The time it takes to do each of your IVIG's depends on the instruction that your doctor has provided to the person giving you the treatment, as pump pressure has a large part to do with the time it will take. Some prescribe starting off slow, and gradually ramping up the pressure every half hour. Particular care is taken, particularly on the first infusions, to prevent possible side effects like nausea, headaches, rash, and in general flu like symptoms. I wouldn't definitely plan on returning to work that day, as you will really have to see how your body adjusts to the infusion. Take it slow and easy, until you know how it goes, and if you have any side effects. The real secret is to hydrate at least two days before, keep hydrating during, and then for up to a week afterwards.