COPD

hey look. it's another monster.

Headline
Etiology smoking, burning of biomass, genetic disposition. Consider α anti-trypsin deficiency if < age 35.
Epidemiology
Clinical presentation Quantify DIB with MRC dyspnoea scale
- ↓ expansion; resonant/hyperresonant percussion note; ↓ breath sounds (eg over bullae); wheeze, cyanosis, cor pulmonale. CXR: hyperinflation
- Right heart failure (hypoxic vasoconstriction = ↑ pulmonary vascular resistance)
Pathogenesis
Diagnostic investigations Spirometry: FEV1/FVC < 0.7 + little/no reversibility
Acute management - NICE thinks we should do peak flows on these patients
- SABA, SAMA, steroids

BTS: NIV should be considered within 60 minutes of hospital arrival in all patients with an acute exacerbation of COPD in whom a respiratory acidosis persists despite maximum medical treatment.
Ongoing management Long-term oxygen therapy - see below

Indications for LTOT

PaO2 < 7.3% on two separate occasions OR pO2 of 7.3-8 kPa and one of:

  • secondary polycythaemia
  • nocturnal hypoxaemia
  • peripheral oedema
  • pulmonary hypertension
  • Aim: increase independence; mortality benefit in COPD in the long term
  • Equipment required: Concentrator
  • Risks: O2 burden – partly psychological