Determination of ED50 and ED95 With Clinical Efficacy of Intranasal Dexmedetomidine Combined With Esketamine for Preoperative Sedation in Pediatric General Anesthesia

This study determines the right dose of two sedative medications — dexmedetomidine and esketamine, given through the nose — to safely calm young children before they receive general anesthesia for surgery. **You may be eligible if:** - Your child is between 1 and 6 years old - Your child needs to have a planned (non-emergency) surgery under general anesthesia - Your child is generally healthy or has only mild health issues (ASA Class I or II) - Your child's weight is within the normal range for their age - You have signed consent for participation **You may NOT be eligible if:** - You or your child refuses to participate - Your child has a known allergy to the study medications or other anesthetics - Your child has a history of heart, brain, liver, kidney, or metabolic disease - Your child had an upper respiratory infection (cold) in the past two weeks - Your child has had an abnormal reaction to anesthesia in the past Talk to your doctor to see if this trial is right for you.