Learning Objectives
By the end of this section, you will be able to:
- Discuss the pathophysiology, risk factors, and clinical manifestations for tuberculosis
- Describe the diagnostics and laboratory values in the disease of tuberculosis
- Apply nursing concepts and plan associated nursing care for the patient with tuberculosis
- Evaluate the efficacy of nursing care for the patient with tuberculosis
- Describe the medical therapies that apply to the care of tuberculosis
While the prevalence of tuberculosis is lower in the United States than in many other countries, more than 1.7 billion people worldwide are estimated to be infected. With 22 percent of the world’s population infected with tuberculosis, it is impossible to overstate the burden of disease and global suffering. India, Sub-Saharan Africa, and the islands of Southeast Asia experience the highest rates of infection, with a rate of 300 cases per 100,000. In the United States, tuberculosis infects less than 25 persons per 100,000. Global poverty, including lack of access to adequate health care and clean water, accounts for this disparity (Horsburgh, 2024).
Link to Learning
Dr. Paul Farmer was a pioneering physician and medical anthropologist who died suddenly in 2022. He cofounded an organization called Partners in Health that is focused on providing high-quality health care to people worldwide in underserved areas.
Pathophysiology
Tuberculosis is caused by the airborne bacterium Mycobacterium tuberculosis (M. tuberculosis). Tiny particles called droplet nuclei are expelled from an infected person during talking, coughing, or singing, and these droplets remain airborne for several hours. While airborne, the infectious particles can be inhaled by others, eventually reaching the alveoli. After exposure, not everyone is infected with tuberculosis. Several factors impact the likelihood of infection:
- immune status of the person who is exposed
- how infectious the ill person is
- environmental factors (e.g., small spaces, inadequate ventilation, recirculation of infectious air)
- proximity, length, and frequency of exposure
Once inhaled, the droplet nuclei bring the tubercle bacilli to the lungs, where they eventually reach the alveoli. Macrophages ingest the tubercle bacilli, damaging and destroying many of them. In some cases, the body will clear the initial infection. In other cases, the initial infection persists but becomes latent. The tubercle bacilli become walled off into a capsule called a granuloma, which prevents spread.
Often, the initial infection will become reactivated, causing the tubercle bacilli to spread to other locations within the lung. Again, the body attempts to control the infection by encasing the tubercle bacilli in a granuloma. During widespread infection, however, this becomes problematic. Granulomas can develop cavities. They are filled with a lipid-rich substance, which can accelerate the spread throughout the lungs and body via the lymphatic or circulatory systems. Distant TB disease is most likely to develop in the brain, bone, kidneys, regional lymph nodes, and the uppermost part of the lungs.
Link to Learning
Watch this short video from the series Rx for Survival, entitled “An Incurable TB?” to learn more about TB.
Risk Factors
In the United States, major risk factors include immunosuppression (including HIV), substance abuse, and malnutrition. Due to TB spreading by close contact, the risks of TB infection increase in high-density living situations, including incarceration and other congregate living settings. Structural poverty diminishes access to health care, so increased rates of infection occur among under-resourced populations. Significant disparities in infection rates exist when comparing demographic groups in the United States, as shown in (Table 11.9).
| Demographic Group | Disease Incidence per 100,000 |
|---|---|
| Asian | 21.7 |
| Black | 15.3 |
| Hispanic | 8 |
| White | 2.8 |
Clinical Manifestations
Patients with active TB infection typically present with systemic symptoms. These can include fever, chills, night sweats, weight loss, weakness, fatigue, and decreased appetite. A chronic cough, lasting longer than three weeks, can be present, along with bloody or purulent sputum. Patients may also report shortness of breath and pleuritic chest pain. Lung sounds may be decreased or demonstrate crackles or wheezing (Loddenkemper et al., 2016).
Assessment and Diagnostics
Accurate assessment and diagnosis of TB is necessary so that infection prevention strategies and treatment can be initiated promptly. There are two types of laboratory tests that can test for TB: a blood test and a skin test. The utility of both blood and skin tests is limited because they are unable to differentiate an active infection from a latent one. An additional challenge related to skin testing is that false positives can occur when people have received a certain type of TB vaccine; additional screening is necessary to conclusively determine TB status.
Imaging is often used to identify abnormal areas of the lungs. Chest x-ray is most often utilized although CT scan can also be used. While abnormalities that look like TB, such as cavitary lesions, can be identified on imaging, it does not confirm a diagnosis. The conclusive way to diagnose TB is by obtaining a sputum sample and examining it for the presence of tubercle bacilli. When evaluating a complete blood count, elevated platelets, elevated white blood cells, and anemia may be present (CDC, 2021).
Nursing Care of the Patient with TB
Nursing care of the patient with TB begins with screening, symptom assessment, and infection prevention. Diagnostic imaging and medication administration are additional key components.
Recognizing Cues and Analyzing Cues
The nurse caring for a patient with suspected or confirmed TB understands that TB is a highly infectious disease, which merits priority interventions and actions. The nurse evaluates both subjective and objective data. Self-reported symptoms may include fever, chills, night sweats, weight loss, weakness, fatigue, and decreased appetite. Many patients with TB will report a chronic cough, lasting longer than three weeks, along with bloody or purulent sputum. Patients may report shortness of breath, and pleuritic chest pain can occur; this type of pain is severe, sudden, and happens with inhalation and exhalation. Patients describe it as burning, stabbing, or sharp. The nurse should also ask the patient about any recent travel or potential exposure. Objectively, vital signs are evaluated with a focus on respiratory rate and oxygen saturation. Lung auscultation may reveal decreased lung sounds, crackles, or wheezing (Loddenkemper et al., 2016).
Prioritizing Hypotheses, Generating Solutions, and Taking Action
In patients with suspected or confirmed TB, prevention of the spread of the infection is a high priority. The nurse should facilitate placement into a negative airflow private room. If a negative airflow room is not available, the patient should always wear a surgical mask and be moved to a location away from others. Necessary staff require personal protective equipment (PPE), including a respirator that has been fit tested for each individual. The nurse may need to monitor vital signs, prepare a patient for imaging, or administer medications. Coaching about the importance of medication compliance is crucial. Instruction on strategies to minimize the risk of transmission at home is important. These include isolating when possible, sleeping alone, avoiding visitors, and covering nose and mouth with sneezing and coughing (CDC, 2021).
Evaluation of Nursing Care for the Patient with TB
Evaluation of nursing care for patients with TB requires a focus on symptom assessment, treatment efficacy, and potential infection transmission. Initial and follow-up imaging is often needed. The most important outcomes related to TB treatment are ensuring the patient’s continued cooperation with the medication regimen, preventing spread of infection during treatment, and continuing treatment until a definitive cure is achieved. An additional treatment goal is to prevent the development of disseminated tuberculosis, where mycobacteria has spread to distant body parts. Additionally, the nurse may assess for any changes in symptoms, such as worsening cough and night sweats. Repeat imaging may be ordered to determine if TB is improving, worsening, or plateaued (CDC, 2021).
Medical Therapies and Related Care
TB generally requires at least six months of treatment. Most of the bacteria are eradicated within the first eight weeks of treatment, but persistent organisms can remain and must be treated to prevent ongoing illness, infectious spread, and antibiotic resistance. The four main TB treatment drugs are isoniazid, rifampin, ethambutol, and pyrazinamide; a four-drug regimen is used (Table 11.10). With appropriate treatment, virtually all patients can be cured. Because TB is disproportionately prevalent in under-resourced areas, inadequate treatment can occur due to medication and staff shortages. This can result in ongoing infections and drug resistance. To help patients complete the long treatment regimen, many treatment centers offer in-person or electronic directly observed therapy (DOT).
| Drug Class | Medication |
|---|---|
| First-line drugs | Isoniazid (INH) |
| Rifampin (RIF) | |
| Pyrazinamide (PZA) | |
| Ethambutol (EMB) | |
| Rifabutin (RBT)* | |
| Rifapentine (RPT) | |
| Second-line drugs | Streptomycin (SM) |
| Cycloserine | |
| Capreomycin | |
| ρ-Aminosalicylic acid | |
| Levofloxacin* | |
| Moxifloxacin* | |
| Gatifloxacin* | |
| Amikacin/Kanamycin* | |
| Ethionamide |
Because the burden of treatment is so complex, collaborative care is crucially important. Successful care of a patient with TB may involve physicians, nurses, laboratory scientists, pharmacists, social workers, and respiratory therapists. Each interdisciplinary team member is assigned a portion of the directly observed therapy short course plan.