Associations Between Breath Sound Frequency Pattern, Capnography and Electroencephalographic Density Spectrum Array During Deep Sedation in High Risk Patients.

Deep sedation is mandatory for many invasive procedures such as the digestive endoscopy, bronchoscopy and cystoscopy. However, deep sedation may induce respiratory adverse effects including airway obstruction, hypoventilation and apnea. These respiratory adverse effects, which may occur in more than 20% of high-risk groups (eg, children, the elderly, and patients with sleep apnea), hence, are the major concerns of the anesthetic care. However, It is difficult for clinicians to objectively quantify the sedation level and find the associations of inadequate sedation level and the occurrence of respiratory adverse effects.

Airway obstruction and respiratory rate decline during deep sedation are conventionally monitored by using capnography(EtCO2 waveform). However, previous studies have tracheal breath sound monitoring can achieve better detection accuracy than the capnography. The novel Airmod smart breathing monitor has the functions of breath sound recording, anti-noise signal processing, event recording and respiratory rate analysis and research. Through the continuous breath sound recording, airway adverse effects during sedation may be detected, and these breathing spectrogram can be presented for image analysis. This is helpful for researcher to identify associations between airway adverse effect and the sedation level.

The state-of-art anesthetic depth is determined by using the electroencephalogram (EEG). Both EEG raw data or the EEG spectrogram graphs may be used for quantify the sedation level with respiratory adverse effects. Accordingly, this study aims to investigate the associations between the sedation level and the airway adverse effects by using the EEG monitor, Airmod breath sound monitor and the capnography.