Abstract

This study tested the hypothesis that injecting a premixed propofol/lidocaine solution will be associated with less pain than if the lidocaine is injected separately before propofol in non-premedicated patients receiving propofol for colonoscopy.
This was a randomized, double-blind, placebo controlled study performed with IRB approval and patients’ informed consent. One group received 40 mg lidocaine IV bolus followed by propofol. The second group received propofol from a syringe containing 19 mL propofol mixed with 20 mg lidocaine.
Patients were asked about symptoms of systemic lidocaine before propofol injection and about occurrence and severity of pain during propofol injection. Fisher's exact test was used to compare the proportion of patients who experienced pain and the incidence of experiencing systemic lidocaine symptoms between the 2 groups. Wilcox rank sum test was used to compare the severity of pain for patients who experienced pain in the two groups.
Sixty percent of patients who received 40 mg lidocaine IV experienced some symptoms of systemic lidocaine. The incidence of pain on propofol injection in all patients was not different between the two groups. However, patients in the Mixed Lidocaine group experienced less severe pain compared to patients in the Lidocaine Bolus group (p

Key words: Propofol pain, propofol/lidocaine mixture, propofol for colonoscopy.