Briggs et al. reported an incidence of 39% when injected into the back of the hand and 3% in the forearm or anterior elbow fossa. Although the pain of the emulsion preparation is less, the relationship between pain and the injection site still applies. 

Briggs and White report that injection pain is rare in the anterior elbow fossa, but occurs frequently (30%) on the back of the hand. McCulloch and Lees[26] came up with similar results: the incidence of pain was 37.5% when the dorsal hand vein was used, compared to 2.5% when the forearm vein was used. Scott et al. [22] noted that propofol administration using the anterior cubital fossa vein is the only method that does not cause pain. 

Hannallah et al. also showed a lower incidence of pain from propofol injection in children when using the anterior cubital vein. The reason for this observation is that because the drug tends to stay in the middle of the blood flow in the large vein, the anterior duct vein is larger and the contact between the drug and the endothelium is reduced. Aspirin and other NSaids have been studied on the use of NSaids to reduce injection pain. 

Bahar et al. showed that preconditioning with 1g intravenous acetylsalicylic acid 15 minutes before propofol injection could significantly reduce the incidence of severe pain from 70% to 20%, but did not reduce the overall incidence of pain. Smith and Power[29] found that a group of patients who received 10 mg of ketorolac intravenously immediately before intravenous propofol had a similar incidence of pain as a control group who did not receive ketorolac. They believe that this is because ketorolac does not block the synthesis of local vascular endothelial prostaglandins, because prostaglandins are not important in the pathogenesis of pain, or because the effect takes longer to produce.