# Asthma, COPD and Respiratory Failure for NEET PG Medicine: Spirometry, ICMR Inhaler Steps, Exacerbations, Oxygen Targets Source: https://tracknation.in/story/asthma-copd-and-respiratory-failure-for-neet-pg-medicine-spirometry-icmr-inhaler-steps-exacerbations-oxygen-targets (TrackNation β€” free UPSC notes with PYQs) > NEET PG Medicine: asthma definition and endotypes, methacholine challenge, ICMR asthma vs COPD table and stepwise inhalers, acute asthma danger signs, COPD causes, signs and spirometric severity, exacerbation features and ICMR treatment, alpha-1 antitrypsin, and hypoxaemic vs hypercapnic respiratory failure with oxygen targets, with a diagram, hooks, MCQs and cards. ## Start Here 🎯 **Exam priority: High.** *Expect: asthma vs COPD from history, the spirometric definition of COPD, methacholine challenge, step-up inhalers (ICMR), danger signs in acute asthma (rising PaCO2), COPD exacerbation features, oxygen target 88–92% in COPD, and type 1 vs type 2 respiratory failure.* CBME mapping: **GM 28.1–28.26**. Lung pathology (emphysema, asthma) is in Pathology article 19; bronchodilator pharmacology in Pharmacology. *Asthma vs COPD, inhaler steps, exacerbations and respiratory failure. Drawn by TrackNation.* ## Asthma - **Definition**: diffuse airway inflammation from triggers causing **partially or completely reversible** bronchoconstriction β€” with airway oedema, hyperreactivity and remodelling. T2-high (eosinophilic) asthma responds to steroids and biologics. Aspirin-exacerbated respiratory disease is a recognised subtype. - **Diagnosis**: clinical, with reversible obstruction on spirometry. If spirometry is normal, provocation with **methacholine** (or histamine, adenosine, exercise): an FEV1 fall of β‰₯ 20% (> 12% in children) supports asthma. - **Control (ICMR, over 4 weeks)**: daytime symptoms or reliever use ≀ 2 a week, no night symptoms, no limitation, FEV1 or PEF > 80% = good control. - **Drugs**: inhaled drugs are the mainstay. LABAs are never used alone. Montelukast (leukotriene antagonist) is less effective than inhaled steroids. Biologics (omalizumab, dupilumab, mepolizumab) are add-ons for severe eosinophilic asthma. - **Acute asthma**: inhaled beta-2 agonist plus anticholinergic, systemic steroids, sometimes magnesium. Danger: PaO2 < 50 mm Hg or a **PaCO2 rising above 40 mm Hg** (tiring patient) β†’ impending respiratory failure. | **ICMR step** | **Asthma** | **COPD** | | 1 | Levosalbutamol 50 Β΅g or salbutamol 100 Β΅g as needed | Mild: levosalbutamol as needed | | 2 | + budesonide 100 Β΅g twice daily | Moderate: + tiotropium 9 Β΅g once daily | | 3 | Formoterol/budesonide 6/200 Β΅g single inhaler, twice daily and as needed | Severe: formoterol/budesonide 6/200 Β΅g twice daily | | 4 | + tiotropium and low-dose oral methylxanthine | + tiotropium and/or low-dose methylxanthine | | 5 | + low-dose oral corticosteroid; refer | Refer if uncontrolled or complications | ## COPD - **Definition**: post-bronchodilator FEV1/FVC < 0.70. Causes: tobacco, solid-fuel cooking smoke, occupational dust; in non-smokers think **alpha-1 antitrypsin deficiency** (protease-driven emphysema). Only about 15% of smokers develop clinical COPD. Rule out TB with sputum AFB if cough lasts > 2 weeks. - **Signs**: barrel chest, hyper-resonance, reduced breath sounds, forced expiratory time > 6 s, pursed-lip breathing, Hoover sign; cor pulmonale (loud P2, raised JVP, oedema) in advanced disease β€” risk rises when FEV1 falls below about 0.8 L. - **Severity**: by FEV1 (table), breathlessness (mMRC scale), exacerbations and complications (respiratory failure, cor pulmonale, secondary polycythaemia). - **Exacerbation**: increased breathlessness, sputum volume and purulence. Severe: cyanosis, RR > 30, HR > 110, SBP < 90, SpO2 < 90%. Treat with oxygen, nebulised bronchodilators, systemic steroids (ICMR: prednisolone 30 mg for 5 days), antibiotics (amoxicillin, azithromycin or doxycycline), and non-invasive ventilation if needed. **Target SpO2 88–92%.** | **COPD severity (post-bronchodilator FEV1, MSD/GOLD)** | **Value** | | Mild | β‰₯ 80% predicted | | Moderate | 50–79% | | Severe | 30–49% | | Very severe | < 30% | ## Respiratory Failure - **Hypoxaemic (type 1)**: inadequate oxygenation β€” PaO2 < 60 mm Hg, PaO2/FiO2 < 300 or SpO2 < 88%. **Ventilatory (hypercapnic, type 2)**: inadequate CO2 removal β€” as in COPD exacerbations or respiratory muscle weakness (Guillain-BarrΓ©, myasthenia gravis, botulism). - **Clues to hypercapnia (ICMR)**: headache, bounding pulse, flapping tremor, papilloedema, drowsiness to coma. - **Oxygen (ICMR)**: start when SpO2 < 90%, titrate to SpO2 < 96% β€” but 88–92% in COPD exacerbation. ## Traps the Examiner Sets - A "normal" PaCO2 in severe asthma is a danger sign. - COPD = post-bronchodilator FEV1/FVC < 0.70. - LABA never alone in asthma. - COPD exacerbation: aim for 88–92%, not 100%. - Young non-smoker with emphysema β†’ alpha-1 antitrypsin. ## Memory Hooks & Shortcuts *Shortcuts to lock in this article's numbers and lists. Each one only re-packages facts proven above.* - 🧠 **Asthma Reverses, COPD Remains (post-BD FEV1/FVC < 0.70)** β€” asthma vs COPD - 🧠 **88–92: COPD's Goldilocks oxygen** β€” oxygen target - 🧠 **Normal CO2 in asthma = Not normal (tiring)** β€” acute asthma - 🧠 **Three Ds of AECOPD: Dyspnoea, Dirty sputum, Dumping more sputum** β€” exacerbation - 🧠 **CO2 retainer: Flap, Full pulse, Fuzzy head** β€” hypercapnia - 🧠 **LABA Lonely = Lethal (never alone)** β€” LABA ## Rapid-Revision Cards - Reversible bronchoconstriction; inflammation, hyperreactivity. - FEV1 fall β‰₯ 20% (12% children). - Eosinophilic; steroid/biologic responsive. - SABA β†’ + budesonide β†’ formoterol/bud β†’ + tiotropium β†’ oral steroid. - Never monotherapy in asthma. - Less effective than ICS. - SABA + SAMA, systemic steroid, Β± magnesium. - PaO2 < 50; PaCO2 > 40 rising. - Post-BD FEV1/FVC < 0.70. - β‰₯ 80 mild, 50–79 moderate, 30–49 severe, < 30 very severe. - Tobacco, solid fuel, occupation; age > 35. - Alpha-1 antitrypsin deficiency. - Barrel chest, FET > 6 s, Hoover, pursed lips. - ↑ dyspnoea, ↑ sputum, ↑ purulence. - RR > 30, HR > 110, SpO2 < 90%, SBP < 90. - Prednisolone 30 mg Γ— 5 days. - 88–92%. - PaO2 < 60, P/F < 300. - Hypercapnia; COPD, GBS, myasthenia. - Headache, bounding pulse, flap, papilloedema. - SpO2 < 90%; target < 96%. ## Sources *Facts in this article were checked against these documents.* - MSD Manual Professional: Asthma; Pharmacologic Treatment of Asthma; Treatment of Acute Asthma Exacerbations; COPD; Treatment of Acute COPD Exacerbation; Alpha-1 Antitrypsin Deficiency β€” Merck & Co. (MSD Manuals), reviewed 2025–26 (link) - MSD Manual Professional: Overview of Respiratory Failure; Ventilatory Failure; Acute Hypoxemic Respiratory Failure β€” Merck & Co. (MSD Manuals), reviewed 2026 (link) - Standard Treatment Workflows: Asthma; Chronic Obstructive Pulmonary Disease; Respiratory Failure β€” ICMR / Department of Health Research, MoHFW, 2019–22 (link) - Competency Based Undergraduate Curriculum, General Medicine (GM 28) β€” National Medical Commission, 2024 ## Test Yourself: Practice Questions Thirty questions in NEET PG style, most of them clinical vignettes. ## Practice Questions (NEET PG pattern) *Original questions written in the style of the exam: +4 for a correct answer, βˆ’1 for a wrong one. Every answer was checked against the sources listed above. NEET PG papers are not published by NBEMS, so these are not past-paper questions.* **Q1.** A 19-year-old with eczema and allergic rhinitis has episodic wheeze and night cough; spirometry shows obstruction that improves markedly after salbutamol. The diagnosis is - (a) interstitial lung disease - (b) COPD - (c) asthma - (d) bronchiectasis **Answer: (c)** β€” Reversible bronchoconstriction. **Q2.** A patient with suspected asthma has normal spirometry. On methacholine challenge, the finding that supports asthma is a fall in FEV1 of at least - (a) 20% (12% in children) - (b) 2% - (c) 5% - (d) 50% **Answer: (a)** β€” Alternatives: histamine, adenosine, exercise. **Q3.** A 60-year-old ex-smoker has progressive breathlessness and daily cough. Post-bronchodilator FEV1/FVC is 0.62. This confirms - (a) restrictive lung disease - (b) normal lungs - (c) COPD - (d) asthma **Answer: (c)** β€” COPD is defined by post-bronchodilator FEV1/FVC < 0.70. **Q4.** A COPD patient's post-bronchodilator FEV1 is 42% of predicted. Airflow limitation is - (a) moderate - (b) very severe - (c) mild - (d) severe **Answer: (d)** β€” Severe = 30–49%. **Q5.** A 32-year-old non-smoker has emphysema and abnormal liver tests. The likely cause is - (a) chronic asthma - (b) alpha-1 antitrypsin deficiency - (c) silicosis - (d) sarcoidosis **Answer: (b)** β€” Unopposed proteases destroy lung tissue. **Q6.** In rural Indian women who have never smoked, an important COPD risk factor listed by ICMR is - (a) solid-fuel cooking smoke - (b) high-protein diet - (c) contact lenses - (d) air travel **Answer: (a)** β€” Also tobacco and occupational exposure. **Q7.** Which bedside finding supports COPD per the ICMR workflow? - (a) clubbing always - (b) pericardial rub - (c) forced expiratory time > 6 seconds - (d) stony dull percussion **Answer: (c)** β€” Also barrel chest, hyper-resonance, reduced breath sounds. **Q8.** Paradoxical inward movement of the lower rib cage during inspiration in severe COPD is the - (a) Kussmaul sign - (b) Hamman sign - (c) Hoover sign - (d) Trousseau sign **Answer: (c)** β€” With pursed-lip breathing and accessory muscle use. **Q9.** COPD patients become at risk of hypoxaemia, hypercapnia and cor pulmonale when FEV1 falls below about - (a) 0.8 L - (b) 3 L - (c) 2 L - (d) 0.1 L **Answer: (a)** β€” Advanced disease. **Q10.** The three cardinal symptoms of a COPD exacerbation are increased - (a) weight, appetite and sleep - (b) fever, rash and joint pain - (c) chest pain, palpitations and syncope - (d) breathlessness, sputum volume and sputum purulence **Answer: (d)** β€” Anthonisen-type features. **Q11.** A COPD patient in exacerbation is given oxygen. The SpO2 target recommended by the ICMR respiratory failure workflow is - (a) 80–84% - (b) 98–100% - (c) 88–92% - (d) any value above 95% **Answer: (c)** β€” Higher targets risk worsening hypercapnia. **Q12.** The ICMR oral steroid regimen for a COPD exacerbation is - (a) dexamethasone 20 mg single dose - (b) prednisolone 60 mg for 6 weeks - (c) prednisolone 30 mg daily for 5 days - (d) no steroids **Answer: (c)** β€” With bronchodilators and antibiotics. **Q13.** Features of a severe COPD exacerbation (ICMR) include - (a) respiratory rate > 30/min and heart rate > 110/min - (b) normal sensorium and RR 18 - (c) mild cough only - (d) SpO2 97% at rest **Answer: (a)** β€” Also cyanosis, SBP < 90, SpO2 < 90%. **Q14.** Complications that place COPD in the severe ICMR category include - (a) respiratory failure, cor pulmonale and secondary polycythaemia - (b) allergic rhinitis - (c) eczema - (d) anaemia only **Answer: (a)** β€” The worst category decides severity. **Q15.** In the ICMR asthma workflow, an uncontrolled patient on as-needed reliever alone should be stepped up by adding - (a) an oral antihistamine - (b) oral antibiotics - (c) inhaled budesonide (a corticosteroid) - (d) oral theophylline only **Answer: (c)** β€” Inhaled drugs are the mainstay. **Q16.** A long-acting beta-agonist in asthma should - (a) be used only in children - (b) replace inhaled steroids - (c) be used only orally - (d) never be used as monotherapy **Answer: (d)** β€” Combine with an inhaled steroid. **Q17.** Montelukast compared with inhaled steroids for persistent asthma is - (a) more effective - (b) identical - (c) less effective - (d) contraindicated **Answer: (c)** β€” A leukotriene receptor antagonist. **Q18.** A severe asthmatic with high blood eosinophils despite maximal inhaled therapy may receive add-on - (a) dupilumab or another biologic - (b) aspirin - (c) atenolol - (d) propranolol **Answer: (a)** β€” Omalizumab, mepolizumab are others. **Q19.** A patient in acute severe asthma becomes drowsy; ABG shows PaO2 48 mm Hg and PaCO2 46 mm Hg. This indicates - (a) improvement - (b) hyperventilation from anxiety - (c) metabolic alkalosis - (d) progression to respiratory failure **Answer: (d)** β€” A rising PaCO2 in asthma is ominous. **Q20.** Standard treatment of an acute asthma exacerbation includes - (a) inhaled beta-2 agonist with anticholinergic plus systemic steroids - (b) antitussives - (c) oral montelukast alone - (d) beta-blockers **Answer: (a)** β€” Sometimes magnesium. **Q21.** Asthma is well controlled (ICMR) when, over the past 4 weeks, FEV1 or PEF is - (a) below 50% - (b) below 80% - (c) above 80% of predicted or personal best - (d) irrelevant **Answer: (c)** β€” With minimal symptoms and reliever use. **Q22.** Asthma that worsens after aspirin intake belongs to - (a) aspirin-exacerbated respiratory disease - (b) Churg-Strauss only - (c) allergic bronchopulmonary aspergillosis - (d) COPD **Answer: (a)** β€” Dysregulated arachidonic acid metabolism. **Q23.** The ICMR asthma vs COPD table says asthma typically begins - (a) only after smoking - (b) only in the elderly - (c) in childhood or early adulthood - (d) in the 5th decade **Answer: (c)** β€” COPD usually starts in the 4th–5th decade. **Q24.** Acute hypoxaemic respiratory failure is defined by - (a) SpO2 < 95% - (b) PaCO2 > 45 only - (c) PaO2 < 60 mm Hg, P/F < 300 or SpO2 < 88% - (d) pH > 7.45 **Answer: (c)** β€” Type 1 failure. **Q25.** A patient with Guillain-BarrΓ© syndrome develops rising PaCO2. This is - (a) normal - (b) hypoxaemic failure from pneumonia only - (c) ventilatory (hypercapnic) respiratory failure from muscle weakness - (d) metabolic acidosis **Answer: (c)** β€” Also myasthenia gravis and botulism. **Q26.** Per ICMR, oxygen therapy should be started when SpO2 falls below - (a) 98% - (b) 90% - (c) 95% in all - (d) 80% **Answer: (b)** β€” Titrate to < 96% (88–92% in COPD). **Q27.** A drowsy COPD patient has headache, bounding pulse and a flapping tremor. The likely abnormality is - (a) hypoglycaemia - (b) hyponatraemia - (c) hypercapnia - (d) hypocalcaemia **Answer: (c)** β€” CO2 retention; papilloedema and coma may follow. **Q28.** Only about what share of smokers develop clinically apparent COPD? - (a) 15% - (b) 90% - (c) 50% - (d) 1% **Answer: (a)** β€” Smoking is still the main risk factor. **Q29.** In the ICMR COPD workflow, a moderate COPD patient is treated with - (a) theophylline alone - (b) oral prednisolone daily - (c) no inhaler - (d) tiotropium once daily plus as-needed levosalbutamol **Answer: (d)** β€” Severe adds formoterol/budesonide. **Q30.** Treatment of an acute COPD exacerbation typically includes all EXCEPT - (a) bronchodilators - (b) antibiotics when indicated - (c) long-term oral steroids for months - (d) oxygen **Answer: (c)** β€” Systemic steroids are short courses; NIV if failure. ### Active Recall From memory: define asthma and describe its diagnosis and ICMR stepwise therapy; list acute asthma treatment and danger signs; define COPD, its causes, signs and severity grades; describe exacerbation recognition, treatment and oxygen target; and contrast hypoxaemic and ventilatory respiratory failure.