High-Flow Nasal Cannula After Major Abdominal Surgery to Prevent Postoperative Pulmonary Complications

April 7, 2026 updated by: Jinbeom Cho, Uijeongbu St. Mary Hospital

High-Flow Nasal Cannula for Prevention of Early Postoperative Pulmonary Complications After Major Abdominal Surgery: A Prospective Single-Center Randomized Controlled Trial

Major abdominal surgery is associated with a substantial risk of early postoperative pulmonary complications, including atelectasis, hypoxemia, pneumonia, and increased need for respiratory support. High-flow nasal cannula (HFNC) provides warmed and humidified oxygen at high flow rates and may improve oxygenation, reduce respiratory workload, and support lung volume during the immediate postoperative period. However, whether routine prophylactic HFNC after major abdominal surgery reduces clinically significant postoperative pulmonary complications remains uncertain.

This prospective, single-center, randomized controlled trial will evaluate whether prophylactic HFNC applied for 24 hours immediately after extubation reduces postoperative pulmonary complications compared with standard postoperative respiratory care in adult patients undergoing major abdominal surgery under general anesthesia with an actual anesthetic duration of 3 hours or longer.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Postoperative pulmonary complications (PPCs) remain an important cause of delayed recovery after major abdominal surgery. Early postoperative respiratory impairment, including atelectasis, impaired oxygenation, secretion retention, and increased respiratory effort, may lead to prolonged hospitalization, escalation of respiratory support, and increased postoperative morbidity. High-flow nasal cannula (HFNC) provides several physiological benefits, including delivery of warmed and humidified oxygen, improved mucociliary clearance, reduction of anatomical dead space, decreased upper airway resistance, and mild positive airway pressure that may help preserve functional residual capacity. Despite these physiological advantages, evidence supporting the routine preventive use of HFNC after major abdominal surgery remains inconclusive.

This study is a prospective, single-center, randomized, controlled, open-label, parallel-group clinical trial designed to evaluate the clinical effectiveness of prophylactic HFNC in adult patients undergoing major abdominal surgery under general anesthesia. Eligible participants are adults aged 19 years or older who undergo protocol-defined major abdominal surgery with an actual anesthetic duration of at least 3 hours and are successfully extubated immediately after surgery. Final eligibility is confirmed after surgery based on the actual surgical procedure performed and the actual anesthetic duration.

After arrival in the post-anesthesia care unit or intensive care unit following extubation, participants will be randomized in a 1:1 ratio to either the HFNC group or the standard postoperative respiratory care group using a centralized web-based randomization system. Randomization will use block randomization with stratification according to surgical approach and surgical category. The HFNC group will receive warmed and humidified high-flow nasal cannula therapy initiated within 30 minutes after arrival and continued for 24 hours in addition to standard postoperative respiratory care. The standard care group will receive conventional postoperative respiratory management, including low-flow oxygen as clinically indicated, deep-breathing and coughing instruction, pain control, early mobilization, respiratory physiotherapy, and secretion clearance support as needed.

The primary outcome is the occurrence of clinically significant postoperative pulmonary complications within 7 postoperative days, assessed using standardized consensus-based definitions. Secondary outcomes include individual respiratory complications, escalation of respiratory support, reintubation, intensive care unit and hospital length of stay, 30-day readmission, 30-day all-cause mortality, and selected postoperative non-pulmonary complications.

This trial is intended to provide high-quality evidence regarding whether short-term prophylactic HFNC during the immediate postoperative period can reduce clinically meaningful pulmonary complications in a clearly defined high-risk population after major abdominal surgery.

Study Type

Interventional

Enrollment (Estimated)

580

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • South Korea
      • Uijeongbu-si, South Korea, 11765
        • Jinbeom cho
        • Contact:
        • Contact:
        • Principal Investigator:
          • Jinbeom Cho, MD, PhD
        • Sub-Investigator:
          • Junhyun Lee, MD, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged 19 years or older.
  • Undergoing major abdominal surgery under general anesthesia.

  • Major abdominal surgery is defined as one of the following:

    1. Upper gastrointestinal surgery: total gastrectomy, distal gastrectomy, proximal gastrectomy, or esophagogastric junction surgery.
    2. Lower gastrointestinal surgery: right or left hemicolectomy, low anterior resection, anterior resection, total colectomy, abdominoperineal resection, or segmental small bowel resection with anastomosis.
    3. Hepatobiliary and pancreatic surgery: hepatic resection (≥1 segment), right or left hepatectomy, central hepatectomy, distal pancreatectomy, pancreaticoduodenectomy (Whipple procedure), or bile duct resection with reconstruction.
    4. Other moderate-to-major intra-abdominal procedures involving major organ resection or reconstruction, as determined by the investigator (e.g., complex cholecystectomy with extensive adhesiolysis, intra-abdominal tumor resection).
  • Actual anesthetic duration ≥ 3 hours, confirmed at the end of surgery.
  • Able to undergo immediate extubation at the end of surgery and be transferred to the post-anesthesia care unit or intensive care unit with spontaneous breathing.
  • Provided written informed consent before surgery. Final enrollment will occur only if the actual surgical procedure and anesthetic duration meet all eligibility criteria after surgery.

Exclusion Criteria:

  • Requirement for postoperative invasive mechanical ventilation. Failed extubation immediately after surgery.
  • Severe intraoperative instability preventing routine postoperative recovery (e.g., major hemodynamic instability, massive bleeding, or cardiopulmonary resuscitation).
  • Requirement for continuous oxygen therapy, noninvasive ventilation, or invasive mechanical ventilation before surgery.
  • Thoracic surgery within 4 weeks before the index surgery. Inability to receive HFNC because of upper airway or nasal anatomical limitations.
  • Planned reoperation at the completion of the index surgery.
  • Inability to complete study participation or follow-up because of impaired decision-making capacity or practical inability to complete follow-up.
  • Any condition that, in the investigator's judgment, makes study participation inappropriate.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: HFNC group
Participants randomized to this arm will receive prophylactic high-flow nasal cannula (HFNC) immediately after extubation following major abdominal surgery. HFNC will be initiated in the post-anesthesia care unit or intensive care unit and maintained for 24 hours postoperatively according to the study protocol.
Device: High flow nasal cannula (HFNC)
High-flow nasal cannula (HFNC) will be applied prophylactically immediately after extubation following major abdominal surgery. Heated and humidified oxygen will be delivered through a high-flow nasal cannula system and maintained for 24 hours postoperatively according to the study protocol.
Active Comparator: Standard oxygen group
Participants randomized to this arm will receive standard postoperative oxygen therapy immediately after extubation following major abdominal surgery. Oxygen will be administered according to usual institutional practice and the study protocol, without prophylactic high-flow nasal cannula.
Other: Standard oxygen therapy
Standard postoperative oxygen therapy will be administered immediately after extubation following major abdominal surgery according to usual institutional practice and the study protocol, without prophylactic high-flow nasal cannula.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative pulmonary complications (PPCs)
Time Frame: Within 7 days after surgery
The primary outcome is the incidence of clinically significant postoperative pulmonary complications (PPCs) within 7 days after surgery. PPCs will be evaluated as a composite endpoint according to predefined criteria in the study protocol.
Within 7 days after surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative pneumonia
Time Frame: Within 7 days after surgery
Incidence of postoperative pneumonia occurring within 7 days after surgery, assessed according to predefined criteria in the study protocol.
Within 7 days after surgery
Clinically significant postoperative atelectasis
Time Frame: Within 7 days after surgery
Incidence of clinically significant postoperative atelectasis requiring therapeutic intervention within 7 days after surgery, assessed according to predefined criteria in the study protocol.
Within 7 days after surgery
Postoperative respiratory failure
Time Frame: Within 7 days after surgery
Incidence of postoperative respiratory failure within 7 days after surgery, including the need for escalation of respiratory support, as defined in the study protocol.
Within 7 days after surgery
Length of postoperative hospital stay
Time Frame: From surgery to hospital discharge (up to 30 days)
Duration of postoperative hospital stay measured from the date of surgery to hospital discharge.
From surgery to hospital discharge (up to 30 days)
Length of postoperative intensive care unit stay
Time Frame: From postoperative ICU admission to ICU discharge (up to 30 days)
Duration of postoperative intensive care unit stay measured from ICU admission after surgery to ICU discharge.
From postoperative ICU admission to ICU discharge (up to 30 days)
All-cause mortality within 30 days after surgery
Time Frame: Within 30 days after surgery
All-cause mortality occurring within 30 days after surgery.
Within 30 days after surgery
Hospital readmission within 30 days after discharge
Time Frame: Within 30 days after hospital discharge
Hospital readmission for any cause within 30 days after discharge following the index surgery.
Within 30 days after hospital discharge

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Uijeongbu St. Mary Hospital

Investigators

  • Principal Investigator: Jinbeom Cho, MD, PhD, Department of Surgery, Uijeongbu St. Mary's Hospital, The Catholic University of Korea

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

July 1, 2026

Primary Completion (Estimated)

December 31, 2027

Study Completion (Estimated)

December 31, 2027

Study Registration Dates

First Submitted

April 7, 2026

First Submitted That Met QC Criteria

April 7, 2026

First Posted (Actual)

April 14, 2026

Study Record Updates

Last Update Posted (Actual)

April 14, 2026

Last Update Submitted That Met QC Criteria

April 7, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • UC26DISI0004

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data (IPD) will not be shared because no formal data-sharing mechanism has been established for this investigator-initiated single-center study, and data access may be limited by institutional and privacy regulations.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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