My mom was 89 years old and had dementia. she yelled a lot. she was enrolled in a state hospice and the home nurse used to give her 1/5 of a quarter tsp morphine, every two hours, as needed. she died two days later. was morphine the reason?

Unlikely: Would need to know why morphine was prescribed. At this dose unlikely to be a cause however. Sorry for your loss.

Pain: Your mother might have had pain and that is why she was yelling out. Morphine is very effective in treating pain very likely it was the reason why she died.

Hard to say: All those enrolled in hospice are close to death. The goal of hospice is to relieve suffering as one goes through the dying process. Calling out in those with advanced dementia often represents pain. In this case use of low dose morphine is often indicated. For specific answers about your mom contact her hospice team.