the use of a drug or other means to make someone calm or to make them go to sleep

Sedation is often given to allow a patient to be comfortable during a surgical or medical procedure. 病人在接受手术或其他医学处理时，通常会给予镇静剂使之感觉舒服。

She's under strong sedation and should not be disturbed. 她服了强效镇静药，不宜被打扰。