A 33-year-old abattoir worker presented to the Emergency Department with a 2 week history of increasing shortness of breath and haemoptysis. He had previously been fit and well. 

On examination he is alert, normotensive but tachypnoeic (35 breaths per minute), centrally 
cyanosed (SaO2 85% on 10L/min O2) and tachycardic (120 beats per minute). Auscultation reveals a systolic murmur at the lower left sternal edge and coarse inspiratory crackles bibasally. The remainder of the examination was unremarkable. 

His chest radiograph demonstrates bibasal consolidation.

List the most likely differential diagnoses, and for each diagnosis, list the specific investigations needed to confirm the diagnosis and the specific treatment required.

[Click here to toggle visibility of the answers]

College Answer

Cause

Investigation

Treatment

Pneumonia
Bacterial         

  • S. pneumonia,
  • H. _nfluenza
  • K. pneumonia

Sputum MC&S
Blood Culture

3rd Generation cephalosporin
(or similar) plus
Azithromycin (or similar)

Atypical          
Viral- Influenza

Serology / PCR
Viral PCR

± Oseltamivir / Ribavarin

Other infective
Infective endocarditis
Leptospirosis

TTE/TOE, bld culture
Serology, PCR

Antibiotics  surgery
Doxycycline / cefotaxime /
benzyl penicillin

Q fever            
Anthrax          

Serology for C. burnetii
Blood culture

Doxycycline, ciprofloxacin
Doxycycline, ciprofloxacin,
benzyl penicillin

Vasculitis                    
Goodpasture’s syndrome
Wegener’s
granulomatosis

Anti-GBM Abs

cANCA

) Steroids
) Plasmapheresis
) Cyclophosphamide

Cardiovascular
Acute mitral regurgitation
Pulmonary infarction

TTE/TOE, screen for acute MI
CTPA, V/Q scan

Surgery
Anticoagulation

Discussion

This question favours the candidate with a physician background.

Really, it's a pub trivia question. "Which bugs can cause pneumonia and haemoptysis in an abbatoir worker?" Most physicians would immeadiately yell "Q Fever!" And that would be the most likely explanation. It tends to produce an atypical pneumonia and endocarditis.

Instead of delving into the specifics of Q Fever, the college model answer unfocuses broadly on thedifferentials of haemoptysis, with an infectious flavour. Table 1 in the linked article lists the usual suspects. That is the concise version.

A less concise version is presented in the answer to Question 2 from the first paper of 2012 (yes, this exact same paper)

References

References

 

Talwar, D., et al. "Massive hemoptysis in a respiratory ICU: causes, interventions and outcomes-Indian study." Critical Care 16.Suppl 1 (2012): P81.

 

Maurin, M., and D. fever Raoult. "Q fever." Clinical microbiology reviews 12.4 (1999): 518-553.

 

Bidwell, JACOB L., and Robert W. Pachner. "Hemoptysis: diagnosis and management.Am Fam Physician 72.7 (2005): 1253-1260.