Sore throat after anesthesia and surgery is quite common – more than 1 in 10 patients who have outpatient (day) surgery complain of this. Along with the sore throat, some patients have cough, hoarseness and pain with swallowing (dysphagia).
Strepsils are often advised for the treatment of sore throat, but I have not been aware of their use for prevention. My mother always gave us Strepsils to soothe a sore throat which I believed to be a classic example of the placebo effect (tablet + a mother’s love is powerful therapy). Plus they taste nice.
In recent research from Iran, patients were given lemon flavored Strepsil(R) tablets, or identically flavored placebo tablets, about 45 minutes before anesthesia. Surprisingly, the patients who got Strepsils had only about one third (13.7%) the incidence of sore throat compared with the placebo tablets (33.3%) when assessed 20 minutes after surgery. The difference was less marked 24 hours after surgery but still significant.
Airway management has the strongest influence on the incidence of sore throat, so if you have an endotracheal tube, which passes through the vocal cords, the risk is greater, compared with other types of airway devices that sit in the throat, and do not come into direct contact with the voice box. Sore throat is also associated with female sex, younger patients, and use of a muscle relaxant drug called succinylcholine.
What’s in Strepsils? They contain 2,4-dichlorobenzyl alcohol and amylmetacresol, with sugar and flavoring. According to wikipedia, the ingredients of Strepsils are antiseptics. If this is the case, it’s hard to understand how they would prevent a sort throat – perhaps there is an anti-inflammatory effects also. Strepsils Plus(R) contain lidocaine, a local anesthetic, but previous studies with lidocaine, oddly enough, found that when applied to endotracheal tubes it did not reduce the risk of sore throat, and may even increase it.
It will be interesting to see if these findings can be replicated in another study elsewhere.
Ebneshahidi, A. Anesthesia & Analgesia 111(4), October 2010, p 892–894