Vaping marijuana is not safer than smoking, and you should not vape on the day of surgery. One source says to stop marijuana products 72 hours before surgery, and another says to avoid smoking marijuana within 72 hours of general anesthesia. Smoking or vaping can also make it harder to breathe well, raise heart rate and blood pressure, and increase airway swelling, which can make anesthesia and breathing tube placement harder. Quitting smoking or vaping at least four weeks before surgery can also help your lungs and recovery. Verify the exact plan with your surgical or anesthesia team in case they want something different for you.