Respi SAQ

Question 1

42/F with dry cough and progressive shortness of breath and dry cough. She presents with periungual ischemia. Arthralgia of the hands but no arthritis on PE. Peri-ungual lesion with nail bed infarct. And she also has bilateral basal fine crackles. CXR show reticulonodular shadow and ground glass opacity in lower lobe

1. Top differential diagnosis (2)
2. Give 3 non-invasive investigation that can be ordered in clinic (you are in SOPD)? and explain how they could help with the definitive diagnosis (6)
3. The respiratory physician decided that definitive diagnosis of lung sample is needed. Name the specimen needed and describe TWO ways to obtain the Tx (2)

Answer 1

1. ILD, secondary to underlying autoimmune disease
2. Autoimmune panel (ANA), lung function test, HRCT
3. Lung biopsy, EBUS transbronchial, USG (transthoracic)

Question 2

A 50-year-old man, an ex-smoker who quit smoking 1 year ago. He has worked in the gem industry polishing precious stones for over 20 years. He was admitted for sudden haemoptysis of about 10 mL of fresh blood. He has been told previously that he has some “occupational lung disease” and abnormal CXR. He also has mild type 2 diabetes mellitus.
CXR showed a 3cm cavitating lesion in right middle zone. There are also multiple 2-4mm small nodules on bilateral lung fields, mostly on upper lobes.

1. history and CXR findings, list 2 top ddx
2. Send sputum for work up for cavitating lesion. Name and explain rationale
3. 2 possible causes of small lung nodules
4. MO wanted to look at his blood glucose and RFT, explain how this may be related to lung condition

Answer 2

1. TB, CA lung, silicosis
2. c/st, cytology (malignancy), AFB smear/ZN stain, TB PCR
3. Miliary TB, silicosis
4. Poorly controlled DM (DM nephropathy), acute renal failure (acute kidney injury) –> predisposing to TB. HypoNa in ectopic ACTH and SIADH as SCLC paraneoplastic syndrome

Question 3

Mr Chu, 67yo, developed a hobby of looking at old houses after retired. Unproductive cough for 4 months. Fever 39.2, left lower lobe consolidation. On call dr made a dx of CAP. 1. 4 bacterial causes of CAP
2. Further hx revealed exposure to hot water tank recently. What is most likely causative organism?
3. 2 diagnostic tests?
4. 2 drugs of different classes of Abx for this patient

Answer 3

1. Strept pneumoniae, haemophilus infuenzae, moraxella catarrhalis, staph aureus, mycoplasma pneumoniae, klebsiella pneumoniae (elderly, DM)
2. Legionella pneumophila causing atypical pneumonia
3. Blood culture (serology for legionella), urine legionall antigen, PCR
4. Macrolides (clarithromycin), fluoroquinolones (levofloxacin)