Abstract:Objective To investigate the effect of nasal mask on preventing respiratory depression and hypoxia during anesthesia under painless gastroscopy.Methods 246 patients underwent elective painless gastroscopy from September 2022 to March 2023 were selected and divided into nasal catheter oxygen group (group C) and nasal mask oxygen group (group M) according to random number table method. The group C was inhaled oxygen by conventional nasal cannula, and in group M, oxygen was inhaled by a nasal mask. Patients in both groups were given 5 L/min preoxygenation for 3 min. After induction of anesthesia, gastroscopy was performed when modified observer’s assessment of alertness/sedation (MOAA/S) score ≤ 1. During anesthesia, hypoxia interventions were performed in group C based on percutaneous arterial oxygen saturation (SpO2) and in group M based on partial pressure of end-tidal carbon dioxide (PetCO2) and SpO2. The incidence of subclinical respiratory depression, hypoxia and severe hypoxia during anesthesia was recorded. The minimum SpO2 value during anesthesia was recorded; Implementation of intervention measures of jaw lifting, mask pressure oxygen and tracheal intubation. Record the number of gastroscope withdrawal cases. Mean arterial pressure (MAP), heart rate (HR), and respiratory rate (RR) were recorded at the time of entry (T0), immediately after induction of anesthesia (T1), at the end of gastroscopy (T2), and 5 minutes after awakening (T3). The occurrence of perioperative adverse events and the satisfaction of anesthesiologists and endoscopists were recorded.Results Compared with group C, the incidence of subclinical respiratory depression, hypoxia and severe hypoxia in group M was significantly decreased (P < 0.05). The minimum value of SpO2 during anesthesia in group M was higher than that in group C (P < 0.05). The incidence of jaw-lifting and mask ventilation were lower in group M than that in group C (P < 0.05). The incidence of gastroscope withdrawal due to airway intervention in group M was lower than that in group C (P < 0.05). Compared with T0, MAP, HR and RR of the two groups were significant reduction at T1 and T2 (P < 0.05). There was no significant difference in the incidence of adverse events between the two groups (P > 0.05). The satisfaction of endoscopists in group M was higher than that in group C (P < 0.05).Conclusion Compared with nasal catheter oxygen inhalation, anesthesia nasal mask can timely detect hypopnea and respiratory depression during gastroscopy, reduce the occurrence of hypoxia, and improve the airway safety of painless gastroscopy patients.