Tuberculosis

Tuberculosis is an infectious disease caused by bacteria (Mycobacterium tuberculosis) that are usually spread from person to person through the air. It usually infects the lung, but can occur at virtually any site in the body. The incidence of tuberculosis is on the rise, especially drug-resistant varieties. HIV-infected patients are especially at risk.
--Pathophysiology/Etiology
A. Transmission
1. The term mycobacterium is descriptive of the organism, which is a bacterium that resembles a fungus. The organisms multiply slowly and are characterized as acid-fast aerobic organisms that can be killed by heat, sunshine, drying, and ultraviolet light.
2. Tuberculosis is an airborne disease transmitted by droplet nuclei, usually from within the respiratory tract of an infected person who exhales them during coughing, talking, sneezing, or singing.
3. When an uninfected susceptible person inhales the droplet-containing air, the organism is carried into the lung to the pulmonary alveoli.
4. Most people who become infected do not develop clinical illness, because the body’s immune system brings the infection under control.
B. Pathology
1. The bacilli of tuberculosis infect the lung, forming a tubercle (lesion).
2. The tubercle
a. May heal, leaving scar tissue.
b. May continue as a granuloma, then heal, or be reactivated.
c. May eventually proceed to necrosis, liquefaction, sloughing, and cavitation.
3. The initial lesion may disseminate tubercle bacilli by extension to adjacent tissues, via bloodstream, via lymphatic system, or through the bronchi.
--Clinical Manifestations
Patient may be asymptomatic or may have insidious symptoms that are ignored.
1. Constitutional symptoms
a. Fatigue, anorexia, weight loss, low-grade fever, night sweats, indigestion.
b. Some patients have acute febrile illness, chills, generalized influenzalike symptoms.
2. Pulmonary signs and symptoms
a. Cough (insidious onset) progressing in frequency and producing mucoid or mucopurulent sputum.
b. Hemoptysis; chest pain; dyspnea (indicates extensive involvement).
3. Extrapulmonary tuberculosis: Mycobacterium can infect any organ in the body including pleurae, lymph nodes, genitourinary tract, bones/joints, peritoneum, central nervous system.
--Diagnostic Evaluation
1. Sputum smear and culture—Diagnosis made by finding the acid-fast bacilli in sputum.
2. Chest x-ray to determine presence and extent of disease.
3. Tuberculin skin test (PPD or Mantoux test)—Inoculation of tubercle bacillus extract (tuberculin) into the intradermal layer of the inner aspect of the forearm (Procedure Guidelines 9-1). It is used to detect Mycobacterium tuberculosis infection, either past or present, active or inactive.
4. Screening tests—multiple puncture tests such as tine test introduce either dried or liquid tuberculin into skin by puncturing the skin with an applicator.
a. Used for screening large groups because there is no way to standardize the amount of tuberculin introduced, which does not allow precise interpretation of test results.
b. All significant reactors to multiple puncture tests must be confirmed with the Mantoux test.
--Management

1. A combination of drugs to which the organisms are susceptible is given to destroy viable bacilli as rapidly as possible and to protect against the emergence of drug-resistant organisms.
2. Current recommended regimen of uncomplicated pulmonary tuberculosis is 2 months of bactericidal drugs isoniazid (INH), rifampin (Rifadin), and pyrazinamide (PYZ) followed by 4 months of isoniazid and rifampin.
3. Six months of therapy is usually effective for killing the three populations of bacilli: those rapidly dividing, those slowly dividing, and those only intermittently dividing.
4. Sputum smears may be obtained every 2 weeks until they are negative; sputum cultures do not become negative for 3 to 5 months.
5. Second-line drugs such as capreomycin (Capastat), kanamycin (Kantrex), ethionamide (Trecator-SC), para-aminosalicylic acid, and cycloserine (Sandimmune) are used in patients with resistance, for retreatment, and in those with intolerance to other agents. Patients taking these drugs should be monitored by health providers experienced in their use.
--Complications
1. Pleural effusion
2. Tuberculosis pneumonia
3. Other organ involvement with tuberculosis
--Nursing Assessment
1. Obtain history of exposure to tuberculosis.
2. Assess for symptoms of active disease—productive cough, night sweats, afternoon temperature elevation, weight loss, pleuritic chest pain.
3. Auscultate lungs for crackles.
4. If patient is on isonizaid, assess for liver dysfunction.
a. Question the patient about loss of appetite, fatigue, joint pain, fever, and dark urine.
b. Monitor for fever, right upper quadrant abdominal tenderness, nausea, vomiting, rash, persistent paresthesias of hands and feet.
c. Monitor results of periodic liver function studies.
--Nursing Diagnoses
1. Ineffective Breathing Pattern related to decreased lung capacity
2. Risk for Infection Transmission related to nature of the disease and patient’s symptoms
3. Altered Nutrition: less than body requirements related to poor appetite, fatigue, and productive cough
4. Noncompliance related to lack of motivation and long-term treatment

--Nursing Interventions
A. Improving Breathing Pattern
1. Administer and teach self-administration of medications as ordered.
2. Encourage rest and avoidance of exertion.
3. Monitor breath sounds, respiratory rate, sputum production, and dyspnea.
4. Provide supplemental oxygen as ordered.
B. Preventing Transmission of Infection
1. Be aware that tuberculosis is transmitted by respiratory droplets or secretions.
2. Provide care for hospitalized patient in a negative pressure room to prevent respiratory droplets from leaving room when door is opened.
3. Enforce that all staff and visitors use standard dust/mist/fume masks (Class C) for any contact with patient.
4. Use high-efficiency particulate masks such as Hepafilter masks for high-risk procedures such as suctioning, bronchoscopy, or pentamadine treatments.
5. Use Universal Precautions for additional protection: gowns and gloves for any direct contact with patient, linens or articles in room, meticulous handwashing, and so forth.
6. Educate the patient to control spread of infection through secretions.
a. Cover mouth and nose with double-ply tissue when coughing/sneezing. Do not sneeze into bare hand.
b. Wash hands after coughing/sneezing.
c. Dispose of tissues promptly into closed plastic bag.
C. Improving Nutritional Status
1. Encourage and explain the importance of eating a nutritious diet to promote healing and improve defense against infection.
2. Provide small frequent meals and liquid supplements during symptomatic period.
3. Monitor weight.
4. Administer vitamin supplements, as ordered, particularly pyridoxine (vitamin B6) to prevent peripheral neuropathy in patients taking isoniazid.


D. Avoiding Noncompliance
1. Educate the patient about the etiology, transmission, and effects of tuberculosis. Stress the importance of continuing to take medicine for the prescribed time because bacilli multiply very slowly and thus can only be eradicated over a long period of time.
2. Review the side effects of the drug therapy (see Table 9-2). Question the patient specifically about common toxicities of drugs being used and emphasize immediate reporting should these occur.
3. Participate in observation of medication taking, weekly pill counts, or other programs designed to increase compliance with treatment for tuberculosis.
NOTE
Patient compliance remains a major problem in eradicating tuberculosis. Therefore, it may be helpful or necessary to have patient take medication in observed setting.
4. Investigate living conditions, availability of transportation, financial status, alcohol and drug abuse, and motivation, which may affect compliance with follow-up and treatment. Initiate referrals to a social worker for interventions in these areas.
--Patient Education/Health Maintenance
1. Review possible complications: hemorrhage, pleurisy, symptoms of recurrence (persistent cough, fever, or hemoptysis).
2. Advise on avoidance of job-related exposure to excessive amounts of silicone (working in foundry, rock quarry, sand blasting), which increases chance of reactivation.
3. Encourage the patient to report at specified intervals for bacteriologic (smear) examination of sputum to monitor therapeutic response and compliance.
4. Instruct in basic hygiene practices and investigate living conditions. Crowded conditions contribute to development and spread of tuberculosis.
5. Encourage follow-up chest x-rays for rest of life to evaluate for recurrence.
6. Instruct on prophylaxis with isoniazid for persons infected with the tubercle bacillus without active disease to prevent disease from occurring, or to people at high risk of becoming infected. Prophylaxis is recommended for the following groups:
a. Household members and other close associates of potentially infectious tuberculosis cases
b. Newly infected persons (positive skin test within 2 years)
c. Persons with past tuberculosis who have not received adequate therapy
d. Persons with significant reactions to tuberculin skin test and who are in special clinical situations (silicosis, diabetes, B-cell malignancies, end-stage renal disease, severe malnutrition, immunosuppression, HIV positive)
e. Tuberculin skin reactors under age 35 years with none of the aforementioned risk factors
--Evaluation
1. Afebrile; dyspnea relieved
2. Universal precautions observed; patient disposing of respiratory secretions properly
3. Maintains body weight
4. Taking medications as prescribed

Tuberculosis