The effect of temperature upon pain during injection of propofol.

Propofol has been shown to cause pain on injection. This study investigated the effect of warming propofol to 37 degrees C on the pain of intravenous injection. One hundred and one women on outpatient gynaecology lists were allocated to receive propofol either at room temperature or at 37 degrees C. Warming propofol decreased the incidence of pain on injection by 37% (p < 0.001), and also decreased the severity of pain reported by patients (p < 0.001). We conclude that warming propofol to 37 degrees C provides a simple and safe method of reducing the incidence of pain on injection without the addition of other agents.