What happened during the first operation Paul performed when he returned to the operating room in Part 2, Section 2?

Paul's dexterity and skills were at their peak as he began his first surgery after he returned to the operating room. Suddenly the edges of his vision dimmed, and he had to turn the operation over to the attending. He had to lay down on a couch and sip orange juice as he got better. As he reviewed what happened, he realized that his spell was simply neurocadiogenic syncope or a case of nerves.