Abstract:Objective To investigate the effect of pronase + simethicone taking at different times before painless gastroscopy and patient’s different position after taking they on gastroscopy.Methods The patients who received painless gastroscopy were randomly divided into the pronase + simethicone group (n = 300), the simethicone group (n = 240), and the control group (lidocaine hydrochloride glue group, n = 200). The endoscopic visual field clarity, the propofol dosage, the endoscopic operation time, the incidence of nausea and vomiting, the detection rate of precancerous lesions and early gastric cancer were observed and compared among the three groups of patients taking the above drugs 5, 10, 15, 20, 25, 30, 45, and 60 min before the painless endoscopy and taking different positions [sitting, standing (intermittent walking) and lying down (intermittent left and right sideways) after taking the drugs].Results The endoscopic visual field clarity, the dosage of propofol, the endoscopy operation time and the detection rate of precancerous lesions and early gastric cancer in the pronase + simethicone group were significantly better than those in the simethicone group and the control group (P < 0.01), the simethicone group was better than that in the control group (P < 0.01); There was no significant difference in the incidence of nausea and vomiting among the three groups (P > 0.05). In the pronase + simethicone group, the clarity of the gastroscope visual field was better after oral administration 20 and 25 min before painless gastroscopy (P < 0.05), but there were no statistically significant difference between the two groups (P > 0.05). In the pronase+simethicone group, the endoscopic visual field clarity in those taking the standing position (intermittent walking) or lying position (intermittent left and right sideways) was better than those taking the sitting position, and the difference were statistically significant (χ21 = 14.56, P1 = 0.000; χ22 = 16.61, P2 = 0.000); There was no obvious difference in the endoscopic visual field clarity between those taking the standing position (intermittent walking) and the lying position (intermittent left and right sideways) (χ23 = 0.12, P3 = 0.733).Conclusion The application of pronase and simethicone before painless gastroscopy can effectively improve the clarity of the gastroscope’s visual field, shorten the endoscopy operation time, reduce the dosage of propofol, and increase the detection rate of precancerous lesions and early gastric cancer; The result was better in those taking the medicine 20 and 25 min before gastroscopy and taking the standing position (intermittently walking) and lying position (intermittently walking sideways).