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

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).

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.

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).

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.