You will need some volunteering over the course of your college career if you intend to apply right out of college. In my opinion, everyone should be able to average 1 hour of service in their local community per week over 156 weeks (three years between HS graduation and the time you apply as a rising college senior). If you have volunteer hours, either clinical or non-clinical, from some other activity, go ahead and drop the hospital. However, consider that you give pre-meds a bad name because the hospital invested resources (employee time, training materials, etc) and that has all been a waste.