Shunt Placement

Hello, I'm new to this forum and am hoping to get some answers or find someone who has had a similar experience as my family and I are grasping at straws to find out what is wrong with my little sister. To give you some background she is a relatively healthy 25 year old with congenital AVM's and mild hydrocephalus. In early 2017 one of her AVM's ruptured and she had a seizure causing her to get in a car wreck and ever since then she has been on Kepra daily. Over the last 6-8 months though her she has had uncontrollable nausea, weakening in her limbs on the left side, poor balance, worsening vision and debilitating headaches. She finally got into see her neurosurgeon who suggested placing a VPS shunt in her head that leads to her abdomen to help control the hydrocephalus. On November 8th she received this procedure woke up, was talking even cracked a few jokes. That night she had a bad seizure and fell out of bed, in hindsight her neurosurgeon probably should have had her in an ICU where they do neuro checks every two hours. The next day she was unable to talk but could move and follow commands with purposeful movement. That evening she was so restless and agitated they gave her Dilaudid for pain and it was so hard for her body to wake up from that medicine she had to receive three doses of Narcan. The proceeding days to come she was unable to talk less and less besides little words like yes, no and mom. Her breathing worsened about two days ago and she has been intubated ever since and in a very coma like state. She falls in and out of consciousness almost and they are saying that the movement she does make does not seem purposeful. She is also fighting an infection of some sort now, despite all her imaging they've done to check for bleeding, an angio to check for blood flow and an EEG to check for seizure activity the doctors have not been able to pin point why she won't wake up. She has brain activity but the doctors are calling her current state an enigma. Has ANYONE experienced something similar to this? We never would have gone through with the shunt placement if we had been made aware she could become almost comatose. We are researching and looking into everything we possibly can to find an answer as the doctors are stumped at this point. Any help anyone can provide would be appreciated.