A 65 year old man has been admitted to your Intensive Care Unit with a presumptive diagnosis of community  acquired pneumonia.  He is sedated, intubated and ventilated, and   is  haemodynamically  stable.     List  specific  historical  information  you  would attempt to obtain and discuss why.

[Click here to toggle visibility of the answers]

College Answer

Various specific pieces of historical information should be ought, including:
- Factors that might alter aetiology: recent or current hospitalisation, nursing home etc (more nosocomial like, including Gram negatives); areas associated with outbreaks (e.g. legionella); exposure to specific scenarios eg. Birds (psittacosis); exposure to communities with specific resistance patterns (eg. Drug resistant pneumococcus), risk for pseudomonas (structural lung disease e.g. bronchiectasis, corticosteroids, previous broad spectrum antibiotic use, undiagnosed HIV), recent travel (e.g. Burkholderia pseudomallei, SARS, bird flu).
- Information regarding specific immunosuppression may also allow better coverage of potential organisms: consider T cell dysfunction (e.g. AIDS, immunosuppressive therapy and risks of Pneumocystis and TB), neutropenia (e.g. Pseudomonas, Fungi), previous splenectomy etc.
- Risk factors for poor prognosis: include age > 65, co-morbidities (eg. Diabetes, renal failure, neoplastic disease, alcoholism, immunosuppression), and possibly rapidity of onset.
- Typical or atypical nature of symptoms is usually sought, but their specificity is poor.
- Usual historical data regarding other major illnesses/co-morbidities, drugs, allergies, etc.

Discussion

This strange question could be managed in a number of ways. Massive amounts of historic information may be relevant.

Lets try to consolidate this into a systematic answer

Patient's medical history of prognostic importance

  • smoking
  • COPD
  • heart disease, including CCF and pulmonary hypertension
  • exercise tolerance
  • immunesuppression, eg. corticosteroids
  • malignancy
  • vaccination history
  • history of exposure to TB, country of origin
  • end-stage organ failure, eg. cirrhosis or dialysis-dependent renal failure

Recent history of aetiological importance

  • swallowing difficulty, history of stroke
  • alcohol binges
  • haemoptysis
  • recent travel
  • recent gardening (Legionella)
  • recent bushwalking
  • exposure to birds or pets
  • recent chemotherapy
  • recent hospital stay
  • recent antibiotic use

Presenting history

  • rapidity of onset
  • associated symptoms eg. copious amounts of sputum, flu-like symptoms, hemoptysis, pleuritic chest pain, and so forth

References

Metlay, Joshua P., Wishwa N. Kapoor, and Michael J. Fine. "Does this patient have community-acquired pneumonia?: Diagnosing pneumonia by history and physical examination." Jama 278.17 (1997): 1440-1445.