A COPD exacerbation at the IMT (Internal Medicine Training) clinical station is answered by controlling the oxygen before anything else, then giving the bundle. NICE NG115 recommends 30 mg oral prednisolone daily for 5 days, and non-invasive ventilation as the treatment of choice for persistent hypercapnic ventilatory failure despite optimal medical therapy.

Key takeaways

  • A COPD exacerbation is defined by NICE NG115 as a sustained worsening of symptoms from the usual stable state, beyond normal day-to-day variation and acute in onset.
  • NICE NG115 asks for a chest X-ray, arterial blood gases with the inspired oxygen concentration recorded, an ECG, full blood count and urea and electrolytes in everyone presenting to hospital with an exacerbation.
  • Oxygen is prescribed to keep saturations within the individualised target range; NICE CG95 prints the familiar figure of 88% to 92% for people with COPD at risk of hypercapnic respiratory failure, until blood gas analysis is available.
  • NICE NG115 recommends oral corticosteroids for everyone admitted with a COPD exacerbation, at 30 mg prednisolone daily for 5 days.
  • NICE NG114 makes antibiotics a considered decision, weighing sputum colour change and volume, admission history and resistance risk, with amoxicillin 500 mg three times a day for 5 days as one first choice.
  • If the patient is hypercapnic or acidotic, NICE NG115 says the nebuliser should be driven by compressed air rather than oxygen, with oxygen given separately by nasal cannulae.

How do you recognise a COPD exacerbation in the scenario?

A COPD exacerbation presents as worsening breathlessness, cough, increased sputum production and a change in sputum colour, and NICE NG115 names exactly those as the commonly reported symptoms.

The station usually gives you a known COPD patient who is drowsy, or whose saturations are 98% on a 15 litre mask, and the diagnosis you are really being asked for is iatrogenic hypercapnia.

In practice the differential is the mark. Say that you would actively exclude pneumonia, pneumothorax, pulmonary embolism, heart failure and an acute coronary syndrome before settling on a COPD exacerbation.

What does the A to E assessment and the first hour look like?

The first hour of a COPD exacerbation is controlled oxygen, nebulised bronchodilators, a steroid and an arterial blood gas, with the inspired oxygen concentration written down next to the result.

  • Airway and breathing: respiratory rate, saturations and controlled oxygen. NICE NG115 says to prescribe oxygen to keep saturations within the individualised target range, and NICE CG95 prints 88% to 92% for people with COPD at risk of hypercapnic respiratory failure until blood gases are available
  • Nebulisers: both nebulisers and hand-held inhalers can be used, but if the patient is hypercapnic or acidotic the nebuliser is driven by compressed air, with oxygen given simultaneously by nasal cannulae, and the driving gas specified in the prescription
  • Steroid: 30 mg oral prednisolone daily for 5 days, given to everyone admitted with an exacerbation in the absence of significant contraindications
  • Circulation and disability: blood pressure, conscious level, and a specific look for the flapping tremor and drowsiness of carbon dioxide retention
  • Blood gases: measure arterial blood gases and record the inspired oxygen concentration in everyone arriving at hospital with a COPD exacerbation, repeating them according to the response

That said, the single most examined sentence in a COPD exacerbation is that pulse oximetry gives no information about the PaCO2 or the pH. NICE NG115 says it in those words.

Which investigations does a COPD exacerbation need?

NICE NG115 lists the investigations for everyone presenting to hospital with a COPD exacerbation, and the list is short enough to say in full.

  • Chest X-ray
  • Arterial blood gas tensions, with the inspired oxygen concentration recorded
  • An ECG, to exclude comorbidities
  • Full blood count, and urea and electrolyte concentrations
  • A theophylline level on admission in anyone taking theophylline therapy
  • A sputum sample for microscopy and culture if the sputum is purulent, and blood cultures if the person is pyrexial

In primary care the answer is different, and saying so shows judgement. NICE NG115 says sputum culture is not recommended in routine practice there, and that pulse oximetry is of value if there are clinical features of a severe exacerbation.

What thresholds decide whether a COPD exacerbation is treated in hospital?

NICE NG115 prints a table of factors that decide whether a patient with a COPD exacerbation is treated at home or in hospital, and three of them are numbers you can quote.

  • An arterial pH below 7.35 favours hospital treatment; a pH of 7.35 or above favours home
  • An arterial PaO2 below 7 kPa favours hospital; 7 kPa or above favours home
  • A saturation below 90% favours hospital
  • The rest of the table is clinical and social: ability to cope at home, severity of breathlessness, general condition, level of activity, cyanosis, worsening peripheral oedema, level of consciousness, existing long-term oxygen therapy, acute confusion, rapid onset, significant comorbidity and changes on the chest radiograph

Give the pH figure rather than the adjective. A candidate who says 'if they are acidotic' has not shown the panel where the ventilation conversation begins.

NICE NG115 also says that hospital-at-home and assisted-discharge schemes are safe and effective, and should be used as an alternative for people who would otherwise need admission, which is the answer to the question about pressure on beds.

What is the definitive management of a COPD exacerbation?

Definitive management of a COPD exacerbation is bronchodilators, a five-day steroid course, antibiotics only where they are justified, and non-invasive ventilation for persistent hypercapnic ventilatory failure.

  • Prednisolone 30 mg daily for 5 days, with clear instructions on why, when and how to stop it, and osteoporosis prophylaxis considered for people needing frequent courses
  • Antibiotics are considered rather than automatic. NICE NG114 asks you to weigh sputum colour change and increased volume or thickness, whether hospital treatment is needed, previous exacerbation and admission history, previous sputum culture results, and the resistance risk of repeated courses
  • First-choice oral antibiotics in NICE NG114 are amoxicillin 500 mg three times a day for 5 days, doxycycline 200 mg on the first day then 100 mg once a day for a 5-day course in total, or clarithromycin 500 mg twice a day for 5 days
  • Intravenous theophylline is only an adjunct where there has been an inadequate response to nebulised bronchodilators, with levels monitored within 24 hours of starting
  • Doxapram is recommended only when non-invasive ventilation is unavailable or inappropriate

Non-invasive ventilation is the answer the panel is waiting for. NICE NG115 recommends it as the treatment of choice for persistent hypercapnic ventilatory failure during exacerbations despite optimal medical therapy.

It adds two conditions that candidates skip. Non-invasive ventilation should be delivered in a dedicated setting by trained and experienced staff, and there should be a clear plan for deterioration with ceilings of therapy agreed.

When and to whom do you escalate a COPD exacerbation?

Escalate a COPD exacerbation to the medical registrar and the respiratory team when the patient remains acidotic and hypercapnic after initial treatment, because that is the trigger for non-invasive ventilation.

Involve critical care when non-invasive ventilation is failing or is not appropriate, and when intubation is being considered. NICE NG115 says hospitalised exacerbations should be treated on intensive care units, including invasive ventilation where that is thought necessary.

On suitability for intubation, NICE NG115 asks you to think about functional status, body mass index, need for oxygen when stable, comorbidities and previous intensive care admissions in addition to age and FEV1, and says neither age nor FEV1 should be used in isolation.

How do you hand over a COPD exacerbation in one minute?

The COPD exacerbation handover uses SBAR and puts the blood gas in the first sentence, because the pH is what the receiving team is deciding on.

Situation: a 71 year old with known COPD, drowsy, pH 7.28, PaCO2 8.9 kPa, PaO2 7.4 kPa on 28% oxygen. Background: two admissions this year, on long-term oxygen at home, no documented ceiling of care.

Assessment: acute hypercapnic respiratory failure on a COPD exacerbation, on controlled oxygen, salbutamol and ipratropium via an air-driven nebuliser, prednisolone 30 mg given. Recommendation: please review now for non-invasive ventilation and help agree a ceiling of therapy with the family.

What does the panel listen for in a COPD exacerbation answer?

The panel listens for controlled oxygen said before any drug, the blood gas with the inspired oxygen concentration recorded, prednisolone 30 mg for 5 days as a number, and non-invasive ventilation named for hypercapnic ventilatory failure.

In practice they also mark the ceilings conversation, because the COPD scenario is written to test whether you can raise it calmly. The internalmedicineinterview bank of 361 questions across 56 scenarios, with AI-marked spoken practice, rehearses both halves of that answer.

What are the common mistakes in a COPD exacerbation station?

  • Putting a drowsy COPD patient on high-flow oxygen and not repeating the blood gas
  • Recording a blood gas without the inspired oxygen concentration, which makes the result uninterpretable
  • Driving the nebuliser with oxygen in a hypercapnic or acidotic patient
  • Saying 30 mg prednisolone for 7 or 14 days rather than the 5 days NICE NG115 recommends
  • Giving antibiotics reflexively when the guideline makes them a considered decision that turns on sputum change and risk
  • Starting non-invasive ventilation without a plan for deterioration and an agreed ceiling of therapy

How this comes up at the IMT interview

A COPD exacerbation maps onto all three parts of the IMT clinical station. Investigations and diagnosis is the blood gas, the chest X-ray and the exclusion of pneumothorax and pulmonary embolism; management is controlled oxygen, bronchodilators, prednisolone 30 mg and the non-invasive ventilation decision; and communication is agreeing a ceiling of treatment with a frightened family.

The handover minute is where the pH, the PaCO2 and the inspired oxygen concentration have to be said together, followed by an explicit request and a time for review.