Takeaway

Preoperative ketamine gargle before induction of general anesthesia is effective to reduce the occurrence of postoperative sore throat (POST) in adult patients undergoing surgery with an endotracheal tube.

Key Points

• Systematic review and metanalysis with 17 randomized controlled trials and included 1552 participants
• Ketamine gargle resulted in fewer patients reporting sore throat post-op
• Patients in the ketamine group had less pain and discomfort
• The benefits lasted up to 24 hours in some studies
• Low systemic absorption with minimal side effects
• Dilute ketamine solution (0.5–1 mg/mL) for 30-60 seconds before intubation, .

Excerpts

A systematic review study stated that the prevalence of postoperative sore throat could reach up to 62% following general anesthesia

Various strategies have been explored to reduce the occurrence and severity of POST. The interventions include both pharmacological and non-pharmacological methods like modifications in intubation techniques. Use of small sized endotracheal tube [4], careful airway management [5], spraying the endotracheal tube cuff with lidocaine and beclomethasone [6], the use of muscle relaxant [7], adjusting endotracheal tube cuff pressure [8], benzydamine hydrochloride and aspirin gargles decreased the occurrence of POST [9].

Another single blind RCT conclude that nebulized ketamine is more effective to reduce the incidence and severity of POST compared to ketamine gargle

These evidences showed that 40-50 mg of preoperative ketamine gargle have been found effective to prevent postoperative sore throat.

Abstract

Background

Postoperative sore throat is a frequent and distressing complication caused by airway instrumentation during general anesthesia. The discomfort can lead to immediate distress, delayed recovery and reduce patient satisfaction. The objective of this study was to determine the effectiveness of preoperative ketamine gargle on the occurrence of postoperative sore throat among adult patients who underwent surgery under general anesthesia with endotracheal tube.

Method

PubMed, Cochrane Library, Google Scholar, and World Clinical Trial Registry were searched to find the eligible randomized control trials comparing the effect of preoperative ketamine gargle and placebo gargle on the occurrence of postoperative sore throat after surgery with endotracheal tube in adult patients. We utilized Review Manager Version 5.4 to perform statistical analyses. Cochrane risk of bias tool for randomized control trials was used to assess the risk of bias of included studies. We explored heterogeneity using the I² test. In addition to this, subgroup analysis, and sensitivity analysis was conducted to confirm the robustness of findings. The risk of publication bias was tested using funnel plot Pooled risk ratio along with 95% confidence interval (CI) was used to analyze the outcome.

Result

In the present systematic review and metanalysis, seventeen [17] randomized controlled trials (RCTs) with 1552 participants were included. Compared with placebo, preoperative ketamine gargle is effective to reduce postoperative sore throat (RR = 0.48; 95%CI [0.45, 0.52] in adult patients undergoing surgery under general anesthesia with endotracheal tube.

Conclusion

Preoperative ketamine gargle before induction of general anesthesia is effective to reduce the occurrence of postoperative sore throat in adult patients undergoing surgery under general anesthesia with an endotracheal tube. Further studies with large sample size, better study quality and optimal reporting could be conducted to determine the long-term efficacy and safety of ketamine gargle in different surgical populations.

Citation

Tadesse, M.A., Alimawu, A.A., Kebede, F.S. et al. Effectiveness of preoperative ketamine gargle to reduce postoperative sore throat in adult patients undergoing surgery with endotracheal tube; systematic review and meta-analysis of randomized control trials. BMC Anesthesiol 24, 449 (2024). https://doi.org/10.1186/s12871-024-02837-7

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