COPD flare (acute exacerbation)
Controlled oxygen to 88–92%, nebulisers, steroids, antibiotics when the sputum is purulent, and NIV early for those who meet the criteria.
A 66-year-old woman who cooked on a wood fire for 40 years is more breathless than usual with green sputum. She arrived on a non-rebreather mask and is now drowsy. SpO₂ 99%. ABG: pH 7.26, PaCO₂ 72 mmHg (9.6 kPa).
What has happened, and what do you do?
- Swap high-flow oxygen for a Venturi mask24% or 28%, aiming for SpO₂ 88–92%.
- ABG nowThen 30–60 minutes after any oxygen change.
- NebulisersSalbutamol and ipratropium. Use air-driven nebulisers if the CO₂ is high, with oxygen by nasal cannula alongside.
- SteroidsPrednisolone 30 mg by mouth.
- Chest X-ray and ECGPneumonia, pneumothorax, heart failure, arrhythmia.
- Antibiotics if the sputum is purulentOr if there is pneumonia.
- NIV if still acidoticpH below 7.35 with high CO₂ after an hour of full treatment.
- Ask about ceiling of careWould they want ventilation? Ask early, not at 3 a.m.
- pH below 7.35 with high CO₂ after an hour of treatment
- pH below 7.25, or drowsy or confused
- New pneumothorax or consolidation
- Low BP or new arrhythmia
- Not responding to first treatment
- Type 2 respiratory failure from too much oxygen
- Pneumothorax hidden among bullae
- Pneumonia
- PE or heart failure mimicking a COPD flare
- Tuberculosis
| Oxygen target | SpO₂ 88–92% for known or suspected CO₂ retainers |
| NIV criteria | pH below 7.35 and PaCO₂ above 49 mmHg (6.5 kPa) despite an hour of full treatment |
| Steroids | Prednisolone 30 mg once daily for 5 days |
| Nebulisers | Salbutamol 5 mg and ipratropium 500 micrograms |
| Antibiotics | 5 days if sputum is purulent. Choice in the treatment section |
Check every dose against a current drug reference and your hospital protocol.
On this page
What is going on
COPD is common in Pakistan and is not only a smoker's disease: huqqa, biomass fuel (wood and dung cooking fires) and dusty jobs all cause it, so women who never smoked can have severe COPD. An exacerbation is a worsening of breathlessness, cough or sputum beyond the usual day-to-day variation. Most are triggered by infections; others by pollution, missed inhalers, PE or heart failure.
The two big mistakes are giving too much oxygen and starting NIV too late.
Some COPD patients run a chronically high CO₂. High-flow oxygen worsens the mismatch between ventilation and blood flow in their lungs and reduces their breathing drive, so the CO₂ climbs further. They become drowsy, acidotic and can stop breathing, while the SpO₂ reads a reassuring 99%. Aim for SpO₂ 88–92% in anyone with known or suspected CO₂ retention until the ABG says otherwise.
Recognising it
- More breathless than usual, more sputum, change in sputum colour.
- Wheeze, tight chest, sometimes fever.
- Signs of a high CO₂: drowsiness, confusion, morning headache, warm hands, bounding pulse, flapping tremor.
- Ankle swelling and a raised JVP suggest right heart failure (cor pulmonale).
History
- Baseline: how far can they usually walk? Home oxygen? Usual inhalers?
- Previous admissions, NIV or ICU.
- Sputum colour and volume, fever.
- Smoking, huqqa, cooking fuel, occupation.
- Weight loss, coughing blood, night sweats: TB or cancer.
- Their wishes about NIV and intubation if things get worse. Ask early, with the family present if the patient agrees.
Examination
- RR, SpO₂, pulse, BP, temperature, conscious level.
- Pursed-lip breathing, use of neck muscles, barrel chest.
- Wheeze, crackles, unequal breath sounds (pneumothorax).
- Signs of high CO₂ and right heart failure.
Other causes of worse breathing
| Condition | Points towards it | Test that helps |
|---|---|---|
| Pneumonia | Fever, focal crackles, new shadowing | Chest X-ray |
| Pneumothorax | Sudden worsening, one-sided signs | Chest X-ray (CT if bullae make it unclear) |
| Pulmonary embolism | Sudden, no infection, low oxygen out of proportion | CT pulmonary angiogram |
| Heart failure | Orthopnoea, crackles, raised JVP, oedema | Chest X-ray, ECG, echo |
| Tuberculosis | Weeks of cough, weight loss, upper lobe changes | Sputum GeneXpert |
| Lung cancer | Weight loss, coughing blood, mass on X-ray | CT chest |
| Fast AF | Palpitations, irregular pulse | ECG |
Reading the ABG
- Compensated. Continue treatment
- Keep SpO₂ 88–92%
- Acute type 2 respiratory failure
- Full medical treatment for 1 hour, then repeat the gas
- Still acidotic: start NIV
- Senior and ICU now
- NIV in HDU or ICU, or intubation if appropriate
- In Pakistan most ABG machines report in mmHg. 1 kPa = 7.5 mmHg.
- High bicarbonate with a normal pH means chronic CO₂ retention: this patient needs a target of 88–92%.
- Repeat the ABG 30–60 minutes after any change in oxygen, and 1–2 hours after starting NIV.
Treatment
- Pneumonia on the X-ray: treat as pneumonia (see Pneumonia).
- Avoid empirical fluoroquinolones (levofloxacin, moxifloxacin) unless your policy says so. TB is common in Pakistan and these drugs can partly treat it, delaying the diagnosis.
- Aminophylline only on senior advice.
NIV (BiPAP)
NIV pushes air in with each breath (inspiratory pressure, IPAP) and keeps the airways open on the way out (expiratory pressure, EPAP). It lowers the CO₂ and can avoid intubation.
pH below 7.35 and PaCO₂ above 49 mmHg (6.5 kPa) that persists after an hour of full medical treatment (controlled oxygen, nebulisers, steroids).
Decide before starting what to do if NIV fails: is intubation appropriate for this patient?
- Explain to the patientA frightened patient fights the mask. Let them hold it on first.
- Choose a well-fitting full face maskLeaks are the commonest reason for failure.
- Start settingsIPAP 15 cmH₂O, EPAP 4–5 cmH₂O. Increase IPAP by 2–5 every 10 minutes towards 20–30 as tolerated.
- Oxygen into the circuitTo keep SpO₂ 88–92%.
- Recheck the ABGAt 1–2 hours and at 4–6 hours. pH and CO₂ should be improving.
- Not improvingCheck the mask leak and settings, then senior or ICU review.
- Pneumothorax that has not been drained.
- Vomiting, unable to protect the airway, or very drowsy (GCS below 8).
- Facial injury or recent upper airway or upper gut surgery.
- Life-threatening low oxygen or cardiac arrest: these patients need intubation.
Before discharge
- Breathing near their usual baseline, SpO₂ at their usual level.
- Steroids and antibiotics completed or prescribed.
- Inhaler technique checked. Review their regular inhalers.
- Stop smoking and huqqa. Advise on smoke from cooking fires and ventilation at home.
- Vaccines: influenza every year, and pneumococcal.
- Pulmonary rehabilitation if available.
- Follow-up in chest clinic, and a home oxygen assessment if they are still low when stable.
Common mistakes
- Leaving a COPD patient on a non-rebreather mask with SpO₂ 99%.
- Not repeating the ABG after changing the oxygen.
- Waiting too long to start NIV.
- Missing a pneumothorax among bullae on the X-ray.
- Never asking the patient what they would want if they got worse.
Frequently asked questions
What is the target oxygen saturation in COPD?
88–92% for patients with known or suspected CO₂ retention, using a 24% or 28% Venturi mask, until the ABG shows otherwise.
When should NIV be started in COPD?
When the pH is below 7.35 and PaCO₂ is above 49 mmHg (6.5 kPa) despite an hour of full medical treatment.
What are the starting BiPAP settings in COPD?
IPAP 15 cmH₂O and EPAP 4–5 cmH₂O, increasing IPAP by 2–5 cmH₂O every 10 minutes towards 20–30 as tolerated, with oxygen to keep SpO₂ 88–92%.
Do all COPD exacerbations need antibiotics?
No. Give antibiotics when the sputum is purulent or there is pneumonia. Steroids are given to most patients.
Test yourself
Exam-style questions on this guide, from our two question banks. Choose an answer to see why each option is right or wrong.
1. A 68-year-old man with COPD was given oxygen by non-rebreather mask in the ambulance. He is now drowsy with SpO₂ 99%, pH 7.24 and PaCO₂ 78 mmHg (10.4 kPa). What is the best immediate action?
Answer: Controlled oxygen to 88–92%. Uncontrolled oxygen in CO₂ retainers can raise CO₂ and cause acidosis and drowsiness. Titrate controlled oxygen to 88–92%, call the senior, and start NIV if acidosis persists after initial treatment.
- Continue high-flow oxygen: Excess oxygen is worsening his CO₂ retention.
- Give IV naloxone: Not opioid toxicity.
- Remove all oxygen: Stopping oxygen suddenly causes dangerous hypoxia.
- Sedate for agitation: Sedation worsens type 2 failure.
2. A COPD patient has had an hour of nebulisers, steroids and controlled oxygen. Gas: pH 7.31, PaCO₂ 62 mmHg (8.3 kPa). What is the next step?
Answer: Start non-invasive ventilation. Persistent acute hypercapnic respiratory failure (pH below 7.35 with PaCO₂ above about 49 mmHg / 6.5 kPa) despite optimal medical treatment is the indication for NIV.
- Continue the same treatment for 24 hours: Persistent acidosis after an hour needs NIV.
- Intubate immediately: NIV comes first unless there are contraindications or failure.
- IV aminophylline as first choice: Not first choice; NIV is the evidence-based step.
- Increase oxygen to 15 L/min: This worsens CO₂ retention.
3. A 60-year-old with a COPD exacerbation needs an antibiotic for purulent sputum. Why is empirical moxifloxacin avoided in Pakistan?
Answer: It can mask tuberculosis. Fluoroquinolones are active against M. tuberculosis. Using them empirically in a high-TB setting can mask TB and promote resistance. Amoxicillin or doxycycline are usual first choices unless policy says otherwise.
- It cannot be given orally: It is well absorbed orally.
- It is too expensive: Cost is not the main reason.
- It causes bronchospasm: Not a recognised reason.
- It does not cover Haemophilus: It does cover Haemophilus.
4. A 60-year-old smoker has chronic cough and breathlessness. Post-bronchodilator FEV₁/FVC is 0.58 and FEV₁ is 55% predicted. What is the diagnosis and GOLD grade?
Answer: COPD, GOLD 2 (moderate). COPD requires a post-bronchodilator FEV₁/FVC < 0.70. GOLD airflow grades: 1 ≥ 80%, 2 50–79%, 3 30–49%, 4 < 30% predicted. Management: smoking cessation (most important), vaccinations (influenza, pneumococcal), pulmonary rehabilitation, LAMA/LABA bronchodilators; ICS added for frequent exacerbations with eosinophils ≥ 300. Long-term oxygen for PaO₂ ≤ 7.3 kPa. Biomass fuel smoke is a major cause in rural Pakistani women.
- Asthma, fully reversible: A post-bronchodilator ratio of 0.58 shows fixed obstruction, not reversible asthma.
- COPD, GOLD 4 (very severe): GOLD 4 is FEV₁ below 30% predicted.
- Restrictive lung disease: In restrictive disease the ratio is normal or high.
5. A 68-year-old with COPD has an exacerbation. After an hour of nebulised bronchodilators, steroids and controlled oxygen (SpO₂ 90%), ABG shows pH 7.28, PaCO₂ 9.2 kPa. He is alert. What is the next step?
Answer: Non-invasive ventilation. Persistent hypercapnic respiratory acidosis (pH < 7.35 and PaCO₂ > 6.5 kPa) despite optimal medical treatment is the main indication for NIV in COPD exacerbations. It reduces intubation and death. Agree a ceiling of care and a plan if NIV fails. More oxygen would worsen hypercapnia.
- High-flow oxygen 15 L/min: High-flow oxygen removes the hypoxic drive and worsens CO₂ retention in COPD; target SpO₂ is 88–92%.
- Immediate intubation: Reserved for NIV failure or contraindications.
- IV aminophylline alone: Aminophylline may help bronchospasm but cannot correct ventilatory failure; acidotic hypercapnia (pH < 7.35) needs NIV.
6. Which pattern of emphysema is typical of cigarette smokers?
Answer: Centriacinar, upper lobes. Smoking damages the respiratory bronchioles at the centre of the acinus first, sparing distal alveoli: centriacinar emphysema, mainly in the upper lobes. Alpha-1 antitrypsin deficiency causes panacinar emphysema, mainly in the lower lobes, at a younger age.
- Panacinar, lower lobes: Alpha-1 antitrypsin deficiency.
- Paraseptal, pneumothorax only: Next to pleura; can cause pneumothorax in young adults, not the main smoking pattern.
- Irregular, around scars: Around scars; usually not significant.
- Bullous, no airflow obstruction: Not the typical smoking pattern.
7. Which is the main concern when giving high-flow oxygen to a patient with an acute exacerbation of COPD?
Answer: Rising CO₂; aim 88–92%. In CO₂ retainers, uncontrolled oxygen worsens hypercapnia mainly by increasing V/Q mismatch (release of hypoxic pulmonary vasoconstriction) and the Haldane effect, and to a lesser extent reduced hypoxic drive. Use 24–28% Venturi masks targeting 88–92%, check ABGs, and use non-invasive ventilation if pH < 7.35 with high PaCO₂.
- Oxygen toxicity within minutes: Requires prolonged high concentrations.
- Hypokalaemia: Not the main issue.
- Bronchospasm: Not caused by oxygen.
- Hypothermia: Not relevant.
References and dose sources
- NICE NG115: COPD in over 16s
- BTS/ICS guideline: ventilatory management of acute hypercapnic respiratory failure
- GOLD report
- NICE NG114 — COPD exacerbation: antimicrobial prescribing
- BTS — emergency oxygen guideline
- Salbutamol dosing: Drugs.com: Albuterol (salbutamol) dosage (see also our salbutamol dose page)
- Ipratropium bromide dosing: Drugs.com: Ipratropium dosage (see also our ipratropium bromide dose page)
- Prednisolone dosing: Drugs.com: Prednisolone dosage (see also our prednisolone dose page)
- Amoxicillin dosing: Drugs.com: Amoxicillin dosage (see also our amoxicillin dose page)
- Doxycycline dosing: Drugs.com: Doxycycline dosage (see also our doxycycline dose page)
International guidance is linked where it reflects good practice. Where your hospital’s protocol differs, follow your hospital.