title: Lidocaine for preventing postoperative sore throat.
abstract: BACKGROUND
  Sore throat is a common side-effect of general anaesthesia and is reported by between 30% and 70% of patients after tracheal intubation. The likelihood of a sore throat varies with the type, diameter, and cuff pressure of the endotracheal tube used. If intubation is essential, it may be helpful to give drugs prophylactically to alleviate postoperative sore throat. Local anaesthetics and steroids have been used for this purpose. This review was originally published in 2009 and was updated in 2015.
  
  
  OBJECTIVE
  The objective of this review was to evaluate the efficacy and any harm caused by topical and systemic lidocaine used prophylactically to prevent postoperative sore throat in adults undergoing general anaesthesia with endotracheal intubation.
  
  
  METHODS
  We searched CENTRAL (The Cochrane Library 2013, Issue 9), MEDLINE (January 1966 to October 2013), and EMBASE (1980 to October 2013). We also contacted manufacturers and researchers in the field. The original search was undertaken in June 2007. We reran the search in February 2015 and found four studies of interest. We will deal with those studies when we next update the review.
  
  
  METHODS
  We included randomized controlled trials (RCTs) of topical and systemic prophylactic lidocaine therapy versus control (using air or saline) that reported on the risk and severity of postoperative sore throat as an outcome.
  
  
  METHODS
  Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information, such as the risk of any adverse effects.
  
  
  RESULTS
  We included 19 studies involving 1940 participants in this updated review. Of those 1940 participants, 952 received topical or systemic lidocaine therapy and 795 were allocated to the control groups. Topical and systemic lidocaine therapy appeared to reduce the risk of postoperative sore throat (16 studies, 1774 participants, risk ratio (RR) was 0.64 (95% confidence interval (CI) 0.48 to 0.85), the quality of the evidence was low), although when only high-quality trials were included (eight studies, 814 participants) the effect was no longer significant (RR 0.71, 95% CI 0.47 to 1.09). Lidocaine given systemically in two studies (320 participants) did not reveal evidence of an effect (RR 0.44, 95% CI 0.19 to 1.05 ). The severity of sore throat as measured on a visual-analogue scale (VAS) was reduced by lidocaine therapy (six trials, 611 participants, (mean difference (MD) -10.80, 95% CI -14.63 to -6.98). The adverse effects of lidocaine were not reported in these studies, though toxicity is generally rare.
  
  
  CONCLUSIONS
  In our revised systematic review, although the results of included studies show generally positive results, they should be interpreted carefully. The effect size of lidocaine appeared to be affected by study quality; drug concentration; route of administration; management of cuff pressure during anaesthesia; the included population; and the type of outcome measured.
authors.affiliation: Central Operation Room, Nara Medical University, Shijo-cho 840, Kasahara-shi, Nara, Japan, 634-8522.
authors.forename: Yuu
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Takeo
authors.initials: T
authors.lastname: Nakayama
authors.forename: Mina
authors.initials: M
authors.lastname: Nishimori
authors.forename: Yuka
authors.initials: Y
authors.lastname: Tsujimura
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kawaguchi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sato
mesh_terms: D000768:Anesthesia, General / Q000009:adverse effects; D000779:Anesthetics, Local / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D007442:Intubation, Intratracheal / Q000009:adverse effects; D008012:Lidocaine / Q000009:adverse effects / Q000627:therapeutic use*; D010612:Pharyngitis / Q000209:etiology / Q000517:prevention & control*; D011183:Postoperative Complications / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine