Tuberculosis

Key Points

• Tuberculosis is a contagious infection caused by Mycobacterium tuberculosis that primarily affects the lungs but may involve multiple body systems.
• TB risk increases with close exposure, immunocompromise, HIV, substance use, crowded living settings, and residence in high-prevalence regions.
• TB diagnostics combine skin or blood screening with imaging and microbiologic testing; sputum testing is the conclusive pathway for pulmonary disease confirmation.
• Active TB requires prolonged multidrug therapy and strict airborne transmission precautions until noninfectious criteria are met.
• Nursing priorities center on medication adherence, infection prevention, nutrition support, psychosocial support, and continuous evaluation.

Pathophysiology

Tuberculosis begins when inhaled droplet nuclei carrying bacilli enter the lungs and reach the alveoli. Infectious droplets can remain airborne for extended periods, so repeated close exposure in poorly ventilated spaces increases transmission risk. Over weeks, macrophages and lymphocytes localize infection and form tubercles. Caseous necrosis can develop in the lesion center. In many immunocompetent patients, infection becomes latent rather than immediately active disease.

Latent lesions may remain dormant for years and reactivate when host defenses decline. Bacilli may be walled off in granulomas, but cavitary progression can occur and promote spread through lymphatic and circulatory pathways. Active disease is transmissible and can spread beyond lungs to neurologic, genitourinary, musculoskeletal, lymphatic, or skin sites.

Classification

• Latent TB infection (LTBI): Organism present without active clinical disease.
• Active TB disease: Clinically active and transmissible pulmonary or extrapulmonary disease.
• Drug-sensitive TB: Responsive to first-line multidrug regimens.
• MDR/XDR TB: Resistant phenotypes requiring prolonged second-line treatment pathways.

Nursing Assessment

NCLEX Focus

Distinguish latent from active disease cues, identify isolation needs early, and prioritize adherence barriers that increase resistance risk.

• Assess respiratory findings: persistent cough over two weeks, sputum changes, hemoptysis, pleuritic pain, dyspnea, and adventitious sounds.
• Assess constitutional findings: fever, night sweats, fatigue, malaise, anorexia, and unexplained weight loss.
• Screen for extrapulmonary cues such as lymphadenopathy, meningeal signs, hematuria/flank pain, bone or joint pain, and skin lesions.
• Review risk profile: recent exposure, HIV or immunosuppression, substance use, malnutrition, homelessness, incarceration, crowded settings, migration or travel to high-prevalence areas.
• Assess prior BCG vaccination history when interpreting tuberculin skin testing.
• In pregnancy-exposure contexts, prioritize prompt TB evaluation and coordinate follow-up testing without delay.

Diagnostic Testing

• Tuberculin skin test (Mantoux): Exposure screening; positive result does not prove active disease; read induration at 48-72 hours.
• IGRA blood tests: Useful when BCG history complicates skin-test interpretation; also cannot distinguish active from latent disease.
• Chest x-ray or CT: Detects pulmonary abnormalities (including cavitary patterns) but cannot independently confirm TB.
• Sputum AFB microscopy and culture: Core microbiologic pathway for confirmation and response monitoring; sputum bacilli detection is the conclusive pulmonary diagnostic step.
• NAAT and molecular testing: Rapid TB detection with rifampin resistance support.
• Bronchoscopy/BAL and biopsy: Used when sputum is unobtainable or extrapulmonary disease is suspected.
• CBC trend context: May show elevated platelets, leukocytosis, and anemia in active disease.

Nursing Diagnoses and Outcomes

Common diagnosis patterns include ineffective airway clearance, impaired gas exchange, fatigue, readiness for enhanced self-management, and social isolation.

Sample measurable outcomes:

• Oxygen saturation remains above 92% or within ordered target range.
• Airway secretions are effectively cleared with improved breath-sound findings.
• The patient verbalizes the importance of full-course adherence to prescribed TB therapy.
• The patient verbalizes at least three coping strategies before discharge.

Interventions

Medical Interventions

• Start multidrug therapy with first-line agents (isoniazid, rifampin, ethambutol, pyrazinamide) for drug-sensitive disease based on ordered regimen.
• Reinforce that treatment commonly requires at least 6 months; even when early bacterial burden improves, prolonged completion is required to prevent relapse and resistance.
• Monitor first-line adverse-effect patterns closely: hepatotoxicity risk across regimens, INH-associated peripheral neuropathy, rifampin-associated flu-like effects, and ethambutol-associated visual changes.
• Reinforce medication-specific teaching: avoid alcohol during treatment, use backup contraception when enzyme-inducing agents reduce oral-contraceptive effectiveness, and report visual changes immediately.
• In pregnancy with active TB, reinforce that isoniazid, rifampin, and ethambutol are commonly used and monitor liver function, hepatitis risk, and drug interactions closely.
• Use individualized second-line regimens for MDR/XDR patterns.
• Continue serial sputum monitoring for AFB response and infectious-status reassessment.
• Apply directly observed therapy (DOT) when indicated to improve completion rates.

Nursing Interventions

• Administer and monitor medications, side effects, and escalation triggers.
• Reinforce strict treatment completion and missed-dose avoidance to reduce resistance risk.
• Place clients with suspected or confirmed active pulmonary TB in negative-pressure isolation when available and maintain airborne precautions with fit-tested N95 use.
• If negative-pressure placement is unavailable, apply patient surgical masking and separate placement away from others while urgent escalation is arranged.
• Teach respiratory hygiene and masking during any essential transport outside the room.
• Teach cough etiquette, tissue disposal, and household infection-control practices, including sleeping separately when feasible, limiting visitors, and covering nose/mouth when coughing or sneezing.
• Monitor nutrition status and coordinate dietitian referral for malnutrition and weight-loss support.
• Provide psychosocial support for stigma, anxiety, and care-access barriers.

Drug-Resistance Risk

Incomplete therapy, missed doses, incorrect regimens, and poor follow-up increase MDR/XDR risk and worsen outcomes.

Evaluation

Evaluate outcomes whenever interventions are implemented, diagnostic results are updated, or the interprofessional plan changes. Mark outcomes as met, partially met, or unmet, then revise the care plan if progress is inadequate.

Prioritize reassessment of symptom trajectory, repeat imaging when ordered, treatment adherence, and ongoing transmission risk during follow-up. Key goals are cure completion and prevention of disseminated TB progression.

Related Concepts

• sputum-culture-and-acid-fast-testing-for-tuberculosis - Specimen strategy and AFB-focused diagnostic workflow.
• transmission-based-precautions - Route-based isolation controls for communicable respiratory pathogens.
• mode-of-transmission - Airborne pathway context for TB spread prevention.
• infection-control - Chain-of-infection interruption strategies during treatment.
• respiratory-system - Respiratory anatomy and gas-exchange context affected by active pulmonary TB.
• antitubercular-medications - Class-level nursing administration and safety considerations for prolonged TB regimens.

Self-Check

1. Which findings and risk factors most strongly indicate possible active TB requiring isolation?
2. How do skin testing, IGRA, imaging, and sputum testing complement each other in TB diagnosis?
3. Which nursing actions best reduce treatment failure and multidrug-resistant TB risk?