Respiratory Pathology Flashcards
1
Q
What does a ‘barrel chest’ indicate?
A
Hyperinflation, as in COPD. In particular, it may be seen in emphysema
2
Q
What do unilateral diminished breath sounds indicate?
A
Pneumothorax
3
Q
What do acute bilateral diminished breath sounds indicate?
A
Asthma (attack)
4
Q
What do chronic bilateral diminished breath sounds indicate?
A
Emphysema (due to reduced lung tissue)
5
Q
What may chronic wheeze suggest?
A
Obstructive disease, e.g. asthma or COPD
6
Q
What may acute wheeze suggest?
A
FB aspiration
7
Q
What does stridor represent?
A
Tracheal or laryngeal obstruction
8
Q
What does dullness to percussion indicate?
A
Lung consolidation, e.g. pneumonia
9
Q
What does increased tactile remits indicate?
A
Lung consolidation, e.g. pneumonia
10
Q
What are the 3 obstructive lung diseases?
A
- COPD (emphysema + bronchitis)
- Asthma
- Bronchiectasis
11
Q
What is the hallmark finding of obstructive lung disease?
A
A reduced FEV1/FVC ratio
12
Q
What 2 diseases does COPD include?
A
- Emphysema
2. Chronic bronchitis
13
Q
What is the underlying pathogenesis of emphysema?
A
= underlying loss of elastic recoil + dilatation of terminal air spaces
14
Q
How may smoking cause emphysema?
A
The enzyme elastase digests elastin. Cigarette smoke both inactivates alpha-1-antitrypsin (which prevents elastase becoming active) and attracts inflammatory cells (which produce elastase)
15
Q
How may hereditary alpha-1-antitrypsin deficiency cause emphysema?
A
There is a lack of alpha-1-antitrypsin and it is alpha-1-antitrypsin that prevent elastase from being constitutively active
16
Q
What proportion of emphysema does hereditary alpha-1-antitrypsin deficiency constitute?
A
1%
17
Q
Where does emphysema shift the compliance curve of the lungs?
A
Up + left
18
Q
How might a typical emphysema patient be described?
A
Pink puffer (not cyanotic, although both ventilation and perfusion are both reduced, the V/Q mismatch is not severe)
19
Q
What are the signs of emphysema O/E?
A
- Cachexic
- Tri-poding
- Accessory muscle use
- Signs of hyperinflation
20
Q
What are the 2 main pathological types of emphysema?
A
- Panacinar
2. Centriacinar
21
Q
What is panacinar emphysema?
A
Primarily affects the lower lobes. Dilatation of the entire acinus. Associated with alpha-1-antitrypsin deficiency
22
Q
What is centriacinar emphysema?
A
Pattern of involvement is irregular, or localised to the upper lobes. Dilatation of the just the proximal part of the acinus, i.e. the respiratory bronchioles. Associated with smoking
23
Q
What is the clinical definition of chronic bronchitis?
A
A productive cough for at least 3/12 per year over 2 consecutive years
24
Q
What is the underlying pathogenesis of chronic bronchitis?
A
- Smoking = proliferation and hypertrophy of bronchial mucous glands. = excessive mucus production, which is also more viscous than normal.
- The cilia lining of the bronchial lumen us also damaged, impeding mucus clearance.
- Inflammatory cell influx = airway inflammation.
25
How might a typical chronic bronchitis patient be described?
Blue bloater (cyanotic - there is significant V/Q mismatch due to the reduced ventilation as a result of damaged airways, but the preservation of perfusion)
26
What are the signs of chronic bronchitis O/E?
1. Obese
2. Peripheral oedema (due to associated right ventricular failure)
3. Cyanosis of peripheries
4. Clubbing - as a result of the hypoxaemia
27
What condition might arise as a result of chronic bronchitis?
Cor pulmonale, as a result of the pulmonary HTN secondary to hypoxaemia and pulmonary vasoconstriction
28
What lung condition may occur in CF patients? + why?
Bronchiectasis. Because the thick mucus secretions produced are difficult to clear + harbour bacteria, resulting in chronic infection
29
What bacteria, although rare, almost exclusively colonises the lungs of patients with CF?
Burkholderia cepacia
30
What bacteria more commonly colonise the lungs of CF patients?
1. Pseudomonas aeruginosa
2. S.aureus
3. H.influenzae
31
What drug may be given to CF patients to break down the thick mucus secretions?
DNase
32
What is bronchiectasis?
Irreversible dilatation of the airways
33
What are the causes of bronchiectasis?
1. CF (due to the thick mucus causing chronic infection)
2. Infection
3. Obstruction (often tumour)
4. Airway clearance defect (e.g. Kartagener syndrome)
(all lead to the inflammatory destruction of airways)
34
What may be seen on a bronchiectasis XR?
Ring shadows
35
What is the preferred method of bronchiectasis diagnosis?
CT
36
What are the patterns of airway dilatation seen in bronchiectasis?
1. Cylindrical
2. Varicose
3. Saccular
37
What is the difference between asthma and COPD?
Asthma = a REVERSIBLE obstructive disease (whereas COPD is IRREVERSIBLE)
38
What are the 2 sub-types of asthma?
1. Extrinsic
| 2. Intrinsic
39
What type of hypersensitivity reaction is extrinsic asthma?
Type I
40
What are the features of extrinsic asthma?
Type I hypersensitivity, involving IgE and mast cells.
Begins in childhood/in those with a FHx of atopy.
Allergens = animal dander (esp. cats); pollen; mold; dust mites
41
What are the features of intrinsic asthma?
Allergens = cold; exercise; cigarette smoke; medication (esp. aspirin); stress
42
Which mediators are associated with inflammation in asthma?
Eosinophils; lymphocytes; histamine; leukotrines; IgE
43
Which growth factors cause fibrosis in asthma?
EGF; IGF-1; PDGF
44
With epithelial-derived mediator causes bronchoconstriction in asthma?
Endothelin-1
45
With epithelial-derived mediators cause vasodilation in asthma?
NO; PGE2; 15-HETE
46
With epithelial-derived mediators (all cytokines) cause inflammation in asthma?
GM-CSF; IL-8; RANTES; Eotaxin
47
What are the 'relievers' used in asthma?
1. Short-acting beta-2-agonists
2. Ipratropium
3. IV steroids
4. Magnesium sulfate
5. Epinephrine
48
What are the 'controllers' used in asthma?
1. PO steroids
2. Inhaled steroids
3. Long-acting beta-2-agonists
4. Xanthines
5. Mast cell stabilisers
6. Leukotrine blockers
7. Omalizumab
49
What is the name of a severe asthma attach refractory to therapy?
Status asthmaticus
50
What actions of steroids are useful in their relief of asthma?
Reduce inflammation by:
1. Decrease cytokine formation
2. Inactivation of a nuclear factor of activated B cells
3. Inhibition of generation of vasodilators
4. Decreasing microvascular permeability
5. Reducing mediator release from eosinophils
51
What is the action of Xanthines?
Increase cAMP in smooth muscle cells though inhibition of phosphodiesterase isoenzymes, leading to airway dilatation
52
What is the action of mast cell stabilisers?
Inhibits the release of inflammatory mediators from mast cells
53
What is the action of leukotrine blockers?
Inhibit 5-lipoxygenase, reducing the conversion of arachidonic acid to leukotrienes
54
What is the action of Omalizumab?
= monoclonal Ab. Binds to circulating IgE
55
What are the 2 categories of restrictive lung diseases?
1. Extrapulmonary disorders
| 2. Interstitial lung diseases
56
What characterises sarcoidosis?
Non-caseating granulomas, often involving multiple organ systems
57
How does hypersensitivity pneumonitis differ from asthma and allergy?
= not a type I hypersensitivity reaction.
It is an alveolar disease, whereas asthma is a disease of the bronchi.
58
How is hypersensitivity pneumonitis definitively diagnosed?
Biopsy - loosely organised granulomas - + consistent Hx
59
What is the usual cause of a spontaneous pneumothorax?
Rupture of an air-filled lung bleb
60
In what direction will the mediastinum/trachea deviate in a tension pneumothorax?
AWAY from the side of the pneumothorax
61
What does the term 'allergy' refer to?
Type I hypersensitivity ---- mediated by IgE ---- results in mast cell degranulation and histamine-mediated vascular permeability
62
How may we test for allergies?
RAST
63
What is the action of first-generation anti-histamines?
Reversible antagonists of H1 histamine receptors, therefore reversing the vascular permeability caused by mast cell degranulation
64
Can first-generation anti-histamines cross the BBB?
Yes, this is responsible for the S/E of drowsiness
65
What is the difference between first-generation and second-generation anti-histamines?
Second-generation does not cross the BBB
66
How do nasal decongestants work?
Reduce congestion and oedema by increasing alpha-1-adrenergic signalling
67
What organism is responsible for 'strep throat'?
Streptococcus pyogenes
68
What may treatment of streptococcus pyogenes, with penicillin V, prevent?
Rheumatic fever
69
What is epiglottitis most commonly caused by?
H.influenzae
70
What may croup be caused by?
1. Parainfluenza virus
2. Influenza virus
3. RSV
71
What is the classic train of croup in a child?
1. Barking cough
2. Stridor
3. Hoarseness
72
What stain is used for TB?
Ziehl-Neelsen acid-fast stain
73
What type of bacterium is mycoplasma tuberculosis?
Aerobic, rod-shaped acid-fast bacterium
74
How does Miliary TB become disseminated?
Haematogenous spread
75
Where is secondary TB most likely to be found in the lungs?
Apices
76
What characterises primary TB?
Ghon complex development, developing into a granuloma, developing into Ranke complex
77
What is a Ghon complex?
= a peripheral parenchymal lesion called a Ghon focus and granulomas in involved hillier lymph nodes
78
What is the type of hypersensitivity reaction of the Mantoux test?
Type IV hypersensitivity reaction
79
What is the treatment for TB? (RIPE)
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
All taken for the first 2 months, rifampicin and isoniazid continued for a further 4 months
80
What are the 4 R's of rifampicin?
```
R = ramps up cP450 metabolism
R = red or orange urine
R = resistance when used alone
R = RNA polymerase inhibition is it's mechanism of action
```
81
How may pneumonia be classified?
Community-acquired vs. hospital acquired
| Typical vs. atypical
82
What does typical pneumonia tend to cause?
Lobar pneumonia and broncho-pneumonia
83
What does atypical pneumonia tend to cause?
Interstitial pneumonia
84
Which organisms are neonates particularly susceptible to?
Group B strep; E.coli; viral pneumonia
85
Which organisms are the elderly particularly susceptible to?
Gram-negative bacilli
86
What is typical pneumonia usually caused by?
S.pneumonia; S.aureus; Haemophilus; Klebsiella
87
What is atypical pneumonia usually caused by?
Mycoplasma; Coxiella; Legionella; Chlamydophila
88
What are the complications of pneumonia?
1. Abscess
| 2. Empyema
89
How does lobar pneumonia appear on CT?
Tends to spread through an entire lobe. Classically caused by streptococcus pneumoniae
90
How does broncho-pneumonia appear on CT?
Patchy, involving more than one lobe. Can be caused by a wide variety of organisms
91
How does interstitial pneumonia appear on CT?
Diffuse + patchy. Sometimes very subtle
92
Whom is most susceptible to viral pneumonia?
Children
93
What viral organisms may be responsible for viral pneumonia?
Influenza virus
Adenovirus
Rhinovirus
RSV
94
How do you treat pneumonia caused by influenzae A?
Amantadine + rimantadine
95
How do we treat pneumonia caused by strep pneumoniae?
Penicillins
Cephalosporins
Macrolides
Some quinolones
96
What is the complication associated with strep pneumoniae?
Empyema
97
How would a pneumonia caused by strep pneumoniae present?
Rust-coloured sputum, lobar pneumonia
98
What type of bacteria is strep pneumoniae?
Gram +ve diplococci
99
What are the common gram-positive bacteria?
Strep pneumoniae
| Staph aureus
100
What are the common gram-negative bacteria?
```
H influenzae
Klebsiella
Pseudomonas aeruginosa
Legionella
Moraxella
```
101
What type of bacteria is staph aureus?
Gram +ve cocci in clusters
102
What type of pneumonia does staph aureus cause?
Bronchopneumonia
103
What are the potential complications of pneumonia caused by staph aureus?
Abscess formation/empyema. Bacterial endocarditis + abscesses of the brain etc. are possible from haematogenous spread
104
How may pneumonia caused by staph aureus treated?
Oxacillin, nafcillin, vancomycin (for MRSA)
105
How may pneumonia caused by H influenzae by treated?
2nd or 3rd generation cephalosporins
106
What are the potential complications of pneumonia caused by H influenzae?
Meningitis, epiglottitis in infants/children
107
What type of bacteria is H influenzae?
Gram -ve coccobacillus
108
What type of pneumonia is caused by H influenzae?
Bronchopneumonia
109
What type of bacteria is Klebsiella?
Gram -ev rod
110
In whom does Klebsiella pneumonia tend to occur?
Diabetic and alcoholic patients. Has high mortality in the elderly
111
How does a pneumonia caused by Klebsiella present?
Red-current jelly sputum bronchopneumonia
112
What are the potential complications of a Klebsiella pneumonia?
Necrosis and abscess formation
113
How may a pneumonia caused by Klebsiella be treated?
Aminoglycosides or 3rd generation cephalosporins
114
What type of bacteria is pseudomonas aeruginosa?
Gram -ve rod
115
In whom is a pseudomonas aeruginosa pneumonia most likely?
Immunocompromised patients or CF patients
116
How do you treat a pseudomonas aeruginosa pneumonia?
Combination therapy of ticarcillin, piperacillin, ciprofloxacin, cefepime or gentamicin
117
What are the complications of a pseudomonas aeruginosa pneumonia?
Focal haemorrhage and necorosis
118
What type of bacteria is legionella?
Gram -ve coccobacillus
119
What culture is used for legionella?
Charcoal yeast agar plus iron and cysteine for culture. It stains poorly
120
How is a pneumonia caused by legionella treated?
Macrolides, quinolones
121
How is legionella spread?
Inhalation of aerosol from contaminated water
122
What type of bacteria is moraxella?
Gram -ve diplococci
123
What type of pneumonia does moraxella cause?
Bronchopneumonia
124
How may a pneumonia be caused by moraxella be treated?
2nd or 3rd generation cephalosporins, macrolides, quinolones
125
What colour is pseudomonas aeruginosa upon culturing?
Blue-green
126
When is a anaerobe most likely to cause a pneumonia?
Upon aspiration
127
How may a pneumonia caused by an anaerobe be treated?
Penicillin, clindamycin
128
What is a frequent cause of interstitial pneumonia in young adults?
Mycoplasma pneumoniae
129
How is pneumonia caused by mycoplasma pneumoniae treated?
Macrolides, quinolones, tetracyclines
130
What are the intracellulars that can cause pneumonia?
Mycoplasma pneumoniae
Chlamydophila pneumoniae
C psittaci
Coxiella burnetii
131
What is most likely to be responsible fro a pneumonia in a individual who works with cattle or sheep (or those that drink unpasteurised milk from infected animals)?
Coxiella burnetii
132
Aside from pneumonia, what else can coxiella brunette cause?
Hepatitis or myocarditis
133
How may a coxiella burnetii pneumonia be treated?
Doxycycline
134
What causes coccidiodomycosis?
Coccidioides immitis
135
What is coccidiodomycosis?
Can cause granulomas, in which fungal spherules containing endosporins can be found.
Found in Southwestern USA, Mexico and S. America
136
How is coccidiodomycosis treated?
Amphotericin B
137
What causes candidiasis infection of the lungs?
Candida albicans (yeast)
138
What is candidiasis infection of the lungs?
An uncommon cause of pneumonia but may be seen in immunocompromised patients
139
How is candidiasis infection of the lungs treated?
Amphotericin B + fluconazole
140
What causes cryptococcosis infection of the lungs?
Cryptococcus neoformans (yeast)
141
What is cryptococcosis infection of the lungs?
Associated with pigeon droppings.
May also cause cryptococcal meningitis, seen with India ink stain, but definitively diagnosed with latex agglutination test
142
How is cryptococcosis infection of the lungs treated?
Cryptococcal meningitis = amphotericin B + flucytosine
| Non-CNS involvement = fluconazole
143
What causes aspergillosis?
Aspergillus (mold)
144
How is aspergillosis treated?
Amphotericin B or itraconazole
145
What causes blastomycosis?
Blastomyces dermatitidis
146
What is blastomycosis?
Lung infection, but there may also be skin lesions, bone lesion and GU involvement.
It is inhaled from soil.
Found in the midwestern and south-eastern USA.
147
How is blastomycosis treated?
Amphotericin B or itraconazole
148
What causes histoplasmosis?
Histoplasma capsulatum
149
What is histoplasmosis?
Caseating granulomas from, in its disseminated form this can involve multi-system involvement.
Found in the river valleys of central USA + in soil contaminated with bird or bat droppings.
150
How is histoplasmosis treated?
Amphotericin B +/- itraconazole
151
What is coccidiodomycosis?
Can cause granulomas, in which fungal spherules containing endosporins can be found.
Found in Southwestern USA, Mexico and S. America.
