No they might interview you and ask for that information, but your height, weight and age are only used to calculate what your blood alcohol would be after drinking a certain amount of alcohol. That part is actually called a 'forward calculation'. They would use this to check if you're telling the truth about how much you drank. A back calculation doesn't use any of that, the numbers are the same for everyone. Every forensic toxicologist in the UK also uses the same numbers, as they are nationally agreed. Those are 9 mg/100mL per hour, average 19 mg/100mL per hour and max 29 mg/100mL per hour. So 8 hours after the accident with a blood level of 60 you would be back calculated to 212 mg/100mL at average alcohol metabolism, and lowest around 130, highest almost 300.
I'm afraid neither a coma nor hospital drugs would have an effect on the calculations. There are other things to consider, but from what you've described it sounds like you're looking at a conviction here.