Efficacy of preoperative prophylactic low dose zinc lozenge in reducing post-operative sore throat in adults scheduled for elective surgeries under general anaesthesia with orotracheal intubation: A prospective randomized double blinded trial

Postoperative sore throat (POST) often occurs succeeding tracheal intubation. It is hypothesized that preoperatively administered prophylactic low dose oral zinc lozenges help in attenuating the POST occurrence due to its anti-inflammatory effect while promoting healing of tissues. This study was done to evaluate its efficacy in preventing POST in adult patients undergoing tracheal intubation as a part of general anaesthesia.  220 Patients posted for surgery with tracheal intubation as a part of general anaesthesia were included into this prospective randomized double blinded study. Those included were randomized into two groups Group Z or Group P and received either zinc  or lozenge containing placebo, respectively, 30 minutes preoperatively. Assessment of incidence and severity of POST was done using a 4-point scale of 0-3 at particular time intervals.  102 Patients and 97 patients were taken up for analysis in Group Z and Group P respectively. The comparison of demographic and intraoperative variables in both the groups were comparable. The lower occurrence of POST was statistically significant after preoperative use of zinc lozenge at intervals 0, 2 and 4 hours (p= 0.001**) except at 24 hours. The POST severity was mild in Group Z at 0, 2, and 4 hours in comparison with the placebo group. However, at 24 hours, both the groups were comparable.  A prophylactic low dose of 18.75 mg zinc lozenge given 30 minutes before surgery is efficacious in reducing the occurrence of POST in the post-operative period in patients undergoing tracheal intubation as a part of general anesthesia.