经鼻高流量湿化氧疗在无痛胃肠镜应用的 临床意义

The Clinical Significance of High-Flow Nasal Cannula Humidified Oxygen Therapy in Painless Gastrointestinal Endoscopy

摘要: 无痛胃肠镜作为现代消化内镜诊疗的核心技术，极大提高了患者的舒适度和诊疗精准度。然而，在传统氧疗支持下，由于患者处于深度镇静镇痛状态，自主呼吸功能受限，低氧血症，高碳酸血症等并发症风险突出。传统氧疗方式如鼻导管(Nasal Cannula, NC)或普通面罩因氧流量有限(通常 < 15 L/min)，不能提供稳定吸入氧浓度(FiO₂)等缺陷，难以满足深度镇静下的氧合需求。经鼻高流量氧疗(High-flow nasal cannula oxygen therapy, HFNC)作为一种新型氧疗方式，通过输送高达80 L/min的加温加湿气体，在成人及儿童患者中显示出良好的临床效果。近年来，经鼻高流量氧疗(HFNC)作为一种新兴的呼吸供氧支持技术，通过其独特的作用机制在无痛胃肠镜检查中逐渐显露优势。本文将重点阐述HFNC的定义、HFNC的生理机制，包括生理死腔冲刷作用、产生气道正压，增加呼气末肺容积、降低气道阻力等，并基于现有证据评价其临床意义。

Abstract: Painless gastrointestinal endoscopy, as a crucial technique in modern digestive endoscopy, significantly enhances patient comfort and diagnostic quality. However, under traditional oxygen therapy, patients in deep sedation and analgesia often experience restricted spontaneous respiration, leading to complications such as hypoxemia and hypercapnia. Conventional oxygen delivery methods like the nasal cannula (NC) or simple face masks, limited by low flow rates (typically <15 L/min) and unstable fraction of inspired oxygen (FiO₂), struggle to meet oxygenation demands during deep sedation. High-flow nasal cannula oxygen therapy (HFNC), an innovative oxygenation approach, delivers heated and humidified gas at rates up to 80 L/min and has demonstrated favorable clinical outcomes in both adult and pediatric patients. In recent years, HFNC has emerged as a promising respiratory support technology in painless gastrointestinal endoscopy, showcasing distinct advantages due to its unique mechanisms. This article focuses on elucidating the definition of HFNC, its physiological mechanisms-including dead space flushing, positive airway pressure generation, increased end-expiratory lung volume, and reduced airway resistance-and evaluates its clinical significance based on current evidence.