Methods and apparatus for oxygenation and/or CO2 removal

An apparatus for oxygenation and CO2 clearance of a patient during a medical procedure involving administration of anesthesia, the apparatus comprising:

• a flow source or a connection for a flow source for providing a gas flow;
• a gas flow modulator;
• and
• a controller operable to control the gas flow modulator when the patient is under anesthesia, wherein the controller is operable to control, during the medical procedure while the patient is under anesthesia, a flow rate of the gas flow by controlling the gas flow modulator to oscillate the flow rate, and the controller is further operable to provide a varying gas flow with an oscillating flow rate comprising a base flow rate of 20 litres/min to 90 litres/min via a non-sealing nasal interface to the patient while the patient is under anesthesia, with the oscillating flow rate having at least one frequency based on a heart activity, wherein the heart activity is determined based on a sensor and/or a trachea gas flow.