Evaluation of palonosetron for the prevention of pain on injection of LCT/MCT propofol: Randomized controlled comparison with lidocaine.

Background: Long-chain triglyceride/medium-chain triglyceride (LCT/MCT) propofol is less painful than standard long chain triglyceride (LCT) propofol; however, there is still a need to reduce severe pain. 5-Hydroxytryptamine type 3 (5-HT₃) receptor antagonists have an analgesic effect during the injection of standard LCT propofol. This study compared the incidence of moderate-to-severe injection pain with LCT/MCT propofol using pretreatment with palonosetron versus pretreatment with saline or lidocaine. Methods: This prospective, randomized double-blind study divided 98 patients scheduled for general anesthesia into three groups: control (n = 33), palonosetron (n = 32), and lidocaine (n = 33) groups. An 18-gauge intravenous catheter was inserted into the peripheral vein at the dorsum of the hand. The patient's vein was occluded by a rubber tourniquet at mid-forearm, and we then administered 2 ml of the pretreatment drug. One minute after venous occlusion, we released the tourniquet and administered LCT/MCT propofol 2 mg/kg for 10-15 seconds. The degree of pain on propofol injection was evaluated using a 4-point scale. Results: The incidence of moderate-to-severe pain in the control, palonosetron, and lidocaine groups was 9.1, 15.6, and 12.1%, respectively. The incidence of overall pain was lower in the lidocaine group than in the control or palonosetron group. Conclusions: Palonosetron and lidocaine pretreatment does not reduce moderate-to-severe pain on injection of 1% LCT/MCT propofol. Lidocaine pretreatment reduced the overall incidence of injection pain. [ABSTRACT FROM AUTHOR]