Tuberculosis (TB)

Introduction:

An infectious disease spread by airborne route. Infection is caused by inhalation
of droplets that contain the tuberculosis bacteria (Mycobacterium tuberculosis).
An infected person can spread the small airborne particles through coughing,
sneezing, or talking. Close contact with those affected increases the chances of
transmission. Once inhaled, the organism typically settles into the lung, but can
infect any organ in the body. The organism has an outer capsule.
Primary TB occurs when the patient is initially infected with the mycobac-
terium. After being inhaled into the lung, the organism causes a localized reac-
tion. As the macrophages and sensitized T-lymphocytes attempt to isolate and kill
off the mycobacterium within the lung, damage is also caused to the surrounding
lung tissue. A well-defined granulomatous lesion develops that contains the
mycobacterium, macrophages and other cells. Necrotic changes occur within this
lesion. Caseous granulomas develop along lymph node channels during the same
time. These areas create a Ghon’s complex which is a combination of the area ini-
tially infected by the airborne bacillus called the Ghon’s focus and a lymphatic
lesion. The majority of people with newly acquired infections and an adequate
immune system will develop latent infection, as the body walls off the infecting
organism within these granulomas. Disease is not active in these patients at this
point and will not be transmitted until there is some manifestation of the disease.
In patients with inadequate immune response, the tuberculosis will be progres-
sive, lung tissue destruction will continue, and other areas of the lung will also
become involved.
In secondary TB, the disease is reactivated at a later stage. The patient may be
reinfected from droplets, or from a prior primary lesion. Since the patient has pre-
viously been infected with TB, the immune response is to rapidly wall off the infec-
tion. Cavitation of these areas occurs as the organism travels along the airways.
Exposure to TB occurs when a person has had recent contact with a person sus-
pected or confirmed having TB. These patients do not have positive skin test, signs
or symptoms of disease, or chest x-ray changes. They may or may not have disease.
Latent TB infection occurs when a person has a positive tuberculin skin test but
no symptoms of disease. Chest x-ray may show granuloma or calcification.
TB disease is confirmed when a person has signs and symptoms of tuberculo-
sis. The chest x-ray typically has abnormalities in the apical aspects of the lung
fields. In HIV patients other areas may also be affected.

PROGNOSIS
Some patients develop drug-resistant TB, making treatment more difficult. The
drug-resistant TB may be resistant at the time of initial infection, or may develop
as a result of medications during treatment. This occurs either because the treat-
ment was not adequate or not taken appropriately.

SIGNS AND SYMPTOMS
• Weight loss and anorexia
• Night sweats
• Fever, possibly low-grade, due to infection
• Productive cough with discolored, blood-tinged sputum
• Shortness of breath due to lung changes
• Malaise and fatigue due to active illness affecting lungs

TREATMENT
Patients with active TB are initially placed on respiratory isolation as inpatients to
reduce the risk of spreading the organism by droplet infection or aerosolization.
Medications are initiated to treat TB and prevent transmission to others. Treatment
may be initiated for active disease or for those without active disease who have had
recent exposure. Combination therapy is typically used to decrease the likelihood
of drug-resistant organisms. Initial treatment times generally range from 6 to 12
months. Longer treatment plans may be necessary for those with HIV infection or
drug-resistant strains of TB. Some patient populations are monitored closely for
compliance with direct observation of drug treatment. Patient teaching is important
for medication protocol compliance and monitoring for side effects. Repeat sputum
cultures are typically taken to see that the treatment for active disease is effective.
• Administer antitubercular medications to treat and prevent transmission:
• isoniazid, rifampin, pyrazinamide, ethambutol, streptomycin
• Respiratory isolation for in-hospital care—the bacteria is spread by droplet.
• Increase protein, carbohydrates, and vitamin C diet for patients.

NURSING DIAGNOSES
• Fatigue
• Ineffective airway clearance

NURSING INTERVENTION
• Monitor respiration for rate, effort, use of accessory muscles, and skin color
changes.
• Increase fluid intake to help liquefy any secretions.
• Record fluid intake and output.
• Explain to the patient:
• How to prevent spreading the disease.
• The importance of finishing all prescribed medication.
• Plan for rest periods during the day.