Assessment of Pulmonary Functions in Adenotonsillar Hypertrophy Patients Using a Newer Modality of Forced Oscillation Technique.

Introduction: Adenotonsillar hypertrophy (ATH) is a common cause of upper airway obstruction in the paediatric population, resulting in sleep disturbances, chronic airway obstruction, and potential cardiopulmonary complications. The Forced Oscillation Technique (FOT) is a sensitive, non-invasive method for assessing pulmonary function and detecting abnormalities of the peripheral airways. Materials and Methods: This prospective pre-post cohort study included 35 patients aged 5-20 years with ATH who underwent FOT assessment before and six weeks after adenotonsillectomy. The parameters evaluated included total airway resistance (R5), central airway resistance (R20), peripheral airway resistance (R5-R20), reactance (X5), area of reactance (Ax), and resonant frequency (Fres). Results: Significant postoperative improvements were observed in R5 (0.46±0.25 to 0.41±0.25 kPa/L/s; p = 0.001), R20 (0.35±0.19 to 0.30±0.18 kPa/L/s; p = 0.001), X5 (-0.24±0.16 to -0.12±0.13 kPa/L/s; p < 0.001), Ax (2.93±2.30 to 2.08±1.71 kPa/L/s; p < 0.001), and Fres (24.89±6.75 to 22.30±6.00 Hz; p < 0.001). Although R5-R20 improved (0.10±0.10 to 0.09±0.10 kPa/L/s), the change was not statistically significant (p = 0.427). As R5-R20, X5, and Ax reflect peripheral airway function, improvements in these parameters suggest enhanced peripheral airway function following adenotonsillectomy. No significant association was found between pulmonary function and the degree of adenoid or tonsillar hypertrophy. Conclusion: FOT effectively detected improvements in pulmonary function following adenotonsillectomy and may be a valuable tool for evaluating respiratory changes in patients with ATH. Larger studies are warranted to better define its clinical utility.