Being in a coma means that your son is in a very deep state of unconsciousness that can last anywhere from a day up to a year and beyond. While your son is in a coma he will not be able to open his eyes or speak to you. Also, depending on how longer your son is in a coma the more likely it is that he will have some type of permanent brain damage.
I know that these things can be hard to hear, especially when it is your own child. But in this case it is imperative that you speak with a Washington personal injury attorney as soon as you can to be able to get the best possible settlement from the insurance company. You will need to get a guardian appointed to file a claim on behalf of your son and the claims process will likely be very long and difficult.