Oral EtCO₂ Sampling May Improve Accuracy of Capnographic Waveform Capture

Background: End-tidal carbon dioxide (EtCO 2 ) is crucial for anesthesia monitoring, providing near–instant ventilation assessment. Standard nasal cannulas may not capture oral EtCO 2 readings, resulting in inaccurate data. Objective: To evaluate EtCO 2 waveforms using nasal-only and combined nasal–oral monitoring to enhance safety by ensuring accurate ventilation assessment across 3 simulated breathing states: nasal breathing, oral breathing, and apnea. Design: Single-blinded, randomized, crossover controlled design. Participants: Healthy adult volunteers from the University of Illinois College of Dentistry. Inclusion criteria were age ≥18 years, English proficiency, and ability to give informed consent. Those with respiratory issues, anatomical airway abnormalities, or edentulism were excluded. Methods: EtCO 2 monitoring was conducted using both nasal-only and combined nasal–oral sampling under 3 simulated breathing conditions: nasal breathing, oral breathing, more...