Resp conditions

Question 1

Give examples of 2 organisms that cause TB

Answer 1

Mycobacterium tuberculosis
Mycobacterium bovis (unpasteurised milk)
+ africanum, microti

Question 2

What makes TB a successful pathogen?

Answer 2

Thick waxy capsule cell wall is able to resist weak disinfectants and survive on dry surfaces for a long time.
Resistant to phagolysosomal killing by macrophages (- granuloma formation).
Able to remain dormant.

Question 3

Describe the pathogenesis of primary tuberculosis

Answer 3

Inhaled into the lung and ingested by alveolar macrophages.
TB resists phagolysosomal killing and proliferates, releasting cytokines resulting in inflammatory involvement of hilar lymph node.
3 weeks later
Granuloma formation around TB (primary ghon focus) and associated lymph node, known together as the Ghon complex.
Caseous necrosis of complex occurs, and it undergoes fibrosis and calcification (Ranke complex)- visible on CXR.
TB is able to remain dormant within the Ranke Complex for many years = latent TB.
Cell-mediated immunity memory to TB is developed.
Reactivation occurs when the individual is immunocompromised.

Question 4

Where in the lung is the primary Ghon complex usually found and why?

Answer 4

In the apex, as this is less well perfused so the TB comes into contact with fewer immune cells

Question 5

Describe what may happen if an individual with a latent TB infection is immunocompromised?

How may the TB spread?

Answer 5

Reactivation occurs.
Memory T cells release cytokines and TB is able to spread to upper lobes (more O2) ans the immune cells contribute to more areas of caseous necrosis.
These areas cavitate, spreading to the rest of the lung (pulmonary TB) or to the vasculature –> systemic miliary TB.

Question 6

Describe some features of systemic miliary TB - where is the infection likely to spread, with what effect?

Answer 6

Kidneys - sterile pyuria
Adrenals - addisons
Meninges - meningitis
Lumbar vertebrae - Pott's disease
Liver - hepatitis
Cervical lymph nodes - scrofula

Question 7

How could you diagnose CNS TB?

Answer 7

CSF would contain bacilli on lumbar puncture

Question 8

What symptoms might be associated with extrapulmonary TB of the following systems?
GI/abdominal
GU
Bone/spine
CNS

Answer 8

GI/abdominal: ascites, ileal malabsorption
GU: epididymitis, frequency, dysuria, haematuria
Bone and spine: pain and swelling of joints, Pott’s
CNS: cranial nerve palsy, raised ICP due to meningeal inflammation, meningitis
Lymph node: swelling +/- discharge

Question 9

How would you diagnose active TB?

Answer 9

CXR: patchy shadows/fibrosis, consolidation. Miliary - normal/miliary shadows.
Sputum/bronchoalveolar lavage: culture
Lumbar puncture for miliary/CNS

Question 10

How is TB cultured and why?

Answer 10

It is acid fast due to waxy cell wall and gram stains weakly, so Ziehl-Nielson is used and appears red if TB.

Question 11

How would you diagnose latent TB?

Answer 11

Mantoux:
Tuberculin injected, stimulates type 4 sensitivity reaction.
Interferon gamma release assays (IGRA) demonstrate exposure but not active infection.

Question 12

What steps would you take immediately following histology + clinical picture consistent with TB?

Answer 12

Notify public health england.
Start treatment without waiting for culture results.
Begin contact tracing.
Isolate until non-infectious.

Question 13

What is the treatment course for TB (apart from CNS)

Answer 13

Rifampicin for 6mo
Isoniazid for 6 mo
Pyrazinamide for first 2 mo
Ethambutol for first 2mo
DOTS: direct observed therapy - medication is taken under supervision.
Individuals must be isolated until no longer infectious, and it is crucial they take the whole course of medication.

Question 14

Symptoms of pulmonary TB

Answer 14

Cough
Haemoptysis
Chest pain
Breathlessness
systemic features

Question 15

Define pneumonia

Answer 15

lower respiratory tract infection - inflammation of lung parenchyma

Question 16

Who is at risk of pneumonia?

Answer 16

Extremes of age
Immunocompromised
Individuals with COPD, CHD, diabetes
Impaired swallow
IVDU, alcohol abuse

Question 17

Describe briefly the pathogenesis of pneumonia

Answer 17

Macrophages cannot phagocytose microbe
Release cytokines to recruit neutrophils, filling the alveolar space with dead bacteria + dead neutrophils + tissue fluid + inflammatory proteins = inflammatory exudate or ‘pus’.
This may lead to long term damage to lung parenchyma

Question 18

symptoms of pneumonia

Answer 18

CHEST: Cough, potential rusty sputum (characteristic of s. pneumoniae), SOB, pleuritic chest pain
INFECTION: fever, sweats, rigors
SYSTEMIC: weakness, malaise

Question 19

describe the features of pleuritic chest pain

Answer 19

Localised, sharp pain that worsens on ddeep breathing and when moving

Question 20

Describe tests used to diagnose pneumonia

Answer 20

FBC shows raised WBC,
biochem U+E/LFTs show dehydration
Raised ESR and CRP indicate inflammation
Sample for culture -> microbio for targetted treatment, however management must start before results return.

Question 21

Describe signs of pneumonia

Answer 21

Vitals: increased HR, resp rate, decreased BP, fever, dehydration, decreased sats
chest exam: signs of consolidation = dull to percussion, inc. vocal resonance, dec. air entry, crackles/wheeze

Question 22

What scale is used to assess severity of pneumonia and therefore treatment course in CAP?

Answer 22

CURB>65
Confusion
Urea
Resp rate
Blood pressure
>65
0-1 = outpatient, amoxicillin
2 = admit, oral amoxicillin + clarithromycin
3-5 = IV coamoxiclav + clarithromycin

Question 23

Principles of treatment with antibiotics for CAP vs HAP?

Answer 23

CAP: narrowest spectrum possible
HAP: start broad spectrum, more likely pt has come into contact with resistant microbes

Question 24

what is parapneumonic effusion and how is it treated?

Answer 24

Parapneumonic effusion is any pleural effusion secondary to pneumonia (bacterial or viral) or lung abscess. Pockets of fluid are in the thoracic cavity. If these are filled with pus, it is known as empyema. Treated by drainage.

Question 25

What is a common cause of lung abcess?

Answer 25

Metastatic - IVDU Aspiration Poor dentition Secondary to LRTI

Question 26

What is aspiration pneumonia?

Answer 26

Inhalation of food/drink/gastric contents causes lung infection. Often in individuals with compromised gag/cough reflex eg due to alcohol, brain injury or dysphagia.

Question 27

what is meant by COPD? | How are conditions characterised?

Answer 27

Group of lung conditions including emphysema and chronic bronchitis characterised by obstruction, progressive nature, not fully reversible, enhanced chronic inflammatory response, and association with smoking.

Question 28

What is emphysema vs chronic bronchitis?

Answer 28

Both COPD. Often coexist. Emphysema defined by structural changes, chronic bronchitis is a clinical diagnosis based on productive cough.

Question 29

Risk factors for COPD?

Answer 29

``` Male Smoker + genetics Infections Occupational Low SE status air pollution congenital small lung size ```

Question 30

Presentation of emphysema vs chronic bronchitis

Answer 30

Emphysema 'pink puffer' Individual exhales slowly through pursed lips to increase alveolar pressure to prevent collapse. Weight loss, pink (not yet hypoxaemic), dyspnoea, SOB, cough. Develops barrel shaped chest after a while, lungs have poor expansion. Chronic bronchitis 'blue bloater' Highly productive cough Overweight Hypoxaemic due to hypercapnia resulting from impaired gas exchange. Productive cough for 3months/year for at least 2yrs. Wheeze, crackles.

Question 31

What is a possible effect of emphysema on the heart?

Answer 31

Respiratory failure Cor pulmonale Poor gas exchange throughout lungs leads to widespread hypoxic vasoconstriction and pulmonary hypertension. R side of heart has to pump harder to overcome pressure, becomes enlarged = heart failure.

Question 32

What type of resp failure is seen in individuals with COPD?

Answer 32

type 2 respiratory failure, hypoxemia (PaO2 <8kPa) with hypercapnia (PaCO2 >7.0kPa).

Question 33

What is the most likely diagnosis in a chronic smoker who has a history of breathlessness and sputum production? What about in a non-smoker?

Answer 33

COPD | Asthma in non-smoker, unless family history of alpha 1 antitrypsin deficiency

Question 34

Treatment of COPD?

Answer 34

Smoking cessation slows deterioration. Bronchodilators: SABA salbutamol to reduce acute symptoms, LAMA tiotropin bromide for prevention. Trial inhaled prednisolone, but risk pneumonia/withdrawal. O2 therapy Pulmonary rehab, exercise, good diet alpha 1 antitrypsin replacement if applicable. Antibiotics for infections.

Question 35

``` Mycobacterium tuberculosis cause pathogenesis symptoms diagnosis treatment ```

Answer 35

Caused by mycobacterium tuberculosis. Latent infection in 90-95%, becomes active if an individual is immunocompromised. Enters alveolar macrophage, proliferates at lung apex. Granuloma forms around TB and associated lymph node with caseous necrosis at centre = ghon complex. Undergoes fibrosis and calcification (visible on CXR). TB may be killed or remain latent, reactivated when immunocompromised - T memory cells produce cytokines - and cavitates, spreading to rest of lung (pulmonary TB) &/or to vasculature (systemic miliary/extrapulmonary TB). Symptoms - general: chronic illness + fever + weight loss pulmonary : cough, chest pain, SOB, haemaptosis extra: GI: abdo ascites, ileal malabsorption hepatitis lymphadenopathy CNS: meningitis, CN palsy, tuberculoma, Pott's disease Joint pain Diagnosis - biopsy and culture is definitive: sputum. CXR,. Mantoux test for latent TB - however reacts to BCG vaccine. IGRA more specific. Treat: Latent: 6mo isoniazid. Only treat if likely to be immunocompromised (eg steroids, chemo) Active: 6mo rifampicin + isoniazid, 3mo pyrazinamide + ethambutol. Isolate, contact trace, inform PHE.

Question 36

``` COPD emphysema cause symptoms diagnosis ```

Answer 36

Immune reaction to irritant (cigarette smoke) = protease recruitment, break down collagen and elastin of alveolar walls. Neighbouring alveoli coallesce = reduced surface area, more compliant so collapse under low pressure holding onto trapped air (obstruction) smoker, male, occupation, pollution, infections, alpha 1 anti-trypsin deficiency (protease inhibitor). Symptoms: SOB, dyspnoea, weight loss, cough with some sputum Diagnosis: 'pink puffer'. Over time CXR may show barrel chest. FEV1:FVC <0.7 shows obstructive lung disease.Host breathless + smoker. Treat: smoking cessation SABA: salbutamol LAMA: tiotropium bromide ICS: prednisolone TRIAL but can exacerbate O2 therapy pul rehab, good diet, exercise

Question 37

``` chronic bronchitis pathophysiology symptoms diagnose treatment ```

Answer 37

Reaction to irritant = hypertrophy and hyperplasia of mucous glands and goblet cells. Cilia damaged, mucous build up traps air and leaves individual prone to lung infections. Productive cough, breathless, dyspnoea. Clinical diagnosis: Highly productive cough for 3mo a year, over 2 years. Wheeze, crackles, overweight. Can lead to cor pulmonale due to poor gas exchange = hypoxic vasoconstriction -> pulmonary hypertension. Treat Smoking cessation, SABA: salbutamol LAMA: tiotropium bromide ICS: prednisolone TRIAL but can exacerbate O2 therapy pul rehab, good diet, exercise

Question 38

Bronchiectasis

Answer 38

Chronic inflamation of aiways leads to scarring, airways WIDEN permanently. This causes a build up of mucus and vulnerability to infection. Cause: Infection - pneumonia, TB, measles, pertussis, whooping cough Cystic fibrosis Allergic Bronchopulmonary Aspergillosis Bronchial obstruction - foreign body, tumour Symptoms: productive cough, dyspnoea, wheeze, infections, chest pain, exacerbations Diagnose: CXR shows dilated bronchi, cysts Sputum culture for infetions - often heamophilus influenzae, strep pneumoniae, s aureus, p aeruginosa. Spirometry shows obstructive pattern, FEV1:FVC <0.7. Treat: mucous clearance - physio, mucolytics, postural drainage antobiotics - amoxicillin, flucloxacillin for s aureus azithromycin anti-inflam Nebulisers and bronchodilators for bad flare ups. Stop smoking, vaccines, exercise, diet.

Question 39

Pulmonary embolism | Risk

Answer 39

Oral contraceptive pill, DVT: immobility, flights, hospital stay/surgery, alcohol, smoking. Symptoms: Sharp pleuritic chest pain, SOB, pain, redness and swelling in one leg (DVT). Diagnosis: plasma D dimer blood test Pulmonary CT angiography shows lung perfusion. Treat: Depends on severity - OAC warfarin/inject heparin. Thrombolysis - IV alteplase if severe Anticoagulants 3mo, clopidogrel.

Question 40

Lung cancer Most common type Risk Diagnosis

Answer 40

90% are carcinoma, arising from epithelial cells in the respiratory tract. Most are metastatic. Non-small cell = most lung cancers smoking, genetics, radon, asbestos, air pollution, XR/CT. Diagnose CXR/CT Symptoms usually asymptomatic until late stage.General malaise and weight loss. Cough, chest infections, SOB, extrapulmonary changes. Treat not very responsive to chemo. Surgery and radiotheraphy mainstay. Pain management.