LUNG 2 Flashcards
- a sudden blockage in a pulmonary
artery that is most often caused by an embolism
of a thrombus usually located in the deep vein of
the leg (MC) or other distant site.
Pulmonary embolism (PE) or thromboembolism
3
rd main cause of CV death
Pulmonary embolism (PE) or thromboembolism
Virchow’s triad
hypercoagulability, vessel injury and
stasis
Respiratory compromise due to
lack of
perfusion
Hemodynamic compromise due to
pulmonary-arterial resistance that is
called cor pulmonale
o Clinically silent (60 to 80%) o Pulmonary hemorrhage or infarction (dyspnea, tachypnea, pleuritic pain, friction rub, signs of effusion, cough and wheezing)
Small vessel emboli:
Main manifestation of medium-sized artery embolus
Medium sized artery embolus
Large vessel obstruction (pulmonary artery):
o Sudden death, cor pulmonale or CV
collapse
ACUTE HEMORRHAGIC PULMONARY INFARCT is located in
Located in lower lobes because perfusion is
greater in the lower lobe
Raised, red-blue (early)→red-brown wedge
shaped
Also called “septic infarcts”
ACUTE HEMORRHAGIC PULMONARY INFARCT
▪ Cause CV collapse, and right sided heart failure
▪ If untreated, it can cause sudden cardia death
SADDLE EMBOLUS
Diagnosis of saddle embolus
o Chest radiography (nonspecific signs-effusion, etc.)
o Perfusion radionuclide scan (V/Q scan)
o Computed tomography pulmonary
angiogram (CTPA- spiral CT)
o Pulmonary angiogram
o D-dimer
o Cardiac panel is also used by some institution (cardiac enzymes)
▪ Most commonly employed imaging because of non-invasiveness ▪ look for “cut-off” sign (abrupt hypo vascularity) sign ▪ after the dye has been seen in the main pulmonary artery there is loss of trachea-bronchial supply
Computed tomography pulmonary
angiogram (CTPA- spiral CT)
▪ Gold standard
▪ Direct visualization of pulmonary
artery
Pulmonary angiogram
▪ Highly sensitive, used for screening
D-dimer
Prognosis of ACUTE HEMORRHAGIC PULMONARY INFARCT
Prognosis:
o Case fatality 1 month after diagnosis is
12%
o Recurrence rate is 1-6% during the first 6 months
In pulmonary hypertension, the mean pulmonary artery pressure is
≥25 mmHg at
rest
Pulmonary HTN pathophysiology
▪ Bone morphogenetic protein receptor type 2
(BMPR2) signaling pathway
o Mutations -> SMC Hyperplasia
o Seen in 75% of familial cases
▪ Activin receptor-like kinase 1 (ALK1) and
endoglein
▪ Drugs & Toxins (“Phen-Phen”)
Pulmonary HTN morphology
▪ Right ventricular hypertrophy ▪ Medial hypertrophy of the pulmonary muscular and elastic arteries o More characteristic of pulmonary hypertension. o Causes complete obliteration of the lumen that leads to hypertension ▪ Atherosclerosis ▪ Plexiform lesions o Tuffs of capillary formation that have developed secondary to pulmonary hypertension. ▪ Atheromatous lesions
Pulmonary HTN is more common in ________ aged ___
women; 20-40 yrs of age
Most common presenting symptom of Pulmonary HTN
Exertional dyspnea
Clinical features of Pulmonary HTN
▪ Exertional dyspnea ▪ Chest pain ▪ Severe respiratory distress ▪ Cyanosis ▪ Right ventricular hypertrophy ▪ Cor Pulmonale (Right-sided heart failure)
Diagnosis for pulmonary HTN
▪ Right heart catheterization
▪ Transthoracic echocardiogram
▪ ECG
Gold standard in diagnosing Pulmonary HTN
o Invasive
Right heart catheterization
Diagnosing technique wherein it shows resistance to airflow
Transthoracic echocardiogram
Treatment for mild cases (Pulmonary HTN)
Vasodilators
Treatment for severe cases (Pulmonary HTN)
Lung transplant
Is a dramatic complication of some interstitial lung
disorders
Diffuse Pulmonary Hemorrhage
Syndromes
▪ Rare disease of children characterized by
Intermittent diffuse alveolar hemorrhage
▪ Cough & hemoptysis
Idiopathic pulmonary hemosiderosis
Diffuse Pulmonary hemorrhage syndromes
Idiopathic Pulmonary Hemosiderosis
Goodpasture Syndrome
Polyangiitis with Granulomatosis
▪ Anti-GBM Ab Disease with Pulmonary
Involvement
▪ Antibodies against a3 chain of collagen IV
▪ Renal disease + Pulmonary hemorrhage
▪ Rapid and progressive pulmonary hemorrhage
Goodpasture syndrome
▪ “Wegener Granulomatosis”
▪ Immune disease typically presenting with hemoptysis
Polyangiitis with Granulomatosis
Important features of Polyangiitis with granulomatosis
Capillaritis and scattered,
poorly formed granulomata
▪ Portal of Entry
pulmonary infection
o Inhalation
o Aspiration
o Hematogenous spread
o Direct spread
▪ Compromised local pulmonary defense
o Loss or suppression of the cough reflex
o Dysfunction of the mucociliary apparatus
o Accumulation of secretions
o Interference with the phagocytic and
bactericidal activities of alveolar
macrophages
o Pulmonary Congestion and Edema
can be very broadly defined as any
infection of the lung parenchyma
Pneumonia
It causes alveoli to be filled with inflammatory
exudates, and can usually result into
consolidation (sort of solidification within the lung)
of lung.
Pneumonia
Pneumonia can be assessed using
X-Rays, using
sethescope on auscultation (decrease breath
sounds) or even in PE when doing tactile fremitus
test (Vibrations are increased over areas of
consolidation).
Pneumonia clinical features
fever and chills, productive cough with yellow-green (pus) or rusty (bloody) sputum, tachypnea with pleuritic chest pain, decreased breath sounds, dullness to percussion, and elevated WBC count
Pneumonia Accdg to anatomic region
o Lobar pneumonia
o Bronchopneumonia ( or Lobular
pneumonia )
o Interstitial pneumonia
Pneumonia Accdg to clinical settings
o Community - acquire pneumonia
o Health care - associated pneumonia (
HCAP )
o Ventilator - associated pneumonia ( VAP)
PRIMARY ATYPICAL
PNEUMONIA
VIRAL AND MYCOPLASMAL
PNEUMONIA
NON INFECTIVE PNEUMONIAS
I. Aspiration (inhalation)
pneumonia .
II. Hypostatic pneumonia
III. Lipid pneumonia
Bacterial lung infection in otherwise
healthy individuals that is acquired from the normal environment
COMMUNITY ACQUIRED BACTERIAL
PNEUMONIA
Most common cause of CAP
Streptococcus
pneumoniae or
Pneumococcus
Most common bacterial cause in COPD. It causes life threatening infections and meningitis in children.
Haemophilus
influenza
Secondary bacterial pneumonia following viral respiratory illnesses. It has high risk of development of abscess.
S. aureus
In debilitated and malnourished people. Including alcoholics. Thick mucoid sputum tinged blood or rusty sputum.
Enterobacteriace
ae (Klebsiella
pneumoniae )
Common in patients
with neutropenia.
Pseudomonas
aeruginosa
Organ transplant
recipients.
Legionella
pneumophila
Patchy consolidation
bronchopneumonia
Usually bilateral basal in location due to gravitation of secretions
Bronchopneumonia
Diffuse inflammation
Lobar pneumonia
Acute (neutrophilic)
suppurative exudation
Bronchopneumonia
Lobar pneumonia 4 stages
- Congestion
- Red hepatization
- Gray hepatization
- Resolution
Affects extremes of age
infants or old
Bronchopneumonia
o The lung is heavy, boggy, and
red.
o Vascular engorgement, intra-alveolar edema fluid with few neutrophils, and the presence of
bacteria, which may be numerous.
Congestion
e initial phase that represents
acute inflammation response to bacterial
infection and it can last for 1-2 days.
Congestion
Congestion (microscopically)
microscopy you can see that there
is dilatation and congestion of capillary
walls and edema in air spaces
o The lobe is red, firm, and airless.
o Massive confluent exudation, neutrophils, red cells, fibrin fill the alveolar spaces.
Red hepatization
Red hepatization lasts for around
2 days
In this
stage RBCS began to lyse and start to
give paler color or grey color on gross
and cut section
Gray hepatization
Gray hepatization (Microscopically)
e fibrous that are denser and more numerous compared to the previous stage, so cellular exudates of neutrophils also start to disintegrate with bacterial organism and other pathogens.
o Progressive disintegration of red cells and the persistence of a fibrinosuppurative exudate, resulting in a color change to grayish-brown
Grey hepatization
Advanced
organizing pneumonia.The exudates have been
converted to fibromyxoid masses rich in
macrophages and fibroblasts
Resolution
the exudate within
the alveolar spaces is broken down by enzymatic
digestion to produce granular, semifluid debris that is resorbed, ingested by macrophages,
expectorated, or organized by fibroblasts growing
into it
Resolution
Clinical features of pneumonia
▪ High fever, rigors and productive cough,
occasionally with hemoptysis;
▪ A friction rub and pleuritic chest pain herald pleural involvement
The whole lobe is ______ in lobar pneumonia
radiopaque
presence of focal opacities in ________
bronchopneumonia
Appropriately treated patients may become
afebrile with few clinical signs ______ hours after
the initiation of antibiotics
48 to 72
Pneumonia diagnosis
▪ CXR
▪ CBC
▪ Sputum Gm stain
▪ Blood culture (in severe cases)
Pneumonia caused by viruses and
intracellular organisms characterized by patchy
inflammatory changes, largely confined to
interstitial tissue of the lungs, usually without any
alveolar exudate and consolidation
COMMUNITY-ACQUIRED VIRAL (ATYPICAL)
PNEUMONIA
the most common
cause of common cold and this common cold can
extend and reach the lower respiratory tract
causing viral pneumonia.
Rhinovirus
Other viruses that can
cause pneumonia are
adenovirus and coxsakie virus
influenza viruses of type A infect
humans, pigs,
horses, and birds and are the major cause of
pandemic and epidemic influenza infections.
Influenza virus is a ___-stranded RNA virus
single
minor mutation. Does not require
a new vaccine.
Antigen drift
major mutation. A new vaccine is
required
Antigen shift
▪ Paramyxovirus
▪ Bronchiolitis and pneumonia in extreme ages and
immunocompromised
METAPNEUMOVIRUS
Such infections are clinically indistinguishable
from those caused by human respiratory syncytial
virus and are often mistaken for influenza
METAPNEUMOVIRUS
Gross morphology of interstitial type pneumonia
Patchy or diffuse
Red-blue and congested
In microscopic morphology of Interstitial type pneumonia, Inflammatory cells are present in the _______ rather than the alveoli and without consolidation
interstitium
predominant feature of Interstitial type pneumonia
Interstitial inflammatory reaction
T or F
In interstitial type pneumonia, Mononuclear infiltrate is present, rather than
neutrophils
T
T or F
In interstitial type pneumonia, Alveolar spaces are usually free of exudate (pus)
T
Clinical features of Interstitial type pneumonia (viral)
▪ Mild to severe upper respiratory tract infections
and continue down to your LRT infection
▪ Myalgias and fever
▪ Dyspnea
▪ Dry cough > productive
▪ Most viral illnesses are mild and spontaneously
resolve
Diagnosis (viral)
▪ CXR
▪ CBC
▪ PCR (To identify etiologic agent
Pneumonia occurring ≤48 hours of
hospital admission in patients with at least 1 risk
factor for MDR bacteria
HEALTHCARE- ASSOCIATED PNEUMONIA (HCAP)
) Pneumonia occurring
≥48 hours of hospital admission. (Prolonged
hospital stay)
HAP
Pneumonia occurring >48 hours after
endotracheal intubation
VAP
Gram positive cocci (HCAP)
S. aureus
Gram negative rods
Enterobacteriaceae and Pseudomonas spp
▪ Non infective in nature
▪ Aspiration of different agents into the lungs
▪ When it becomes infected - Polymicrobial:
aerobes» anaerobes
Aspiration pneumonia
able to aspirate gastric
contents which can present as hemoptysis and
dyspnea secondary to pulmonary hemorrhage
and edema
Chemical pneumonitis
aspirate infective material
coming from oropharynx or nasopharynx and can
present as pulmonary necrosis and suppuration.
Bronchopneumonia
Histology: Biopsy lung secondary to aspiration
pneumonia
foreign body type
granulomatous inflammation because of the
foreign materials that had been aspirated
Local suppurative process that produces necrosis
of lung tissue.
Chronic pneumonia
Lung abscess
most common cause of primary lung abscess
Aspiration of infected material
develops as a
complication of some other disease of the lung or
from another site.
Secondary lung abscess
most common
microbes introduced in the lung
aerobic and anaerobic streptococci, S. aureus,
and a host of gram-negative organisms
anaerobic organisms normally found in what part of pharynx
Oropharynx
common causes of Lung abscess
o Aspiration of infective material
o Antecedent primary bacterial infection
o Septic emboli from infected thrombi or
right sided endocarditis
o Obstructive tumors
o Direct traumatic punctures or spread of
infection from adjacent organs
anaerobes
(Bacteroide,
Fusobacterium, and Peptococcus)
primary abscess
single
secondary lung abscess
multiple
size (lung abscess)
5-6cm
Lung abscess microscopic appearance
Suppurative necrosis of the lung parenchyma
within the central area of cavitation
Clinical features of lung abscess
much like those of bronchiectasis and
characteristically include cough, fever,
and copious amounts of foul-smelling
purulent or sanguineous sputum
clubbing due to hypoxemia
Complications (lung abscess)
o Extension of the infection into the pleural cavity o Hemorrhage o Septic emboli o Secondary amyloidosis
causative agent of Histoplasmosis
Histoplasma capsulatum
▪ Microconidia in bird/bat dropping ▪ Macrophages ingest but cannot kill the organism without T-cell help ▪ Granulomas with coagulative necrosis - clinically mimics tuberculosis
Histoplasmosis
Histoplasmosis
3-5 um, thin-walled cyst
silver stain
Blastomycosis C.A.
▪ Blastomyces dermatitidis
▪ Inhalation of spores in the ground
types of blastomycosis
▪ Pulmonary, disseminated, and cutaneous
blastomycosis
type granuloma in blastomycosis
suppurative
size and morphology of blastomycosis
▪ 5-15 um, thick-walled yeast with broad-based
budding
▪ Clinically mimics tuberculosis
delayed-type of hypersensitivity reaction to the fungus, most remain asymptomatic
coccidiomycosis
T or F
Infectivity of C. immitis is that infective
arthroconidia, when ingested by alveolar
macrophages, block fusion of the phagosome
and lysosome and so resist intracellular killing
T
Micro morphology of coccidiomycosis
Macrophages or giant cells, thick walled, often
filled with small endospores
Opportunistic infection agents
o P. aeruginosa, Mycobacterium species, L. pneumophila, and Listeria monocytogenes o CMV and herpesviruses o Pneumocystis, Candida, Aspergillus and Cryptococcus neoformans
common causes of pneumonia in HIV
o S. pneumoniae, S. aureus, H, infuenza
and gram-negative rods
> 200/uL CD-4 T-cell count
Bacteria, including
tuberculosis
50 to 200/uL CD4 T cell count
Pneumocystis
<50/uL CD4 Tcell count
CMV and Mycobacterium avium
comple
