Frailty and Intraoperative Hypoxemia Risk in Elderly ERCP Patients
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Hypoxemia. Basic parameters: from 65 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Center list to be confirmed — check the primary protocol.
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
The Predictive Value of Frailty for Intraoperative Hypoxemia in Elderly Patients Undergoing ERCP: A Two-Directional Cohort Study and Predictive Model Construction
Overview
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.
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.
Primary outcome measures
- Intraoperative hypoxemia [Time frame: Intraoperatively]
Secondary outcome measures (6)
- Severe intraoperative hypoxemia [Time frame: Intraoperatively]
- Postoperative hypoxemia [Time frame: Within 2 hours after completion of ERCP]
- Intraoperative hemodynamic instability [Time frame: Intraoperatively]
- Serious anesthesia-related adverse events [Time frame: up to 1 month]
- Serious procedure-related adverse events [Time frame: up to 1 month]
- Intraoperative respiratory depression and apnea [Time frame: Intraoperatively]
Eligibility criteria
Inclusion criteria
- Age 65 years or older
- Elective endoscopic retrograde cholangiopancreatography (ERCP) under anesthesia sedation
- American Society of Anesthesiologists (ASA) physical status II-IV
- Expected procedure duration less than 60 minutes
- Available and complete intraoperative pulse oximetry (SpO₂) monitoring data
Exclusion criteria
- Emergency ERCP
- 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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
Center list to be confirmed — check the primary protocol.
Identifiers
NCT: NCT07568912 · ZRYH-Hypoxemia-Frailty-2026