Ketamine eliminates propofol pain but does not affect hemodynamics during induction with double-lumen tubes

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.