Midazolam has been used in rapid sequence intubation for a long time, and the recommended dose is 0.1mg/kg. In some studies, however, the reduced dose has been used with the concern of hemodynamic instability. We would like to investigate that the low dose midazolam could be used rather than the standard recommended dose, and also compare it to the etomidate, recently used sedatives, with respect to the side effects and the easy performance of intubation.