The research will be carried out in order to determine the optimal lidocaine concentration in propofol lidocaine mixture to prevent pain on propofol injection during induction of general anesthesia using a modified Dixon's up-and-down method. We hypothesized that focusing on lidocaine concentration and not dose could be more convenient and valuable to alleviate pain with propofol injection.~Patients & methods include assessment of severity of pain on propofol injection using nine concentrations of lidocaine in in lidocaine propofol mixture in ASA I&II patients aged 18-60 years with exclusion of patients with history of drug allergy, hepatic or renal impairment, cardiac problems, neurologic deficits or psychiatric disorders.~Demographic data, type and duration of surgery, Time for unconsciousness, volume of propofol-lidocaine mixture used, pain scale during injection, increase in heart rate and/or hand or forearm withdrawal during injection, patient satisfaction (will be assessed in the recovery room after regaining consciousness),
The research will be carried out in order to determine the optimal lidocaine concentration in propofol lidocaine mixture to prevent pain on propofol injection during induction of general anesthesia using a modified Dixon's up-and-down method. We hypothesized that focusing on lidocaine concentration and not dose could be more convenient and valuable to alleviate pain with propofol injection.~Patients & methods include assessment of severity of pain on propofol injection using nine concentrations of lidocaine in lidocaine propofol mixture in ASA I&II patients aged 16-60 years with excluxion of patients with history of drug allergy, hepatic or renal impairment, cardiac problems, neurologic deficits or psychiatric disorders.~Demographic data, type and duration of surgery, Time for unconsciousness, volume of propofol-lidocaine mixture used, pain scale during injection, increase in heart rate and/or hand or forearm withdrawal during injection will be recorded and patient satisfaction (will be assessed in the recovery room after regaining consciousness),