Test 3 Ch. 19 Tuberculosis Flashcards
A contagious chronic bacterial infection that primarily affects the lungs, although it may involve almost any part of the body
Tuberculosis (TB)
TB is classified as (3)
- Primary TB
- Reactivation TB
- Disseminated TB
What is another word for primary TB?
Primary infection stage
Primary TB follows the pt’s
first exposure to the TB pathogen, Mycobacterium TB
A rod shape bacterium w/ a waxy capsule is called
Mycobacterium TB
Primary TB begins w/ the
inhaled bacili implant of the alveoli
What is the name for the protective cell wall that the lung tissues surrounds?
tubercle or granuloma
The tubercles work to
encapsulate or trap the TB, in a nut shell structure
The initial lung lesion on a chest radiograph is called
Ghon nodules
The combination of tubercles and the involvement of the lymph nodes in the hilar region is known as the
Ghon complex
Tubercle consists of a central core containing caseous necrosis and TB bacilli also called (2)
- caseous lesion
- caseous granuloma
Bacilli can multiple over a
3- 4 week period
A tubercle takes about
2- 10 weeks to form
The function if the tubercle is to
contain the TB bacilli and prevent from spreading
Once the bacilli are controlled the healing process begins. What replaces the tubercle?
Tissue fibrosis and classification of the lung parenchyma
In some cases, the classification and fibrosis cause the bronchi to distort and
dilate, this is to cause bronchiectasis
When the bacilli are isolated within the tubercle, the TB remains _________ for months, years or life
dormant
People with _______ TB (or _______ TB)do not feel sick or have any TB- related symptoms
- dormant (latent )
This is a term that is used to describe the reappearance of TB months or even years after the initial infection has been controlled
Reactivation TB
What is another name for for reactivation TB (3)
- postprimary TB
- reinfection TB
- secondary TB
Most reactivation TB cases are associated in pts w/ the following
- Malnourished individuals
- Ppin Institutional housing
- Ppl living in overcrowded conditions
- Immunosuppressed pts
- HIV
- Alcohol abuse
What is the leading cause of death in pts w/ HIV
TB
Refers to infection from TB bacilli that escapes from a tubercle and travel to other sites throughout the body by means of bloodstream or lymphatic
Disseminated TB
Other names for disseminated TB (3)
- extra pulmonary TB
- military TB
- TB disseminated
TB that enter the body by means of the bloodstream usually gather and multiply in portions of the body that have
higher tissue oxygen tension
The most common location for TB to gather and multiply is the
apex of the lungs
Other oxygen rich area in the body include:
- the regional lymph nodes
- kidneys
- long bones
- genital tract
- brain
- meninges
The major pathologic stuctual changes in TB ( moderate to severe reactivation)
- Alveolar consolidation
- Alveolar- capillary membrane destruction
- Caseous tubercles or granulomas
- Cavity formation
- Fibrosis and secondary calcification of lung parenchyma
- Distortion and dilation of the bronchi
- Increased bronchial secretions
In ancient times TB was often called
- “consumption”
- “Captain of the Men of Death”
- the white plague
WHO reported the TB is one of the top ___ causes of death worldwide
10
In human cases TB is primarily caused by
Mycobacterium TB
What is the transmission of TB caused by?
Aerosol droplets produced by coughing, sneezing, or laughing of an individual w/ active TB
It has been shown that in very fine aerosolized spray droplets (0.5 to 1.0), the TB bacilli can remain suspended in the air for
several hours after a cough or a sneeze
Along with chest radiology, these methods are also used to diagnose TB
- Mantoux tuberculin skin test
- acid- fast bacilli (AFB) sputum cultures
- QuantiFERON-TB Gold test (QFT-G)
- rapid Xpert MTB/RI assay
The most widely used tuberculin test is the
Mantoux test
Mantoux test consists of an intradermal injection of a small amount of
purified protein derivative (PPD) of the tuberculin bacillus
After the PPD, the skin is observed for
induration ( a wheal) after 48- 72 hours
An induration test of less than ___ mm is a _________ test
5, negative
An induration of ___ to ___ mm is considered ____________ and ____________ is required
5 to 9
suspicious
retesting
An induration of ____ mm or greater is considered __________
10, positive
Positive reaction does not mean that the pt has active TB but only the pt has been
exposed to the bacillus and has developed latent TB
Because m.TB has an unusual waxy coating on the cell surface, which the cell impervious to staining, an
acid-fast bacteria test ( sputum smear) is performed instead
The frequently used
Ziehl- Neelsen stain reveals a bright red AFB against a blue background
This technique revels luminescent yellow- green bacilli against a dark brown background
fluorescent acid- fast stain
The fluorescent acid- fast stain is becoming more popular b/c it is
easier to read
Sputum cultures is often necessary to differentiate
M. TB from other acid- fast organisms
B/c polycythemia and cor pulmonale are associated with severe TB the following may be seen
- Distended neck veins
- Pitting edema
- Enlarged and tender liver
Chest Assessment findings (fluid)
- Increased tactile and vocal fremitus
- Dull percussion note
- Bronchial breath sounds
- Crackles, wheezing
- Pleural friction rub (if extends into the pleural surface)
- Whispered pectoriloquy
Abnormal Lab Test and Produce results
- Positive PPD
- Positive sputum acid-fast bacillus (AFB) stain test
- Positive ABF sputum culture
- Positive QuantiFERON- TB Gold Test
Radiologic Findings
- Increased opacity
- Ghon nodule
- Ghon complex
- Cavity formation
Cavitary lesion containing an air- fluid level - Pleural effusion
- Calcification and fibrosis
- Retraction of the lung segments or lobe
- Right ventricular enlargement
The standard pharmacological agents to treat M. TB consists of
two to four drugs for 6 to 9 months
Questions from the back
What are the first stage of TB
- Primary TB
- Primary infection stage
What is the name of the protective wall that surrounds and encases lung tissue infected w/TB?
- Granuloma
- Tubercle
The tubercle bacillus is
- Highly aerobic
- Acid fast
- Capable of surviving for months outside the body
- Rod-shaped
At which stage is a tuberculin skin test considered to be positive
Greater than 10 mm
What is often prescribed as a prophylactic daily dose for 1 year in individuals who have been exposed to TB bacilli
Isoniazid
What are the first line agents prescribed for the entire 9 months?
- Isoniazid
- Rifampin (Rifadin)
Six month treatment protocol: For the first 2 months (induction phase) the pt takes a daily dose of
- isoniazid (INH)
- rifampin (RIF)
- pyrazinamide (PZA)
- either ethambutol (EMB, E) or streptomycin (SM)
In noncompliance pts, it is recommended that TB be treated by
directly observed therapy (DOT),
The ingestion of medications is directly observed by a responsible individual
DOT
