Normative Swallowing Physiological Metrics of Pharyngeal High-Resolution Impedance Manometry in Chinese Adults

Normative Swallowing Physiological Metrics of Pharyngeal High-Resolution Impedance Manometry and Videofluoroscopic Swallowing Study in Chinese Adults

As Taiwan enters a super-aged society in 2025, the number of elderly patients and patients with multiple comorbidities continues to increase, and the risk of dysphagia rises with advancing age. Due to neuronal degeneration and muscle atrophy, older adults often experience delayed recovery of swallowing function after general anesthesia, and it may take up to seven days to regain their baseline swallowing ability. Therefore, postoperative monitoring of swallowing function and early rehabilitative intervention are crucial for reducing complication risks and facilitating early discharge.

Currently, there is limited literature regarding normative data for pharyngeal swallowing assessment using high-resolution pharyngeal manometry with impedance as well as videofluoroscopic swallowing studies in the Chinese population. This project aims to recruit 80 healthy adults to establish normative reference values.

To ensure relative consistency in the physiological, pathological, and psychological conditions of participants, this study will recruit 80 healthy adults without swallowing difficulties using convenience sampling from outpatient clinics and the general healthy population at National Taiwan University Hospital (NTUH). All participants will undergo both videofluoroscopic swallowing study (VFSS) and high-resolution pharyngeal manometry with impedance (HRIM). Inclusion criteria include adults aged ≥18 years without subjective dysphagia. Exclusion criteria include major systemic diseases (e.g., heart failure, liver cirrhosis, end-stage renal disease, scleroderma, or diabetes mellitus), history of vasovagal syncope, acute inflammation, nasal or esophageal stenosis/obstruction, upper gastrointestinal symptoms within the past 3 months, use of medications affecting gastrointestinal motility, recent anticoagulant or antiplatelet use within 1 week before enrollment, or bleeding tendency. After informed consent is obtained, participants will fast for 4-8 hours before testing. Assessments will include a rapid swallowing test, anthropometric measurements and InBody analysis, limb ultrasound and muscle strength evaluation using the MicroFET2™ wireless handheld dynamometer and handgrip dynamometer, ultrasonographic assessment of hyoid bone movement and swallowing-related muscles (e.g., masseter muscle), HRIM and VFSS examinations, and blood sampling (5 cc) for biochemical analysis including LDL, HDL, cholesterol, white blood cell count, and hemoglobin.

Inclusion Criteria:

• Adults aged 18 years or older without subjective swallowing difficulty.

Exclusion Criteria:

• (1) Major systemic diseases, including heart failure, liver cirrhosis, end-stage renal disease, scleroderma, or diabetes mellitus; (2) History of vasovagal syncope, acute inflammation, or nasal or esophageal stenosis/obstruction; (3) Presence of upper gastrointestinal symptoms within the past 3 months, including dysphagia, chest pain, heartburn, reflux, or globus sensation; (4) Current use of medications that may affect gastrointestinal motility; (5) Use of anticoagulant or antiplatelet agents within 1 week prior to enrollment; or (6) History of bleeding tendency.