A comparative study between a small dose of ketamine, lidocaine 1 %, and acetominophen infusion to decrease propofol injection pain

Abstract EN

Background and objectives Pain during the injection of propofol is one of its drawbacks.

The aim of this prospective, randomized and double-blinded study was to compare ketamine (K), lidocaine (L) 1%, and paracetamol (P) infusion as pretreatment before propofol injection regarding pain during injection.

Patients and methods A total of 200 patients aged between 20 and 60 years, ASA I or II physical status, were randomly assigned into four equal groups.

All patients received pretreatment solutions made up in 20-ml syringes with isotonic saline 0.9%.

All the patients were pretreated over a period of 20 s.

In group K, patients received ketamine 0.5 mg/kg.

In group L, patients received lidocaine 0.5 mg/kg.

In group P, patients received paracetamol (perfagan 10 mg/ml) 2 mg/kg.

In group C (which served as a control group), patients received isotonic saline.

We placed a rubber tourniquet on the forearm for 50 s to occlude the venous blood before giving the study drug.

A blinded researcher assessed the patient’s pain on propofol injection using a four-point scale, hemodynamics, the incidence of complications, and the dose of propofol used to induce anesthesia.

Results There was a signifi cant increase in the pain in group L compared with group K and group P.

Also, there was a signifi cant increase in the pain in group C compared with all other groups.

After propofol injection, there was a signifi cant decrease in the mean arterial pressure in P, L, and C groups in comparison with the baseline values.

There was a signifi cant decrease in the propofol dose for the induction of anesthesia in the ketamine group in comparison with the other groups.

Conclusion Pretreatment with paracetamol 2 mg/kg, ketamine 0.5 mg/kg, and lidocaine 0.5 mg/kg were signifi cantly effective in attenuating the pain of propofol.

However, pretreatment with lidocaine 0.5 mg/kg was the least effective and pretreatment with paracetamol 2 mg/kg was the most effective in attenuating propofol pain.

The incidence of complications was not signifi cant in all groups.