Leave Related to Critical Illness

Hello, 
Recently in Manitoba a new leave came in to place- the Leave Related to Critical Illness. I am having a hard time seeing how this leave differs from the compassionate Care Leave. I understand that the length of time for the leave is different, but am not sure when an employee would go on one leave vs. the other. 
At first, it seemed like Compassionate Care Leave was when someone was most likely to pass within 26 weeks, and that critical illness was not necessarily an imminent passing. However, Manitoba Employment Standards website is defining Critically ill child/adult as: a person 18 years or older (or not if a child) with a life-threatening illness or injury. 
Any clarification would be much appreciated.