Risk Indicators and IPI Performance in Sedation-Related Respiratory Deterioration in COPD

Chronic obstructive pulmonary disease (COPD) is a progressive disorder characterized by persistent airflow limitation, with dyspnea and productive cough being the predominant clinical features. According to the GOLD 2024 guidelines, the one-year history of exacerbations, including both the number of exacerbations and associated hospitalizations, represents the strongest predictor of future risk in COPD. The A-B-E classification system, based on symptom severity (CAT score) and exacerbation history, provides a structured framework for defining the clinical risk level of COPD patients.

Sedation in individuals with COPD can lead to rapid deterioration of respiratory function due to markedly limited ventilatory reserve. In this high-risk population, hypoventilation, apnea, desaturation, or alterations in capnographic waveforms during sedation constitute key indicators of respiratory compromise. While conventional monitoring parameters such as SpO₂, EtCO₂, respiratory rate, and pulse rate evaluate specific components of respiratory physiology individually, the Integrated Pulmonary Index (IPI) consolidates these four parameters into a single composite score reflecting both oxygenation and ventilation status. This integrated approach may facilitate earlier and more reliable detection of respiratory deterioration.

This prospective observational study focuses on two primary questions. First, it aims to investigate the relationship between respiratory deterioration occurring during sedated procedures and clinical risk indicators such as symptom severity (CAT score), the number of exacerbations in the previous year, and associated hospital admissions. Second, it seeks to evaluate the predictive performance of the IPI for identifying such respiratory deterioration and to compare its accuracy with classical respiratory monitoring parameters, namely SpO₂ and EtCO₂. This comparison will help determine whether the IPI provides an additional early-warning advantage for COPD patients undergoing sedation.

All participants will be included in a single COPD cohort, and the study involves no randomization or intervention arms. During data analysis, patients will be classified according to whether clinical interventions, such as increased oxygen supplementation, repositioning, or respiratory support, become necessary during the procedure. This classification reflects routine clinical decision-making and does not represent an intervention introduced by the study protocol.

The study hypothesizes that respiratory deterioration during sedation is associated with established clinical risk indicators and that the IPI will demonstrate higher predictive accuracy than conventional respiratory monitoring parameters.

This minimal-risk observational investigation is based solely on the assessment of standard clinical monitoring data obtained during routine sedated endoscopic procedures; no additional procedures or interventions are performed within the scope of the study.

Inclusion criteria

Age ≥ 18 years

Diagnosed with Chronic Obstructive Pulmonary Disease (COPD) according to GOLD 2024 criteria

Classified as ASA physical status I-IV

Undergoing elective gastrointestinal endoscopic procedure under sedation analgesia

Suitable for sedation outside the operating room

Provided written informed consent -

Exclusion criteria

Age < 18 years

Unstable cardiovascular or respiratory condition

Requirement for general anesthesia or advanced airway management

Pregnancy

Known hypersensitivity to sedative medications

Refusal or inability to provide informed consent

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