Licorice tastes good, and it also can help prevent postoperative sore throat. (Image source: Thinkstock)

Licorice tastes good, and it also can help prevent postoperative sore throat. (Image source: Thinkstock)

Common side effects after anesthesia include postoperative nausea and vomiting (PONV), sore throat, shivering and headache.  Postoperative nausea and vomiting gets the most press: It’s listed as a specific MeSH® (Medical Subject Headings), and over 2500 manuscripts use PONV as a MeSH term compared to fewer than 600 articles where MeSH terms include sore throat and postoperative complications.  Nonetheless, sore throat is a bothersome complication, particularly after the use of an endotracheal tube.  In the manuscript “A Randomized, Double-Blind Comparison of Licorice Versus Sugar-Water Gargle for Prevention of Postoperative Sore Throat and Postextubation Coughing” published this month in Anesthesia & Analgesia, Dr. Daniel I. Sessler, Department of Outcomes Research, Cleveland Clinic, Cleveland, Ohio, and coauthors had patients gargle with licorice solution before induction of anesthesia.

This was a study of 236 patients who underwent elective thoracic surgery where a double-lumen endotracheal tube was used.  Patients were randomized to gargle a solution that contained either sugar-water or a licorice solution for five minutes.  A 37-cm left-sided double-lumen tube was used for women and a 39-cm left-sided double-lumen tube was used for men.  The endotracheal tubes were not lubricated prior to insertion.  Analgesics given for the surgical incision included paracetamol and opioids.  Four hours after surgery the incidence of sore throat for patients who gargled with licorice was 21% vs. 45% for patients who gargled with sugar-water.  Sore throat incidence when measured at earlier time periods that included 30 min and 1.5 hrs after arrival in the PACU as well as on the morning of the first postoperative day was also less after patients gargled with licorice.  The incidence of coughing measured at the different postoperative time points was also less after patients preoperatively gargled with licorice.

Overall sore throat incidence was less in this study compared to others.  Whether the experience of the anesthesiologist who intubated the patients’ trachea, type of anesthesia, type of endotracheal tube or other patient characteristics were responsible for the lower overall incidence is not clear.  Other intravenous drugs and other types of gargling solutions have also been shown to effectively prevent or treat postoperative sore throat.  Simply because PONV has been studied more does not mean that treatment or prevention of postoperative sore throat is also important.