My Husband Had A Heart Attack And Went Into Cardiac

My husband had a heart attack and went into cardiac arrest with CPR for 60 minutes. He has been in ICU for 2 weeks now. He is still on the ventilator and tube feeding. He wakes up and looks around but I do not think he is actually aware. He does not respond yet to commands like squeeze my hand, but there is occasional movement. What is a reasonable length of time to wait to see any kind of response before I move him to the comfort stage?