A 28-year-old woman with a 2-year history of episodic wheeze and dyspnea presents to the pulmonology clinic. Baseline spirometry shows FEV1 of 68% predicted with FEV1/FVC ratio of 0.62. She is asked to withhold her salbutamol inhaler for 6 hours, and then post-bronchodilator spirometry is performed 15 minutes after inhalation of 400 µg salbutamol via spacer. The post-bronchodilator FEV1 improves to 82% predicted, representing an absolute increase of 240 mL. The spirometric pattern marked **A** in the diagram (post-bronchodilator FEV1 improvement of ≥12% AND ≥200 mL) is demonstrated in this patient. Which of the following is the most appropriate next step in management according to GINA 2024 guidelines?

Explanation

## Why "Initiate low-dose inhaled corticosteroid-formoterol combination as both controller and reliever (Track 1 approach)" is right The spirometric pattern marked **A** — post-bronchodilator FEV1 improvement of ≥12% AND ≥200 mL — is the classic criterion for significant reversibility and strongly supports an asthma diagnosis (GINA 2024, ATS/ERS 2022). In this patient, the 14% relative improvement (240 mL absolute) confirms reversible airflow obstruction. GINA 2024 has shifted away from SABA-only monotherapy (which increases exacerbation and mortality risk) toward a preferred Track 1 approach: low-dose ICS-formoterol as both maintenance controller AND reliever medication, starting from Step 1. This patient requires anti-inflammatory therapy, and the combination ICS-LABA (formoterol) provides both baseline control and rapid relief due to formoterol's fast onset. ## Why each distractor is wrong - **Prescribe salbutamol monotherapy as needed, with review in 6 weeks**: This is the outdated, non-guideline-concordant approach. GINA 2024 explicitly recommends against SABA-only therapy due to increased exacerbation risk and mortality. Even mild asthma (Step 1) now requires ICS-formoterol as reliever. - **Perform high-resolution CT chest to exclude structural lung disease**: Imaging is not indicated in a patient with clear reversibility on spirometry and a clinical history consistent with asthma. The significant bronchodilator response makes structural obstruction unlikely and would delay appropriate anti-inflammatory therapy. - **Refer for bronchial provocation testing with methacholine**: Provocation testing is reserved for patients with clinical suspicion of asthma but NORMAL or near-normal baseline spirometry. This patient already has documented airflow obstruction with significant reversibility, making provocation testing unnecessary and delaying diagnosis and treatment. **High-Yield:** ≥12% AND ≥200 mL post-bronchodilator FEV1 improvement = significant reversibility = asthma diagnosis confirmed. GINA 2024 Step 1: low-dose ICS-formoterol as reliever (not SABA monotherapy). [cite: GINA Global Strategy for Asthma Management and Prevention 2024; ATS/ERS Stanojevic et al. Eur Respir J 2022; Harrison's 21st ed., Ch. 287]