She wrote simply, "Please don't go."
Kendall is most likely getting updates from her family members. Khloé, Kim, and mom Kris all rushed to Desert View Hospital once they learned about Lamar's condition.
The 19-year-old is not present in Nevada since she is working in China for Shanghai Fashion Week.
Odom is reportedly in a coma after he was found unconscious at Love Ranch South, a legal brothel in Crystal, Nevada, on Tuesday.