Happy Birthday Supernoodle!
After the shock of hitting the wall began to wear off, Dean realised he was having trouble breathing. A lot of trouble. In the few moments that passed before Sam was at his side, he had slipped comfortably into the arms of unconsciousness.
After laying his brother out flat on his back, Sam checked Dean's pulse – or rather, he tried to check Dean's pulse – but he couldn't find one. Choking back rising panic, he numbly started CPR. After what seemed like hours, but was in fact mere minutes, Dean started to breathe again. It was only then Sam noticed the bleeding…