Gargled ketamine versus magnesium for prevention ofpostoperative sore throat: a randomized clinical trial

Sore throat after surgery is the second most common cause of complications in recovery. It causes decreased patient satisfaction, and it affects patients’ well-being after surgery. The aim of this study was to compare the effects of ketamine and magnesium sulfate gargle on sore throat after laminectomy.

In this randomized clinical trial, 69 candidates for laminectomy patients in Shohade-Tajrish hospital from June 2021 to December 2022 were randomly assigned to three groups of ketamine (n=25), magnesium (n=23) and control (n=21). The Magnesium group received magnesium sulfate gargle (30 mg/kg in a total of 30 ml 5% Dextrose water), Ketamine gargle (0.5 mg/kg in a total of 30 ml 5% Dextrose water), and the control group received 30 ml 5% Dextrose water gargle. Standard similar anesthesia protocols were applied for all patients. In PACU (0) and 2, 4, 24 hours afterward sore throat was assessed using a visual analog scale (VAS) scoring.

The study showed that the incidence of sore throat in the magnesium group was lower than ketamine. Comparison of the three groups at the time of recovery (0), 2, 4, and 24 hours after surgery showed that the differences between the three groups were significant in terms of sore throat. Also, the difference in the incidence of sore throat within each group in the four times in all three groups was statistically significant (P=0.001). There was no statistically significant difference between age, gender, body mass index, heart rate, blood pressure, duration of intubation, duration of surgery and anesthesia, size of laryngoscopy insertion and Cormack and Lehane score in the three studied groups. A drop in systolic blood pressure was observed in the both groups half an hour after the operation, which was statistically significant. Changes in diastolic blood pressure were significant only in the magnesium group.

The preventive effect of "magnesium sulfate gargle" on sore throat after laminectomy is much better than "ketamine" or "placebo" gargle.