[Pain-free injection of propofol].

Pain on injection is one of the well-known side effects of propofol. Previous studies have shown several methods to alleviate this discomfort. We employed all these methods together to clarity whether pain-free injection of propofol was possible. Sixty adult patients premedicated with midazolam were studied. Control group patients (n = 20) received an induction dose of propofol via a vein on the dorsum of the hand at a slow injection speed with carrier i.v. fluid. Study group patients (n = 40) received i.v. fentanyl 0.1 mg, followed by bolus injection of cold propofol premixed with lidocaine (final concentration of lidocaine was 0.2%) in a forearm vein without carrier i.v. fluid. Eighteen patients (90%) in the control group experienced injection pain. In the study group, however, no patients complained of pain or discomfort. In conclusion, pain-free injection of propofol was possible when prior-administration of fentanyl, premixing of lidocaine, cooling to 4 degrees C, and rapid injection via a forearm vein without carrier i.v. fluid was the adopted precedure.