Department of Anesthesia and Pain Management, Toronto Western Hospital, University Health Network, Toronto, ON, Canada; Royal Brisbane and Women's Hospital, Brisbane, Australia.
Department of Anesthesia and Pain Management, Toronto Western Hospital, University Health Network, Toronto, ON, Canada.
Br J Anaesth. 2020 Jul;125(1):e75-e80. doi: 10.1016/j.bja.2020.02.023. Epub 2020 Mar 31.
High-flow, heated, and humidified nasal oxygen therapy (HFNO) is frequently used in critical care and perioperative settings for a range of clinical applications. Much of the benefit of HFNO is attributed to generation of modest levels of positive airway pressure. Concern has been raised that this positive airway pressure may cause gastric insufflation, potentially increasing the risk of regurgitation and aspiration in an unprotected airway.
A prospective, interventional, assessor-blinded study was undertaken to evaluate the effects of HFNO on gastric content and gastric distension in healthy fasted adult volunteers assessed by ultrasonography. The primary outcome was the volume of gastric secretions. The secondary outcomes were the incidence of gastric air insufflation and the distribution of gastric antral grades.
Sixty subjects were enrolled. No subject was found to have air gastric distension either at baseline or after treatment with HFNO. All subjects had either a Grade 0 or Grade 1 antrum, with similar distribution of antral grades and similar volume of gastric secretions before and after treatment with HFNO.
There was no evidence that treatment with HFNO at flow rates of up to 70 L min for 30 min resulted in gastric distension or an increase in gastric secretions in healthy individuals breathing spontaneously. The generalisability of these findings to subjects under anaesthesia and patients with incompetence of the lower oesophageal sphincter or impaired gastric emptying requires further investigation.
NCT03134937.
高流量、加热和湿化鼻氧疗法（HFNO）常用于重症监护和围手术期，用于多种临床应用。HFNO 的大部分益处归因于产生适度水平的气道正压。人们担心这种气道正压可能导致胃充气，在未受保护的气道中潜在增加反流和误吸的风险。
一项前瞻性、干预性、评估者盲法研究评估了超声评估的健康禁食成年志愿者中 HFNO 对胃内容物和胃扩张的影响。主要结局是胃分泌物的体积。次要结局是胃充气的发生率和胃窦等级的分布。
共纳入 60 例受试者。无论是在基线还是在 HFNO 治疗后，都没有受试者出现胃充气。所有受试者的胃窦均为 0 级或 1 级，胃窦等级分布相似，HFNO 治疗前后胃分泌物的体积也相似。
在高达 70 L/min 的流量下治疗 30 分钟，HFNO 治疗并未导致健康个体自主呼吸时胃扩张或胃分泌物增加。这些发现对麻醉下的受试者、下食管括约肌功能不全或胃排空受损的患者的推广性需要进一步研究。
NCT03134937。
