(^122) Medical-Surgical Nursing Demystified
- Explain to the patient:
- How to administer oxygen therapy.
- How to perform turning, coughing, and deep-breathing exercises.
Tuberculosis (TB)
WHAT WENT WRONG?
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.14