A 65 year old woman with chronic airways disease presents with acute respiratory failure.

Outline how you would determine the severity of her underlying airways disease.

[Click here to toggle visibility of the answers]

College Answer

History: consider – exercise tolerance; ADLs; home O2 use; home CPAP/NIV use; respiratory medication use and compliance; steroid use; need for heart failure medication; frequency of hospitalisations or previous mechanical ventilation.

Examination: consider – steroid skin; cachexia / nutritional assessment; plethora secondary to polycythaemia.

Investigations:  consider – previous ABGs (degree of hypoxaemia/hypercapnoea/metabolic compensation); Electrolytes: especially tCO2 indicative of bicarbonate compensation of chronic hypercapnoea; previous spirometry (FEV1/FVC - degree of emphysema/hyperexpansion/evidence of left or right heart failure); formal Pulmonary Function Tests (DLCO/flow-vol loops); ECG (?chronic right heart strain pattern); Hb (polycythaemia secondary to chronic hypoxaemia).

Discussion

This question asks about the assessment of the severity of COPD.

Historical features

  • exercise tolerance
  • breathlessness with everyday activities
  • presence of chronic cough
  • high volume of sputum, suggestive of bronchiectasis
  • haemoptysis, suggestive of malignancy
  • home O2 requirement
  • home CPAP requirement
  • pattern of bronchodilator use
  • pattern of steroid use
  • frequency of hospitalisations
  • previous mechanical ventilation
  • anorexia and weight loss

Examination

  • features of malnutrition
  • features of obesity (sedentary lifestyle)
  • features of chronic steroid use
  • central cyanosis
  • breathlessness at rest
  • hyperexpanded chest
  • degree of air entry
  • signs of right heart failure

Investigations

  • Bicarbonate levels
  • Hb (polycythaemia)
  • Spirometry, pre and post bronchodilator
  • Formal lung function tests
  • ABGs to determine degree of hypoxia and hypercapnea
  • TTE (pulmonary pressures)
  • High-resolution CT to assess the severity of emphysematous changes

References

References

Siafakas, N. M., et al. "Optimal assessment and management of chronic obstructive pulmonary disease (COPD)." European Respiratory Journal 8.8 (1995): 1398-1420.