High-flow nasal oxygen does not increase the volume of gastric secretions during spontaneous ventilation

Elizabeth McLellan; Karen Lam; Elizabeth Behringer; Vincent Chan; Didem Bozak; Nicholas Mitsakakis; Anahi Perlas

doi:10.1016/j.bja.2020.02.023

High-flow nasal oxygen does not increase the volume of gastric secretions during spontaneous ventilation

Br J Anaesth. 2020 Jul;125(1):e75-e80. doi: 10.1016/j.bja.2020.02.023. Epub 2020 Mar 31.

Authors

Elizabeth McLellan¹, Karen Lam², Elizabeth Behringer³, Vincent Chan⁴, Didem Bozak², Nicholas Mitsakakis⁵, Anahi Perlas⁶

Affiliations

¹ Department of Anesthesia and Pain Management, Toronto Western Hospital, University Health Network, Toronto, ON, Canada; Royal Brisbane and Women's Hospital, Brisbane, Australia.
² Department of Anesthesia and Pain Management, Toronto Western Hospital, University Health Network, Toronto, ON, Canada.
³ Department of Cardiovascular Surgery, Kaiser Permanente Los Angeles Medical Center, Los Angeles, CA, USA.
⁴ Department of Anesthesia, University of Toronto, Toronto, ON, Canada; Toronto Western Hospital, University Health Network, Toronto, ON, Canada.
⁵ Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada; Biostatistics Research Unit, University Health Network, Toronto, ON, Canada.
⁶ Department of Anesthesia, University of Toronto, Toronto, ON, Canada; Toronto Western Hospital, University Health Network, Toronto, ON, Canada. Electronic address: Anahi.perlas@uhn.ca.

PMID: 32241548
DOI: 10.1016/j.bja.2020.02.023

Abstract

Background: 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.

Methods: 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.

Results: 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.

Conclusions: There was no evidence that treatment with HFNO at flow rates of up to 70 L min^-1 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.

Clinical trial registration: NCT03134937.

Keywords: airway management; gastric volume; high-flow nasal oxygen; oxygen inhalation therapy; pulmonary aspiration; stomach; ultrasonography.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Female
Gastric Juice / diagnostic imaging
Gastric Juice / physiology*
Humans
Male
Middle Aged
Nasal Cavity
Oxygen Inhalation Therapy / methods*
Prospective Studies
Respiration*
Ultrasonography / methods
Young Adult

Associated data

ClinicalTrials.gov/NCT03134937