Capnographic Monitoring during Endoscopic Submucosal Dissection with Patients under Deep Sedation: A Prospective, Crossover Trial of Air and Carbon Dioxide Insufflations

Abstract

Background and Aims: The safety of carbon dioxide (CO₂) insufflation has not been fully established for esophageal and gastric endoscopic submucosal dissection (ESD) under deep sedation, because CO₂ retention is not only caused by CO₂ insufflation but also by the sedation level and the patient’s respiratory status. To clarify the clinical safety of CO₂ insufflation, we conducted a crossover trial of air and CO₂ insufflations. Methods: A total of 60 patients with early esophageal or gastric cancers underwent ESD during which insufflation was switched from CO₂ to air or from air to CO₂; transcutaneous partial pressure CO₂ (PtcCO₂) was monitored in all patients. We also assessed respiratory function, arterial blood gas analysis, and smoking history. Results: Although significant increases in PtcCO₂ from baseline were observed, there were no significant differences in PtcCO₂ levels during CO₂ insufflation compared with levels during air insufflation in groups that received CO₂ preceding air or air preceding CO₂. All patients underwent ESD safely without adverse events, including 20 patients with subclinical respiratory dysfunction. The sedation protocol was the only significant predictor of CO₂ retention, independent of CO₂ insufflation. Conclusions: CO₂ insufflation can be used as safely as air insufflation during ESD under deep sedation.