Response to the Letter Regarding “Effectiveness and Safety of Nasal Herbal Steam Therapy for Post-Extubation Respiratory Symptoms After Thyroidectomy”

To the editor:

We sincerely appreciate the thoughtful comments from the authors of the Letter regarding our study on nasal herbal steam therapy (NHST) for post-extubation respiratory symptoms (PERS) following thyroidectomy. ¹ Their constructive critique provides an opportunity to clarify several methodological considerations and to outline future directions for this line of research.

While objective measures such as laryngeal edema grading or spirometry could further strengthen the evidence, we respectfully note that patient-reported recovery often serves as the most sensitive and clinically relevant indicator of postoperative comfort. The Wisconsin Upper Respiratory Symptom Survey (WURSS), ² a validated tool for assessing upper-airway symptom burden, was chosen to capture the patient’s real-world recovery experience. We acknowledge the importance of integrating both subjective and objective outcomes in future trials to provide a more comprehensive assessment of effectiveness.

This study was designed as a pilot randomized controlled trial to explore the preliminary effectiveness and safety of NHST and to inform the design of larger-scale confirmatory research. The sample size was calculated using effect sizes derived from previous steam inhalation studies, balancing feasibility with sufficient statistical power for exploratory interpretation. We concur that longer observation windows will be essential to evaluate the durability of NHST effects on recovery trajectories and postoperative complications.

Our trial adopted a pragmatic design to maximize real-world applicability, consistent with the PRECIS framework that situates studies along the pragmatic–explanatory continuum. ³ While sham or placebo steam controls could theoretically isolate specific mechanisms, such artificial conditions may undermine ecological validity by deviating from actual clinical practice. Expectation bias was minimized through standardized participant instructions, treatment environments, and intervention timing across both groups. In forthcoming explanatory trials, we plan to incorporate validated expectancy questionnaires and temperature-matched sham steam conditions to further delineate specific treatment effects. ⁴

We emphasize that our NHST protocol did not employ direct heating devices or boiling vapor sources, thereby minimizing any risk of thermal injury. ⁵ All participants were carefully monitored for adverse events during both intervention and follow-up, with special attention to respiratory, mucosal, and dermatologic reactions. Nonetheless, we agree that larger-scale studies with extended observation periods will be crucial to fully characterize the safety profile of NHST in broader clinical contexts.

We appreciate the opportunity to engage in this scientific exchange and share the view that further well-controlled studies are warranted. Our ongoing multi-center trial aims to address the above limitations by incorporating objective airway assessments and extended follow-up. We hope that these efforts will contribute to advancing non-invasive supportive therapies in perioperative recovery.

Sung-Eun Hong, DKM, BS* Integrative Cancer Center, CHA Ilsan Medical Center, CHA University School of Medicine, Goyang-si, Gyeonggi-do, Republic of Korea Myung Han Hyun, MD, PhD*Integrative Cancer Center, CHA Ilsan Medical Center, CHA University School of Medicine, Goyang-si, Gyeonggi-do, Republic of Korea Sang Hyung Lee, MD, PhDIntegrative Cancer Center, CHA Ilsan Medical Center, CHA University School of Medicine, Goyang-si, Gyeonggi-do, Republic of Korea Bup-Woo Kim, MD, PhDDepartment of Surgery, CHA Ilsan Medical Center, CHA University School of Medicine, Goyang-si, Gyeonggi-do, Republic of Korea Hee Jun Kim, MD, PhDDepartment of Surgery, CHA Ilsan Medical Center, CHA University School of Medicine, Goyang-si, Gyeonggi-do, Republic of Korea Jee Young Lee, DKM, PhDIntegrative Cancer Center, CHA Ilsan Medical Center, CHA University School of Medicine, Goyang-si, Gyeonggi-do, Republic of Korea *These authors contributed equally to this work.