Pulmonary Tuberculosis Nursing Care Management and Study Guide

Pulmonary tuberculosis is an airborne, communicable disease, and your two jobs are clear: protect everyone else from transmission and get the patient through a long drug regimen they have to finish. Early identification, AFB isolation, and adherence are what stop the spread.

What is Pulmonary Tuberculosis?

Pulmonary tuberculosis (PTB) is a chronic respiratory disease common in crowded, poorly ventilated areas. It is an acute or chronic infection caused by Mycobacterium tuberculosis and is characterized by pulmonary infiltrates, granulomas with caseation, fibrosis, and cavitation. TB primarily affects the lung parenchyma but can spread to the meninges, kidneys, bones, and lymph nodes. The primary agent, M. tuberculosis, is an acid-fast aerobic rod that grows slowly and is sensitive to heat and ultraviolet light.

Pathophysiology

TB is highly infectious and airborne. It begins when a susceptible person inhales mycobacteria and becomes infected. The bacteria travel through the airways to the alveoli and are also carried via the lymph system and bloodstream to other parts of the body. The immune system responds with an inflammatory reaction: phagocytes engulf many of the bacteria, and TB-specific lymphocytes lyse the bacilli and normal tissue. Granulomas, new tissue masses of live and dead bacilli, are surrounded by macrophages that form a protective wall. These transform into a fibrous tissue mass whose central portion is called a Ghon tubercle. The bacteria and macrophages turn into a cheesy mass that may calcify and form a collagenous scar. At this point the bacteria become dormant with no further progression of active disease. After initial exposure and infection, active disease can develop when the immune response is compromised or inadequate.

Classification

History, physical examination, TB test, chest x-ray, and microbiologic studies classify TB into one of five classes. Class 0: no exposure, no infection. Class 1: exposure but no evidence of infection. Class 2: latent infection but no disease. Class 3: clinically active disease. Class 4: disease but not clinically active. Class 5: suspected disease, diagnosis pending.

Statistics and Incidences

TB is a worldwide public health problem closely tied to 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 worldwide. 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

Risk factors include close contact with someone who has active TB, low immunity (HIV, cancer, transplanted organs), substance abuse (IV or injection drug use, alcoholism), inadequate health care (the homeless, impoverished, and minorities), immigration from countries with high TB prevalence, and overcrowded, substandard housing.

Clinical Manifestations

After an incubation period of 4 to 8 weeks, TB is usually asymptomatic in primary infection. Nonspecific symptoms include fatigue, weakness, anorexia, weight loss, night sweats, and low-grade fever, with fever and night sweats as the typical hallmarks. The patient may have a cough with mucopurulent sputum, occasional hemoptysis or blood in the saliva, and chest pain.

Prevention

Prevent transmission through early identification and treatment of persons with active TB, control of infectious droplet nuclei by source control methods and reduction of microbial contamination of indoor air, and surveillance of health care workers through routine, periodic tuberculin skin testing.

Complications

Untreated or mistreated PTB can lead to respiratory failure, one of the most common complications; pneumothorax; and pneumonia, one of the most fatal complications because it can spread infection throughout the lungs.

Assessment and Diagnostic Findings

Sputum culture is positive for Mycobacterium tuberculosis in the active stage. The Ziehl-Neelsen acid-fast stain applied to a smear of body fluid is positive for acid-fast bacilli (AFB). On skin tests (purified protein derivative [PPD] or Old tuberculin [OT] given by intradermal injection [Mantoux]), a positive reaction (an area of induration 10 mm or greater occurring 48 to 72 hr after intradermal 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 clinically ill patient means active TB cannot be dismissed. A significant reaction in healthy persons usually signifies dormant TB or infection by a different mycobacterium.

ELISA or Western blot may reveal 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; more advanced TB may show cavitation and scar or fibrotic tissue. CT or MRI determines the degree of lung damage and may confirm a difficult diagnosis. Bronchoscopy shows inflammation and altered lung tissue and can obtain sputum when the patient cannot produce an adequate specimen. Histologic or tissue cultures (gastric washings; urine and cerebrospinal fluid [CSF]; skin biopsy) are positive for Mycobacterium tuberculosis and may indicate extrapulmonary involvement. Needle biopsy of lung tissue is positive for granulomas of TB, with giant cells indicating necrosis. Electrolytes may be abnormal depending on location and severity, for example hyponatremia from abnormal water retention in extensive chronic pulmonary TB. ABGs may be abnormal depending on location, severity, and residual lung damage. Pulmonary function studies show decreased vital capacity, increased dead space, increased ratio of residual air to total lung capacity, and decreased oxygen saturation secondary to parenchymal infiltration or fibrosis, loss of lung tissue, and pleural disease.

Medical Management

PTB is treated primarily with antituberculosis agents for 6 to 12 months. First-line agents are isoniazid (INH), rifampin (RIF), ethambutol (EMB), and pyrazinamide. For most adults with active TB, the recommended dosing gives all four drugs daily for 2 months, followed by 4 months of INH and RIF. Latent TB is usually treated daily for 9 months.

Treatment guidelines for newly diagnosed PTB have two parts, an initial phase and a continuation phase. The initial phase is a multiple-medication regimen of INH, rifampin, pyrazinamide, and ethambutol and lasts 8 weeks. The continuation phase includes INH and rifampin or INH and rifapentine and lasts an additional 4 or 7 months. Prophylactic INH treatment involves daily doses for 6 to 12 months. Directly observed therapy (DOT) may be selected, with an assigned caregiver directly observing the administration of the drug.

Pharmacologic Therapy

Isoniazid (INH) is a bactericidal agent used as prophylaxis for neuritis, with side effects of peripheral neuritis, hepatic enzyme elevation, hepatitis, and hypersensitivity. Rifampin (Rifadin) is a bactericidal agent that turns urine and other body secretions orange or red, with common side effects of hepatitis, febrile reaction, purpura, nausea, and vomiting. Pyrazinamide is a bactericidal agent that increases blood uric acid, with common side effects of hyperuricemia, hepatotoxicity, skin rash, arthralgias, and GI distress. Ethambutol (Myambutol) is a bacteriostatic agent to use with caution in renal disease, with common side effects of optic neuritis and skin rash.

Nursing Management

Nursing Assessment

Assess the complete past and present medical history, including both parents' histories. On physical examination, the TB patient loses weight dramatically and may show that loss in physical appearance.

Nursing Diagnosis

Major nursing diagnoses 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 decreased effective lung surface, activity intolerance related to imbalance between oxygen supply and demand, and imbalanced nutrition: less than body requirements related to inability to ingest adequate nutrients.

Nursing Care Planning and Goals

The major goals are to promote airway clearance, adhere to the treatment regimen, promote activity and adequate nutrition, and prevent spread of tuberculosis infection.

Nursing Interventions

Promote airway clearance by teaching correct positioning to facilitate drainage and increasing fluid intake for systemic hydration. Drive adherence by teaching that TB is communicable and that taking medications is the most effective way to prevent transmission. Promote activity and nutrition with a progressive activity schedule that builds activity tolerance and muscle strength and a nutritional plan of small, frequent meals. Prevent spread by teaching hygienic measures: mouth care, covering the mouth and nose when coughing and sneezing, proper disposal of tissues, and handwashing. Initiate AFB isolation immediately, including a private room with negative pressure relative to surrounding areas and a minimum of six air changes per hour. Place a covered trash can nearby or tape a lined bag to the side of the bed for used tissues. Stay alert for adverse effects of medications.

Evaluation

Expected outcomes are promoted airway clearance, adherence to the treatment regimen, promoted activity and adequate nutrition, and prevented spread of tuberculosis infection.

Discharge and Home Care Guidelines

Instruct the patient to cough and sneeze into tissues and dispose of all secretions in a separate trash can, to wear a mask when leaving the room, to rest and eat balanced meals to aid recovery, and to watch for adverse effects of medications and report them to the physician immediately.

Documentation Guidelines

Document recent or current antibiotic therapy; signs and symptoms of the infectious process; breath sounds, presence and character of secretions, and use of accessory muscles for breathing; character of cough and sputum; respiratory rate, pulse oximetry, oxygen saturation, and vital signs; level of activity; causative or precipitating factors; client reports of difficulty or change; caloric intake; individual cultural or religious restrictions and personal preferences; the plan of care; the teaching plan; responses to interventions, teaching, and actions performed; attainment or progress toward desired outcomes; modifications to the plan of care; and discharge needs.