Abstract: Objective　To explore the effect and mechanism of abdominal pressure lifting apparatus on painless gastroscopy in overweight and obese patients. Methods　A total of 210 overweight and obese patients who underwent painless gastroscopy were selected and divided into the experimental group (n=105) and the control group (n=105) according to random number table method. Before the examination, patients were given pure oxygen at a flow rate of 5 L/min for 3 min, and then slowly injected remifentanil 0.25 μg/kg and propofol 2 mg/kg successively. Gastroscopy was performed when the modified observer’s assessment of alert /sedation (MOAA/S) was ≤3. Abdominal lifting and pressing were carried out for 10 times in the experimental group at the time of 90 s after anesthesia, while no intervention was performed in the control group. Basic vital signs of patients were monitored throughout the whole process. Data of systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and oxygen saturation of finger pulse (SpO2) were recorded and compared when the patients entered the room (T0), the eyelash reflex disappeared (T1), the time of 90 s after anesthesia (T2), at the end of examination (T3), at the time of recovery from anesthesia (T4) and at the time of leaving the clinic (T5). The incidence and degree of respiratory related adverse events were recorded and compared between the two groups, and drug dosage, examination time, anesthesia time, awakening time, independent sitting time, leaving time and the occurrence of adverse events were also recorded and compared. Results　At the time of T0, there were no significant differences in HR, SBP, DBP and SpO2 between the two groups. At the time points of T0 to T5, there were no significant differences in SBP and HR between the two groups. At the time points of T1 and T4, DBP was significantly lower in the experimental group than that of the control group (P＜0.05). At time points of T3 and T4, the SpO2 was significantly higher in the experimental group than that of the control group (P＜0.05). There were no significant differences in the general information, drug dosage, anesthesia time, examination time, awakening time and leaving time between the two groups. However, the independent sitting time was significantly shorter in the experimental group than that of the control group (P＜0.05). The proportion of patients with subclinical respiratory depression was significantly higher in the experimental group than that in the control group, but the proportion of patients with hypoxia, severe hypoxia, mandibular support and mask pressure oxygen supply was lower in the experimental group than that in the control group (P＜0.05). There was no significant difference in the occurrence of adverse reactions between the two groups (P＞0.05). Conclusion　The use of abdominal pressure lifting apparatus during painless gastroscopy in overweight and obese patients reduces the overall incidence of respiratory adverse events and the number of respiratory interventions.

Key words: gastroscopy, obesity, overweight, propofol, monitoring, intraoperative, abdominal pressure lifting apparatus, respiratory related adverse events