Effect of Palatable Lidocaine Gel on Gag Reflex for Patients Undergoing Upper Gastrointestinal Endoscopy

* The development of upper gastrointestinal endoscopy (UGIE) has greatly expanded the diagnostic and therapeutic capabilities of gastroenterologists. The patient's tolerance to procedure and endoscopist's satisfaction increase when sedation is used along with topical pharyngeal anesthesia.
* Numerous agents are available for moderate sedation in endoscopy such as propofol, midazolam, ketamine, fentanyl and dexmedetomidine, the choice of a particular sedative agent depends on its availability, cost and experience of the endoscopist and patient with that sedative agent. However, these i.v. anesthetics may be associated with complications especially in elderly patients or in those with other comorbidities, as apnea, hypoxia, hypotension, and paradoxical agitation, in which the patient becomes agitated rather than sleepy from the sedation, leading to increased morbidity and the duration of the patient's hospitalization.
* Local application of lidocaine to the oral cavity and the oropharynx, will attenuate or even abolish the gag reflex increasing the patient's comfort thus decreasing the dose of i.v. anesthetics with their potential complications.
* Up to our knowledge, there is no study done to evaluate the effect of palatable lidocaine gel versus I .v dexmedetomidine on the incidence of gag reflex and total propofol consumption during elective upper gastrointestinal endoscopy.

Upper gastrointestinal tract endoscopy (UGIE) is a valuable procedure that is commonly used for the diagnosis of possible causes of upper gastrointestinal tract (GIT) symptoms such as bleeding, pain, dysphagia, recurrent vomiting and reflux. Moreover, it is a safe and easy procedure for taking biopsy samples for suspected esophageal, gastric and duodenal diseases, grading and even ligating varices \[1, 2\].

UGIE is widely performed under propofol sedation that considered a safe sedation technique and alleviates the sympathetic response to the procedure. However, gag reflex and retching still exist in approximately 29% of those patients despite being under propofol sedation \[3\]. Any further trial of deepening sedation in order to minimize gagging may compromise hemodynamics and cause respiratory depression. These complications add to the overall costs as it increases morbidity and duration of patients' hospitalization. On the other hand, continued gag reflex could affect the safety of the procedure, patient's tolerance and endoscopist's satisfaction \[4\].

Dexmedetomidine, a short-acting selective α2-agonist, has been used frequently as a sedoanalgesic in many diagnostic and therapeutic procedures \[5\]. It provides unique sedative activity not present in conventional sedatives so it is unlikely to cause restlessness or respiratory depression was seen with Gaba aminobutyric acid (GABA) receptor agonists such as propofol. Therefore it minimizes physical and emotional distress and enhances successful completion of the procedure without remarkable gag reflex \[6\]. However, many clinicians may have qualms regarding the safety profile of dexmedetomidine usage in such endoscopic procedures due to its well known hemodynamic side effects (especially bradycardia and hypotension) \[7\].

Topical pharyngeal anesthesia(TPA) has been used to avoid such complications resulting from deepening sedation through increase i.v anesthetic doses of propofol or adjuvants that may be used as dexmedetomidine. TPA is preferred in many centers, particularly for diagnostic endoscopy \[8, 9\].

Lidocaine is widely used for TPA. The spray, gel and inhaler forms of it are commercially available. However, application of lidocaine gel to the oral cavity and the oropharynx, especially the base of the tongue, palate, uvula, palatopharyngeal, palatoglossal folds and posterior pharyngeal wall will attenuate or even abolish the gag reflex while introducing the UGIE, thus increasing the patient's comfort and tolerance to the procedure and decreasing the dose of i.v. anesthetics with their potential complications \[10, 11\].

Palatable lidocaine gel is a local anesthetic that stabilizes the neuronal membrane through hindering the ionic fluxes that initiate and transmit impulses, thereby giving a local anesthetic action. It is a safe, well-tolerated and quite promising TPA particularly in elderly patients and in patients with comorbidities in office-based endoscopy \[12\].

We hypothesize that the usage of topical palatable lidocaine gel may have an impact on decreasing the incidence of gag reflex and total propofol consumption during upper gastrointestinal endoscopy.

Eligibility Criteria:
Inclusion Criteria:

* Patient acceptance. Age 21-60 years old of either sex. BMI \< 30 kg/m2 ASA I and ASA II. scheduled for elective upper GIT endoscopy

Exclusion Criteria:

* History of clinically significant cardiovascular, respiratory diseases (as obstructive sleep apnea, severe COPD or asthma) History of psychiatric disease History of allergy to any of the study drugs