Background: Pharyngeal anesthesia is widely used as an adjunct to sedation during upper endoscopy. Methemoglobinemia and anaphylactic reactions are rare but serious complications of topical anesthetic agents. Individual studies produce variable results about the effectiveness of pharyngeal anesthesia in improving patient tolerance.
Objective: A systematic review was performed to evaluate the effectiveness of pharyngeal anesthesia in improving patient tolerance and ease of endoscopy during sedated upper endoscopy.
Design: A MEDLINE search, an EMBASE search, and manual searches were performed to identify pertinent English language articles. Randomized controlled trials (RCT) comparing the efficacy of pharyngeal anesthesia to placebo or no treatment were identified. Duplicate data extraction about patient tolerance of the procedure and endoscopist assessment regarding the ease of endoscopy was performed.
Results: From a pool of 53 studies, 5 RCTs evaluated a total of 491 patients and provided interpretable data. Patients who rated their discomfort during the sedated procedure as none/minimal were more likely to have received pharyngeal anesthesia (odds ratio [OR] 1.88, 95% confidence interval [CI] 1.13-3.12). Endoscopists were more likely to rate the procedure as "not difficult" for patients who received pharyngeal anesthesia (OR 2.60, 95% CI 1.63-4.17).
Limitations: Lack of standardized outcome measurements and standardized sedation strategies led to heterogeneity in the patient-tolerance portion of the meta-analysis.
Conclusions: Pharyngeal anesthesia before upper endoscopy improves ease of endoscopy and also improves patient tolerance.