COPD exacerbation with weak cough and hypercapnia
Youssef, a 72-year-old retired farmer, is admitted with an acute exacerbation of COPD. On day 3 he has SpO2 89% on 2 L/min nasal cannula, respiratory rate 26/min, heart rate 104/min, blood pressure 138/82 mmHg, and he is using accessory muscles. He has copious thick secretions and a weak cough; he cannot clear sputum. Arterial blood gas on 2 L/min: pH 7.35, PaCO2 52 mmHg, PaO2 60 mmHg. He is drowsy but rousable. He has a 50 pack-year smoking history and two exacerbations in the past year. His chest X-ray shows hyperinflation but no consolidation. He is on ipratropium, salbutamol, and oral prednisolone. He weighs 58 kg and has a body mass index of 19. His sputum is yellow-green. The team asks whether he should start chest physiotherapy and exercise.
1. Prioritise your physiotherapy problem list for today and justify whether airway clearance or exercise should come first. Identify any signs that would make you withhold physiotherapy and escalate.
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Today the priority is ineffective airway clearance and impaired gas exchange, not exercise. He has copious secretions, a weak cough, drowsiness, PaCO2 52, and SpO2 89% on 2 L/min. Exercise would increase ventilatory demand and fatigue before secretions are cleared. However, drowsiness and hypercapnia mean he needs medical review first: check blood gases, consider non-invasive ventilation, and ensure he can cooperate. I would withhold active physiotherapy and escalate if: worsening drowsiness, confusion, RR >30, HR >120, SpO2 <88% despite oxygen, chest pain, fever, or inability to protect the airway. Positioning and suction should be nurse/physio coordinated. Physiotherapy should be brief and focused.
2. Select two airway clearance techniques appropriate for his weak cough and explain how you would position him and monitor tolerance.
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Choose manually assisted cough and positioning with vibration/expiratory technique. Assisted cough: sit him up, place hands on lower ribs or upper abdomen, coach a huff, and apply a coordinated inward/upward squeeze during expiration; this augments cough flow when the cough is weak. Positioning: side-lying or sitting to improve secretion movement, with chest wall vibration during expiration, followed by huffing. If he can cooperate, add active cycle of breathing. Monitor SpO2, HR, RR, fatigue, and secretion clearance. Avoid prolonged head-down positioning because of drowsiness and risk of aspiration/reflux. Suction if secretions are audible and he cannot clear them.
3. Outline a graded exercise plan for later in the admission, specifying intensity using a validated scale and safety limits.
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Once secretions are controlled and he is more alert, start interval exercise rather than a single long session. Use sit-to-stand 5–10 repetitions, then walk in the corridor for 2–3 minutes, with rest. Intensity: dyspnoea Borg 3–4 (moderate) or RPE 11–13; SpO2 ≥88–90%; HR below 70% of predicted maximum (220 − 72 = 148; 70% ≈ 104), but also use symptoms because beta-agonists raise HR. Stop for SpO2 <88%, RR >30, HR >120, chest pain, dizziness, or worsening dyspnoea. Progress by 1–2 minutes per session and add a second daily session. Include airway clearance before exercise and a bronchodilator as prescribed.