Dyclonine vs. Tetracaine for Local Anesthesia in Unsedated Gastroscopy

Dyclonine Hydrochloride Mucilage Versus Tetracaine Hydrochloride Jelly for Local Anesthesia in Unsedated Gastroscopy: A Non-inferiority Randomized Controlled Trial

Gastroscopy is a key diagnostic approach for upper gastrointestinal diseases, but pharyngeal passage of the gastroscopy often causes participants' discomfort. Topical pharyngeal anesthetics are routinely used to alleviate such discomfort. Dyclonine hydrochloride mucilage and tetracaine hydrochloride jelly are the two most commonly used topical pharyngeal anesthetics in clinical practice. Although both agents are widely used, their comparative efficacy in unsedated gastroscopy remains unclear, and high-quality evidence is scarce. This study aims to compare their anesthetic efficacy,participant comfort, and safety.

A total of 208 participants undergoing unsedated gastroscopy will be enrolled and randomly assigned in a 1:1 ratio to either the dyclonine group or the tetracaine group. Participants in the dyclonine group will receive dyclonine hydrochloride mucilage for pharyngeal topical anesthesia, whereas those in the tetracaine group will receive tetracaine hydrochloride jelly. The primary outcome is participant comfort assessed using the Visual Analogue Scale (VAS, range 0-10) during the gastroscopy. Secondary outcomes include antifoaming efficacy, the incidence of nausea and vomiting, the duration of gastroscopy, participant and endoscopist satisfaction, and the incidence of adverse events.

Inclusion Criteria:

• Age 18-75 years, of either sex;
• Scheduled for an unsedated gastroscopy;
• American Society of Anesthesiologists (ASA) physical status class I or II;
• Able to understand and cooperate with Visual Analogue Scale (VAS) comfort assessment;
• Willing to provide written informed consent voluntarily.

Exclusion Criteria:

• Known allergy to the study agents;
• Severe cardiopulmonary disease or hepatic/renal insufficiency;
• Long-term use of sedatives or analgesics, or history of alcohol abuse;
• Pregnancy or lactation;
• Dysphagia or trismus (limited mouth opening);
• Contraindications to upper gastrointestinal endoscopy, including acute perforation and active massive bleeding;
• Mental or cognitive disorders that may preclude cooperation with the procedure;
• Scheduled for therapeutic endoscopic procedures with an anticipated procedure time exceeding 15 minutes;
• Altered upper gastrointestinal anatomy due to prior total gastrectomy, esophagectomy, or subtotal gastrectomy.