<prompt> Pain is caused by injection ofKetamineMethohexitoneDi-isopropyl alcoholThiopentone  <response>: Ans. is d i.e., Thiopentone Thiopentone is an ultrashort acting Barbiturate.It is usually given intravenously to achieve rapid induction of anaesthesia.Inadvertent intra-arterial injection or extravasation of Thiopentone leads to thrombosis and necrosis. This produces intense pain. 