Reduction of Rocuronium-induced Injection Pain With Aspiration of Blood

The goal of this clinical trial is to learn about reduction of rocuronium injection pain in participants receiving general anesthesia. The main question aims to answer is whether diluting rocuronium with blood can reduce rocuronium injection pain. Rocuronium is a rapid onset muscle relaxant used in general anesthesia. Lidocaine is a local anesthetic. Researchers will • inject diluted rocuronium in participant's intravenous catheter during induction. • record withdrawal movement and rocuronium onset time and duration measured by train-of-four (TOF). Researchers will compare between rocuronium diluted with blood, lidocaine and normal saline to see if blood can reduce rocuronium injection pain.