Retrospective Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 21, 2016; 22(47): 10398-10405
Published online Dec 21, 2016. doi: 10.3748/wjg.v22.i47.10398
High-flow nasal oxygen availability for sedation decreases the use of general anesthesia during endoscopic retrograde cholangiopancreatography and endoscopic ultrasound
Roman Schumann, Nikola S Natov, Klifford A Rocuts-Martinez, Matthew D Finkelman, Tom V Phan, Sanjay R Hegde, Robert M Knapp
Roman Schumann, Robert M Knapp, Department of Anesthesiology and Perioperative Medicine, Tufts Medical Center, Boston, MA 02111, United States
Nikola S Natov, Sanjay R Hegde, The Gastroenterology/Hepatology Division, Tufts Medical Center, Boston, MA 02111, United States
Klifford A Rocuts-Martinez, Critical Care Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, United States
Matthew D Finkelman, Tufts University School of Dental Medicine, Boston, MA 02111, United States
Tom V Phan, Tufts University School of Medicine, Boston, MA 02111, United States
Author contributions: Schumann R contributed to study design, data collection, data analysis, and manuscript preparation; Natov NS, Knapp RM contributed to data collection and manuscript preparation; Rocuts-Martinez KA, Phan TV contributed to study design and data collection; Finkelman MD contributed to data analysis and manuscript preparation; Hegde SR contributed to manuscript preparation.
Supported by The Department of Anesthesiology and Perioperative Medicine, Tufts Medical Center, Boston, United States.
Institutional review board statement: The study was reviewed and approved by the Tufts Medical Center and Tufts University Health Sciences Campus Institutional Review Board.
Informed consent statement: Written consent for both the endoscopic procedures (ERCP and/or EUS) and administration of anesthesia (general anesthesia or deep sedation) was obtained from all patients or their designated legal agent(s). This is a retrospective study on data from clinical care. As such this study was deemed to be minimal risk by the Tufts institutional review board and a waiver of informed consent for this study was granted (see also attached IRB approval document).
Conflict-of-interest statement: None of the authors report a conflict of interest.
Data sharing statement: Technical appendix, statistical code, and the datasets are available from the corresponding author at A waiver of informed consent was obtained from the institutional review board, and data are de-identified with a minimal risk of loss of confidentiality. The benefit of results sharing outweigh this potential risk.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Roman Schumann, MD, Professor of Anesthesiology, Department of Anesthesiology and Perioperative Medicine, Tufts Medical Center, 800 Washington Street, Boston, MA 02111, United States.
Telephone: +1-617-6366044 Fax: +1-617-6368384
Received: August 19, 2016
Peer-review started: August 19, 2016
First decision: October 20, 2016
Revised: November 3, 2016
Accepted: November 28, 2016
Article in press: November 28, 2016
Published online: December 21, 2016

To examine whether high-flow nasal oxygen (HFNO) availability influences the use of general anesthesia (GA) in patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) and associated outcomes.


In this retrospective study, patients were stratified into 3 eras between October 1, 2013 and June 30, 2014 based on HFNO availability for deep sedation at the time of their endoscopy. During the first and last 3-mo eras (era 1 and 3), no HFNO was available, whereas it was an option during the second 3-mo era (era 2). The primary outcome was the percent utilization of GA vs deep sedation in each period. Secondary outcomes included oxygen saturation nadir during sedation between periods, as well as procedure duration, and anesthesia-only time between periods and for GA vs sedation cases respectively.


During the study period 238 ERCP or EUS cases were identified for analysis. Statistical testing was employed and a P < 0.050 was significant unless the Bonferroni correction for multiple comparisons was used. General anesthesia use was significantly lower in era 2 compared to era 1 with the same trend between era 2 and 3 (P = 0.012 and 0.045 respectively). The oxygen saturation nadir during sedation was significantly higher in era 2 compared to era 3 (P < 0.001) but not between eras 1 and 2 (P = 0.028) or 1 and 3 (P = 0.069). The procedure time within each era was significantly longer under GA compared to deep sedation (P≤ 0.007) as was the anesthesia-only time (P≤ 0.001).


High-flow nasal oxygen availability was associated with decreased GA utilization and improved oxygenation for ERCP and EUS during sedation.

Keywords: Endoscopic ultrasound, Endoscopic retrograde cholangiopancreatography, Endoscopy, Sedation, Anesthesia, Oxygenation, High flow nasal oxygen

Core tip: This retrospective study demonstrates a decreased use of GA when HFNO is available in the endoscopy unit for patients undergoing endoscopic retrograde cholangiopancreatography and endoscopic ultrasound under sedation. Provision of HFNO and deep sedation was associated with decreased procedure and anesthesia-only times, and oxygenation was improved compared to sedation without HFNO. These findings justify further prospective trials to fully elucidate the role of HFNO during sedation in gastrointestinal endoscopy. HFNO may have the potential to alter sedation practices in the endoscopy suite.