Here is a link to the CDC guidelines on laundry in health care facilities. I hope this helps
https://www.cdc.gov/infectioncontrol/guidelines/environmental/background/laundry.html
The key points are:
- contamination from dirty laundry is very rare
- dealing with getting the dirty linens to the place where they are washed is more important than the actual washing process
- a pre-rinse, plenty of soap, ordinary bleach, and a good rinse, often an acid one, is all that is needed. Hot water (160 F) also helps.
Items that are not sheets (eg surgical gowns) may also be autoclaved.
Note: this article is concerned with the issue of contamination and not with how patients and their families might feel if they saw a stained sheet.