Question 11

College comments

Syllabus topic/section: 2.1.5 Respiratory Intensive Care. Pneumonia L1

Discussion: 

Part a):

Most candidates performed well, correctly listing six factors predicting poor antibiotic response. No classification was required as the question specifically asked for six factors.

Part b):

As an assessment question, candidates were expected to provide a focused history, examination, and investigation targeting causes of non-resolving pneumonia and non-infective contributors to refractory respiratory failure.

Higher marks were awarded to structured responses that explored the underlying aetiology and complications of disease processes contributing to ongoing respiratory failure. A thorough history was expected, including:

• Atypical infections: Travel history, occupational exposures, animal contacts
• Connective tissue diseases: Rash, haemoptysis, arthralgia, renal symptoms Key investigations included:
• Repeat cultures (blood, sputum), sensitivities
• BAL and consideration of multi-resistant organisms (MROs)
• Tests for atypical pathogens: Brucellosis, Q fever, Ross River virus, QuantiFERON-TB Gold
• Comprehensive workup:
  • Autoimmune/vasculitis screen
  • High-resolution CT chest
  • Consideration of lung biopsy if diagnosis remains unclear

Well-organised, thorough answers incorporating these elements scored higher, particularly when investigations were logically aligned with differential diagnoses. Use of bullet points to present a complete investigation list was acceptable and efficient.

Interpretation

a) A list of risk factors for non-response to antibiotics, which, we are instructed, did not need to be subdivided into classifications.

But if you were suffering from a chronic obsession with classification, you could do something like:

• Patient factors:
  • Elderly patient
  • Multiple comorbidities
  • Alcoholism
  • Smoking (and COPD)
  • Malignancy
  • Immune deficiency
• Disease factors
  • Multilobar pneumonia
  • Bacteraemia
  • Empyema and lung abscess
  • Legionella pneumonia
  • Polymicrobial pneumonia

b) "Outline your assessment of this patient with respiratory failure that is refractory to standard treatment for CAP" is a rare case of a stem repeating itself, where the college examiners again made an emphasis on the fact that the patient is in respiratory failure, is not improving, and that appropriate treatment has been ongoing.

History, because you have been looking after this patient for seven days and only now  realise that this is not your standard CAP, you will look sheepish if you approach the family after ignoring them for some days, and start asking about:

• Travel, occupation, pets, hobbies 
• Immune suppression history
• Vaccinations
• Chronic features preceding the ICU admission that might give clues to malignancy, or an organising pneumonia (eg. a history of a flu-like illness with cough which "he never quite got over")

Examination aims to exclude barndoor-obvious reasons for the apparent failure of the antibiotics to work, such as the presence of heart failire and cancer. It's not that the antibiotics are not working, it's that they were pointless to begin with.

• Lymphadenopathy
• Features of heart failure (murmurs, oedema, JVP, etc)
• Features of connective tissue disease, eg. haematuria, vasculitic rash, joint effusions and deformities, skin changes, etc.

Investigations

• Culture again! You have selected some sort of Horrendomonas with your empirical therapy, and it will require a different antibiotic cocktail.
• TTE: the contribution of cardiogenic pulmonary oedema to the respiratory failure needs to be considered.
• CT chest; particularly high-resolution CT: it will reveal the fll extent of the pneumonia, and it will unveil new cavitating lesions, loculated collections and bronchial masses.
• Sputum eosinophils: eosinophilic pneumonitis may be to blame.
• Acid-fast bacilli: it would be embarrassing to miss tuberculosis
• Aspergillus investigations as well as the other fungi
• CMV, VZV, HSV - PCR on sputum (though inlikely in an immunocompetent host)
• Autoimmune screen; perhaps this "pneumonia" is in fact a pulmonary manifestation of a systemic autoimmune disease, eg. SLE, RA, Sjögren's syndrome, mixed connective tissue disease, Wegener's granulomatosis, Churg-Strauss syndrome, Goodpasture's syndrome,  ankylosing spondylitis, and so on and so forth.
• Bronchoscopy: it will reveal any bronchial obstruction, and it may allow the lavage of a lobe, thereby collecting valuable specimens.
• Lung biopsy: Even though this is invasive, it may be indicated in situations where the diagnosis is uncertain and the potential treatments are aggressive and mutually incompatible (eg. high dose steroids vs. high dose antibiotics)