pathophysiology of TB

1. TUBERCULOSIS

2. TUBERCULOSIS BACILLUS
oThis is a contagious infection that
mainly affects the lungs
oIt may also spread to other parts
of the body e.g. brain, spine
oIt is mainly caused by
Mycobacterium tuberculosis

3. Types of TB
• Latent TB infection – first infections to can
turn active TB. Those infected do not
develop overt disease. They do not present
with symptom and the chest, X-ray may be

4. • normal
The only manifestation of their encounter tuberculin skin test or
Infection Gamma Release Assay( IGRA). The infection can be
escalated to active disease if the patient inhales the bacteria
The infection can be escalated to active disease in case the pt
is HIV positive or using medication that is immune suppressed

5. Miliary TB
This is a rare form of active TB that occurs
when TB bacteria finds its way to the
bloodstream. In this form is quickly spread all
over the body in ting nodular and affect which
helps organs at once their form of TB is highly
fatal.

6. Active TB disease/Pulmonary TB
• This illnesses the TB bacteria and rapidly
multiply and evading different organs of the
body. A person may spread TB t others by
airborne transmission of infections
particularly coughed in the air.
• Hence you may get TB of any part of the body
2-3 weeks after exposure

7. • TB is mainly developed by the
primary and secondary.
• In primary TB the infection mainly
occurs in the lungs while in secondary
is TB infection in any other part apart
from the lungs

8. Multidrug Resistant Tb
This refers of form Tb infection caused by
bacteria that are resistant to treatment with
at least two of the most powerful first-line
anti-TB medication i.e, Isoniazid and
rifampicin

9. EXTENTIVELY DRUG RESISTANT TB
• This is mainly affects pt. who do not
complete TB medication, commonly
spend time with pt. with DRT since XDR
is also airborne
• Extensively drug- resistant Tb (XDR Tb) is
a rare type of MDR that is resistant to
isoniazid and rifampicin and any type of
Fluoroquionolones and at least one of
the injectable 2nd line drugs (Amikacin,
kanamycin)

10. EXTRA PULMONARY TB
• Extra pulmonary TB is located within another
location of the body other than the lungs.
• It occurs in 15-20% of active cases
• XPR can affect any other part of the body
excluding the nails, hair and enamel

11. ETIOLOGY
• TB is caused by bacterium called
mycobacterium tuberculosis which is a non
inflammatory, slow growing, non
sporulating acid fast which secret niacin.
• The bacillus is transmitted via
aerosolization (airborne)
• It spreads when one person has active Tb
disease coughs or sneezes and someone
inhales

12. • Although PTB spreads similarly to cold
its not highly infectious .
• Those mostly infected are those having
repeated close contact with an
infectious person who is not diagnosed
with TB.
• Risk of transmission is greatly reduced
after two to three weeks of proper
medication

13. • Risk of transmission is greatly reduced
after two to three weeks of proper
medication
• TB infections occurring outside the lung
are not infectious

14. Pathophysiology of T.B
 A susceptible person inhales
mycobacterium bacilli and becomes
infected. The bacteria are transmitted
through airway to the alveoli; where
they are deposited of begin to multiply.
 The bacilli also are transported via the
lymph system and bloodstream to other
parts of the body (Kidneys, bones,
cerebral cortex) and other areas of
lungs (upper robes)

15. Pathophysiology of T.B
 The body ‘s immune system responds
by initiating an inflammatory reaction.
Phagocytes (neutrophils and
macrophages) engulf many of the
bacteria for T.B.
Specific lymphocytes lyse (destroy) the
bacilli and normal tissue

16. Pathophysiology of T.B
 This tissue reaction results in the accumulation
of exudate in the alveoli, causing
bronchopneumonia. The initials infection
usually occurs 2-10 weak, after exposure.
 Granulomas, new tissue masses of live and
dead bacilli are surrounded by macrophages,
which form protective wall around the
granulomas.

17. Pathophysiology of T.B
 Granulomas are then transformed
to a fibrous tissue mass, the
central portion of which is called
a Ghon tubercle.
 The intri (bacteria and
macrophages) becomes necrotic,
forming a cheesy mass.

18. Pathophysiology of T.B
 This cheesy mass become calcified and forms
a collagenous scar. At this point, the bacteria
become dormant and there is no further
progression of active disease.
 After initial exposure and infection, the
person may develop active disease because of
a compromised or inadequate immune system
response.
.

19. Pathophysiology of T.B
 Active disease also may occur with
reinfection and activation of dormant
bacteria.
 In this case, the Ghon tubercle ulcerates,
releasing the cheesy intri into the bronchi
 The bacteria then become airborne, resulting
in further spread of the disease, them the
ulcerated tubercle heals and forms scar
tissue

20. Pathophysiology of T.B
 This causes the infected lung to become
more inflamed, resulting in further
development of broncho pneumonia and
tubercle emation.

22. Clinical manifestation
The client with TB usually progressively
has
• Fatigue
• Lethargy
• Nausea
• Anorexia
• Weight loss
• Irregular menses
• Low grade fever ( present for weeks or
months) this is accompanied by night
sweats

23. • Patient may notice a productive cough
with blood streak
• Chest tightness and a dull aching chest
pain may be accompany the cough
• There is dullness with percussion over the
parenchymal areas
• Bronchial breath sounds
• Crackles and increased transmission of
spoken or whispered sounds
 Partial obstruction of the bronchus because of
endobronchial disease or compression by
lymph nodes may produce localized
wheezing

24. DIAGNOSTIC PROCEDURES
TB Tests - Tests for diagnosis of TB, sputum
test, blood test
-There are several different types of TB test. There
are TB tests available to diagnose TB. There are also
TB tests to find out if someone has TB bacteria that
are susceptible to tb drug treatment. If the bacteria
are susceptible to treatment, it means that the
treatment should work. The opposite of being
susceptible to treatment is being drug resistant. A TB
test to find out if someone has drug resistant TB, is
known as a drug susceptibility test.

25. Even if a person has symptoms of TB it is
often difficult to diagnose TB, and it is
particularly difficult to diagnose rapidly.
Rapid diagnosis is what is needed to provide
effective TB treatment for drug resistant TB.
The development of TB disease is a two
stage process. In the first stage, known as
latent TB, a person is infected with TB
bacteria. In the second stage, known as active
TB or TB disease, the bacteria have
reproduced sufficiently to usually cause the
person to have become sick. Some tests are
for latent TB, others are for active TB, and
some are for both.

26. TB Culture Test
A culture test involves studying bacteria by
growing the bacteria on different substances.
This is to find out if particular bacteria are
present. In the case of the TB culture test the
test is to see if the TB bacteria Mycobacterium
tuberculosis, are present.
The substances are either solid substances on
culture plates, or bottles of liquid known as
culture broths. The substances are chosen to
make it as easy as possible for the bacteria to
grow.

27. TB Interferon gamma release assays (IGRAs)
The Interferon Gamma Release Assays
(IGRAs) are a new type of more accurate TB
test. In this context referring to an assay is
simply a way of referring to a test or
procedure.
IGRAs are blood tests that measure a person’s
immune response to the bacteria that cause TB.
The immune system produces some special
molecules called cytokines. These TB tests
work by detecting a cytokine called the
interferon gamma cytokine.

28. In practice you carry out one of these TB tests
by taking a blood sample and mixing it with
special substances to identify if the cytokine is
present
Sputum smear microscopy as a test for TB
A sputum smear stained using fluorescent acid fast
stain and being used as a test for TB.
A sputum smear stained using fluorescent acid fast
stain and being used as a test for TB.
Sputum is a thick fluid that is produced in the lungs
and the airways leading to the lungs. A sample of
sputum is usually collected by the person coughing.

29. Fluorescent microscopy
The use of fluorescent microscopy is a way of
making sputum TB tests more accurate. With
a fluorescent microscope the smear is
illuminated with a quartz halogen or high
pressure mercury vapour lamp, allowing a
much larger area of the smear to be seen and
resulting in more rapid examination of the
specimen.

30. Chest X-ray as a TB test
If a person has had TB bacteria which have
caused inflammation in the lungs, an abnormal
shadow may be visible on a chest x-ray.12 Also,
acute pulmonary TB can be easily seen on an X-
ray. However, what it shows is not specific. A
normal chest X-ray cannot exclude extra
pulmonary TB.

31. GENE EXPERT
This is a molecular test for TB which diagnosis TB by
detecting the bacteria as well as testing for drug resistance,
drug Rifampicin
It detects DNA in TB bacteria through the sputum sample
and gives results in two hours
Advantages
 Main method used to test for MDR.i.e
rifampicin
It is reliable when compared to sputum
microscopy
It is faster compared to culture test
Although sputum microscopy is cheap and fast

32. Abbreviation of
the regimen
2RHZE/4RH
Phase Intensive phase Continuation
Phase
Duration Directly observed
Treatment (DOT),
for two months
Directly observed
Tx(DOT) for 4
Months
Drugs used Ritampicin ( R)
Isoniazid (H)
Pyrazinamide (Z)
Ethambutol ( E )
2 Months i.e.
2RHZE
Rifampicin ®
Isoniazid (H)
4 Months i.e. 4RH
TREATMENT OF TB
Treatment of Regimen for New Adult TB pts.

33. Abbreviation of
The Regimen
2SRHZE/1RHZE/5RHE
Phase Intensive Phase Continuation
phase
Duration of tx Daily tx with
Appropriate pt
Support for 2
month
Daily tx with
appropriate pt
support for 1
months
Daily tx with
appropriate pt
Support for 5
months
Drugs used Streptomycin (s)
+Ethambutol (
E)
+Ritampicin ( R)
+Isoniazid (H)
+Pyrazinamide
i.e 2SRHZE
Ethambutol ( E)
+Ritampicin ( R)
+Isoniazid ( H)
+Pyrazinamide (
Z) for a Month
i.e 1RHZE
Ethambutol ( E)
+Ritampicin ( R)
+Isoniazed ( H)
For 5 months i.e
5RHE
Treatment regimen for continuing pts

34. DRUG DOSAGE
DRUG FORMULATION OVER 55KG 40-54kg 30-39kgs
STREPTOMYCIN IM INJECTION 1g 3 2
(R)150mg+(H)75mg+(Z
)400mg+(E)275mg
4-FDC TABLET
RHZE
4 3 2
(R)150mg+(H)75mg+(Z
)400mg
3-FCD TABLET
RHZE
4 3 2
R)150mg+(H)75mg 2-FDC TABLET 4 3 2
R)150mg+(H)75mg+(E)
275mg
TABLET RHE 4 3 2
Isoniazid
150mg&Ethambutol
400mg
TABLET EH 2 2 2

35. TREATMENT OF MDR TB
Fluoroquionolones,(Norfloxacin,
Moxifloxacine)
Aminoglycosides(Amikacin,kanamycin)
TB VACCINATION
TB is vaccine is called Bacilli Calmette-
Gue’rin(BCG) and is used in most
countries to prevent Tb
• BCG is vaccinated at birth and a repeat
dose done after two weeks if scaring
does not occur

36. Complications of TB.
 Special pain, back pain and stiffness are
common complications of TB
 Joint damage. TB arthritis usually
affects hips and legs
 Meningitis poor mental change.
 Liver and kidney complications
 Heart diseases

37. Risk factors
 Smoking
 HIV/AIDS infection
 Malnutrition
 Drug users
 There is contact with
infected individuals

38. NURSING MANAGEMENT
 Prevention of transmission by
Early identification of clients with TB
Isolation of the clients with TB in negative
pressure rooms; this prevents airway from flowing
out into the hallway when the door is opened
 PPE- Monitoring health care workers TB status
Place pt in semi or high fowler’s position – help
maximize lung expansion and decrease respiratory
effort

39.  Assist pt with coughing and deep
breathing exercise – for maximum
ventilation which opens atelectatic
areas and promote movement of
secretion into longer airways for
expectorations
 Suction secretion from mouth to
trachea- prevents destruction and
aspiration

40. Maintain fluid intake at least 2500ml/day
unless contraindicated – high fluid intake
helps thin secretion hence easier to
expectorate
 Humidity inspired air O2 – Prevents
drying mucous membrane and helps thin
secretion

41. Promote bed rest or limit activity and assist with
ADL – reducing O2 consumption and demand
during periods of respiratory compromise may
reduce severity of symptoms
Provide supplemented O2 as appropriate – aids in
correcting the hyperemia that may occur
secondary to decreased ventilation and diminished
alveolar lung surface

42. Position pt with good lung dependent –
Increase ventilation ,encourage
diaphragmatic breathing, Abstain from
alcohol esp. when on INH-Alcohol + INH
can increase the risk of hepatitis
Encourage client to abstain from smoking –
increase likelihood of respiratory
dysfunction or bronchitis