title: Effectiveness of ketamine gargle in reducing postoperative sore throat in patients undergoing airway instrumentation: a systematic review.
abstract: BACKGROUND
  Postoperative sore throat is a common, minor adverse event, second to postoperative nausea and vomiting, occurring in individuals undergoing general anesthesia. Postoperative sore throat has the potential to not only diminish patient satisfaction, but also increase the need for adjunct pain therapy in the post anesthesia care unit. Many techniques are utilized to reduce postoperative sore throat; however no one intervention has proven to be completely effective. The use of ketamine gargle is a novel intervention but the effectiveness of administering it prior to induction of general anesthesia is still uncertain. Therefore, further evaluation of current evidence is needed to determine the effectiveness of ketamine gargle in reducing the incidence of postoperative sore throat.
  
  
  OBJECTIVE
  The objective of this review was to determine the effectiveness of ketamine gargle in comparison to placebo or another intervention in reducing the incidence of postoperative sore throat in patients undergoing airway instrumentation.
  
  
  METHODS
  The participants in this review were adult patients who received ketamine gargle or placebo prior to induction of general anesthesia for a variety of surgical procedures requiring endotracheal intubation.This review examined studies that evaluated the effectiveness of ketamine gargle compared to placebo or another intervention in reducing the incidence of postoperative sore throat.This review considered studies that measured the incidence of postoperative sore throat using a direct question survey with a four-point scale (0 = no sore throat; 1,2,3 = presence of sore throat).This review included randomized controlled trials only; no other types of articles were discovered upon searching.
  
  
  METHODS
  The comprehensive search strategy aimed to find both English language studies prior to August 2014.Databases used were: EMBASE, CINAHL, MEDLINE, ProQuest, Web of Science and Cochrane Central Register of Controlled Trials. Google Scholar, MEDNAR, New York Academy of Medicine Grey Literature Report and ProQuest Dissertations and Theses were used to locate unpublished studies. Initial keywords included: ketamine, gargle or mouthwash, postoperative, sore throat or pharyngitis, and airway management.
  
  
  METHODS
  Two independent reviewers used the Joanna Briggs Institute Critical Appraisal Checklist for Experimental Studies, a standardized critical appraisal instrument, to assess papers selected for inclusion.
  
  
  METHODS
  Incidence of postoperative sore throat for both the treatment and control groups was extracted from the included studies using the Joanna Briggs Institute Data Extraction Form for Experimental Studies.
  
  
  RESULTS
  Extracted data was pooled in a meta-analysis utilizing the DerSimonian and Laird random effects model using the JBI Meta-Analysis of Statistics Assessment and Review Instrument. Relative risk and 95% confidence intervals were calculated for analysis. Heterogeneity was assessed using the standard chi-square test.
  
  
  RESULTS
  Five randomized controlled-trials were included in the meta-analysis. Ketamine gargle caused a statistically significant (p <0.015, RR <0.53) reduction in the incidence of postoperative sore throat compared to placebo across all five time intervals studied (0, 2, 4, 8, and 24 hours).
  
  
  CONCLUSIONS
  Administration of ketamine gargle (40-50 mg) prior to induction of anesthesia significantly reduces the incidence of postoperative sore throat across all studied time intervals in patients undergoing general anesthesia requiring endotracheal intubation.
  
  
  CONCLUSIONS
  Administration of ketamine gargle prior to induction of general anesthesia with airway instrumentation may improve patient satisfaction by decreasing patient discomfort and the need for adjunct pain therapy in the post anesthesia care unit. This impacts current practice and patient outcomes in that this may decrease the need for adjunct pain therapy and decrease length of stay in the post-anesthesia care unit.
  
  
  CONCLUSIONS
  Additional research is needed to determine the systemic effects of ketamine gargle and whether other n-methyl-d-aspartate antagonists are effective in reducing postoperative sore throat. Future research should include previously excluded populations and expanded to include other methods of airway manipulation.
authors.affiliation: 1School of Nurse Anesthesia, Texas Christian University, Texas, USA2Texas Christian University Center for Evidence Based Practice and Research: a collaborating center of the Joanna Briggs Institute.
authors.forename: Jillian
authors.initials: J
authors.lastname: Mayhood
authors.forename: Kayla
authors.initials: K
authors.lastname: Cress
mesh_terms: D000293:Adolescent; D000328:Adult; D000700:Analgesics / Q000627:therapeutic use; D000768:Anesthesia, General / Q000009:adverse effects / Q000295:instrumentation*; D005260:Female; D006801:Humans; D015994:Incidence; D007442:Intubation, Intratracheal / Q000009:adverse effects*; D007649:Ketamine / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009067:Mouthwashes / Q000627:therapeutic use; D010612:Pharyngitis / Q000188:drug therapy*; D011183:Postoperative Complications / Q000188:drug therapy* / Q000453:epidemiology / Q000517:prevention & control; D016032:Randomized Controlled Trials as Topic; D055815:Young Adult
chemical_list: D000700:Analgesics; D009067:Mouthwashes; D007649:Ketamine