Efficacy of Intravenous Paracetamol Dilutions Compared with Lidocaine for Prevention of Propofol-induced Pain During Induction of Anesthesia

Abstract

Background: Propofol is an intravenous anesthetic drug that is commonly used for induction of anesthesia; pain during
induction of anesthesia with propofol is a common problem (with a prevalence of 28-90%) that can be distressful for
patients. We aimed to compare the efficiency of intravenous paracetamol in different dilutions and lidocaine in prevention
of propofol-induced pain.
Methods: In this randomized, double-blind clinical trial, 200 patients scheduled for elective surgery under general
anesthesia with propofol was randomly assigned to 4 groups of 50 persons. In Group 1, 40 mg lidocaine in 5 ml normal
saline; in group 2, 2 mg/kg Paracetamol in 5 ml normal saline; in group 3, 2 mg/kg Paracetamol in 20 ml normal saline, and
in group 4, 5 ml normal saline were injected as control. Then, 25% of the calculated dose of Propofol (2.5 mg/kg) was
injected at a speed of 0.5 ml/sec and the patient’s pain was determined based on VRS score from 0-3. Then, general
anesthesia was induced.
Results: In the four groups, there were no statistically significant differences in terms of age and sex. The amount of pain
in Lidocaine group was significantly lower, compared to the control group (P=0.001), in the paracetamol group (P=0.03),
in the diluted paracetamol group (P=0.009), but there was no significant difference among the three groups in terms of pain
reduction.
Discussion: Both 2 mg/kg paracetamol in 5 ml normal saline and in 20 ml normal saline are as effective as 40 mg lidocaine
in 5 ml normal saline.