This clinical trial is focused on understanding the effects of certain medications during a medical procedure called a gastroscopy, which is a test to look inside the stomach using a small camera. The study involves the use of three medications: Propofol, Lidocaine, and Sodium Chloride. Propofol is a medication that helps patients relax and fall asleep during medical procedures. Lidocaine is used to numb areas of the body and reduce pain. Sodium Chloride, also known as salt water, is often used in medical settings to help deliver medications through the veins.

The purpose of this study is to see how an injection of Lidocaine affects the amount of Propofol needed to keep patients comfortable during a gastroscopy. The study is designed to be double-blinded, meaning neither the patients nor the researchers know who is receiving which treatment, to ensure unbiased results. Participants will receive either the medications or a placebo, and the effects will be carefully monitored. The study will also look at how these medications affect things like breathing, blood pressure, and any side effects that might occur.

Throughout the study, participants will be closely observed to ensure their safety and comfort. The researchers will measure how well the medications work by looking at how much Propofol is needed to keep patients still during the procedure and by checking for any side effects. The study will also gather feedback from both the doctors performing the procedure and the patients themselves to understand their satisfaction with the process. This research aims to improve the experience and safety of patients undergoing gastroscopy by finding the best way to use these medications together.