lungs. Narrowing of the openings in the tracheobronchial tree increases resistance to the flow of air, making it difficult for oxygen to enter and contributing to air trapping; therefore exhalation is also difficult. Asthma, emphysema, and chronic bronchitis are examples of obstructive lung diseases. Tumor in the lung can also obstruct airflow to the alveoli.

Respiratory Disorders

Prevention

The best ways to prevent infection and inflammation of the respiratory system are to practice hand hygiene frequently; stay out of crowds, especially during cold and flu season; refrain from smoking; avoid known allergens as much as possible; maintain adequate nutrition; and obtain sufficient rest to help keep the immune system healthy. Nurses should identify persons that have a high risk for infection (Box 13-2).

Box 13-2

Factors that Increase Risk for Respiratory Infection

• Older than 65 years of age

• Cigarette smoking

• Residing in extended-care facilities

• Chronic respiratory disorders (includes asthma)

• Congenital or chronic cardiovascular disorders

• Chronic renal disease

• Diabetes mellitus or a chronic metabolic disorder

• Compromised immune response

Allergy to airborne substances causes the mucous membranes of the nose and sinuses to become irritated and inflamed. When these membranes are inflamed, bacteria and viruses can more easily invade the cells and cause infection. By controlling inhaled allergens we can decrease the incidence of upper respiratory infection (URI).

Elder Care Points

The elderly should not be exposed to children with colds and coughs. If an elderly person is confined to the house or a long-term care facility, he or she will not have the immunity to common viruses and bacteria that younger, more socially active people do.

Elimination of such widespread respiratory diseases as the common cold and influenza is not possible; therefore nurses must practice good hand hygiene and use Standard Precautions and airborne or droplet precautions when working with patients with respiratory infections. For certain groups such as the elderly and the chronically ill, immunization against influenza is an effective means of reducing the incidence of respiratory disease. Physicians, nurses, and others involved in providing health care should also be immunized. Among the more serious reactions to influenza vaccine are allergic reactions, fever, malaise, or muscle soreness. Guillain-Barre syndrome occurs in about 1 in 100,00 individuals. The vaccine is prepared from chicken embryos; therefore vaccination is contraindicated for anyone with an allergy to eggs, chicken, or feathers.

The U.S. Public Health Service Advisory Committee on Immunization also recommends immunization against pneumococcal infection for high-risk persons.

Perhaps one of the most important preventive measures is to avoid prolonged and repeated inhalation of irritating substances. Such substances include tobacco smoke, industrial gases, coal dust, soot and other carbons, and air polluted by automobile exhaust. Proposed Healthy People 2020 objectives include reducing tobacco use by adults, adolescents, and pregnant women. Smoking cessation efforts are supported by increasing insurance coverage for evidenced-based interventions, increasing smoke-free environments, and strengthening tobacco laws. Beginning in early 2010, the Joint Commission began to develop and define Core Measures for the assessment and treatment of tobacco use. Nurses should participate by identifying patients at risk for tobacco-related disease and encourage cessation programs.

Think Critically

Can you think of three changes in lifestyle that might prevent you or a family member from developing a chronic or serious respiratory disorder?

Health Promotion

Smoking and Tobacco Cessation

There are “five As” for helping your patients to quit smoking: Ask about tobacco use. Advise about the health benefits of quitting. Assess readiness to quit. Assist in creating a cessation plan. Arrange follow-up. For those patients who are resistant to the five As model, an alternative model is the “Five Rights.” Help the patient identify the personal Relevance, Risks, Rewards, and Roadblocks, and Repeat these at every visit (Agency for Healthcare Research and Quality, 2008).

Nursing Management

Assessment (Data Collection)

History Taking

Observe respiratory function while you are talking with the patient and ask about frequency of URIs, known inhalant allergies, and sinus problems. Chest pain can occur with frequent coughing, pleurisy, or trauma to the lungs; however whenever there is a complaint of chest pain be vigilant for cardiac problems. Patients with sinus problems may complain of headache, malaise, a bad taste in the mouth, nasal congestion or obstruction, purulent drainage from the nose, and painful upper teeth. Those with pharyngitis often report a sore or “scratchy” throat, malaise, headache, and sometimes a cough. Dysphagia also might be a problem for patients with pharyngitis, because swallowing involves pushing the food back against the inflamed oropharynx. Hoarseness and loss of the voice (aphonia) are common symptoms of laryngitis. Hoarseness or a sore throat that lasts longer than 2 weeks, should be noted as this will assist in the early detection of throat malignancy. If the patient is in obvious respiratory distress, ask only a few