2010-B3 Pathophysiology lung

Pneumonia
Pathology:
Alveolar

Bronchopneumonia
(Streptococcus pneumoniae,
p
influenza,
f
z ,
Haemophilus
Staphylococcus aureus)
Lobar (Streptococcus
pneumoniae)
Interstitial (Influenza virus,
Mycoplasma pneumoniae)

Pathogenesis
Inhalation of air droplets
Aspiration
p
of infected
secretions or objects
Hematogenous spread
1

Oct-1, 2010, 4th

Pulmonary infectionsPredisposing factors

Decreased cough
g reflex
Injury
j y to cilia
Decreased function of alveolar macrophages
Edema or congestion
Retention of secretions

Lungg abscess
Localized suppurative necrosis
Organisms commonly cultured:

Staphylococci
Streptococci
Gram-negative
Anaerobes
Frequent mixed infections

Pathogenesis:

Aspiration
Pneumonia
Septic emboli
T
Tumors
Direct infection

Pulmonary tuberculosis

Pulmonaryy tuberculosis

Secondary

Caused by Mycobacterium
tuberculosis.
Transmitted
T
itt d through
th
h iinhalation
h l ti
of infected droplets
Primary

Infection (mostly through

p
y
reactivation)) in a previously
sensitized individual.
Pathology
Cavitary fibrocaseous
lesions
Bronchopneumonia
Miliary TB

Single granuloma within

parenchyma and hilar lymph
nodes
d (Gh
(Ghon complex).
l )
Infection does not progress
(most common).
Progressive primary
pneumonia
Miliary dissemination (blood
stream).

Miliary

Granuloma

Opportunistic
pp
p
pneumonias

Chronic obstructive pulmonary disease (COPD)

Chronic bronchitis

Infections that affect

immunosuppressed patients
Associated disorders:

Definition
Persistent cough with sputum
production for:
at least 3 months,
in at least 2 consecutive years.

AIDS
Iatrogenic
Cancer patients
Transplant recipients
Aspergillus

Pathology
Inflammation of airways
Hyperplasia of
mucous producing cells
Squamous metaplasia
Injury to cilia

Cytomegalovirus
7

Pneumocystis carinii

Chronic obstructive pulmonary disease (COPD)

Emphysema

Destructive enlargement of
airspaces distal to terminal
bronchioles
Two main
i types

The pathogenesis of COPD

Centriacinar
Destruction of central portion
with
ith sparing of distal airways
air a s
Upper lobes > lower
Cause: smoking
Panacinar
Unform injury
Lower lobes > upper
Cause: alpha-1-antitrypsin
deficiency

10

Bronchial Asthma

Bronchiectasis

Chronic inflammatory disorder of the airways

resulting in contraction of bronchial muscle
Types
T

Dilatation of bronchi
and bronchioles
secondary to chronic
inflammation
Associated conditions

Extrinsic (atopic, allergic).

Allergens:
g
food, p
pollen, dust, etc.

Intrinsic (non-atopic)
Initiated by infections, drugs, pollutants, chemical
irritants

Obstruction
Ob
i
Cystic fibrosis
Immotile cilia syndromes
Necrotizing pneumonia

ATOPIC ASTHMA
Allergen
I E
IgE

Mucus
secretion

Mast cell

Epithelial cell injury

Muscle
contraction

Mucus
secretion

Muscle contraction

11

Release of inflammatory
mediators
Recruitment of leukocytes

Acute phase

12

Late-phase

Atelectasis

Common asthma triggers

gg
Animals (pet hair or dander)
Dust
Changes in weather (most
often cold weather)
Chemicals in the air or in
food
Exercise
Mold
Pollen
Respiratory infections, such
as the common cold
Strong emotions (stress)
Tobacco
T b
smoke
k

Emergency symptoms:
p
Bluish color to the lips
and face
Decreased level of
alertness
l
suchh as severe
drowsiness or confusion,
g an asthma attack
during
Extreme difficulty
breathing
Rapid pulse
Severe anxiety due to
shortness of breath
Sweating

Collapse or incomplete expansion

of part or all of the lung
Types:
Resorption (obstruction of airway).
airway)
Compressive (pleural effusion or
pneumothorax)

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Pulmonaryy edema

Diffuse alveolar damage

g

Oncotic pressure

Acute respiratory distress syndrome

(respiratory failure and arterial
hypoxemia
i refractory
f
to O2 therapy).
)
Basic lesions: injury to pneumocytes
and endothelial cells by:

Hydrostatic pressure
Normal
Oncotic pressure

Hydrostatic pressure

Oxygen-derived free radicals

Activated neutrophils and macrophages
Loss of surfactant
surfactant.

Causes:
- Heart
H t failure
f il
- Mitral stenosis

Etiology:

Hydrostatic pressure

Causes:
- Infections
p
- Aspiration
- Drugs
- Radiation

Oncotic pressure
Causes:
- Nephrotic
y
syndrome
- Liver diseases

Infections (viral)
Gas inhalation or liquid aspiration
Drugs, chemical, radiation
Hypotension, sepsis, trauma

Pathology:
Acute (exudative) stage
Proliferative or organizing stage

Microvascular injury

15

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Pulmonary embolism
Most emboli arise in veins
from the legs
Large emboli (10%) are a
cause of sudden death
Small emboli (70%) may
be:
Clinically
y silent
Cause infarctions (in patients
with heart failure).
Cause hemoptysis

Medium sized emboli

((20%)) generally
g
y cause
infarctions.

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18

Hypersensitivity pneumonitis

Pulmonaryy hypertension
yp
Secondary (most
common):
)

Immunologically mediated disorder affecting

airways and interstitium.

Primary (idiopathic)

Chronic
obstructive
pulmonary
l
disease
Chronic
interstitial
pulmonary
di d
disorders
Chronic heart
failure
Recurrent
pulmonary
emboli

Farmers lung
Thermophilic actinomycetes in hay

Pigeon
breeder s
breeders

Air-condition lung

19

Th
Thermophilic
hili bacteria
b t i

20

Usual interstitial pneumonia /

idiopathic pulmonary fibrosis

Pneumoconioses
Disorders caused by inhalation
of inorganic elements,
primarily metals.
metals
Injury is determined by:

Progressive
fibrosing
g disorder
off off unknown
cause
Adults 30 to 50 y/o
Respiratory and
heart failure (cor
pulmonale)
l
l )~5y

Length of exposure
Physicochemical
Ph i h i l characteristics
h
t i ti
Host factors

Carbon dust - Coal workers

pneumoconiosis:
Anthracosis
Simple coal workers
pneumoconiosis
Progressive massive fibrosis

Silicosis
Silicotic nodules

Asbestos
Asbestosis (pulmonary fibrosis)
Pleural disease (fibrous plaques,
plaques
mesothelioma).

21

Smoking-related diseases

22

Classification of Lung Carcinoma

100
(Major Types)
patients

Squamous cell carcinoma

Adenocarcinoma
Small cell carcinoma
Large cell carcinoma

35%
30%
25%
10%

35
operable

25 30
25-30
resected for c

23

8-12
survive for 5 y
24
(30% of those
res

Adenocarcinoma

Squamous cell carcinoma

Frequency: 35%
Smoking: X 25 (increased risk)
Males > females
S
Survival
i l (5 years):
) 15 - 20%
Arises in bronchial squamous metaplasia
Centrally located
25
May cavitate

Bronchioloalveolar carcinoma

26

Frequency: 25 %
Smoking: 95% of patients
M l >> females
Males
f
l
Survival (5 years): 1 - 5 %.

27

28

Mesothelioma

Large Cell Carcinoma

Mesothelioma:

Frequency: 10 %
Gross
G

Malignant tumor of
mesothelial cells
Highly malignant
neoplasm with short
survival
Most p
patients ((70%))
have an asbestos
exposure history

Peripheral lesion

Microscopic
Wastebasket group of tumors
that do not fit the criteria of a
squamous cell carcinoma,
carcinoma
adenocarcinoma, or small
cell carcinoma

A
Asbestos
b t exposure
also increases the risk
of pulmonary cancer
Smoking is not related
to mesothelioma

Prognosis
Similar to adenocarcinoma

Frequency: 30%
Smoking: X 3 (increased risk)
M l < females
Males
f
l
Survival (5 years): 15 - 20%
Peripheral

Small cell carcinoma

Frequency: 2 %
Smoking: yes
Males = females
Survival (5 years): 25 a 40 %
%.
Presentation:
Single or multiple tumor nodules
Miliary tumor
Pneumonic form

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