The effect of lidocaine cuff filling with two different concentrations 2% and 4% on the incidence of cough and severity of sore throat after surgery and compared with the control group

Background: Common complications of intubation is cough and sore throat after surgery, which increase the complications and dissatisfaction of patients, therefore, it is necessary to find a way to treat this complication. Therefore, the aim of this study was to evaluate the effect of lidocaine injection with two different concentrations (2% and 4%) in the tracheal cuff on cough and sore throat after surgery and compared with control group (normal saline).

Methods: This study was performed on 96 patients undergoing surgery (32 patients in each group). Patients were randomly assigned into three groups (2 to 5 cc lidocaine 2%, lidocaine 4%, and normal saline) and the drugs were prescribed preoperatively in cuff of the endotracheal tube. Vital signs, sore throats and frequency of coughing were recorded in the patients. Chi-square and ANOVA tests were used to compare the data.

Results: The mean score of pain in recovery and 24 hours after extubation in the lidocaine group was 4% and was the highest in the normal saline group (P = 0.002 and P = 0.019). The prevalence of cough after 12 and 24 from extubation in the lidocaine 4% group (2.6% and 0 respectively) and in the normal saline group was highest (37.5% and 25% respectively) (P=0.003 and P=0.007, respectively).

Conclusion: The results of our study showed that the prevalence of cough and the mean pain in patients receiving lidocaine 4% was significantly better than the 2% and normal saline groups, and also no other complications such as hemodynamic changes was not observed in the three groups.