Hemoglobin of 4, Internal Hemmorhaging

My stepdad is in the hospital with internal hemorrhagin. He is in end stage liver cancer and his blood vessels in his stomach and esophagus are enlarged and bleeding. He had a procedure done to stop the bleeding on Monday, but last night started bleeding again. Yesterday his hemoglobin was at 12, then 9, then 7, then 6 and now it is at 4.

We are not getting any clear answers from the doctors about what this means. I assume this is extremely serious since he should be around 12. He has been waiting for an ICU bed since Sunday. I am wondering how much lower his hemoglobin can fall before his body completely shuts down. I found one site that said the body will usually go into a coma at a level below 4. Does anyone know about this?

Thanks for any help you can offer.