Frailty and Intraoperative Hypoxemia Risk in Elderly ERCP Patients

May 1, 2026 updated by: Li Fang Wang, China-Japan Friendship Hospital

The Predictive Value of Frailty for Intraoperative Hypoxemia in Elderly Patients Undergoing ERCP: A Two-Directional Cohort Study and Predictive Model Construction

Intraoperative hypoxemia is a common and serious complication during monitored anesthesia care for elective endoscopic retrograde cholangiopancreatography (ERCP), especially in older adults. Frail patients have reduced physiologic reserve and are at increased risk of life-threatening events including unplanned intubation, hemodynamic collapse, and hypoxic brain injury. However, the independent relationship between frailty and intraoperative hypoxemia during sedated ERCP remains poorly defined, and no validated risk prediction model exists for this high-risk population. This single-center, dual-cohort study will be conducted at China-Japan Friendship Hospital to evaluate whether preoperative frailty can predict intraoperative hypoxemia in patients aged 65 years and older undergoing elective ERCP. Frailty will be assessed primarily using the Frailty Index (FI), with secondary screening by the Modified Frailty Index-11 (mFI-11), Edmonton Frail Scale (EFS), Clinical Frailty Scale (CFS), FRAIL scale, and Fried phenotype. The primary outcome is intraoperative hypoxemia, defined as SpO₂ < 90% for 5 seconds or longer. In the retrospective phase (n = 313), investigators will identify risk factors and develop a preliminary prediction model. In the prospective phase (n = 388), the model will be validated, refined, and internally tested for discrimination, calibration, and clinical utility. This study aims to establish frailty as a reliable preoperative risk marker and provide a clinically practical prediction tool to support risk stratification, personalized sedation strategies, and perioperative safety in elderly patients undergoing ERCP.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

This dual-cohort study investigates the predictive value of preoperative frailty for intraoperative hypoxemia in patients aged 65 years and older undergoing elective endoscopic retrograde cholangiopancreatography (ERCP) under monitored anesthesia care at China-Japan Friendship Hospital, with a total target enrollment of 701 patients (313 retrospective and 388 prospective). Intraoperative hypoxemia, defined as pulse oxygen saturation (SpO₂) < 90% for 5 seconds or longer from anesthesia induction to procedure completion, serves as the primary outcome, while secondary outcomes include severe hypoxemia, postoperative hypoxemia, time to oxygen discontinuation, hemodynamic instability, anesthesia- and procedure-related adverse events, respiratory depression, and apnea. Frailty will be assessed primarily using the Frailty Index (FI) as the core instrument, with additional secondary screening performed using the Modified Frailty Index-11 (mFI-11), Edmonton Frail Scale (EFS), Clinical Frailty Scale (CFS), FRAIL questionnaire, and Fried frailty phenotype. Eligible patients are aged 65 years or older with ASA class II-IV status, scheduled for elective ERCP with a planned procedure duration of less than 60 minutes and complete intraoperative SpO₂ monitoring data; those requiring emergency surgery, severe anemia, pre-existing severe respiratory or hemodynamic instability, or impaired consciousness will be excluded. The retrospective phase will use existing electronic health records to identify risk factors and construct a preliminary prediction model, with propensity score matching, univariate and multivariable logistic regression, bootstrap internal validation, and random forest for feature importance ranking. The prospective phase will prospectively collect standardized data, validate the association between frailty and hypoxemia using adjusted logistic regression, refine the prediction model, compare the performance of different frailty scales using Delong's test, and evaluate machine learning models with SHapley Additive exPlanations (SHAP) values for interpretability. The final model will be tested in an internal validation cohort for discriminative ability, calibration, and clinical utility. All statistical analyses will be performed using R and SPSS software at a two-sided significance level of α = 0.05, with multiple imputation for missing data and Holm-Bonferroni correction for multiple comparisons.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
701

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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

This observational cohort study will enroll elderly patients aged 65 years and older who are scheduled for elective endoscopic retrograde cholangiopancreatography (ERCP) under anesthesia sedation at China-Japan Friendship Hospital. The study population consists of two sequential cohorts: a retrospective cohort of 313 patients with complete electronic health record data and a prospective cohort of 388 patients to be recruited prospectively. Eligible participants include those with American Society of Anesthesiologists (ASA) physical status II-IV and an expected procedure duration of less than 60 minutes, with adequate intraoperative pulse oximetry monitoring.

Description

Inclusion Criteria:

  1. Age 65 years or older
  2. Elective endoscopic retrograde cholangiopancreatography (ERCP) under anesthesia sedation
  3. American Society of Anesthesiologists (ASA) physical status II-IV
  4. Expected procedure duration less than 60 minutes
  5. Available and complete intraoperative pulse oximetry (SpO₂) monitoring data

Exclusion Criteria:

  1. Emergency ERCP
  2. Severe anemia (hemoglobin < 60 g/L) or conditions interfering with accurate 3. SpO₂ measurement

4. Pre-existing severe respiratory insufficiency requiring long-term oxygen therapy 5. Unstable hemodynamics requiring continuous vasopressor infusion Impaired consciousness, delirium, or cognitive dysfunction that prevents reliable frailty assessment

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

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Frailty-Hypoxemia ERCP Cohort
This study employs a dual-cohort design consisting of a retrospective cohort and a prospective cohort. The retrospective cohort includes 313 patients aged 65 years and older who underwent elective ERCP under anesthesia sedation with complete electronic health record data. The prospective cohort will enroll 388 consecutive eligible patients aged 65 years and older undergoing elective ERCP under anesthesia sedation, with prospective frailty assessment and standardized perioperative data collection. This cohort will be used to validate the independent association between frailty and hypoxemia, refine the prediction model, and assess its performance in terms of discrimination, calibration, and clinical utility. Frailty will be assessed primarily using the Frailty Index (FI), with supplementary screening using other validated scales. All patients will be managed according to routine clinical practice without additional investigation.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Intraoperative hypoxemia
Time Frame: Intraoperatively
Intraoperative hypoxemia defined as pulse oxygen saturation (SpO₂) < 90% lasting 5 seconds or longer during the procedure.
Intraoperatively

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Severe intraoperative hypoxemia
Time Frame: Intraoperatively
Severe hypoxemia defined as SpO₂ < 90% for more than 1 minute, or SpO₂ < 75%.
Intraoperatively
Postoperative hypoxemia
Time Frame: Within 2 hours after completion of ERCP
Hypoxemia on admission to the ward, defined as SpO₂ < 90% on room air.
Within 2 hours after completion of ERCP
Intraoperative hemodynamic instability
Time Frame: Intraoperatively
Clinically significant hypotension, hypertension, or arrhythmia requiring intervention.
Intraoperatively
Serious anesthesia-related adverse events
Time Frame: up to 1 month
Aspiration, circulatory instability, unplanned endotracheal intubation, hypoxic encephalopathy, or death.
up to 1 month
Serious procedure-related adverse events
Time Frame: up to 1 month
Post-ERCP pancreatitis, bleeding, perforation, or cholangitis.
up to 1 month
Intraoperative respiratory depression and apnea
Time Frame: Intraoperatively
Respiratory rate < 8 breaths per minute or apnea (respiratory pause ≥ 15 seconds).
Intraoperatively

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
China-Japan Friendship Hospital

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Lifang Wang, M.D., China-Japan Friendship Hospital, Department of Anesthesiology

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 30, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 23, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 1, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 6, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 6, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 1, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ZRYH-Hypoxemia-Frailty-2026

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Individual participant data (IPD) will be shared with qualified researchers upon reasonable request, following publication of the study results. Shared data will include de-identified clinical information (baseline characteristics, intraoperative parameters, postoperative outcomes) and biomarker data, excluding direct identifiers to protect participant privacy. Data access will require approval from the institutional review board of China-Japan Friendship Hospital and a signed data use agreement specifying the purpose of use and confidentiality obligations. The data will be shared via a secure research data repository for up to 5 years after study completion

IPD Sharing Time Frame

Individual participant data (IPD) and supporting information will be made available within 1 month after the publication of study results, with access maintained for 5 years after study completion.

IPD Sharing Access Criteria

Eligible researchers must submit a research application specifying the purpose of data use and research plan, which will be reviewed and approved by the Institutional Review Board of China-Japan Friendship Hospital.A data use agreement must be signed, committing to use the data solely for scientific research, protect participants' privacy, refrain from unauthorized data transfer, and cite this study in published outcomes.De-identified data will be accessible through the hospital's designated secure data repository.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

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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