The invention relates to sterile pharmaceutical compositions for parenteral administration which comprise an oil-in-water emulsion in which a free radical scavenging sedative agent dissolved in an omega-3 rich water-immiscible solvent, is emulsified with water and stabilised by means for a surfactant, the composition being suitable either directly or after dilution with a liquid diluent for parenteral administration to a warm-blooded animal; in particular to such compositions comprising propofol, and which optionally further comprise a metal ion chelating agent (such as edetate), and the use of such compositions in improving survival in critically ill patients.