'They're Pretty Sure This Is It': Khloé Kardashian Forced to Make Medical Decisions for Lamar, Source Says
updated 10/15/2015 AT 12:20 PM EDT
•originally published 10/14/2015 AT 06:50 PM EDT
"They're pretty sure this is goodbye, but they're praying for a miracle," a source close to the family tells PEOPLE. "They know that God has the power to heal him, but that's really the last hope at this point. This is really bad."
Estranged wife Khloé Kardashian has not left Odom's side since rushing to the hospital where he is being treated. Kim Kardashian West and Kris Jenner have also rallied around the former basketball player, and Kardashian, 31, arranged for his two children from a previous relationship to fly out from New York.
Though Kardashian and Odom, 35, both signed divorce papers in July, a judgement has not yet been entered into court, meaning they are still legally married – and the reality star is in charge of his medical care, PEOPLE has learned.
"He never signed a living will, so Khloé is making decisions for him," the source says, adding it's "very stressful. She is lost."
The couple wed on national TV in September 2009. The marriage fell apart after Odom's very public cheating scandal and drug relapse, and Kardashian filed for divorce in 2013.
A source told PEOPLE that doctors found cocaine and opiates in Odom's system and that he has had "a couple strokes" in the hospital.