Abstract

Introduction: Pain during the injection of anesthetic agents may be distressing to the patients and can reduce the acceptability of an otherwise useful agent such as propofol for short cases and day care surgeries. Lidocaine and ketamine both are used as pre-treatment to decrease propofol-related injection pain. This study aims to compare the effectiveness of ketamine injection to decrease propofol- induced pain in comparison to lidocaine injection.
Method: This is a cross-sectional comparative study. 89 cases were divided into two groups where group K received ketamine 2 ml (0.2 mg/kg) whereas group L received lidocaine 2% 2 ml (0.5 mg/kg) as pre-treatment medication after venous occlusion with rubber tourniquet. 1/4th dose of propofol was injected 1 min after release of tourniquet and pain accessed at 0, 1 and 2 minutes of propofol injection with a verbal response and behavioral signs. Chi-square test and paired T-test were used and a p-value less than 0.05 were considered significant.
Results: Regarding hemodynamic, oxygenation, and adverse effects there was no significant difference between the two groups. Immediately after propofol injection, only one patient from the ketamine group had mild pain (2.22%) while 12 patients from the lignocaine group had mild pain (27.27%) which was statistically significant with a p-value of 0.009. Two minutes after propofol injection, only 12 cases had mild pain i.e. 13.48% (1 from the ketamine group i.e. 2.22% and 11 from lignocaine group i.e. 25%) which was statistically significant (p-value 0.002). Ketamine with its local anesthetic and analgesic effect can be equally effective to lidocaine.
Conclusion: Our study helps prove that low-dose ketamine is more effective in reducing the incidence and severity of pain on injection of propofol in comparison to lidocaine. Better hemodynamic of ketamine with no any emergence incidence improves its efficacy.

Keywords: Propofol; Ketamine; Lidocaine; Pain; Pretreatment