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Flashcards in week 11- TB Deck (39)


WHO reports there were 9.2 million new cases of TB in 2006
1600 new cases reported in Canada each year

Kills more people worldwide than any other infectious disease

Between 19% and 43% of world’s population estimated to be infected


TB did not disappear by 2000 as anticipated

Multidrug-resistant strains of M. tuberculosis


Who is at Risk?

• Immunocompromised Patients
o Organ transplants
o Lung disease
o Chronic kidney failure requiring dialysis
o Cancer of the head and neck
o Taking glucocorticoids or TNF-alpha inhibitors (eg: for RA)
o Diabetes
• Previous infection with TB bacteria within the past two years
• CXR showing signs of old TB
• Being underweight (BMI equal to or less than 20)
• Being under five years of age when first infected
• Cigarette smoking (one ppd or more)
• ETOH intake greater than 3 drinks/day


Spread via airborne droplets when infected person



Tuberculosis involves

usually lungs
lymph nodes
brain and spinal cord
bones and joints


Bacteria can stay in the air for hours *brief exposure rarely causes infection

Infectiousness directly related to the number of infected droplet nuclei in the air


Body’s immune system may kill the TB bacteria

If not, they can remain alive but inactive in your body= Latent TB Infection
If TB becomes active = Active TB Disease
Symptoms present with active disease and it is transmissible


TB Transmission

• TB is not easily transmitted. Household and non-household contacts sought. Highest priority: household contacts, children under 5 and immunocompromised
• People have a higher risk of developing active TB disease within the first two years of getting latent TB infection.
• Contacts who have been infected will be offered treatment of latent TB infection to help their immune system fight the infection and reduce their risk of developing active TB disease
• Infectiousness usually rapidly declines with effective treatment but may vary person to person*


Higher Risk of infection with:

Poor ventilation
Longer exposure
Closer proximity


Etiology and Pathophysiology

• Spread
o Inhaled bacilli pass down bronchial system and implant themselves on bronchioles or alveoli
o Multiply with no initial resistance
o Replicates slowly and spreads via the lymphatic system


Clinical Manifestations

Early stages are usually free of symptoms

Cough longer than 2 weeks
Weight loss
Low-grade fevers
Night sweats


clinical manis- Cough becomes frequent

o Produces mucoid or mucopurulent sputum
o May have dull or tight chest pain
o Hemoptysis is not common and is usually associated with advanced disease


Acute symptoms

o High fever * not typical-usually low grade fever
o Chills
o Generalized flu-like symptoms
o Pleuritic pain
o Productive cough


Steps in Diagnosing Active TB

• Complete hx and physical exam
o S &S?
o Exposure to active TB?
o History of latent or active TB?
o Risk factors? (includes travel to endemic areas)
• Sputum AFB and C&S (ID strain and determine abx resistance)


Diagnosing Latent TB

• Mantoux or TB skin test
• Reaction measured by HCP 48 to 72 hours after test
• If no reaction or not positive at 48 hrs, check at 72 hrs
• Measured in mm and interpreted as ‘positive’ or ‘negative’
• >10mm is positive
• >5mm may be considered positive in patients with HIV


Latent tuberculosis (TB)

infection may develop into active TB disease if your body’s defence (immune) system can’t stop the TB germs (bacteria) from growing. You are at the highest risk (about five per cent) of active TB disease within the first two years of becoming infected. After the first two years, there is only another five per cent chance of you developing active TB disease in your lifetime.


Mantoux or TB skin testing
(also called PPD-purified protein derivative)

o Intradermal administration of tuberculin
 Induration at injection site indicates exposure
 Sensitivity remains for life and individual should not be tested again


Skin Testing

• Positive TB skin test usually means latent TB infection
• CXR and sputum C &S may follow to investigate for active TB
• Positive test without latent TB infection can happen in people who have been vaccinated with BCG vaccine
• Negative TB skin test usually means no infection
• BUT:
o negative test can happen if only recently infected (takes three to eight weeks after exposure to a person with infectious TB disease for the skin test to become positive)
o A negative test can also happen if immune system is weak (ie: HIV or active TB)


Skin testing

Two-step testing recommended for health care workers getting repeated testing and those with decreased response to allergens


Contraindications for skin test:

• Patients with documented active TB or a clear history of treatment for TB infection or disease
• Patients with severe blistering tuberculin reactions in the past
• Patients with extensive burns or eczema
• Patients with major viral infections or live-virus vaccinations in the past month e.g., MMR


Chest x-ray

Cannot make diagnosis solely on x-ray


Bacteriological studies

o Stained sputum smears examined for
acid-fast bacilli (AFB)
o Sputum tests for AFB:
 3 consecutive mornings confirms positive diagnosis. Also used during or after treatment to determine pt is no longer infectious or no longer has TB



 New test used in Canada as of 2007
 Rapid blood test (few hours)
 Does not replace cultures


Collaborative Care

• Hospitalization not necessary for most clients
• Can be sent home, even if infectious, if:
o Follow up organized with Public Health
o Standard treatment has been initiated and DOT therapy organized
o No infants, children under 5, or adults with immune-compromise: unless also being treated
o Willing to comply with isolation
o Drug therapy used to prevent or treat active disease


Active disease

o Four drugs are used in initial phase for maximum effectiveness
 Treatment is aggressive to combat resistant strains of TB



• Initially started on all four drugs:
• Ethambutol (EMB) *stopped if cultures indicate bacteria susceptible to all 4 drugs
• Pyrazinamide (PZA) * continued for only 2 months if cultures indicate bacteria susceptible to all 4 drugs
• Rifampin (RIF) * 6 months
• Isoniazid (INH) * 6 months
• Therapy continued for 9 months if risk for relapse
• 2nd line treatment: fluorquinolones, injectable streptomycin


Active disease

Clients should be taught about side effects and when to seek medical attention
Liver function should be monitored


Latent TB infection

o Individual is infected with M. tuberculosis, but is not acutely ill
o Must carefully rule out active disease
o Usual treatment: isoniazid (INH) for 6 to 9 months
o HIV clients should take INH for 9 months
o If pregnant, should start treatment 3 months post-partum unless at very high-risk of developing active disease (HIV, close-contacts, STS conversion)
o Can take if breast-feeding
o Monitor for hepatotoxicity



Bacille Calmette-Guérin (BCG) vaccine to prevent TB is currently in use in many parts of the world

Efficacy not clear



o Productive cough
o Night sweats
o Afternoon temperature elevation
o Weight loss


Directly observed therapy (DOT)

o Noncompliance is major factor in multidrug resistance and treatment failures
o Requires observing ingestion of every dose of medication for entire course of treatment
o Preferred to ensure adherence


Nursing diagnoses

o Ineffective breathing pattern
o Imbalanced nutrition: Less than body requirements
o Noncompliance
activity intolerance
ineffective health maintenance.


Planning Goals

o Comply with therapeutic regimen
o Have no recurrence of disease
o Have normal pulmonary function
o Take appropriate measures to prevent spread of disease


Nursing implementation

o Ultimate goal in Canada is eradication
o Selective screening programs in high-risk groups to detect TB
o Identify contacts of client with TB


Airborne isolation

Respirator for HCPs (eg: N95), surgical mask for patient
Negative airflow ventilation room in hospital
Well ventilated room at home
Sleep alone
Do not have visitors when infectious
Collect sputum specimens in well-ventilated area of home, away from family members


Acute intervention

 Teach client to cover nose and mouth with tissue when coughing, sneezing, or producing sputum
 Teach hand washing after handling sputum-soiled tissues
 Family members should be tested, if positive, consider also testing close contacts
 Use natural ventilation (eg: open windows) and HEPA air filters
 Home isolation until 3 negative sputum tests


Ambulatory and home care

 Ensure client can adhere to treatment
 Teach symptoms of recurrence
 Address issues of social isolation and stigma


Patients may not need airborne precautions if all three of the following apply:

3 consecutive negative sputum AFB results
Reduction in S &S: afebrile, decreased cough and sputum
On standard multidrug treatment for at least 2 weeks


Expected outcomes

Complete resolution of disease
Normal pulmonary function
Absence of any complications
No transmission of TB