19 yrs old male brought to ER by an ambulance following head t | sᴘᴏᴛ ᴅɪᴀɢɴᴏsɪs

19 yrs old male brought to ER by an ambulance following head trauma he lost consciousness for 1 minutes, vomited twice in the ambulance OEx : GCS/ 15, BP: 120/67 otherwise unremarkable. Best next step