Nasal Airway Resistance

Definition

• Nasal airway resistance (NAR) refers to the opposition to airflow through the nasal passages
• Measured in units of pressure (cmH2O) per unit of flow (L/min)

Importance in 24-hour Nasal Condition Assessment

• NAR is a key indicator of nasal function and breathing comfort
• Elevated NAR can lead to nasal congestion, mouth breathing, and decreased quality of life
• 24-hour assessment of NAR provides a comprehensive understanding of nasal function throughout the day

Methods of Measurement

• Rhinomanometry: a non-invasive, objective method that measures nasal pressure and flow
• Peak nasal inspiratory flow (PNIF): a simple, non-invasive method that measures maximum nasal airflow during inspiration
• Acoustic rhinometry: a non-invasive method that uses sound waves to measure nasal cavity dimensions and calculate NAR

Normal Values

• NAR values vary depending on the measurement method and population being studied
• Generally, NAR values < 2.5 cmH2O/L/min are considered normal

Factors Affecting NAR

• Nasal anatomy (e.g., septal deviation, turbinate hypertrophy)
• Allergic rhinitis and other nasal inflammatory conditions
• Medications (e.g., decongestants, antihistamines)
• Hormonal changes (e.g., pregnancy, menstruation)
• Environmental factors (e.g., air pollution, temperature, humidity)

鼻道阻力

定義

• 鼻道阻力（NAR）是指鼻腔中氣流通過的阻力
• 以壓力（cmH2O）和流量（L/min）之間的比值衡量

在24小時鼻腔狀態評估中的重要性

• NAR是鼻腔功能和呼吸舒適度的重要指標
• 高NAR可能導致鼻塞、口呼吸和生活品質下降
• 24小時NAR評估能夠綜合了解鼻腔功能的全天候變化

測量方法

• 鼻阻力測量術（Rhinomanometry）：一种非侵入、客觀的方法，用於測量鼻腔壓力和流量
• 峰值鼻吸氣流量（PNIF）：一种簡單、非侵入的方法，用於測量吸氣時的最大鼻腔氣流量
• 音響鼻腔測量術（Acoustic rhinometry）：一种非侵入的方法，用於測量鼻腔腔室尺寸並計算NAR

正常值

• NAR值因測量方法和研究人群而異
• 一般认为，NAR值< 2.5 cmH2O/L/min為正常值

影響NAR的因素

• 鼻腔解剖结构（例如鼻中隔偏移、 turbinate腫大）
• 过敏性鼻炎和其他鼻腔炎症
• 藥物（例如解充血药、抗組織胺）
• 激素變化（例如懷孕、月經）
• 環境因素（例如空氣污染、氣溫、濕度）