Zinc supplementation for postoperative sore throat prevention: evidence from a systematic review and meta-analysis

Postoperative sore throat (POST) is a frequent complication of tracheal intubation that compromises patient comfort and satisfaction. This is due to airway irritation and inflammation. Zinc, which is known for its anti-inflammatory and wound-healing effects, has been investigated as a preventive treatment for POST. This protocol was registered in PROSPERO (CRD420250651708).Three databases, PubMed, The Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov were searched using the keywords "Post operative sore throat," and "zinc." A literature search led to the retrieval of six clinical trials, of which three studies were included in the meta-analysis and all six studies were included in the systematic review. The data were synthesized using Cochrane Review Manager v.5.4.1. The Cochrane risk-of-bias 2.0 tool was used to assess the methodological quality of evidence. The pooled analysis included 248 patients (105 males and 143 females). Study findings suggested that zinc reduces the overall incidence of POST in comparison to placebo (P < 0.0001, OR = 0.29 [95% CI 0.16-0.53], I² = 0%). However, the effects of zinc on POST severity varied. The incidence of mild POST was significantly lower in the zinc-administered group at 0 (OR = 0.06 (95% CI 0.01-0.21), I² = 0%, P < 0.0001), 2 (OR = 0.27 (95% CI 0.13-0.57), I² = 0%, P = 0.0006) and 4 h (OR = 0.14 [95% CI 0.04-0.45], I² = 0%, P = 0.0010) post-extubation. There was no significant difference in the severity of moderate and severe POST between the zinc-supplemented group and the placebo group. Pooled analysis of our current evidence demonstrates that zinc significantly reduced the overall incidence of POST, with a maximum effect observed in mild POST.