Postoperative sore throat and postextubation coughing can be a very serious problem for anesthesiologists. Licorice, has been reported by Michael Vlessides to be an unlikely treatment for this problem in an article in Anesthesiology News, "Preinduction Licorice Gargle Relieves Post-Op Sore Throat, Cough." A recent study by Kurt Rützler, MD, and colleagues at the Medical University of Austria, in Vienna, in collaboration with Daniel I. Sessler, MD at the Cleveland Clinic, in Ohio, found that when patients gargled with a licorice solution immediately before induction of anesthesia, the incidence and severity of sore throat was significantly reduced on the first postoperative day.
Dr. Sessler has said “There was a small study published previously on this topic by a Turkish research group. The results of Agarwal et al [Anesth Analg 2009;109:77-81] were striking because it’s hard to understand how just gargling for a few minutes before surgery could prevent postoperative sore throat through the first postoperative morning. Furthermore, Agarwal and colleagues reported a 50% treatment effect, which sounded too good to be true.”
The researchers pursued a new study to determine the plausibility of these results. In their study preoperative gargling with licorice decreased the mean score for sore throat pain at postanesthesia care unit (PACU) arrival by 68%, compared with gargling with sugar water; the mean score decreased by 77% at 90 minutes after PACU arrival and by 54% four hours after PACU arrival . The researchers stated that the complete study included 236 patients with similar results and even greater statistical significance.
Dr. Sessler told Anesthesiology News “It’s quite unusual to have a large study show as big a treatment effect as an initial small study. Almost always, larger replication trials find much smaller effects than the original trials. That wasn’t true in this case, despite the fact that our study employed more involved operations with much larger, stiffer endotracheal tubes. There’s no question this finding is true.”
It is not understood at this time exactly why this effect occurs with licorice. Dr. Sessler has said “Licorice is a complicated compound and contains many molecules known to have biologic activity. I don’t know which of the proposed mechanisms is the important one, but it is not completely implausible that licorice would have an effect.” A benefit from use of ketamine, azunol and Strepsils lozenges, and spraying the endotracheal tube with benzydamine hydrochloride has been demonstrated by other researchers.
Dr. Sessler has recommended that institutions give serious thought to the option of using licorice due to the relative ease with which licorice solutions might be incorporated into clinical practice. Dr. Sessler has said “Licorice gargling is something that is dirt cheap, risk-free, simple to use and has a substantial effect on a very real complication. Furthermore, substantial efficacy is now well documented. So, why wouldn’t you use it?”
