Kris Jenner and Kim Kardashian West have ''dropped everything'' to support Khloé Kardashian, as Lamar Odom continues to fight for his life.

The 'Keeping Up with the Kardashians' star, 31, rushed to be by her ex-husband's side in Las Vegas after he was found unconscious at a Nevada brothel from an alleged ''overdose'' yesterday (13.10.15), and her mother, 59, and pregnant sister, 34, have cleared their schedules to rallying around after being advised his condition is ''extremely serious.''

A source said: ''Everyone has dropped everything to get there. There are a lot of calls and texts going back and forth as everyone is figuring out how they can help and be there for each other. They are asking their close friends to pray for Lamar, for healing and strength. There is confusion about his condition, and they don't know the extent of his injuries, but I'll tell you this: they wouldn't just drop everything unless it was serious. The family has been told that this isn't just a minor thing; that it was extremely serious.''

While Khloé filed for divorce from Lamar, 35, in December 2013 after four years of marriage following months of rumours he was addicted to crack cocaine and cheating on her, she continued to ''check in'' on him because she was concerned for his welfare.

The insider told ''Khloé was very hurt by Lamar, but she never got to the point where she hated him or was indifferent to him. She wanted him, and still wants him, to pull it together and live a happy life.

''Everyone is very upset. They know that Lamar has his demons, but the fact is that he was a very important part of Khloé's life for so long, and she's very upset about this. They all are.''