How To Cure Vomiting Sensation After Having A Head Injury?

my brother got hit in the head with a baseball running from 1st base to 2nd base, he had a helmet on but they are not padded very well. about 2 hours later he started throwing up, 5 times from 9pm to 7am. Now he cannot keep anything down, food or water. He feels better after he throws up...should we take him into the doctor or the emergnecy room?