Effect of Palatable Lidocaine Gel on Gag Reflex for Patients Undergoing Upper Gastrointestinal Endoscopy
Condition: Gastro-Intestinal Disorder
MeSH terms: Intestinal Diseases; Gastrointestinal Diseases; Digestive System Diseases; Gagging
Study type: Interventional

Summary: 
      -  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.
    

Detailed description: 
      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.
    

Intervention name(s): Propofol Injection [Diprivan]; Dexmedetomidine [Precedex]; Palatable Lidocaine Topical Gel
Intervention type(s): Drug; Drug; Drug
Intervention description(s): patients will be sedated with 50 mg propofol(10 mg/ml) given slowly intravenously over 1 min; patients will received 0.5 mcg/ kg dexmedetomidine intravenously followed by syringe containing 50 mg propofol(10 mg/ml).; 15 g of palatable lidocaine gel will be gradually applied 3-5 min before the endoscopy at three consecutive 30-s intervals to the base of the tongue, the palate and the peritonsillar areas and the patients will be informed to spread it within their mouth with their tongue and swallow it later to cover the oropharynx and esophagus. Patients will be asked to register the onset of numbness, then patient will receive syringe containing 50 mg propofol (10 mg/ml) intravenously as a sedation.
Other intervention name(s): propofol; propofol
Intervention MeSH terms: Lidocaine; Dexmedetomidine; Propofol
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: palatable lidocaine; dexmedetomidine; gag reflex; gastrointestinal endoscopy