--- **Patient details:** - Age: 70 years old - Gender: Male - Smoking status: Ex-smoker - BMI: 26 - Examination (if not performed): Suggestive of airways disease. >[!question]- How would you investigate this patient? > - **Blood tests:** FBE (raised WCC for infection, raised Hb in secondary polycythaemia), UEC (low K; can get worse with bronchodilators), A1AT assay and LFTs (A1AT deficiency) > - **Lung function:** Spirometry with BD response and DLCO (to assess for an obstructive ventilatory defect) > - **Imaging:** Chest X-ray (assess for hyper-inflation, narrow heart shadow, bullae, increased retrosternal airspace, prominent pulmonary vasculature). CT Chest could be used (if needed) to clarify any abnormalities seen on CXR, or evaluate for other pathologies as indicated (e.g. lung mass/nodule, interstitial lung disease, plan towards surgical intervention(s)) --- **Respiratory function tests** ![[Case AE RFTs 1.png]] >[!example]- Flow-volume loop >![[O-FC.png|center]] > [!question]- Describe the findings of these respiratory function tests > - The FER is less than 0.70, consistent with the presence of an **obstructive ventilatory defect**. > - The FEV1 is 1.30L (50% predicted), consistent with a moderate-severe obstructive ventilatory defect (*ATS/ERS 2005*). > - The FVC is reduced at 2.20L (66%), which in the context of an obstruction, may represent gas trapping or true restriction. Static lung volumes could be performed to evaluate this further. > - There is **no** acute bronchodilator response. > - Diffusion capacity is moderately reduced (50% pred), and remains low despite correction for alveolar volume (KCO 51% pred), suggestive of pulmonary parenchymal and/or pulmonary vascular disease. > - The flow-volume loop demonstrates a concave, 'scooped-out' appearance of the expiratory phase, consistent with obstructive lung disease. > - **Summary:** Respiratory function tests demonstrate a moderate-severe obstructive ventilatory defect with a reduced FVC, which in this context may represent associated gas trapping or true restriction but requires static lung volumes to confirm. There is no bronchodilator response. Diffusion capacity is reduced, and does not correct for alveolar volume, suggestive of underlying pulmonary parenchymal and/or vascular disease. > - **These results are/are not consistent with my provisional diagnosis of (XYZ)** >[!info] Scroll down for chest imaging when ready --- **Chest imaging** *Chest X-ray*: ![[Case AE - Imaging.jpg]] >[!example]- Please comment on the relevant findings of this X-ray > The most prominent finding on this chest X-ray is that of lung hyperinflation. There are 10 posterior ribs visible and there is diaphragmatic flattening. > > Other findings on chest X-ray imaging include: > - There is a small area of opacity in the left lower zone, which is non-specific and may represent various pathologies, such as infection/inflammation, or a lung mass/nodule. > - Mild prominence of the pulmonary vasculature. Otherwise, there is no other significant pathology seen. > > **These findings reinforce/go against my differential diagnosis of (XYZ)** >[!info] Scroll down for discussion when ready --- **Discussion questions** > [!question]- What are the causes of COPD? > The most common causes of COPD are: > - Cigarette smoking > - Other fume/dust exposure (e.g. occupational, household biomass, passive smoke) > > Less common causes of COPD include: > - Alpha-1 antitrypsin deficiency > - Poorly-controlled asthma with progression to fixed airflow limitation > - Pulmonary/systemic infections: Tuberculosis, childhood pneumonia, HIV >[!question]- What are the differential diagnoses for an obstructive ventilatory defect? >Differentials for an obstructive ventilatory defect include: >- Chronic obstructive pulmonary disease (COPD) >- Chronic asthma, with fixed airway obstruction >- Bronchiectasis >- Other, less common causes include central airway obstruction or bronchiolitis >[!question]- What are the general principles of COPD management? > > The principles of COPD management are: > > - **Smoking cessation** and avoidance of other airway irritants > - **Pharmacological management:** > - Inhaled pharmacotherapy: Long-acting bronchodilation (LAMA, or LAMA/LABA), with consideration of ICS if experiencing frequent exacerbations > - If exacerbations persist, consider addition of other therapies (e.g. prophylactic antibiotics, Dupilumab if Eos >0.3) > - **Other non-pharmacologic management:** > - Routine immnunisations (COVID-19, Influenza +/- Pneumococcal) > - Pulmonary rehabilitation referral > - **Referral to a Respiratory service** for monitoring/management. In the long-term, consider the role of home oxygen therapy and on-referral to other services as appropriate (e.g. interventional bronchoscopy, transplantation, palliative care). >[!question]- What are the requirements for long-term oxygen therapy in patients with COPD? >Patients must have **stopped smoking**, which can be corroborated with a normal carboxyhaemoglobin level. In these patients, arterial blood gas analysis is performed on room air to evaluate for resting, chronic hypoxaemia. > >The criteria for long-term oxygen therapy are ***either***: > >- Arterial PaO2 <55mmHg (equivalent to SpO2 88%) >- Arterial PaO2 <60mmHg (equivalent to SpO2 90%) **AND** the patient has one of the following: pulmonary hypertension, RV dysfunction, or secondary polycythaemia. > --- **References:** - CXR: [Case courtesy of Frank Gaillard, Radiopaedia.org, rID: 8512.](https://radiopaedia.org/cases/chronic-obstructive-pulmonary-disease-marked-hyperinflation) - Flow-volume loop: [Deranged Physiology](https://derangedphysiology.com/main/cicm-fellowship-exam/past-papers/2023-paper-1-saqs/question-282#answer-anchor) - RFTs: Randomly generated to fit the case. - Discussion: 1. [Clinical Medicine for the MRCP PACES (Volume 1: Core Clinical Skills) (2010)](https://global.oup.com/academic/product/ost-medical-cases-for-mrcp-paces-pack-9780199578689) 2. [2025 GOLD Report on COPD](https://goldcopd.org/2025-gold-report/)