End-Tidal CO2 Instability Predicts Hypoxia and Optimizes Sedation Safety During Endoscopic Submucosal Dissection

Area of Science:

• Gastroenterology
• Anesthesiology
• Respiratory Medicine

Background:

• Endoscopic submucosal dissection (ESD) demands deeper sedation, increasing ventilation-related risks.
• Conventional monitoring may not detect early respiratory compromise during prolonged procedures.

Purpose of the Study:

• Evaluate capnography's utility in early hypoxia detection during ESD.
• Compare capnography to pulse oximetry for respiratory compromise.
• Assess nasal high-flow oxygenation (NHFO) efficacy in managing ESD-related hypoxia.

Main Methods:

• Prospective observational study of 98 patients undergoing ESD with capnography and pulse oximetry.
• Recorded end-tidal carbon dioxide (EtCO2) and stratified patients by hypoxia.
• Analyzed NHFO efficacy and identified hypoxia predictors via logistic regression.

Main Results:

• EtCO2 instability independently predicted intraprocedural hypoxia (OR 2.427, p=0.002).
• Higher Mallampati score, oral breathing tendency, and lower baseline oxygenation predicted EtCO2 instability.
• NHFO significantly improved oxygen saturation and sedation quality in hypoxic patients.

Conclusions:

• EtCO2 instability is an early hypoxia indicator during ESD.
• Continuous capnography enables timely intervention for respiratory compromise.
• NHFO enhances safety and efficiency by reducing sedation adjustments.