I Have A 5 Year Old That Is Autistic And

I have a 5 year old that is autistic and he had and episode of eyes rolling back in head at school and became pale His CT came back clear, his UA was clear but some of his labs came back high... He had another episode today but his mood remained good. Just trying to understand what we should be looking for exactly with him we are to follow up ped neurologist asap but until we get in what should we do?