Keep an eye on his blood pressure. If his pulse pressure (The difference between systolic and diastolic) starts to widen, you have some problems as this is an indication of increased ICP (intracranial pressure). Also keep an eye (pun) on his pupils as unequal, sluggish pupils are also a sign of increased ICP. Make sure there are no battle signs (bruising around the back of the ears) and periorbital echymosis. Check for otorhea. If there is otorhea do a bullseye test to check for CSF (cerebral spinal fluid) in case of a positive bullseye test, pack with sterile gauze; if the previous signs are present he more likely than not has a basilar skull fracture, and his odds of surviving are not good. From what you've described there is a decrease in his GCS. Ask him questions such like "do you know where you are?" "What's your friend's last name" "What month is it?" To check for his level of awareness. Immobilize the spine since he has had a head injury, and has signs and symptoms of increased ICP. Do a CSM (circulation, sensation, movement) test on his extremities. Do full secondary assessment to make sure he isn't hurt anywhere else. At this point, my main concern would of course be his unequal,sluggish pupils and decreased GCS since again, this is a very good sign of increased ICP and possible intracranial bleeding. You're also going to want to keep an eye on his skin to make sure it stays warm, pink and dry, and doesn't start to get pale, cool diaphoretic. And hope to God he doesn't start going into flexion, extension or trismus posturing cause if he does, he is in serious trouble. Watch out for nausea and vomiting (specially projectile vomiting; that is very bad sign). Another thing that has me thinking increased ICP is his breathing; sure it's only slightly elevated for an 8 year old whose probably frightened and anxious, but this could mean his brain is getting hypoxic (lack of oxygen to the brain). I think I'll leave it at that since I'm tired of typing. If you want more, I could go on into more detail about head injuries.