During transfer to theatre from the anaesthetic room the patient is apnoeic and there is a brief interruption to patient monitoring. Before transfer, therefore, ensure the patient is stable and the FRC is full of O₂.

Once in theatre, the patient is connected to the circuit, usually a circle system. The selected gas mixture (air/O₂ or N₂O/O₂) and a volatile agent are started, using high gas flows (at least 6 L/min) initially, whichever breathing system is used.

A number of manual ventilations should be given prior to transfer to the operating table.

Disconnect the patient from the circuit during transfer to the operating table to avoid accidental extubation.

Turn the ventilator on and confirm that it is functioning correctly. Adjust the ventilator settings and gas flows into the circuit as necessary.

All patients receiving muscle relaxants should be monitored using a nerve stimulator to detect when further doses of MR may need to be administered.