An asthmatic patient is taken into the OT for removal of a tumor from colon. Which of the following anaesthetic agent is preferred in this patient?

Ventilatory drive is minimally affected by induction doses of ketamine, although rapid intravenous bolus administration or combinations of ketamine with opioids occasionally produce apnea. Racemic ketamine is a potent bronchodilator, making it a good induction agent for asthmatic patients. Ref: Butterwoh IV J.F., Mackey D.C., Wasnick J.D. (2013). Chapter 9. Intravenous Anesthetics. In J.F. Butterwoh IV, D.C. Mackey, J.D. Wasnick (Eds), Morgan&Mikhail's Clinical Anesthesiology, 5e.