Hospital beds in nursing home.

My mother is 92 years old, and she lives in a nursing home. My mother is complaining that the hospital bed is not comfortable. They have changed and provided her with a new hospital bed, but she is still complaining. We have gone out and purchased a mattress topper and mattress pad, but the staff has rejected both of them. They said what we purchased was rejected because sometimes she wet her bed, and they need something they can easily wipe and sanitize. My question is "Does anyone know what else we could put on her bed where she can be comfortable in, and the staff can wipe down easily and sanitize?"Thanks.Ann