FFS: COPD

Chronic Obstructive Pulmonary Disease (COPD) is a major global public health issue, characterised by partially reversible airflow obstruction with components of:

  • Emphysema
  • Chronic bronchitis
  • Asthma

Exacerbations are a common ED presentation, often requiring ventilatory support. Non-invasive ventilation (NIV) is the mainstay of acute hypercapnic respiratory failure, but remains underutilised.

Early discussions about intubation limitations and care planning are critical.

Pathophysiology

Definitions

  • Chronic bronchitis: Productive cough ≥3 months/year for ≥2 years
  • Emphysema: Destruction of distal airways with alveolar wall destruction

Diagnosis

  • Formal diagnosis = clinical assessment + lung function testing
  • GOLD staging system used to classify severity

Causes

CategoryExamples
SmokingMost common cause worldwide
Occupational/environmentalPollutants, industrial exposure
CongenitalAlpha-1 antitrypsin deficiency, CF

Exacerbations

Definition

An acute worsening of baseline symptoms (dyspnoea, cough, sputum) requiring a change in therapy.

Common Triggers

  1. Infection (bacterial/viral)
  2. CCF
  3. ACS
  4. PE
  5. Poor medication compliance
  6. Continued smoking
  7. Environmental pollutants

No clear cause in some cases — may reflect natural disease progression.

Infective Exacerbations — Common Pathogens

  • Strep pneumoniae
  • Haemophilus influenzae
  • Moraxella catarrhalis
  • Later: Staph aureus, Pseudomonas aeruginosa (esp. severe disease)

Clinical Assessment

Key History

  • Patient’s own severity rating
  • Previous ICU/NIV/intubation
  • Home oxygen/steroid use
  • Duration of current episode
  • Change in sputum (volume, colour)
  • Functional baseline
  • Advanced care plans

Key Examination

  • Consciousness
  • Work of breathing
  • Speech
  • Pulse rate
  • Air entry (wheeze, silence)
  • Cyanosis (late sign)
  • PEFR/FEV1 (if possible)
  • ABG/VBG (esp. CO₂ trend)

Severity Classification

ParameterMildModerateSevere/Life-Threatening
ConsciousnessNormalNormalAltered
Respiratory effortNormal↑ WOBExhaustion ± paradoxical breathing
SpeechSentencesPhrasesWords/none
Pulse rate<100100–120>120 or bradycardia
Breath soundsWheezeLoud wheezeSilent chest, poor entry, PTX
PEFR (% predicted)>75%50–75%<40% or <100 L/min
FEV1 (% predicted)>75%50–75%<40% or <1L
SpO₂>95%92–95%<92%
PaCO₂Normal>40 = severe>45 mmHg (respiratory failure)
PaO₂NormalMay drop<60 mmHg (respiratory failure)

Investigations

TestNotes
FBC, CRPInfection screen
U&Es, GlucoseMonitor for salbutamol-induced hypokalaemia
ABG/VBGPaCO₂ >45 = respiratory failure; VBG suitable in many cases
CXRLook for infection, CCF, pneumothorax
ECGCommon arrhythmias: MFAT, AF
Sputum M&CIf cooperative
Cardiac enzymesConsider if chest pain or ACS suspected
BNPIf CCF suspected
Blood culturesIf febrile/unwell

Management

1. ABC + Monitoring

  • Pulse oximetry
  • ECG monitoring
  • BP monitoring
  • Avoid unnecessary arterial lines early

2. Oxygenation

  • Priority: oxygen first (SaO₂ ≥90–92%)
  • Accept 88% in severe disease
  • Start with nasal prongs or Hudson mask
  • Consider Venturi mask (28%) for CO₂ retainers
  • Avoid excessive O₂ due to Haldane effect

3. Humidification

  • Use heated humidifiers for long-term O₂

4. High Flow Nasal Oxygen

  • Tolerable alternative
  • Some CPAP effect, less effective for hypercapnia

5. Non-Invasive Ventilation (NIV)

  • Indicated when:
    • Oxygenation inadequate
    • Rising CO₂
    • Exhaustion
  • BIPAP preferred (active ventilatory support)
  • Monitor for barotrauma

6. Bronchodilators

  • Salbutamol 5 mg neb PRN (can be continuous)
  • Ipratropium 500 mcg q20min × 3, then hourly

7. Corticosteroids

  • IV dexamethasone 10 mg TDS
    or
    Hydrocortisone 100 mg IV QID
  • Oral prednisolone 30–50 mg daily × up to 2 weeks

8. Antibiotics

  • Cefotaxime 1–2 g IV
  • +/- Azithromycin 500 mg IV

9. Antivirals

  • If influenza likely → Oseltamivir

10. Aminophylline

  • Not recommended routinely due to side effects

11. Sedation

  • Avoid sedation unless required to tolerate NIV

Intubation & Mechanical Ventilation

Considerations

  • Diagnosis confirmed
  • Reversible cause
  • Functional baseline
  • Patient preferences/ACP

Indications

  • Exhaustion
  • ↓ LOC, confusion
  • ↑ CO₂
  • SpO₂ <88% or PaO₂ <60 despite NIV

Permissive Hypercapnia Strategy

SettingTarget
FiO₂Start 100%, then titrate
Vt≤6 mL/kg IBW (↓ to 3–4 mL/kg if needed)
Rate↓ to 6–8/min
PEEPOff
I:E Ratio≥1:4
pH tolerance>7.1

Avoid bicarbonate. Do not treat hypercapnia by ↑ RR — risk of barotrauma.

Additional Measures

  • Deep sedation ± paralytics
  • NG tube for gastric decompression
  • Disconnect ventilator for dynamic hyperinflation
  • Monitor SpO₂, capnometry, chest rise (not alarms)
  • Adjust alarms for low Vt/PIP if needed

Disposition

Admit:

  • Almost all patients
  • NIV usually excludes short-stay suitability
  • HDU/ICU if:
    • Poor response
    • Prior ICU/NIV
    • Advanced care planning in place

End-of-life Planning

  • ACP does not exclude NIV trial
  • Consider palliation if unresponsive to NIV after discussion

Follow-Up

  • Refer to respiratory outreach services
  • Aim: education, care plans, reduce readmissions
  • Early treatment may prevent progression

References

FOAMed

Resources

Fellowship Notes

Dr James Hayes LITFL Author Medical Educator

Educator, magister, munus exemplar, dicata in agro subitis medicina et discrimine cura | FFS |

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