Cox wheels a "dead lady" around and her glasses continually disappear and reappear between shots.
When JD and Dr Cox first meet, JD is asked to place an IV. He makes the attempt with a butterfly catheter. These are used primarily for blood draws and one time IV infusions. They are not used for emergency venous access.
When Dr. Cox asks the young boy to do a urine sample for him, the cup he passes him is already filled when the boy takes it into the cubicle.
In some scenes there are pieces of hair/thread visible on the camera, mainly on the bottom of the screen.
Dr. Kelso tells JD to keep a female patient on dialysis, and not put her on the transplant list, because she doesn't have insurance. In the U.S., all patients who have kidney failure and are on dialysis are eligible for Medicare, which also pays for a kidney transplant.