Evaluation of the usefulness and safety of percutaneous CO2 monitoring during bronchoscopic intervention

Background End-tidal carbon dioxide (ETCO₂) monitoring is limited during rigid bronchoscopic procedures due to open airway conditions. This study aimed to evaluate the utility and safety of transcutaneous carbon dioxide (TcCO₂) monitoring as a surrogate for arterial CO₂ (PaCO₂) during therapeutic bronchoscopy. Methods In this prospective observational study, adult patients undergoing rigid bronchoscopy between June 2024 and January 2025 were enrolled. TcCO₂ was continuously monitored using the Sentec Digital Monitoring System. Arterial blood gas samples were collected at 7.5, 15, and 35 minutes after intervention initiation. Spearman’s rank correlation and Bland-Altman analyses were used to assess agreement between TcCO₂ and PaCO₂, and between SpO₂ and SaO₂. Results Thirty patients were analysed. Mean PaCO₂ increased over time, while TcCO₂ peaked at 15 minutes. Strong correlations were observed between PaCO₂ and TcCO₂ (ρ = 0.86–0.89, p < 0.001) and between SaO₂ and SpO₂ (ρ = 0.81–0.84, p < 0.001). Bland-Altman analysis confirmed good agreement at all time points for both gas exchange pairs. Conclusion TcCO₂ monitoring is a reliable, non-invasive alternative to PaCO₂ measurement during rigid bronchoscopy. It provides real-time ventilation assessment in settings where ETCO₂ monitoring is not feasible, supporting its clinical integration.