Background and objective: Propofol injection during induction of anesthesia induces pain. Ketamine has been shown to reduce the injection pain. However, ketamine has unfavorable adverse effects, including increased secretion production and hemodynamic responses, which might induce pulmonary or hemodynamic adverse events, especially in patients undergoing lung surgery who require a double-lumen tube (DLT). The aim of this study was to determine whether ketamine can safely reduce propofol injection pain during induction of anesthesia for lung surgery.
Methods: Forty-five patients scheduled for elective lung surgery requiring DLT were randomly allocated into three groups. Patients received saline (control), ketamine 0.5 mg kg(-1) (0.5 ketamine), or ketamine 1.0 mg kg(-1) (1.0 ketamine), followed by 5 ml propofol 30 s later. An anesthesiologist blinded to the study group assessed pain score during induction, hemodynamics during DLT placement, and secretion production during anesthetic management.
Results: Pretreatment of 0.5 mg kg(-1) ketamine reduced the incidence and intensity of propofol injection pain, whereas 1.0 mg kg(-1) ketamine completely eliminated the pain. There were no significant differences regarding oxygenation during one-lung ventilation (OLV) and hemodynamics during induction among the three groups, although ketamine increased secretion production.
Conclusions: One milligram per kilogram of ketamine completely eliminated pain associated with propofol injection without affecting hemodynamics during induction of anesthesia and oxygenation during OLV.