Tuberculosis is an infectious disease that primarily affects the lung parenchyma.
What is Pulmonary Tuberculosis?
Pulmonary tuberculosis (PTB) is a chronic respiratory disease common among crowded and poorly ventilated areas.
- An acute or chronic infection caused by Mycobacterium tuberculosis, tuberculosis is characterized by pulmonary infiltrates, formation of granulomas with caseation, fibrosis, and cavitation.
- Tuberculosis is an infectious disease that primarily affects the lung parenchyma.
- It also may be transmitted to other parts of the body, including the meninges, kidneys, bones, and lymph nodes.
- The primary infectious agent, M. tuberculosis, is an acid-fast aerobic rod that grows slowly and is sensitive to heat and ultraviolet light.
Tuberculosis is a highly infectious, airborne disease.
- Inhalation. Tuberculosis begins when a susceptible person inhales mycobacteria and becomes infected.
- Transmission. The bacteria are transmitted through the airways to the alveoli, and are also transported via lymph system and bloodstream to other parts of the body.
- Defense. The body’s immune system responds by initiating an inflammatory reaction and phagocytes engulf many of the bacteria, and TB-specific lymphocytes lyse the bacilli and normal tissue.
- Protection. Granulomas new tissue masses of live and dead bacilli, ate surrounded by macrophages, which form a protective wall.
- Ghon’s tubercle. They are then transformed to a fibrous tissue mass, the central portion of which is called a Ghon tubercle.
- Scarring. The bacteria and macrophages turns into a cheesy mass that may become calcified and form a collagenous scar.
- Dormancy. At this point, the bacteria become dormant, and there is no further progression of active disease.
- Activation. After initial exposure and infection, active disease may develop because of a compromised or inadequate immune system response.
- Pathophysiology and Schematic Diagram for Pulmonary Tuberculosis
Data from the history, physical examination, TB test, chest xray, and microbiologic studies are used to classify TB into one of five classes.
- Class 0. There is no exposure or no infection.
- Class 1. There is an exposure but no evidence of infection.
- Class 2. There is latent infection but no disease.
- Class 3. There is a disease and is clinically active.
- Class 4. There is a disease but not clinically active.
- Class 5. There is a suspected disease but the diagnosis is pending.
Statistics and Incidences
Tuberculosis is a worldwide public health problem that is closely associated with poverty, malnutrition, overcrowding, substandard housing, and inadequate health care.
- M. tuberculosis infects an estimated one-third of the world’s population and remains the leading cause of death from infectious disease in the world.
- According to the WHO, an estimated 1.6 million deaths resulted from TB in 2005.
- In the United States, almost 15,000 cases of TB are reported annually to the CDC.
- After exposure to M. tuberculosis, roughly 5% of infected people develop active TB within a year.
Causes of acquiring tuberculosis include the following:
- Close contact. Having close contact with someone who has an active TB.
- Low immunity. Immunocompromised status like those with HIV, cancer, or transplanted organs increases the risk of acquiring tuberculosis.
- Substance abuse. People who are IV/injection drug users and alcoholics have a greater chance of acquiring tuberculosis.
- Inadequate health care. Any person without adequate health care like the homeless, impoverished, and the minorities often develop active TB.
- Immigration. Immigration from countries with a high prevalence of TB could affect the patient.
- Overcrowding. Living in an overcrowded, substandard housing increases the spreading of the infection.
After an incubation period of 4 to 8 weeks, TB is usually asymptomatic in primary infection.
- Nonspecific symptoms. Nonspecific symptoms may be produced such as fatigue, weakness, anorexia, weight loss, night sweats, and low-grade fever, with fever and night sweats as the typical hallmarks of tuberculosis.
- Cough. The patient may experience cough with mucopurulent sputum.
- Hemoptysis. Occasional hemoptysis or blood on the saliva is common in TB patients.
- Chest pains. The patient may also complain of chest pain as a part of discomfort.
To prevent transmission of tuberculosis, the following should be implemented.
- Identification and treatment. Early identification and treatment of persons with active TB.
- Prevention. Prevention of spread of infectious droplet nuclei by source control methods and by reduction of microbial contamination of indoor air.
- Surveillance. Maintain surveillance for TB infection among health care workers by routine, periodic tuberculin skin testing.
If left untreated or mistreated, pulmonary tuberculosis may lead to:
- Respiratory failure. Respiratory failure is one of the most common complication of pulmonary tuberculosis.
- Pneumothorax. Pneumothorax becomes a complication when tuberculosis is not treated properly.
- Pneumonia. One of the most fatal complications of tuberculosis is pneumonia as it could cause infection all over the lungs.
Assessment and Diagnostic Findings
To diagnose tuberculosis, the following tests could be performed:
- Sputum culture: Positive for Mycobacterium tuberculosis in the active stage of the disease.
- Ziehl-Neelsen (acid-fast stain applied to a smear of body fluid): Positive for acid-fast bacilli (AFB).
- Skin tests (purified protein derivative [PPD] or Old tuberculin [OT] administered by intradermal injection [Mantoux]): A positive reaction (area of induration 10 mm or greater, occurring 48–72 hr after interdermal injection of the antigen) indicates past infection and the presence of antibodies but is not necessarily indicative of active disease. Factors associated with a decreased response to tuberculin include underlying viral or bacterial infection, malnutrition, lymphadenopathy, overwhelming TB infection, insufficient antigen injection, and conscious or unconscious bias. A significant reaction in a patient who is clinically ill means that active TB cannot be dismissed as a diagnostic possibility. A significant reaction in healthy persons usually signifies dormant TB or an infection caused by a different mycobacterium.
- Enzyme-linked immunosorbent assay (ELISA)/Western blot: May reveal presence of HIV.
- Chest x-ray: May show small, patchy infiltrations of early lesions in the upper-lung field, calcium deposits of healed primary lesions, or fluid of an effusion. Changes indicating more advanced TB may include cavitation, scar tissue/fibrotic areas.
- CT or MRI scan: Determines degree of lung damage and may confirm a difficult diagnosis.
- Bronchoscopy: Shows inflammation and altered lung tissue. May also be performed to obtain sputum if patient is unable to produce an adequate specimen.
- Histologic or tissue cultures (including gastric washings; urine and cerebrospinal fluid [CSF]; skin biopsy): Positive for Mycobacterium tuberculosis and may indicate extrapulmonary involvement.
- Needle biopsy of lung tissue: Positive for granulomas of TB; presence of giant cells indicating necrosis.
- Electrolytes: May be abnormal depending on the location and severity of infection; e.g., hyponatremia caused by abnormal water retention may be found in extensive chronic pulmonary TB.
- ABGs: May be abnormal depending on location, severity, and residual damage to the lungs.
- Pulmonary function studies: Decreased vital capacity, increased dead space, increased ratio of residual air to total lung capacity, and decreased oxygen saturation are secondary to parenchymal infiltration/fibrosis, loss of lung tissue, and pleural disease (extensive chronic pulmonary TB).
Pulmonary tuberculosis is treated primarily with antituberculosis agents for 6 to 12 months.
- First line treatment. First-line agents for the treatment of tuberculosis are isoniazid (INH), rifampin (RIF), ethambutol (EMB), and pyrazinamide.
- Active TB. For most adults with active TB, the recommended dosing includes the administration of all four drugs daily for 2 months, followed by 4 months of INH and RIF.
- Latent TB. Latent TB is usually treated daily for 9 months.
- Treatment guidelines. Recommended treatment guidelines for newly diagnosed cases of pulmonary TB have two parts: an initial treatment phase and a continuation phase.
- Initial phase. The initial phase consists of a multiple-medication regimen of INH, rifampin, pyrazinamide, and ethambutol and lasts for 8 weeks.
- Continuation phase. The continuation phase of treatment include INH and rifampin or INH and rifapentine, and lasts for an additional 4 or 7 months.
- Prophylactic isoniazid. Prophylactic INH treatment involves taking daily doses for 6 to 12 months.
- DOT. Directly observed therapy may be selected, wherein an assigned caregiver directly observes the administration of the drug.
The first line antituberculosis medications include:•
- Isoniazid (INH). INH is a bactericidal agent that is used as prophylaxis for neuritis, and has side effects of peripheral neuritis, hepatic enzyme elevation, hepatitis, and hypersensitivity.
- Rifampin (Rifadin). Rifampin is a bactericidal agent that turns the urine and other body secretions into orange or red, and has common side effects of hepatitis, febrile reaction, purpura, nausea, and vomiting.
- Pyrazinamide. Pyrazinamide is a bactericidal agent which increases the uric acid in the blood and has common side effects of hyperuricemia, hepatotoxicity, skin rash, arthralgias, and GI distress.
- Ethambutol (Myambutol). Ethambutol is a bacteriostatic agent that should be used with caution with renal disease, and has common side effects of optic neuritis and skin rash.
Nursing management includes the following:
The nurse may assess the following:
- Complete history. Past and present medical history is assessed as well as both of the parents’ histories.
- Physical examination. A TB patient loses weight dramatically and may show the loss in physical appearance.
Based on the assessment data, the major nursing diagnoses for the patient include:
- Risk for infection related to inadequate primary defenses and lowered resistance.
- Ineffective airway clearance related to thick, viscous, or bloody secretions.
- Risk for impaired gas exchange related to decrease in effective lung surface.
- Activity intolerance related to imbalance between oxygen supply and demand.
- Imbalanced nutrition: less than body requirements related to inability to ingest adequate nutrients.
Nursing Care Planning & Goals
Main Article: 5 Pulmonary Tuberculosis Nursing Care Plans
The major goals for the patient include:
- Promote airway clearance.
- Adhere to treatment regimen.
- Promote activity and adequate nutrition.
- Prevent spread of tuberculosis infection.
Nursing interventions for the patient include:
- Promoting airway clearance. The nurse instructs the patient about correct positioning to facilitate drainage and to increase fluid intake to promote systemic hydration.
- Adherence to the treatment regimen. The nurse should teach the patient that TB is a communicable disease and taking medications is the most effective means of preventing transmission.
- Promoting activity and adequate nutrition. The nurse plans a progressive activity schedule that focuses on increasing activity tolerance and muscle strength and a nutritional plan that allows for small, frequent meals.
- Preventing spreading of tuberculosis infection. The nurse carefully instructs the patient about important hygienic measures including mouth care, covering the mouth and nose when coughing and sneezing, proper disposal of tissues, and handwashing.
- Acid-fast bacillus isolation. Initiate AFB isolation immediately, including the use of a private room with negative pressure in relation to surrounding areas and a minimum of six air changes per hour.
- Disposal. Place a covered trash can nearby or tape a lined bag to the side of the bed to dispose of used tissues.
- Monitor adverse effects. Be alert for adverse effects of medications.
Expected patient outcomes include:
- Promoted airway clearance.
- Adhered to treatment regimen.
- Promoted activity and adequate nutrition.
- Prevented spread of tuberculosis infection.
Discharge and Home Care Guidelines
Before the discharge, the nurse should instruct the patient to:
- Disposal of secretions. Cough and sneeze into tissues and to dispose of all secretions in a separate trash can.
- Isolation. Wear a mask when going outside of the room.
- Activity and nutrition. Remind the patient to take a lot of rest and to eat balanced meals to aid recovery.
- Adverse effects. Advise the patient to watch out for adverse effects of medications and to report them to the physician immediately.
The focus of documentation should include:
- Recent or current antibiotic therapy.Signs and symptoms of infectious process.
- Signs and symptoms of infectious process.Breath sounds, presence and character of secretions, and use of accessory muscles for breathing.
- Breath sounds, presence and character of secretions, and use of accessory muscles for breathing.Character of
- Character of cough and sputum.Respiratory rate, pulse oximetry, oxygen saturation, and vital signs.
- Respiratory rate, pulse oximetry, oxygen saturation, and vital signs. Level of activity.
- Level of activity.Causative or precipitating factors.
- Causative or precipitating factors.Client reports of difficulty or change.
- Client reports of difficulty or change.Caloric intake.
- Caloric intake.Individual cultural or religious restrictions and personal preferences.
- Individual cultural or religious restrictions and personal preferences.Plan of care.
- Plan of care.Teaching plan.
- Teaching plan.Responses to interventions, teaching, and actions performed.
- Responses to interventions, teaching, and actions performed.Attainment or progress toward desired outcomes.
- Attainment or progress toward desired outcomes.Modifications to
- Modifications to plan of care.Discharge needs.
- Discharge needs.
Practice Quiz: Pulmonary Tuberculosis
1. Characteristics of the Mycobacterium tuberculosis include all of the following except:
A. It can be transmitted only by droplet nuclei.
B. It is acid-fast.
C. It is able to lie dormant within the body for years.
D. It survives in anaerobic conditions.
1. Answer: D. It survives in anaerobic conditions.
- D: Mycobacterium tuberculosis is an aerobic microorganism that cannot survive in an anaerobic environment.
- A, B, C: All options are characteristics of Mycobacterium tuberculosis.
2. It is estimated that Mycobacterium tuberculosis infects about what percentage of the world’s population?
2. Answer: C. 35%.
- C: M. tuberculosis infects an estimated one-third or almost 35% of the world’s population.
- A, B, D: The following percentages are not calculated as one-third of the world’ population that is infected with M. tuberculosis.
3. For the tubercle bacilli to multiply and initiate a tissue reaction in the lungs, it must be deposited in:
A. The alveoli.
B. The bronchi.
C. The trachea.
D. All of the above.
3. Answer: A. The alveoli.
- A: Upon reaching the alveoli, the tubercle bacilli starts to multiply and initiate a tissue reaction.
- B, C, D: The bacteria, once deposited in the alveoli and not in any body part or organ, begin to multiply.
4. Prophylactic isoniazid drug treatment is necessary for about how many months?
A. 3 months.
B. 3 to 5 months.
C. 6 to 12 months.
D. 13 to 18 months.
4. Answer: C. 6 to 12 months.
- C: Prophylactic INH treatment involves taking daily doses for 6 to 12 months.
- A&B: A 3 to 5 months treatment is insufficient to kill the bacteria completely.
- D: 13 to 18 months of treatment is more than sufficient to completely destroy the tubercle bacilli.
5. A Mantoux skin test is considered not significant if the size of the induration is:
A. 0 to 4 mm.
B. 5 to 6 mm.
C. 7 to 8 mm.
D. 9 mm.
5. Answer: A. 0 to 4 mm.
- A: A reaction of 0 to 4 mm induration is considered as not significant in Mantoux skin test.
- B, C, D: A reaction of 5 mm or greater induration is considered as significant.