The overall purpose of this study is to investigate the effects of preoperative administration of oral zinc lozenges on postoperative sore throat syndrome which consists of pain, dysphagia, and in extreme cases hoarseness. It is associated with coughing (which may increase surgical related pain) and difficulty with oral intake. The study will look at the changes in incidence and severity of POST in the immediate postoperative period.

Postoperative sore throat (POST) syndrome is a very common complication of endotracheal intubation Prior to earlier studies larger endotracheal tubes were utilized for providing general anesthesia. The incidence of POST at that time was 48%, with smaller tubes the incidence decreased to 22%. It is now standard of care to utilize endotracheal tubes based on size and gender of the patient. In subsequent studies to further reduce the incidence of POST, the rate of sore throat in the control groups have been between 17-90%. The cause of POST is related to direct local tissue trauma leading to inflammation of the pharyngeal mucosa and possibly the drying effect of non-humidified gases across the mucous membranes. Although there have been multiple treatments recommended for POST, none of them have been exactly effective, and the symptoms usually ameliorate within 72 hr without treatment. Even though this is the case, it is still recommended to take preventive measures for POST. The presence of POST after surgery is a patient satisfaction issue and has also been associated with a longer stay in in the post anesthesia recovery unit(Higgins et al). Both pharmacologic and non-pharmacologic measures have been recommended in past studies. Nonpharmacological methods for attenuating POST have included using smaller-sized endotracheal tubes, lubricating the endotracheal tube with water-soluble jelly, careful airway instrumentation, and minimizing cuff pressure. Pharmacologic measures have included gargles with lidocaine, aspirin, or ketamine preoperatively, inhalation of beclomethasone or fluticasone propionate, and recently the use of licorice gargle or magnesium lozenges 30 min preoperatively (Ruetzler, Borazan H).

Zinc has been utilized for many years as a topical agent to promote epithelial health and recovery after injury. Several studies have evaluated the effect of zinc on wound healing and epithelial tissue health. These studies have shown that supplementation with zinc sulfate causes rapid recovery of leg and gastric ulcers (Worthington et al). It seems zinc not only increases re-epithelialization, but it also decreases bacterial activity and causes rapid wound healing (Arbabi-kalati et al). Zinc has also been shown to be an immunomodulatory agent that monitors and modifies the immune system and T-lymphocytes. Decreases in zinc serum levels lead to lymphopenia and declines in cellular and humoral immunity. The effect of oral zinc sulfate has also been utilized for treatment of oral wounds by oral surgeons; moreover, research has shown zinc supplementation assists with the recovery of mucosal wounds and treatment of tongue ulcers (Worthington et al). A recent study by Arbabi-kalati, showed that high dose oral zinc sulfate (220 mg TID) decreased the intensity of mucositis, xerostomia, and pain in individuals undergoing chemotherapy or radiotherapy treatments. The mechanism by which zinc improves tissue health was investigated by Sharir et al. and in a model of epithelial injury showed that topical zinc directly activates receptors that promote epithelial repair.

Keeping the above studies in mind, the investigators built this study using the protocols devised by Borazan H, in which they evaluated the efficacy of magnesium lozenges on POST. There are currently no known studies that look at the efficacy of zinc in the prevention of POST. The investigators will use custom compounded lozenges from a local pharmacy with 40 mg of elemental zinc (equivalent to 174 mg of zinc sulfate) per lozenge, which is the tolerable upper intake level for zinc in adults as defined by the US department of Food and Nutrition Board.

The possible knowledge gained from this study for POST syndrome can be extended to people undergoing surgeries requiring endotracheal intubation in the future.