Why was Pony so concerned whether he had asked for Darry as well as Soda when he was dazed and sleeping?

After the death of their parents, Darry drops out if school to care for his two younger brothers. Because he wants to do a good job raising them, Darry acts more like a father figure than a brother, imposing strict rules and a tough love attitude.
As a result, Ponyboy generally resents Darry, not fully aware of the sacrifices Darry has made in order to provide Ponyboy and Sodapop with a relatively stable childhood. Ponyboy also believes that Darry prefers Soda, which deepens this resentment.
When Ponyboy goes to the hospital after the church fire, however, Darry is distraught over his youngest brother’s condition. Witnessing Darry’s reaction, Ponyboy finally realizes how much his brother truly does care for him.
This is why Ponyboy worries whether he called out for Darry while he was in and out of consciousness. He does not want to have hurt Darry, whom Ponyboy now understands loves his brothers very much.