A high level of oxygen exerts which of the following effects on the lung?
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Solution
Reduces amount of functional alveolar surface area
Oxygen toxicity causes direct pulmonary trauma, reducing the amount of alveolar surface area available for gaseous exchange, which results in increased carbon dioxide levels and decreased oxygen uptake.
A client diagnosed with active TB would be hospitalized primarily for which of the following reasons?
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Solution
To prevent spread of the disease
The client with active TB is highly contagious until three consecutive sputum cultures are negative, so he’s put in respiratory isolation in the hospital.
A client is diagnosed with active TB and started on triple antibiotic therapy. What signs and symptoms would the client show if therapy is inadequate?
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Solution
Positive acid-fast bacilli in a sputum sample after 2 months of treatment.
Continuing to have acid-fast bacilli in the sputum after 2 months indicated continued infection.
A client with a productive cough, chills, and night sweats is suspected of having active TB. The physician should take which of the following actions?
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Solution
Admit him to the hospital in respiratory isolation
The client is showing s/s of active TB and because of a productive cough is highly contagious. He should be admitted to the hospital, placed in respiratory isolation, and three sputum cultures should be obtained to confirm the diagnosis. He would most likely be given isoniazid and two or three other antitubercular antibiotics until the diagnosis is confirmed, then isolation and treatment would continue if the cultures were positive for TB. After 7 to 10 days, three more consecutive sputum cultures will be obtained. If they’re negative, he would be considered non-contagious and may be sent home, although he’ll continue to take the antitubercular drugs for 9 to 12 months.
A client with a positive skin test for TB isn’t showing signs of active disease. To help prevent the development of active TB, the client should be treated with isoniazid, 300 mg daily, for how long?
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Solution
9 to 12 months
Because of the increased incidence of resistant strains of TB, the disease must be treated for up to 24 months in some cases, but treatment typically lasts for 9-12 months. Isoniazid is the most common medication used for the treatment of TB, but other antibiotics are added to the regimen to obtain the best results.
A chest x-ray should a client’s lungs to be clear. His Mantoux test is positive, with a 10mm if induration. His previous test was negative. These test results are possible because:
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Solution
He’s a “tuberculin converter,” which means he has been infected with TB since his last skin test.
A tuberculin converter’s skin test will be positive, meaning he has been exposed to an infected with TB and now has a cell-mediated immune response to the skin test. The client’s blood and x-ray results may stay negative. It doesn’t mean the infection has advanced to the active stage. Because his x-ray is negative, he should be monitored every 6 months to see if he develops changes in his x-ray or pulmonary examination. Being a seroconverter doesn’t mean the TB has gotten into his bloodstream; it means it can be detected by a blood test.
A client with a positive Mantoux test result will be sent for a chest x-ray. For which of the following reasons is this done?
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Solution
To determine the extent of the lesions
If the lesions are large enough, the chest x-ray will show their presence in the lungs. Sputum culture confirms the diagnosis. There can be false-positive and false-negative skin test results. A chest x-ray can’t determine if this is a primary or secondary infection.
Which of the following diagnostic tests is definitive for TB?
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Solution
Sputum culture
The sputum culture for Mycobacterium tuberculosis is the only method of confirming the diagnosis. Lesions in the lung may not be big enough to be seen on x-ray. Skin tests may be falsely positive or falsely negative.
A client has active TB. Which of the following symptoms will he exhibit?
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Solution
Chills, fever, night sweats, and hemoptysis
Typical signs and symptoms are chills, fever, night sweats, and hemoptysis. Chest pain may be present from coughing, but isn’t usual. Clients with TB typically have low-grade fevers, not higher than 102*F. Nausea, headache, and photophobia aren’t usual TB symptoms.
A client was infected with TB 10 years ago but never developed the disease. He’s now being treated for cancer. The client begins to develop signs of TB. This is known as which of the following types of infection?
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Solution
Active infection
Some people carry dormant TB infections that may develop into active disease. In addition, primary sites of infection containing TB bacilli may remain inactive for years and then activate when the client’s resistance is lowered, as when a client is being treated for cancer. There’s no such thing as tertiary infection, and superinfection doesn’t apply in this case.