The “Six Days Seven Nights” actress is not expected to survive, her family has said, after a car crash earlier this week left her vehicle engulfed in flames.
Anne Heche, 53, remains in a coma and has “a severe anoxic brain injury,” they said as a result of being deprived of oxygen.
“We want to thank everyone for their kind wishes and prayers for Anne’s recovery and thank the dedicated staff and wonderful nurses,” the family said.
Her car crashed into a two-storey home in Los Angeles last week.
Police said on Friday that preliminary blood tests have revealed the presence of drugs in her system – but extra testing was needed to rule out any substances given in hospital.
The Los Angeles Police Department told PA news agency the incident was being investigated as a felony driving-under-the-influence traffic collision.
The mother-of-two has featured in films including “Donnie Brasco”, “Cedar Rapids”, “Volcano” and the 1998 “Psycho” remake.
Heche has also appeared on “Dancing with the Stars” show.
She is also the former partner of US talk show host Ellen DeGeneres.
According to the LA Fire Department, Heche’s vehicle “erupted in heavy fire” after it was driven 30ft into a two-storey home, leaving the property “uninhabitable”, the BBC said.
She is being cared for at the Grossman Burn Center at West Hills hospital and is on life support to determine whether her organs are viable for donation, her family said in their statement.
