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Respiratory

Asthma and COPD

Distinguish variable airway disease from persistent obstruction, interpret lung tests, and tailor asthma and COPD treatment to risk and physiology.

A bronchodilator response is a physiological observation, not a disease label. Asthma can leave persistent obstruction, and COPD can show substantial reversibility. The useful distinction combines symptom variability, exposure history, objective airflow testing and the treatment needed to prevent the next dangerous episode.

Find the site of the airflow problem

Asthma is a heterogeneous disease with variable respiratory symptoms and variable expiratory airflow limitation. Wheeze, breathlessness, chest tightness and cough may fluctuate with allergens, exercise, viral infections or work exposures and may worsen at night or early morning. Childhood onset and atopy support the diagnosis but are not requirements. Adult-onset asthma and asthma in smokers are real. A quiet interval does not exclude the disease. [1]

COPD combines persistent respiratory symptoms with persistent airflow obstruction arising from airway and/or alveolar abnormalities. Tobacco, biomass smoke, occupational dusts and gases, impaired early lung development and genetic susceptibility can all contribute. Symptoms often accumulate over years, but age and smoking history alone cannot confirm COPD. Exacerbations and coexisting diseases alter the course. [2]

Two anatomical routes to difficulty exhaling

The airway narrows

Asthma combines smooth-muscle constriction, mucosal inflammation and mucus. Chronic bronchitic COPD adds small-airway remodeling and mucus obstruction.

A narrower lumen increases resistance. Anti-inflammatory treatment addresses asthma risk; bronchodilation relaxes airway muscle in either disease.

The airway loses support

Emphysema destroys alveolar walls and the attachments that help hold small airways open. Elastic recoil and gas-exchange surface area decline.

During expiration, poorly supported airways compress early. Air trapping and hyperinflation increase the work of breathing.

The same low expiratory flow can reflect airway narrowing, lost recoil or both. Destroyed alveolar surface cannot be restored by an immediate bronchodilator response.

In type 2 asthma, IL-4 and IL-13 support allergic pathways and IgE production, while IL-5 supports eosinophils. Mast-cell mediators can rapidly constrict airway muscle. Not all asthma is eosinophilic, and some COPD is eosinophilic. Blood eosinophils and exhaled nitric oxide support phenotype assessment; neither test independently proves asthma or excludes it when low. [1] [2]

Chronic bronchitis is a clinical mucus phenotype, traditionally productive cough for at least three months in each of two consecutive years after other causes are excluded. It can occur without spirometric COPD. Emphysema is structural destruction distal to terminal bronchioles. The two often coexist. Avoid using body habitus, complexion or stereotyped patient labels as substitutes for physiology.

Alpha-1 antitrypsin deficiency deserves special attention. Reduced antiprotease protection predisposes to emphysema, often with a basilar panacinar pattern. Retention of abnormal protein in hepatocytes explains associated liver disease through a different mechanism. Young age, limited smoking and family liver disease raise suspicion, but guidelines recommend testing all patients with COPD. Use an appropriate combination of protein measurement and genotype or phenotype confirmation. [4]

Measure obstruction, variability and gas transfer separately

FEV1 is the volume exhaled in the first second of a forced expiration. FVC is the total forced exhaled volume. Their ratio asks how much of the available volume leaves promptly. A flow-volume loop plots flow against volume, so FEV1 is not a time point that can be read directly from that graph. Obstruction typically produces a concave expiratory limb; a volume-time curve instead displays first-second volume and the final plateau. [3]

GOLD confirms COPD with a post-bronchodilator FEV1/FVC below 0.70 in the appropriate clinical setting. Values close to the boundary merit repeat testing. A fixed ratio can overclassify older adults and miss younger adults relative to age-appropriate lower limits of normal. Use reference limits when interpreting physiology generally, especially in children; 0.70 is not a universal asthma threshold. [2] [3]

GINA 2026 retains an adult positive bronchodilator response of at least 12% and at least 200 mL increase from baseline in FEV1 or FVC. In children, the FEV1 criterion is an increase of at least 12% of predicted. The 2022 ERS/ATS technical standard instead expresses a significant response as more than 10% of predicted FEV1 or FVC. These calculations have different denominators and different purposes. State which standard is being used rather than silently interchanging them. [1] [3]

Normal spirometry between episodes does not exclude asthma. Repeat testing during symptoms, document serial peak-flow variability, or obtain an appropriate bronchial challenge. Methacholine responsiveness supports asthma in context but is not perfectly specific; a properly performed negative test in an untreated symptomatic patient makes active asthma less likely. Avoid challenge testing in pregnancy or when contraindications such as substantial baseline obstruction make it unsafe. Work-related symptoms merit serial measurements at work and away plus specialist assessment. [1]

Tests answer different physiological questions
FindingWhat it supportsWhat it does not prove
Low FEV1/FVCExpiratory obstructionAsthma versus COPD by itself
Low FVC with a preserved ratioPossible restriction or a nonspecific patternRestriction without TLC below its lower limit of normal
High RV and RV/TLCAir trappingEmphysema as the only cause
Low DLCOReduced effective gas transfer, as in emphysemaEmphysema alone, since anemia, vascular disease and interstitial disease also reduce it

Asthma often has normal or high DLCO; chronic bronchitis without major emphysema may preserve DLCO. Interpret diffusion capacity with hemoglobin and the rest of the lung assessment. FEF25-75 is variable and depends on FVC and test performance. It should not diagnose early small-airway disease by itself. [3]

Match asthma relief with inflammation control

Inhaled corticosteroid is abbreviated ICS, short-acting beta agonist SABA, long-acting beta agonist LABA and long-acting muscarinic antagonist LAMA. Formoterol has sufficiently rapid onset for evidence-based ICS-formoterol reliever regimens. Salmeterol does not serve as an interchangeable reliever. A LABA must not be used alone in asthma because airway relaxation without appropriate anti-inflammatory treatment increases serious risk. [1]

For adults and adolescents, GINA's preferred Track 1 uses low-dose ICS-formoterol as the reliever. At the lower steps it can be used as needed without scheduled maintenance; patients with more frequent symptoms or higher risk need maintenance ICS-formoterol as well. Maintenance-and-reliever therapy, or MART, uses the appropriate same combination for both scheduled and symptom-driven doses. Follow the age-specific product, dose and maximum daily inhalations. If Track 1 is unavailable or unsuitable, use an ICS-containing alternative, including ICS-SABA or ICS whenever SABA is used at the lowest step, and daily controller treatment when indicated. SABA alone is not the default asthma plan. [1]

Children 6 to 11 years need their own treatment pathway. GINA 2026 includes as-needed low-dose ICS-formoterol or ICS plus SABA, in a suitable combination or separate inhalers, at Step 1. For children who need Step 2, daily low-dose ICS remains preferred; evidence does not yet establish equivalence of as-needed ICS-formoterol to daily ICS in this age group. More advanced steps offer age-appropriate ICS-LABA or MART options. Do not extrapolate these regimens to preschool wheeze or assume every formulation has local approval for every age. The CARE trial supports the reliever change but used a specific pediatric population and formulation. [1] [16]

Before increasing treatment, observe inhaler use, check adherence and access, review exposures, and confirm that current symptoms are asthma. Rhinitis, reflux, obesity, dysfunctional breathing and inducible laryngeal obstruction can sustain symptoms. A prescription written four weeks ago does not prove adequate treatment delivery.

Persistent uncontrolled disease despite optimized high-dose ICS-LABA requires specialist assessment. LAMA can be an add-on, and biologic selection depends on eligibility and phenotype, such as allergic IgE-mediated disease, eosinophilic disease or other eligible severe asthma pathways. A blood count alone does not choose a biologic. Long-term oral corticosteroid exposure should be minimized. During pregnancy, continue necessary ICS-containing treatment and monitor control; uncontrolled asthma and exacerbations threaten both parent and fetus. Do not routinely step down treatment or perform methacholine challenge during pregnancy. [1]

Separate COPD symptoms from exacerbation prevention

GOLD spirometric grades describe FEV1 after obstruction is confirmed. Grade 1 is at least 80% predicted, grade 2 is 50 to 79%, grade 3 is 30 to 49%, and grade 4 is below 30%. These grades are not the A, B and E treatment groups. Initial inhaler choice also needs symptom burden and the previous year's exacerbations. [2]

GOLD 2026 places a patient with even one moderate or severe exacerbation in the previous year into Group E. With no such events, low symptom burden corresponds to A and higher burden to B. The usual symptom cutoffs are CAAT, formerly CAT, of 10 or mMRC of 2. A short question that says only “moderate COPD” cannot support one universal first inhaler.

Relieve daily breathlessness

Group A receives a bronchodilator guided by benefit. Group B generally starts LABA plus LAMA when accessible and tolerated. Persistent breathlessness on one long-acting bronchodilator often supports dual treatment after technique and other causes are reviewed.

Prevent another exacerbation

Group E generally starts LABA plus LAMA. Consider initial triple therapy with ICS when eosinophils are at least 300 cells/µL. During follow-up, exacerbations on dual therapy support adding ICS when the likely benefit outweighs risk, with benefit more likely from about 100 cells/µL and greater at higher counts.

[2]

Eosinophil thresholds describe a continuum of expected ICS benefit, not absolute biological switches. Review exacerbation history and pneumonia risk. ICS monotherapy is not usual COPD treatment, and LABA-ICS is generally less favored than triple therapy when ICS is indicated. The prohibition on LABA alone in asthma does not mean LABA monotherapy is intrinsically prohibited in COPD. If asthma coexists, retain an ICS-containing asthma-safe regimen. [2] [1]

Continued exacerbations despite optimized therapy require checking adherence, infection, bronchiectasis and other causes. Selected patients may qualify for roflumilast with chronic bronchitis and severe obstruction, a macrolide strategy, or phenotype-directed biologic treatment under current criteria. These are specialist decisions with specific benefits and adverse effects, not a reason to replace the initial bronchodilator assessment with a memorized drug ladder. [2]

Recognize failing ventilation before the chest becomes quiet

In acute asthma, inability to speak comfortably, exhaustion, altered consciousness, poor air entry or a silent chest can indicate severe obstruction. A falling wheeze volume is not necessarily improvement. PaCO2 is often low early; normal or rising CO2 with distress raises concern for ventilatory failure. Give rapid inhaled bronchodilation and early systemic corticosteroids for moderate or severe attacks, adding ipratropium in severe attacks and intravenous magnesium when severe obstruction responds poorly. Escalate airway support without waiting for a dramatic blood gas. Anaphylaxis requires epinephrine promptly, with bronchodilators as adjuncts. [1]

GINA 2026 revises oxygen use. In routine assessment of adults, adolescents and children 6 to 11, supplemental oxygen is indicated when saturation is below 92%; when given, target the 92 to 95% range rather than indiscriminate maximal saturation. Severe or life-threatening presentations require immediate resuscitation and controlled oxygen. The under-6 pathway is separate. Mild presentations may be treated with an appropriate ICS-formoterol regimen or SABA according to the setting and plan. Reassess response rather than giving escalating bronchodilator doses automatically; excess beta agonist can cause lactate-associated tachypnea. [1]

For a COPD exacerbation, start short-acting bronchodilator treatment, often SABA with or without SAMA, and assess for pneumonia, heart failure, PE or pneumothorax. Significant exacerbations commonly warrant prednisone-equivalent 40 mg daily for 5 days. Antibiotics are selected for evidence suggesting bacterial benefit, such as purulent sputum with increased dyspnea or sputum volume, or a need for mechanical ventilation; they are not required for every wheezy viral illness. Selection and duration follow severity, resistance risk and local guidance. [2] [15]

Titrate acute COPD oxygen, commonly to SpO2 88 to 92%, and check blood gases when hypercapnia or deterioration is a concern. Oxygen can worsen CO2 retention through redistribution of perfusion toward poorly ventilated units and the Haldane effect, in which oxygenated hemoglobin carries less CO2. Changes in ventilation also contribute, but “removing the hypoxic drive” is an inadequate explanation. Treat hypoxemia while controlling delivery; never withhold necessary oxygen out of fear of CO2. [6] [7] [2]

Bilevel NIV reduces intubation and mortality in suitable COPD exacerbations with acute respiratory acidosis, generally pH at or below 7.35. Response, airway protection, secretion burden, hemodynamics and available monitoring determine suitability. Worsening consciousness, shock, inability to protect the airway or failure to improve demands prompt escalation. A single pH cutoff does not automatically select an ordinary ward, ICU or intubation for every patient. [8]

Protect function and recognize a different disease

Smoking cessation slows lung-function loss and remains worthwhile after COPD is established. It does not regenerate destroyed alveoli. Offer treatment for nicotine dependence, reduce other harmful exposures, maintain recommended vaccination, encourage activity and use pulmonary rehabilitation when indicated. Recheck inhaler technique and provide an understandable action plan. [11] [2]

Long-term oxygen improves survival in severe chronic resting hypoxemia. ATS criteria include PaO2 at or below 55 mmHg or SpO2 at or below 88%, or PaO2 56 to 59 or SpO2 89% with edema, hematocrit at least 55% or P pulmonale. Establish persistence in a stable patient and reassess oxygen prescribed during an exacerbation. At least 15 hours daily is the traditional evidence-based duration. Moderate resting desaturation alone does not confer the same established survival benefit. [5]

Oxygen is not the only intervention with mortality evidence. Selected populations have benefited from triple inhaled therapy and from lung-volume-reduction surgery. NETT identified benefit in carefully selected upper-lobe predominant emphysema with low exercise capacity after rehabilitation. FEV1 at or below 20% plus either DLCO at or below 20% or homogeneous emphysema identified high surgical risk. Endobronchial valves also require anatomical selection, including assessment of collateral ventilation. A low FEV1 or recurrent exacerbations alone do not establish candidacy. [9] [10] [2]

Sudden unilateral pleuritic pain and reduced breath sounds in emphysema may indicate secondary spontaneous pneumothorax. A symptomatic patient with physiological compromise needs urgent drainage-based management, not routine outpatient observation. A new solid pulmonary nodule requires CT characterization, comparison with prior imaging and malignancy-risk assessment. For nodules above 8 mm, PET can help characterize an intermediate-probability lesion; tissue sampling or resection depends on risk and procedural feasibility. Not seeing a lesion on an old chest radiograph does not prove it appeared recently. [14] [13]

Bilateral hilar lymphadenopathy, erythema nodosum or uveitis should broaden the differential toward sarcoidosis and its alternatives. Serum ACE alone does not confirm sarcoidosis; compatible clinical findings, granulomatous tissue when needed and exclusion of infection or other mimics establish the diagnosis. Inspiratory noise and throat tightness during exercise suggest inducible laryngeal obstruction, which can coexist with asthma. New edema warrants assessment for cardiac, renal, hepatic or venous disease rather than assuming routine-dose ICS has a mineralocorticoid effect. [12] [1] [2]

Apply the lesson

Case 1

A 55-year-old with a 35 pack-year smoking history has progressive exertional dyspnea and daily sputum over several years. Post-bronchodilator FEV1/FVC remains 0.58 on repeat testing. FEV1 increases 8% after bronchodilator. Which conclusion is best?

Show answer and explanations for case 1

  1. A. The history and persistent post-bronchodilator obstruction support COPD. (Best answer)

    Longstanding exposure, progressive symptoms and repeated obstruction fit COPD; the 8% response is not the sole diagnostic criterion.

  2. B. Any bronchodilator response excludes COPD. (Why this does not fit)

    COPD can respond to bronchodilators while obstruction persists.

  3. C. The smoking history excludes coexisting asthma. (Why this does not fit)

    Asthma can occur in smokers and can coexist with COPD; additional history remains relevant.

  4. D. COPD is confirmed by age alone without needing spirometry. (Why this does not fit)

    Age is a risk context, not diagnostic evidence; objective persistent obstruction is essential.

Takeaway: Combine exposure, symptoms and post-bronchodilator physiology.

Case sources: [1] [2]

Case 2

An adult with seasonal nocturnal wheeze has pre-bronchodilator FEV1 of 2.00 L and post-bronchodilator FEV1 of 2.32 L. Using the adult GINA 2026 criterion, which interpretation is correct?

Show answer and explanations for case 2

  1. A. The response is negative because it is below 400 mL. (Why this does not fit)

    400 mL increases diagnostic confidence but is not the minimum positive threshold.

  2. B. The 320 mL and 16% increase documents a positive bronchodilator response. (Best answer)

    Both at least 200 mL and at least 12% from baseline are met; the symptom pattern also supports asthma.

  3. C. Only the change in FEV1/FVC is needed to calculate this response. (Why this does not fit)

    The specified response uses change in FEV1 volume relative to baseline, not the ratio change.

  4. D. This response proves COPD cannot coexist. (Why this does not fit)

    Bronchodilator responsiveness is not exclusive to asthma.

Takeaway: Report both the absolute change and the denominator used for the percentage.

Case sources: [1] [3]

Case 3

A 25-year-old has recurrent nighttime cough and wheeze during pollen season. Spirometry is normal today while asymptomatic. There is no pregnancy or contraindication to bronchial challenge. What is the best next diagnostic strategy?

Show answer and explanations for case 3

  1. A. Exclude asthma permanently because today's spirometry is normal. (Why this does not fit)

    Variable disease may produce normal testing between episodes.

  2. B. Diagnose emphysema without further testing. (Why this does not fit)

    The variable seasonal pattern and normal test do not support structural emphysema.

  3. C. Repeat symptomatic testing or use peak flows or bronchial challenge. (Best answer)

    These approaches can capture variable airflow limitation missed during a quiet interval.

  4. D. Treat a positive methacholine test as perfectly specific for asthma. (Why this does not fit)

    Responsiveness must be interpreted with the clinical pattern and alternatives.

Takeaway: Normal interval spirometry calls for better-timed or alternative objective testing.

Case sources: [1]

Case 4

A baker develops wheeze late in the workweek and improves during a two-week holiday. Baseline spirometry is normal on return from leave. Which investigation is most useful for the suspected exposure relationship?

Show answer and explanations for case 4

  1. A. Peak flow at work and away plus specialist assessment (Best answer)

    Repeated measurements linked to exposure can reveal work-associated variability that one off-work test misses.

  2. B. A single chest radiograph to exclude occupational asthma (Why this does not fit)

    A normal radiograph cannot exclude variable airway disease or establish the work relationship.

  3. C. A smoking questionnaire as the only investigation (Why this does not fit)

    Smoking assessment is useful, but the strong work-related pattern requires objective exposure-linked evaluation.

  4. D. Immediate lung biopsy (Why this does not fit)

    Biopsy is not the usual diagnostic route for this episodic exposure-associated airway pattern.

Takeaway: Ask when symptoms improve as well as when they occur.

Case sources: [1]

Case 5

A 32-year-old with little smoking exposure has basilar panacinar emphysema and a parent with unexplained cirrhosis. Which evaluation is most appropriate?

Show answer and explanations for case 5

  1. A. No genetic evaluation because COPD occurs only in older smokers. (Why this does not fit)

    This presentation strongly suggests a genetic contributor, and COPD is not restricted to heavy smokers.

  2. B. Serum ACE to confirm emphysema (Why this does not fit)

    ACE does not diagnose emphysema or explain the familial lung-liver pattern.

  3. C. Methacholine testing as the only required investigation (Why this does not fit)

    Airway responsiveness does not address the structural emphysema and liver history.

  4. D. Test alpha-1 antitrypsin protein and genotype or phenotype. (Best answer)

    Early basilar panacinar disease and family liver disease are characteristic reasons for testing; all COPD patients merit testing even without these features.

Takeaway: The classic alpha-1 pattern heightens suspicion but is not a prerequisite for testing.

Case sources: [4]

Case 6

A 70-year-old former smoker has hyperinflation, persistent obstruction and DLCO 38% predicted after accounting for hemoglobin. CT shows extensive emphysema. What explains the low DLCO?

Show answer and explanations for case 6

  1. A. Isolated bronchial smooth-muscle constriction with intact alveoli (Why this does not fit)

    That mechanism can cause obstruction in asthma but does not explain the CT destruction and marked gas-transfer loss.

  2. B. Loss of alveolar-capillary surface area (Best answer)

    Emphysematous destruction reduces effective gas-exchange area in this patient.

  3. C. Increased alveolar surface area from hyperinflation (Why this does not fit)

    Larger airspaces after wall destruction do not provide more exchange surface.

  4. D. A low DLCO uniquely identifies emphysema in every patient. (Why this does not fit)

    Anemia, vascular and interstitial disease can also reduce DLCO; the CT and other findings make emphysema persuasive here.

Takeaway: DLCO tests gas transfer and must be combined with anatomical and clinical evidence.

Case sources: [2] [3]

Case 7

A patient has productive cough for four months in each of the last three years. Other causes have been assessed. Spirometry shows persistent obstruction, but DLCO is normal and CT shows little emphysema. Which description best fits?

Show answer and explanations for case 7

  1. A. COPD with a chronic bronchitic phenotype (Best answer)

    The cough duration meets the traditional chronic bronchitis definition; preserved DLCO is compatible with predominantly airway disease.

  2. B. Emphysema is mandatory because obstruction is present. (Why this does not fit)

    Small-airway disease and mucus can cause obstruction without extensive alveolar destruction.

  3. C. Normal DLCO excludes COPD. (Why this does not fit)

    Gas transfer can be preserved in airway-predominant COPD.

  4. D. The cough definition alone proves COPD in every person. (Why this does not fit)

    Chronic bronchitis can exist without spirometric obstruction; this patient has both findings.

Takeaway: A clinical mucus phenotype and a spirometric diagnosis answer different questions.

Case sources: [2] [3]

Case 8

A breathless patient has FVC 65% predicted and a preserved FEV1/FVC ratio. The clinician suspects restrictive disease. Which test is needed to confirm the physiological restriction?

Show answer and explanations for case 8

  1. A. FEF25-75 alone (Why this does not fit)

    Mid-expiratory flow does not measure total lung volume and is too variable to establish restriction.

  2. B. A bronchodilator response alone (Why this does not fit)

    Responsiveness does not establish whether total lung capacity is reduced.

  3. C. Measurement of total lung capacity against its lower limit of normal (Best answer)

    Low FVC can reflect restriction, air trapping or a nonspecific pattern. Reduced TLC establishes restriction.

  4. D. A fixed FEV1 cutoff of 80% in isolation (Why this does not fit)

    FEV1 alone does not define restriction and fixed percent cutoffs ignore reference limits.

Takeaway: Confirm restriction with lung volumes rather than a low FVC alone.

Case sources: [3]

Case 9

A patient with occasional cough has technically acceptable spirometry with normal FEV1, FVC and FEV1/FVC. FEF25-75 is low. Which interpretation is most appropriate?

Show answer and explanations for case 9

  1. A. Definite early COPD requiring triple therapy (Why this does not fit)

    An isolated mid-flow result does not establish COPD or an indication for ICS-containing triple treatment.

  2. B. This finding alone cannot diagnose small-airway disease. (Best answer)

    FEF25-75 is variable and influenced by FVC; the clinician should interpret symptoms and more robust measurements.

  3. C. Definite restrictive lung disease (Why this does not fit)

    A flow measure does not establish a low TLC.

  4. D. Definite severe asthma despite the otherwise normal test (Why this does not fit)

    Asthma requires clinical and objective support; this isolated result does not establish severity.

Takeaway: Do not promote a noisy secondary measurement into a stand-alone diagnosis.

Case sources: [3]

Case 10

A 12-year-old with eczema develops wheeze after visiting a home with cats. Variable airflow limitation has been documented, and blood eosinophils are increased. Which mechanism best fits this phenotype?

Show answer and explanations for case 10

  1. A. An allergic type 2 pathway involving IgE and eosinophils (Best answer)

    Atopy, the sensitizing exposure and documented variability support allergic asthma; IL-4/IL-13 and IL-5 participate in these pathways.

  2. B. Universal absence of inflammation in asthma (Why this does not fit)

    Inflammation is central to this allergic phenotype and supports ICS-containing treatment.

  3. C. Alpha-1 protein accumulation in alveoli as the immediate trigger (Why this does not fit)

    Alpha-1 deficiency causes a different emphysema mechanism and does not explain rapid cat-associated episodes.

  4. D. A blood eosinophil count that alone proves asthma in any patient (Why this does not fit)

    Eosinophilia is supportive here because the symptom pattern and airflow variability are established; it is not specific alone.

Takeaway: Use biomarkers to characterize a demonstrated clinical pattern.

Case sources: [1]

Case 11

A 21-year-old with confirmed asthma has symptoms about once weekly and no recent exacerbations. An appropriate ICS-formoterol inhaler is available. Which plan aligns with GINA's preferred adult lower-step strategy?

Show answer and explanations for case 11

  1. A. Albuterol alone indefinitely (Why this does not fit)

    Symptom frequency does not eliminate severe exacerbation risk, and GINA recommends ICS-containing treatment.

  2. B. Salmeterol alone as the rescue inhaler (Why this does not fit)

    LABA alone is unsafe in asthma and salmeterol is not the rapid reliever used in MART or AIR regimens.

  3. C. Daily oral prednisone (Why this does not fit)

    The stem does not justify the systemic harms of maintenance oral corticosteroid.

  4. D. As-needed low-dose ICS-formoterol with an action plan and follow-up (Best answer)

    This provides symptom relief together with anti-inflammatory treatment at the lower adult steps.

Takeaway: Even infrequent asthma symptoms need an ICS-containing strategy.

Case sources: [1]

Case 12

A 7-year-old with confirmed asthma has symptoms twice monthly and uses only albuterol. The clinician is applying GINA 2026 and can provide a suitable age-specific product and instructions. Which change is most appropriate?

Show answer and explanations for case 12

  1. A. Use an age-appropriate ICS-containing reliever strategy. (Best answer)

    GINA 2026 includes these Step 1 options for ages 6 to 11; the exact device and regimen must be age appropriate.

  2. B. Continue SABA alone because symptoms are less than weekly. (Why this does not fit)

    The updated pathway includes ICS with reliever treatment even at Step 1.

  3. C. Use adult-dose salmeterol alone whenever symptoms occur. (Why this does not fit)

    Salmeterol alone is neither an appropriate rescue treatment nor asthma-safe therapy.

  4. D. Assume the same recommendation applies unchanged to every preschool child. (Why this does not fit)

    The under-6 pathway is separate and cannot be inferred from the 6-to-11-year recommendation.

Takeaway: State the age group and guideline version when selecting childhood asthma treatment.

Case sources: [1] [16]

Case 13

A 9-year-old newly diagnosed with asthma has symptoms four days per week but no current exacerbation. Technique and family ability to administer medication have been assessed. Which established Step 2 controller strategy is preferred in GINA 2026?

Show answer and explanations for case 13

  1. A. No anti-inflammatory treatment unless hospitalized (Why this does not fit)

    Frequent symptoms justify controller treatment before a severe event occurs.

  2. B. Daily low-dose ICS with an appropriate reliever plan (Best answer)

    Daily low-dose ICS remains preferred for children needing Step 2; as-needed ICS-formoterol has not been shown equivalent to daily ICS for this group.

  3. C. Long-term oral prednisone as the first controller (Why this does not fit)

    Systemic corticosteroid toxicity makes this inappropriate for initial treatment of this child.

  4. D. Tiotropium alone as the universal first controller (Why this does not fit)

    LAMA does not replace ICS as foundational asthma anti-inflammatory therapy.

Takeaway: New reliever options do not erase the established role of daily ICS for persistent childhood symptoms.

Case sources: [1]

Case 14

An adult reports daily symptoms four weeks after starting ICS-LABA. During review, the patient demonstrates actuating the inhaler after finishing inspiration and has not been using the prescribed spacer. What is the best next step?

Show answer and explanations for case 14

  1. A. Immediately label the disease steroid-resistant. (Why this does not fit)

    Medication has not been delivered effectively, so a biological treatment failure has not been established.

  2. B. Stop ICS and use LABA alone. (Why this does not fit)

    This would leave asthma without appropriate anti-inflammatory treatment.

  3. C. Correct technique and adherence before escalating treatment. (Best answer)

    The observed delivery problem is a modifiable reason for poor control.

  4. D. Begin a biologic without checking the diagnosis or phenotype. (Why this does not fit)

    Severe asthma assessment requires optimization and confirmation before biologic selection.

Takeaway: Watch the inhaler being used before deciding the drug has failed.

Case sources: [1]

Case 15

A patient with asthma remains symptomatic despite verified low-dose ICS adherence and correct technique. The clinician selects maintenance-and-reliever therapy with an appropriate budesonide-formoterol product. Which instruction describes MART?

Show answer and explanations for case 15

  1. A. Use ICS-formoterol for maintenance and relief. (Best answer)

    MART uses the same appropriate combination for both roles, with explicit maximum daily doses and an action plan.

  2. B. Use salmeterol alone for all extra doses. (Why this does not fit)

    Salmeterol is not the rapid-onset reliever in MART, and LABA alone is inappropriate in asthma.

  3. C. Stop all scheduled treatment once a reliever is available. (Why this does not fit)

    This patient has been assigned a maintenance regimen because control remains inadequate.

  4. D. Use unlimited doses because the inhaled route prevents toxicity. (Why this does not fit)

    Combination inhalers have age-specific maximum doses and escalation instructions.

Takeaway: MART is a defined regimen using a suitable ICS-formoterol product, not any ICS-LABA inhaler.

Case sources: [1]

Case 16

A patient has recurrent severe asthma exacerbations despite specialist-confirmed diagnosis, reliable high-dose ICS-LABA use and corrected exposures. Eosinophils remain high. What is the most appropriate next assessment?

Show answer and explanations for case 16

  1. A. Switch to SABA alone to reduce medication burden. (Why this does not fit)

    This would withdraw protective anti-inflammatory treatment from severe disease.

  2. B. Select an anti-IgE drug solely because eosinophils are high. (Why this does not fit)

    Anti-IgE eligibility requires an appropriate allergic phenotype and other criteria; eosinophils alone do not establish it.

  3. C. Prescribe indefinite oral prednisone without reviewing alternatives. (Why this does not fit)

    Maintenance systemic steroid harms favor assessment of appropriate add-on and biologic options first.

  4. D. Assess phenotype-specific biologics and add-on LAMA eligibility. (Best answer)

    The prerequisite optimization is documented; specialist selection can now address severe asthma pathways and eligibility.

Takeaway: Persistent severe asthma requires a phenotype-based decision after treatment delivery is optimized.

Case sources: [1]

Case 17

A pregnant patient with previously controlled asthma asks whether to stop the ICS-containing inhaler. There are no adverse effects, and symptoms recur when doses are missed. What is the best plan?

Show answer and explanations for case 17

  1. A. Stop ICS because untreated wheeze cannot affect pregnancy. (Why this does not fit)

    Poor control and exacerbations can harm both parent and fetus.

  2. B. Continue necessary ICS-containing therapy and monitor control. (Best answer)

    Maintaining control generally outweighs the risks of withdrawing effective therapy; pregnancy is not a routine time to step down.

  3. C. Perform methacholine challenge before continuing treatment. (Why this does not fit)

    Bronchial provocation is contraindicated during pregnancy and is unnecessary to justify continuing established effective treatment.

  4. D. Guarantee that every asthma medication is risk-free in every pregnancy. (Why this does not fit)

    Treatment requires drug-specific assessment; benefit from necessary therapy does not imply universal absence of risk.

Takeaway: Pregnancy increases the importance of maintaining good asthma control.

Case sources: [1]

Case 18

A 63-year-old smoker has persistent post-bronchodilator obstruction and a well-documented history of variable allergic asthma since adolescence. Which treatment principle is essential?

Show answer and explanations for case 18

  1. A. Retain an ICS-containing regimen while treating the COPD components. (Best answer)

    Coexisting asthma requires anti-inflammatory treatment; persistent obstruction does not justify withdrawing ICS automatically.

  2. B. Treat with LABA alone because the patient now has COPD. (Why this does not fit)

    LABA monotherapy is inappropriate when asthma coexists.

  3. C. Exclude asthma because the obstruction is persistent. (Why this does not fit)

    Longstanding asthma can produce persistent limitation, and the diseases can coexist.

  4. D. Choose treatment using age alone. (Why this does not fit)

    The documented asthma history and current physiology, not age alone, determine treatment safety.

Takeaway: Coexisting asthma changes the minimum safe COPD inhaler strategy.

Case sources: [1] [2]

Case 19

A newly diagnosed COPD patient has mMRC grade 1 breathlessness, CAAT score 6 and no moderate or severe exacerbation in the past year. There is no asthma history. Which initial approach best fits GOLD 2026?

Show answer and explanations for case 19

  1. A. Mandatory ICS-LABA-LAMA regardless of symptoms (Why this does not fit)

    There is no exacerbation history or coexisting asthma to justify automatic triple therapy.

  2. B. Use a bronchodilator guided by symptoms and benefit. (Best answer)

    This is a low-symptom Group A pattern; treatment is individualized, with long-acting therapy generally preferred except for very occasional symptoms.

  3. C. ICS alone as the standard COPD regimen (Why this does not fit)

    ICS monotherapy is not the usual foundational COPD treatment.

  4. D. Maintenance prednisone because spirometry confirms obstruction (Why this does not fit)

    Persistent obstruction alone does not justify chronic systemic corticosteroids.

Takeaway: Initial COPD treatment needs symptoms and exacerbation history, not the diagnosis alone.

Case sources: [2]

Case 20

A treatment-naive patient with COPD has CAAT score 19 and mMRC grade 2 dyspnea, with no moderate or severe exacerbations in the previous year. Dual therapy is affordable and tolerated. What initial maintenance treatment is preferred?

Show answer and explanations for case 20

  1. A. LABA plus LAMA (Best answer)

    The high symptom burden without recent exacerbations fits Group B, for which dual long-acting bronchodilation is preferred.

  2. B. ICS alone (Why this does not fit)

    The stem supplies no indication for ICS monotherapy, which is not standard COPD treatment.

  3. C. No inhaler because there has been no exacerbation (Why this does not fit)

    Persistent breathlessness warrants symptom-directed treatment even without exacerbations.

  4. D. A mandatory LAMA-only regimen for every symptomatic patient (Why this does not fit)

    Monotherapy can be individualized when dual therapy is unsuitable, but that limitation is absent here.

Takeaway: GOLD Group B generally starts dual bronchodilation when feasible.

Case sources: [2]

Case 21

A newly evaluated COPD patient has a CAAT score of 7 and had one exacerbation treated with systemic corticosteroids four months ago. No hospitalization occurred. How is this patient grouped for initial treatment in GOLD 2026?

Show answer and explanations for case 21

  1. A. Group A because symptoms are mild today (Why this does not fit)

    The previous moderate exacerbation places the patient in the exacerbation-risk group despite low current symptoms.

  2. B. Group B because any steroid use defines high daily symptoms (Why this does not fit)

    B describes higher symptom burden without a moderate or severe event in the previous year.

  3. C. Group E because one moderate exacerbation now meets the risk threshold (Best answer)

    GOLD 2026 includes at least one moderate or severe exacerbation during the previous year.

  4. D. GOLD spirometric grade 4 regardless of FEV1 (Why this does not fit)

    A, B and E are not spirometric grades; FEV1 is needed to assign the latter.

Takeaway: The 2026 Group E threshold includes a single moderate exacerbation.

Case sources: [2]

Case 22

A patient with COPD has three treated exacerbations despite verified LABA-LAMA use, good technique and pulmonary rehabilitation. Eosinophils are 420 cells/µL and there is no recurrent pneumonia. Which inhaler adjustment is best supported?

Show answer and explanations for case 22

  1. A. Replace both bronchodilators with ICS alone. (Why this does not fit)

    ICS is added to appropriate long-acting bronchodilation when indicated; it does not replace both agents here.

  2. B. Stop all long-acting drugs after each exacerbation. (Why this does not fit)

    That would withdraw maintenance prevention from a patient with repeated events.

  3. C. Add ICS solely to improve an isolated low DLCO. (Why this does not fit)

    The relevant indication is exacerbation prevention with a favorable eosinophil profile, not diffusion capacity.

  4. D. Add ICS to form triple therapy. (Best answer)

    Repeated exacerbations on dual therapy and eosinophils well above 300 predict a greater likelihood of benefit.

Takeaway: Eosinophils help estimate ICS benefit in the context of actual exacerbations.

Case sources: [2]

Case 23

A patient with COPD has persistent exertional dyspnea on tiotropium but no exacerbations. Eosinophils are 50 cells/µL, and there have been two pneumonias. Technique is correct and alternative causes are being assessed. Which inhaler change best targets the residual COPD symptom?

Show answer and explanations for case 23

  1. A. Add a LABA to provide dual bronchodilation. (Best answer)

    Persistent dyspnea on one long-acting bronchodilator supports dual therapy; the history does not favor adding ICS for exacerbation prevention.

  2. B. Add ICS because every COPD symptom is steroid-responsive. (Why this does not fit)

    Low eosinophils, no exacerbations and recurrent pneumonia argue against indiscriminate ICS addition.

  3. C. Avoid all LABAs because LABA monotherapy increases asthma risk. (Why this does not fit)

    The asthma safety rule is not a prohibition on LABA use in COPD; this patient is receiving a LAMA and has no asthma history.

  4. D. Start indefinite oral corticosteroids. (Why this does not fit)

    Chronic systemic steroid toxicity is not justified for this stable symptom pattern.

Takeaway: Treat persistent dyspnea and recurrent exacerbations as different therapeutic questions.

Case sources: [2]

Case 24

During a COPD exacerbation, a patient receives high-concentration oxygen and later becomes more hypercapnic. Minute ventilation has changed only modestly. Which explanation best fits the physiology?

Show answer and explanations for case 24

  1. A. Complete loss of all respiratory drive is the only possible mechanism. (Why this does not fit)

    CO2 can rise substantially without a matching fall in ventilation, so a drive-only explanation is incomplete.

  2. B. V/Q mismatch and the Haldane effect contribute to CO2 retention. (Best answer)

    Oxygen can redirect perfusion toward poorly ventilated units and reduce hemoglobin CO2 carriage. Controlled delivery and blood-gas reassessment are needed.

  3. C. Oxygen should be stopped even if severe hypoxemia returns. (Why this does not fit)

    Hypoxemia still requires treatment. Titrate oxygen, commonly to 88 to 92%, while treating ventilatory failure.

  4. D. Oxygen creates new emphysema within minutes. (Why this does not fit)

    Acute CO2 retention reflects gas-exchange physiology, not immediate destruction of alveolar walls.

Takeaway: Titrate oxygen and support ventilation rather than withholding oxygen or relying on the hypoxic-drive myth.

Case sources: [6] [7] [2]

Case 25

A patient with COPD develops increased dyspnea, sputum volume and new purulent sputum over three days. Pneumonia and heart failure have been assessed. The patient can take oral medication and has a significant exacerbation. Which plan is most appropriate?

Show answer and explanations for case 25

  1. A. Only increase long-term ICS and wait a week. (Why this does not fit)

    The acute episode needs rapid bronchodilation and assessment for systemic steroid and antibiotic benefit.

  2. B. Give 14 days of systemic steroids to every patient, regardless of clinical response, adverse effects, comorbidities, or recovery. (Why this does not fit)

    A shorter course is standard for many COPD exacerbations and reduces steroid exposure.

  3. C. Use short-acting bronchodilators, a usual 5-day prednisone-equivalent course and an appropriate antibiotic. (Best answer)

    The increased dyspnea and purulent sputum pattern supports antibiotic benefit, while significant exacerbations commonly warrant prednisone-equivalent 40 mg daily for 5 days.

  4. D. Antibiotics are indicated for every future mild viral wheeze. (Why this does not fit)

    The indication here depends on the episode's features; it does not justify universal antibiotic use.

Takeaway: Acute treatment depends on severity and evidence for bacterial benefit, not the COPD label alone.

Case sources: [2] [15]

Case 26

A COPD patient remains tachypneic after initial exacerbation treatment. ABG shows pH 7.28, PaCO2 65 mmHg and bicarbonate 30 mmol/L. The patient is alert, cooperative, stable and protecting the airway. What support is most appropriate?

Show answer and explanations for case 26

  1. A. Immediate discharge because chronic COPD explains any acidosis (Why this does not fit)

    Persistent acute acidemia and increased work of breathing require treatment and monitoring.

  2. B. High-dose sedative to suppress respiratory effort (Why this does not fit)

    Suppressing ventilation risks worsening CO2 retention and airway protection.

  3. C. Bicarbonate instead of ventilatory assistance (Why this does not fit)

    The dominant problem is inadequate CO2 elimination, and alkali generates additional CO2.

  4. D. A monitored bilevel NIV trial with early response assessment (Best answer)

    This is an appropriate acute hypercapnic respiratory failure scenario for NIV, with escalation if response or airway protection deteriorates.

Takeaway: NIV eligibility depends on the whole clinical picture, and the trial must be reassessed.

Case sources: [8]

Case 27

A patient with severe asthma initially had PaCO2 28 mmHg. Despite treatment, the patient becomes exhausted, speaks only single words and has very poor air entry. PaCO2 is now 42. What does this change mean?

Show answer and explanations for case 27

  1. A. Possible failing ventilation requiring urgent escalation (Best answer)

    A rising CO2 from a low value in a still-distressed, exhausted patient is ominous, even before it exceeds the usual reference range.

  2. B. Definite recovery because CO2 is now normal (Why this does not fit)

    The clinical deterioration and reduced ventilation outweigh reassurance from the reference range.

  3. C. Asthma has been excluded because wheeze is quieter (Why this does not fit)

    Severe obstruction can reduce airflow enough to make the chest quiet.

  4. D. The patient should perform repeated maximal spirometry before further treatment. (Why this does not fit)

    Testing must not delay resuscitation or airway decisions in an exhausted patient.

Takeaway: A quiet chest and a normalizing CO2 can mark worsening asthma.

Case sources: [1]

Case 28

An adult with an asthma exacerbation has room-air SpO2 of 89% and no history of chronic hypercapnia. Controlled supplemental oxygen is started. Which saturation range reflects GINA 2026 guidance for this age group?

Show answer and explanations for case 28

  1. A. 100% continuously regardless of dose (Why this does not fit)

    The updated guidance favors controlled oxygen and an upper target of 95%, not indiscriminate hyperoxia.

  2. B. 92 to 95% (Best answer)

    The saturation is below the 92% treatment threshold, and the adult target range has an upper limit of 95%.

  3. C. 82 to 86% to preserve hypoxic drive (Why this does not fit)

    This leaves clinically important hypoxemia and imports an inaccurate physiological rationale.

  4. D. No oxygen because bronchodilators replace oxygen therapy (Why this does not fit)

    Bronchodilators address obstruction, but current hypoxemia requires oxygen treatment as well.

Takeaway: Apply the current asthma oxygen target rather than assuming more oxygen is always better.

Case sources: [1]

Case 29

A stable COPD patient has repeated room-air PaO2 measurements of 52 mmHg after recovery from an exacerbation. Which intervention has established benefit for this physiological subgroup?

Show answer and explanations for case 29

  1. A. Long-term oxygen for at least 15 hours daily. (Best answer)

    Persistent severe resting hypoxemia meets established LTOT criteria and is the subgroup with demonstrated survival benefit.

  2. B. Oxygen only when the patient feels breathless, regardless of measurements (Why this does not fit)

    Symptoms alone do not define the prescription or the evidence-based duration.

  3. C. Withhold oxygen because chronic hypercapnia is always a contraindication (Why this does not fit)

    Hypercapnia does not negate severe hypoxemia as an indication; delivery and ventilation need appropriate assessment.

  4. D. Assume the same survival benefit at any mildly reduced saturation (Why this does not fit)

    Moderate resting desaturation does not have the same established LTOT survival evidence.

Takeaway: Confirm stable severe hypoxemia before applying long-term oxygen evidence.

Case sources: [5]

Case 30

A patient with newly diagnosed COPD asks whether stopping smoking still matters now that emphysema is present. Which explanation is most accurate?

Show answer and explanations for case 30

  1. A. Stopping smoking regenerates all destroyed alveolar walls. (Why this does not fit)

    Cessation reduces continuing injury but does not reconstruct established emphysema.

  2. B. Cessation has no effect once FEV1 is abnormal. (Why this does not fit)

    The Lung Health Study showed reduced subsequent lung-function decline in people with established mild obstruction.

  3. C. Sustained cessation can slow further FEV1 loss and reduce ongoing harm. (Best answer)

    The benefit persists after disease is recognized, although existing structural damage may remain.

  4. D. A bronchodilator permanently replaces the benefit of cessation. (Why this does not fit)

    Bronchodilation treats airflow symptoms and does not eliminate continued smoke injury.

Takeaway: Smoking cessation is treatment at every stage, with realistic expectations about existing damage.

Case sources: [11]

Case 31

A former smoker remains severely limited after optimized COPD treatment and rehabilitation. CT shows upper-lobe predominant emphysema, exercise capacity is low, FEV1 is 32% predicted and DLCO is 36%. What is the most appropriate next consideration?

Show answer and explanations for case 31

  1. A. Automatic surgery based only on FEV1 below 50% (Why this does not fit)

    Selection needs anatomical distribution, exercise capacity, comorbidity and procedural assessment, not a lone FEV1 value.

  2. B. No procedure can benefit any emphysema patient. (Why this does not fit)

    NETT identified selected patients who benefited from lung-volume reduction.

  3. C. Endobronchial valves without assessing collateral ventilation (Why this does not fit)

    Valve candidacy requires suitable anatomy and assessment of collateral ventilation.

  4. D. Specialist evaluation for lung-volume reduction. (Best answer)

    The upper-lobe and low-exercise pattern merits evaluation; this is a referral decision, not proof that surgery is appropriate.

Takeaway: Lung-volume reduction is selected by phenotype and procedural risk, not by a generic severe-COPD label.

Case sources: [9] [2]

Case 32

A 68-year-old with emphysema develops sudden right pleuritic pain and marked breathlessness. SpO2 is 85%, right breath sounds are reduced and imaging confirms a large right pneumothorax. Blood pressure is currently maintained. What is the best approach?

Show answer and explanations for case 32

  1. A. Urgent drainage-based management in hospital. (Best answer)

    Underlying lung disease, hypoxemia and substantial symptoms make routine outpatient observation inappropriate; the patient needs prompt treatment and monitoring.

  2. B. Discharge solely because blood pressure is normal. (Why this does not fit)

    Normotension does not remove the gas-exchange risk in a compromised emphysema patient.

  3. C. Treat only with additional ICS. (Why this does not fit)

    ICS will not evacuate pleural air or restore the affected lung's expansion.

  4. D. Assume it is an ordinary COPD exacerbation despite imaging. (Why this does not fit)

    The confirmed pleural air identifies a separate acute cause requiring its own management.

Takeaway: Sudden asymmetric findings in COPD should prompt evaluation for pneumothorax.

Case sources: [14]

Case 33

CT identifies a 2 cm solid pulmonary nodule in a former smoker. Prior CT is unavailable, and an old chest radiograph did not show the lesion. The estimated malignancy probability is intermediate. Which next approach is most appropriate?

Show answer and explanations for case 33

  1. A. Declare rapid growth solely because the old radiograph was negative. (Why this does not fit)

    A chest radiograph may miss a lesion; absence on that study does not establish CT growth.

  2. B. Use risk-based evaluation with PET when appropriate. (Best answer)

    For a solid nodule above 8 mm with intermediate probability, PET can help characterize risk, while procedural and patient factors guide subsequent sampling.

  3. C. PET can only stage an already proven cancer and has no characterization role. (Why this does not fit)

    PET also has a role in evaluating intermediate-probability solid nodules.

  4. D. Ignore the nodule because COPD explains all respiratory symptoms. (Why this does not fit)

    COPD does not make a 2 cm nodule clinically irrelevant.

Takeaway: Separate a nodule's probability of malignancy from whether it was visible on a less sensitive prior study.

Case sources: [13]

Case 34

A patient with cough has bilateral hilar lymphadenopathy and uveitis. Serum ACE is increased. Which diagnostic statement is most accurate?

Show answer and explanations for case 34

  1. A. ACE alone confirms sarcoidosis. (Why this does not fit)

    ACE lacks sufficient sensitivity and specificity to establish the diagnosis independently.

  2. B. The findings prove emphysema. (Why this does not fit)

    Hilar adenopathy and uveitis suggest a different systemic process.

  3. C. Assess for sarcoidosis and exclude alternatives. (Best answer)

    Infection, malignancy and other granulomatous conditions must be considered; biopsy need depends on the presentation.

  4. D. A response to albuterol would exclude sarcoidosis. (Why this does not fit)

    Airway responsiveness is not a definitive discriminator for this systemic pattern.

Takeaway: Use compatible findings and exclusion of mimics rather than a single sarcoidosis biomarker.

Case sources: [12]

Case 35

A COPD patient on stable-dose inhaled corticosteroid develops bilateral leg edema and orthopnea. Which response is most appropriate?

Show answer and explanations for case 35

  1. A. Diagnose an ICS mineralocorticoid effect without examination. (Why this does not fit)

    Routine-dose ICS is not a sufficient explanation for this new syndrome; attributing edema to it risks missing organ disease.

  2. B. Stop all bronchodilators and ignore oxygenation. (Why this does not fit)

    The cause of edema and breathlessness needs assessment while essential respiratory treatment is reviewed appropriately.

  3. C. Assume every COPD patient with edema has right-heart failure. (Why this does not fit)

    Cor pulmonale is possible, but left-heart, renal, hepatic and venous causes remain important.

  4. D. Assess cardiac and systemic causes, including cor pulmonale. (Best answer)

    New orthopnea and edema require clinical examination and targeted investigation rather than automatic medication attribution.

Takeaway: A familiar lung diagnosis must not obscure a new multisystem problem.

Case sources: [2]

Case 36

A runner reports abrupt throat tightness and inspiratory noise at peak exercise, with rapid resolution after stopping. Albuterol has not helped. Which investigation best addresses the suspected alternative to exercise-induced bronchoconstriction?

Show answer and explanations for case 36

  1. A. Laryngeal assessment during exercise or symptoms (Best answer)

    The inspiratory throat symptoms and rapid recovery suggest inducible laryngeal obstruction; visualization during the event can establish the mechanism.

  2. B. Diagnose severe eosinophilic asthma from exercise symptoms alone. (Why this does not fit)

    The symptom quality and poor bronchodilator response warrant evaluation of an upper-airway mechanism.

  3. C. Exclude all asthma permanently without lower-airway testing. (Why this does not fit)

    Laryngeal obstruction and asthma can coexist; each suspected component needs appropriate testing.

  4. D. Use a normal resting examination to exclude exercise-related disease. (Why this does not fit)

    The suspected abnormality is episodic and may be absent at rest.

Takeaway: The phase of breathing and timing during exercise can identify the anatomical site of symptoms.

Case sources: [1] [3]

Case 37

A patient with symptomatic COPD and repeated exacerbations asks whether oxygen is the only treatment ever shown to affect survival. Which statement is most accurate?

Show answer and explanations for case 37

  1. A. Yes; no other COPD intervention has mortality evidence. (Why this does not fit)

    This ignores selected triple-therapy trials and appropriately selected lung-volume-reduction populations.

  2. B. No; mortality benefit exists for selected interventions and patients. (Best answer)

    LTOT evidence applies to severe resting hypoxemia, while triple therapy and surgery have evidence in particular selected populations.

  3. C. Every COPD inhaler has identical proven survival benefit for every patient. (Why this does not fit)

    Effects depend on intervention, comparison and population; benefits cannot be generalized that broadly.

  4. D. All patients should undergo surgery to obtain a survival benefit. (Why this does not fit)

    Some physiological and anatomical groups have high operative risk and little expected benefit.

Takeaway: Mortality evidence is population-specific and should not become an absolute slogan.

Case sources: [5] [9] [10]

Case 38

A patient has post-bronchodilator FEV1/FVC 0.55 and FEV1 42% predicted, but few daily symptoms and no exacerbations in the previous year. Which classification statement is correct?

Show answer and explanations for case 38

  1. A. The patient must be Group E solely because FEV1 is below 50%, regardless of symptom burden, exacerbation history, clinical context, or any other GOLD criteria. (Why this does not fit)

    Group E is determined by the exacerbation history, not the spirometric grade alone.

  2. B. GOLD grade 3 means the same thing as Group B. (Why this does not fit)

    Spirometric grades and symptom/exacerbation groups describe different dimensions.

  3. C. The patient has GOLD spirometric grade 3, while initial treatment grouping depends on symptoms and exacerbations. (Best answer)

    FEV1 42% falls in the 30-to-49% band. The low-symptom, no-exacerbation history can still correspond to Group A.

  4. D. The obstruction is excluded because symptoms are mild. (Why this does not fit)

    The post-bronchodilator ratio confirms persistent obstruction in the appropriate clinical context despite low perceived symptom burden.

Takeaway: Do not substitute FEV1 grade for symptom and exacerbation assessment.

Case sources: [2]

Sources

  1. GINA 2026 Strategy Report, Global Strategy for Asthma Management and Prevention (2026)

    Diagnosis, adult and child anti-inflammatory relievers, MART, severe asthma assessment, pregnancy and updated acute oxygen guidance. See printed pages 28, 32, 80-106, 135 and 180-187.

  2. GOLD 2026 Report, Global Strategy for Diagnosis, Management and Prevention of COPD (2025)

    2026 edition, version dated 8 December 2025. COPD diagnosis, ABE classification, inhaled treatment, eosinophils, exacerbations and follow-up. See printed pages 43, 64-66, 76 and 103-108.

  3. ERS/ATS technical standard on interpretive strategies for routine lung function tests (2022)

    Lower limits of normal, lung volumes, bronchodilator response reporting, flow-volume interpretation and limitations of mid-expiratory flow.

  4. The Diagnosis and Management of Alpha-1 Antitrypsin Deficiency in the Adult (2016)

    Testing all patients with COPD, protein and genotype assessment, lung and liver manifestations.

  5. Home Oxygen Therapy for Adults with Chronic Lung Disease, Official ATS Clinical Practice Guideline (2020)

    Severe chronic resting hypoxemia thresholds, long-term oxygen and limits of benefit in moderate hypoxemia.

  6. Effect of high flow oxygen on mortality in COPD patients in the prehospital setting, randomized controlled trial (2010)

    Titrated oxygen in acute COPD and harm of indiscriminate high-concentration oxygen.

  7. Effects of the administration of O2 on ventilation and blood gases in COPD during acute respiratory failure (1980)

    Primary physiology showing that oxygen-associated hypercapnia is not explained simply by loss of respiratory drive.

  8. Official ERS/ATS clinical practice guidelines, Noninvasive ventilation for acute respiratory failure (2017)

    NIV in COPD with acute respiratory acidosis and need for close reassessment and escalation.

  9. A Randomized Trial Comparing Lung-Volume-Reduction Surgery with Medical Therapy for Severe Emphysema (2003)

    NETT selection, upper-lobe predominant emphysema with low exercise capacity, and high-risk surgical physiology.

  10. Reduced All-Cause Mortality in the ETHOS Trial of Budesonide/Glycopyrrolate/Formoterol for COPD (2021)

    Mortality evidence for selected triple therapy populations, preventing the false claim that oxygen is the only beneficial intervention.

  11. Effects of smoking intervention and an inhaled anticholinergic on FEV1 decline, The Lung Health Study (1994)

    Sustained smoking cessation and slower loss of lung function.

  12. Diagnosis and Detection of Sarcoidosis, Official ATS Clinical Practice Guideline (2020)

    Compatible presentation, granulomatous pathology when required, and exclusion of alternative causes; ACE is not diagnostic alone.

  13. Evaluation of Individuals With Pulmonary Nodules, ACCP Evidence-Based Clinical Practice Guidelines (2013)

    Risk-based assessment of solid nodules above 8 mm, PET characterization in intermediate probability and tissue decisions.

  14. British Thoracic Society Guideline for pleural disease (2023)

    Secondary spontaneous pneumothorax, physiological compromise and drainage-based management.

  15. Short-term vs Conventional Glucocorticoid Therapy in Acute Exacerbations of COPD, REDUCE trial (2013)

    Primary trial comparing 5 and 14 days of systemic glucocorticoids.

  16. Budesonide-formoterol versus salbutamol as reliever therapy in children with mild asthma, CARE trial (2025)

    Primary pediatric trial informing GINA 2026 anti-inflammatory reliever options; trial ages 5 to 15 do not automatically define approved product ages.

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