Comparison Between Lidocaine Inhalation and Intravenous Dexamethasone in Reducing Postoperative Sore Throat Frequency After Laryngeal Mask Insertion.

Background: The frequency of postoperative sore throat (POST) after laryngeal mask airway insertion (LMA) was relatively high. Lidocaine might reduce the pain and inflammatory response. Additionally, inhalation form might result in a better distribution, which results in a better airway analgesia and minimal systemic effect.

Objectives: To compare the incidence of sore throat post LMA insertion after 1.5 mg/kg of lidocaine inhalation and 10 mg of intravenous dexamethasone.

Methods: This was a single-blinded randomized clinical trial, which included 128 patients who underwent ophthalmic surgery under general anesthesia with LMA insertion. Inclusion criteria were individuals 18 - 65 years old, ASA 1 or 2, Mallampati class I or II, and no sore throat before surgery. After University of Indonesia Research Ethical Committee approval and informed consent, all subjects were randomly divided into two groups: lidocaine inhalation group, which would receive lidocaine inhalation 2% 1.5 mg/kg (additional NaCl 0.9% until total 6 mL volume) and intravenous 2 mL NaCl 0.9%, and dexamethasone group, which would received NaCl 0.9% inhalation (6 mL volume) and dexamethasone 10 mg intravenously 10 minutes before LMA insertion. POST incidence and pain severity assessment were done 2 hours postoperatively. Statistical analysis were done with SPSS version 21.

Results: There were 10.9% of subjects in the lidocaine inhalation group and 9.4% subjects in the dexamethasone group who suffer from POST postoperatively (P > 0.05). The median of POST pain in the lidocaine inhalation group was 0 (0 - 1), whereas in dexamethasone group it was 0 (0 - 3). This study did not find any side effects on both groups.

Conclusions: Lidocaine inhalation 1.5 mg/kg was proportional to intravenous dexamethasone 10 mg in reducing the incidence and severity of POST after LMA insertion.