I was doing a water change, and he managed to swim into the siphon. He is too big to get sucked in, but he managed to get his face stuck in the hose. I was doing dishes while the tank was draining, and I look over there and see him stuck. I quickly freed him... his face was all swollen and his lips engorged with blood... he was floating upside down for a while, and barely breathing. He is right side up now, but still very out of it... I know this accident could have been prevented if I paid more attention, but is there anything I can do to ease its pain?