OPA1 DIAGNOSTIC VALUE OF THE METHACHOLINE CHALLENGE TEST IN PATIENTS PREVIOUSLY TREATED FOR BRONCHIAL ASTHMA WITH A NEGATIVE BRONCHODILATOR REVERSIBILITY TEST: THE ALOR SETAR EXPERIENCE

Kughanishah Jeyabalan, Nur ‘Afifah binti Abd Samad, Nurul ‘Izzati binti Ahmad Shukri, Chan Tha A Hing, Arvindran Alaga.
Hospital Sultanah Bahiyah, Kedah, Malaysia.

Introduction

Bronchial asthma can be challenging to diagnose due to its nonspecific symptoms. The methacholine challenge test (MCT), a type of bronchial provocation test, is a valuable diagnostic tool that helps assess airway hyperresponsiveness. This test aids in the diagnosis or exclusion of bronchial asthma, especially in patients with uncontrolled symptoms despite optimal management.

Objectives

This study aims to describe the demographics of patients and evaluate the usefulness of MCT in diagnosing or excluding bronchial asthma in patients with asthma-like symptoms and normal spirometry results.

Methodology

We conducted a retrospective analysis of 15 patients who underwent MCT at Hospital Sultanah Bahiyah, Alor Setar, from April 2023 to May 2024. Results were classified according to the provocative dose of methacholine required to achieve a 20% fall in FEV1 (PD20).

Results

The study included 15 patients (3 male and 12 female) with an average age of 38.7 years (range 14-67 years). The most common presenting symptoms were cough and shortness of breath. Thirteen patients were initially treated as having bronchial asthma and started on inhalers. MCT revealed 5 positive results, and these patients continued treatment for bronchial asthma and are currently doing well. The other patients were evaluated and diagnosed as alternative causes of breathlessness such as ventricular septal defect, gastroesophageal reflux disease, and obstructive sleep apnea, allowing them to discontinue inhaler use.

Conclusion

MCT is a useful tool for investigating patients with asthma-like symptoms, particularly in those with a questionable diagnosis of asthma. We were able to accurately identify airway hyperresponsiveness, thus avoiding incorrect treatment for non-asthmatic patients and potentially reducing costs.