Respiratory

Question 1

Comment on this CXR

Answer 1

Consolidation in the right middle lobe consistent with pneumonia

Question 2

Comment on this CXR

Answer 2

Right lower lobe collapse

Question 3

Comment on this CXR

Answer 3

A well defined thick walled cavitatory lesion is noted in the right para-hilar area in the midzone of right lung

aka Pulmonary TB

Question 4

Define COPD

Answer 4

‘a chronic disease characterised by progressive airflow limitation that is not fully reversible and characterised by chronic bronchitis and emphysema’

Question 5

Define Obstructive Sleep Apnoea Syndrome

Answer 5

Recurrent episodes of partial or complete upper airway (pharyngeal) obstruction during sleep, intermittent hypoxia and sleep fragmentation manifesting as excessive daytime sleepiness

Question 6

Describe an approach to the analysis of blood gases in clinical practice

Answer 6

Always look at pO2 first to assess if the patient is in respiratory failure or requires additional oxygen

Next look at the pCO2 to determine Type 1 vs Type 2 Resp. Failure

Then look at the acid-base balance to determine if:

Acute Resp. Acidosis (Elevated pCO2, Normal Bicarb, Acidosis)

Comp. Resp. Acidosis (Elevated pCO2, Elevated Bicarb, Not Acidotic)

Acute on Chronic Resp. Acidosis (Elevated pCO2, Elevated Bicarb. Acidosis)

Question 7

Describe clinical features of pulmonary embolism

Answer 7

Tachypnoea

Crackles

Tachycardia

Fever

Signs of Peripheral DVT

Pleuritic Chest Pain

Dyspnoea

Cough

Haemoptysis

Syncope

Question 8

Describe investigations for pulmonary embolism

Answer 8

Modified Geneve Score (Risk Assessment)

D-Dimer (Raised, >230mg/L)

ABGs (Resp. Alkalosis with Reduced PaCO2)

Troponin

ECG

Echocardiogram

Radiology (CXR, CT-Pulmonary Angiogram, V/Q Scan)

Question 9

Describe pathological features in the lung which lead to pneumothorax

Answer 9

Sub-Pleural Blebs (blister-like air pockets) at the apex of the lung

Diffuse, microscopic emphysema below the surface of the visceral pleura

Spontaneous rupture can lead to a tear in the visceral pleura

Question 10

Describe the clinical diagnosis of Pulmonary Fibrosis

Answer 10

Clinical manifestation of UIP

Fibrotic lung disease, usually with no definitive cause

Progressive Breathlessness, Bibasilar Crackling, Hacking Dry Cough, Fatigue, Weakness, Finger Clubbing, Appetite and Weight Loss

Question 11

Describe the clinical presentation of Sarcoidosis

Answer 11

May present with pulmonary, neurological, cardiac, dermatological or ocular findings

Systemic symptoms: Fever, Anorexia, Fatigue, Night Sweats, Weight Loss

Pulmonary symptoms: Cough, Haemoptysis, Dyspnoea on Exertion, Chest Pain

May be asymptomatic

Question 12

Describe the clinical application of the Alveolar Air Equation

Answer 12

Arterial pO2 can be directly measured by ABG analysis, whereas Alveolar pO2 must be calculated

The difference between Alveolar pO2 and Arterial pO2 is known as the Alveolar-Arterial Oxygen Gradient

Normally, this should be less than 2-4kPa

Higher than this suggests a V/Q mismatch

Question 13

Describe the distant spread of lung cancer

Answer 13

Haematogenous - Liver, Bone, Brain, Adrenal

Lymphatic - Cervical Lymph Nodes

Question 14

Describe the effects of cigarette smoke on the airways and how this leads to pathology

Answer 14

Mucus Gland and Goblet Cell Hypertrophy –> Increased Mucus Production –> Cough and Sputum

Reduced Cilial Motility –> Decreased Mucus Clearance –> Increased Infection Risk

Anti-Protease Inhibition –> Increased Protease Activity –> Inflammation

Question 15

Describe the features of Usual Interstitial Pneumonia

Answer 15

Heterogenous appearance with areas of normal lung punctuated by marked fibrosis and honeycombing (mainly in subpleural areas) and fibroblastic foci (dense proliferations of fibroblasts and myofibroblasts)

Question 16

Describe the immediate management of pulmonary embolism

Answer 16

Massive:

(PE associated with SBP <90mmHg or a drop in SBP of >40mmHg in <15 Minutes)

Give Unfractionated Heparin IV

Fluid Resuscitation

Thrombolysis with Alteplase if Fails to Improve

Sub-Massive:

Initially LMWH

Then Oral Anti-Coagulant for 3 Months (Factor Xa Inhibitors or Warfarin)

Question 17

Describe the investigations used in the diagnosis of Obstructive Sleep Apnoea Syndrome

Answer 17

History (from Pt and Family)

Clinical Exam

Daytime Sleepiness Assessment (Epworth Score)

Limited Polysomnography (Home, 5 Channel; O2 Sats, HR, Flow, Thoracic and Abdominal Effort and Position)

Full Polysomnography (In-Hospital, Multi-Channel; EEG, Video, Audio, Thoracic/Abdominal Bands, Position, Flow, O2 Sats, Limb Leads, Snore)

Transcutaneous Oxygen Saturation and Carbon Dioxide Assessment

Question 18

Describe the mechanism of action of anti-fungal drugs

Answer 18

• Azoles
  
  • e.g. Miconazole, Imidazole, Triazole, Thiazole
  • Inhibitors of 14-methylsterol alpha-demethylase which produces ergosterol
  • Ergosterol is an essential component of the fungal plasma membrane
  • Does not occur in animal or plants cells
• Amphotericin B
  
  • Also exploits the ergosterol/cholesterol difference
  • It is not an enzyme inhibitor
  • Binds to ergosterol to form a pore in fungal membranes, leading to cell death

Question 19

Describe the methods of management of Obstructive Sleep Apnoea Syndrome

Answer 19

Weight Loss

Avoidance of Triggers (e.g. Alcohol)

Treatment of Underlying Factors

Continuous Positive Airway Pressure (Splints airway open to stop snoring and sleep fragmentation to reduce daytime sleepiness and improve quality of life)

Mandibular Advancement Device

Sleep Position Training

Question 20

State the pathological classification of Lung Cancer

Answer 20

Small Cell

Non-Small Cell (Large Cell, Adenocarcinoma or Squamous Cell)

Question 21

Describe the pathological consequences of local spread of lung cancer

Answer 21

Bronchial Obstruction

Lung Collapse or Consolidation (Retention Pneumonia)

Pleura - Haemorrhagic Effusion

Blood Vessels - Haemoptysis

Pericardium - Pericardial Effusion

Mediastinum - SVC Obstruction

Pancoast Tumour - Horner’s Syndrome, Brachial Plexus Compression

Question 22

Describe the pathology and presentation of Extrinsic Allergic Alveolitis

Answer 22

T-Cell mediated (immunological) inflammatory reaction in the alveoli and respiratory bronchioles

(N.B. EAA is NOT atopy)

May present with flu-like illness, cough, fever, chills, myalgia, malaise, dyspnoea

Question 23

Describe the pathology of Adenocarcinoma Non-Small Cell Lung Cancer

Answer 23

Common tumour in females

Also seen in non-smokers

Two-thirds arise in the periphery

Appearance: Glandular, Solid, Papillary or Lepidic with Mucin Production

Question 24

Describe the pathology of COPD

Answer 24

Increased number of mucus-secreting cells

CD8 lymphocyte driven inflammation of the airways, leading to scarring and thickening

Neutrophil infiltration

Loss of defined alveolar air spaces leading to loss of elasticity and air trapping

Causes airway collapse, and blockage of airways

Question 25

Describe the pathology of Large Cell (Non-Small Cell) Lung Cancer

Answer 25

Usually arises centrally Undifferentiated malignant epithelial tumour that lacks the cytological features of SCLC and glandular or squamous differentiation

Question 26

Describe the pathology of Small Cell Lung Cancers

Answer 26

Most aggressive form, often metastasising early and widely Often a good initial response to chemotherapy, but most patients relapse Appearance: Oval to Spindle Shaped Cells, Inconspicuous Nucleoli, Scant Cytoplasm, Nuclear Moulding

Question 27

Describe the pathology of Squamous Non-Small Cell Lung Cancer

Answer 27

Tends to arise centrally from major bronchi Slow growing and late to metastasise Often within dysplastic epithelium following squamous metaplasia Appearance: Malignant Epithelial Tumour showing Keratinisation and/or Intracellular Bridges

Question 28

Describe the serum biochemical adaptations to acute and chronic respiratory failure

Answer 28

In acute resp. failure, there is insufficient time for full renal compensation so the pH is low with a high/normal bicarbonate In chronic resp. failure the kidneys are able to compensate with a raised bicarbonate and normal pH

Question 29

Describe the spirometric pattern that would be expected in obstructive versus restrictive respiratory disease

Answer 29

Obstructive (e.g. COPD/Asthma) - Reduced FEV1:FVC (\<70%), Reversibility (\>15% AND 400ml in Post-BD FEV1) in Asthma but NOT in COPD Restrictive - Preserved FEV1:FVC (\>70%) with Reduced % Predicted FVC

Question 30

Describe the typical features of a 'Blue Bloater'

Answer 30

Usually in chronic bronchitis Due to CO2 retention (becomes insensitive to it) Low Resp. Drive and Type 2 Resp. Failure (Low PaO2 and High PaCO2) Cyanosis, Obesity, Crackles and Wheeze, Peripheral Oedema Chronic Productive Cough, Purulent Sputum

Question 31

Describe the typical features of a 'Pink Puffer'

Answer 31

Due to Emphysema CO2 responsive with compensatory hyperventilation Desaturates on Exercise, Pursed Lip Breathing, Use of Accessory Muscles, Wheeze, Indrawing of Intercostals, Tachypnoea, Cachectic Appearance High Resp. Drive, Type 2 Resp. Failure Low PaO2 and PaCO2

Question 32

Describe the pathological processes in Sarcoidosis

Answer 32

Chronic granulomatous disorder characterised by accumulation of lymphocytes and macrophages in organs (typically the lungs and intrathoracic lymph nodes) Non-necrotising granulomas with multi-nucleated giant cells in the centre

Question 33

Outline the diagnostic features of spontaneous pneumothorax

Answer 33

Pleuritic Chest Pain Dyspnoea Respiratory Distress Reduced Air Entry on Affected Side Hyper-Resonance to Percussion Reduced Vocal Resonance Tracheal Deviation (If Tension)

Question 34

Outline the initial management of spontaneous pneumothorax

Answer 34

Observation if small or not very symptomatic Aspiration (urgently if tension) with syringe in 2nd intercostal space, midclavicular line Intercostal drain with underwater seal

Question 35

State cancers which most commonly metastasise to the lungs

Answer 35

Bowel, Breast, Prostate, Bladder, Kidney

Question 36

State indications for the use of non-invasive ventilation in COPD

Answer 36

Acute Exacerbations of COPD with Persistent Hypercapnic Respiratory Failure (should be considered in the presence of respiratory acidosis with pH \<7.35 or if acidosis persists despite maximal medical management)

Question 37

State pathological and clinical features that predispose to pulmonary embolism

Answer 37

Surgery \<12 Weeks Previously Immobilisation \>3 Days in Previous 4 Weeks Previous DVT/PTE FHx of PTE/DVT Lower Limb Fracture Pregnancy or Post-Partum Long Distance Travel Oestrogen-Containing OCP Use Antithrombin Deficiency Protein S or C Deficiency Factor V Leiden

Question 38

State potential drug interactions and pitfalls when using theophylline

Answer 38

Side effects include GI upset, palpitations, tachycardia/arrhythmias, headache, insomnia and hypokalaemia Caution in liver disease and with concomitant use of enzyme inducers (rifampicin) and inhibitors (clarithromycin, ciprofloxacin) Smoking increases theophylline clearance – dose may need to be adjusted following smoking cessation

Question 39

State risk factors which predispose to development of Obstructive Sleep Apnoea Syndrome

Answer 39

Obesity Male Sex Post-Menopause (Women) Large Neck Circumference (\>40cm) Maxillomandibular Anomalies (Narrowing, Retrognathia) Increased Tonsil/Adenoid/Tongue Size FHx

Question 40

State some clinically differentiating features of Asthma and COPD

Answer 40

Episodic SOB in Asthma Nocturnal Symptoms and Diurnal Variation in Asthma Productive Cough in COPD Asthma is Not Progressive, Has Exacerbations and Variable Symptoms COPD is Progressive, Has Exacerbations and Persistent Symptoms

Question 41

State the Alveolar Air Equation

Answer 41

PaO₂ = FiO₂ - (1.25 x PaCO₂) PaO₂ - Alveolar Oxygen Partial Pressure, kPa FiO₂ - Inspired Oxygen Concentration, kPa

Question 42

Using the Alveolar Air Equation comment on the following patient: Man with COPD, on 28% Oxygen pO2 - 7.6 pCO2 - 6.6

Answer 42

Alveolar pO2 = 28 - (1.25 x 6.6) = 19.75 Therefore, A-a = 19.75 - 7.6 = 12.15 Alveolar-Arterial Gradient is increased, suggesting V/Q mismatch