Prevention Of Pain On Injection Of Propofol: A Comparison Of Lidocaine With Fentanyl

Objective: Propofol causes pain on IV injection in 28%-90% of patients. A number of techniques have been tried to minimize propofol-induced pain. We compared the efficacy of pretreatment with lidocaine 0.5 mg/kg and 40 mg and fentanyl 50μg after venous occlusion for prevention of propofol-induced pain. Methods: In a randomized, double blinded, placebo-controlled clinical trial, 200 adult female patients,ASA physical status I-II,undergoing elective surgery were randomly assigned into 4 groups of 50 each , Group A received lidocaine 0.5 mg/kg iv , Group B received 2 % lidocaine 40 mg iv, Group C received f entanyl 50μg iv, and Group D received 0.9% saline 2ml iv (placebo group) All pretreatment drugs were made in 2 ml and were accompanied by manual venous occlusion for 1 min, after release of venous occlusion, followed by administration of propofol into a dorsal hand vein until patients lost of consciousness. Pain was assessed with a four-point scale: 0 = no pain, 1 = mild pain, 2 = moderate pain, and 3 = severe pain at the time of propofol i njection, and re-assessed using visual analogue scale (VAS) system when patients awake from anesthesia. Recall of pain was considered with a visual analogue scale (VAS) score>0, the incidence and severity of pain were evaluated. Results: Using four-point scale system: 40 patients (80%) in the placebo group, 19 patients(38 %)in the lidocaine 0.5 mg/kg group (P < 0.05), 25 patients (50%) in the 40 mg lidocaine group (P <0.05),and 32patients (64%) in the fentanyl 50μg group (P >0.05) complained of pain. Analysis showed a significant difference between group A and group D, group B and group D as well as between group C and group D. Using VAS scores system: 37 patients (74%) in the placebo group, 16 patients(32%) in the lidocaine 0.5 mg/kg group (P < 0.05), 22 patients (44%) in the 40 mg lidocaine group (P <0.05),and 30 patients (60%) in fentanyl 50μg group (P <0.05) recall of pain. The difference in the incidence of pain between the lidocaine group and placebo group was significant, as well as between group A and group C, There was no significant difference between fentanyl 50μg group and placebo group. The differences in the severity of pain between four groups have same results. Conclusion: Pretreatment with Lidocaine 0.5 mg/kg or 40 mg along with venous occlusion for 1 min can reduce the incidence and severity of propofol-induced pain.