“Chicago Trauma” (Nat Geo Channel, 10pm) is better than good – it’s bordering on great. Yet, it is so extremely graphic that it may be too difficult to watch.

The show takes place at the trauma center at Chicago’s Cook County Hospital. This isn’t the emergency room. The ER is for relatively mundane emergencies. The trauma center takes brink-of-death cases, about 5,000 every year, including a lot of gang-related gunshots and stabbings.

As soon as “Chicago Trauma” begins, your heart is racing. It doesn’t stop until an hour later when the show ends.

Up first is a young man who has been shot in his penis – a seemingly common occurrence in gangs. Blood is everywhere and he is in excruciating pain. But his case is far from the worst on “Chicago Trauma.”

Among the others is a stabbing of a young man whose blood is drained from his body. He arrives at the hospital dead. The trauma unit surgeons scramble to revive him.

A woman arrives severely injured from a car accident. She lives but will never be the same. Another car accident victim is ripped open by surgeons – too much to watch – in a futile attempt to fix her injuries.

The cases keep coming over a 30-hour shift that surgeons at the trauma unit work twice a week.

In that way, the show is not unlike BBC America’s “24 Hours in the ER,” where cameras follow doctors on their shifts. On “Chicago Trauma,” though, there aren’t as many light moments.

“Chicago Trauma” tracks Dr. Andrew Dennis and Dr. Fred Starr as they introduce this horrific world – their lives – to young medical residents.

To watch these doctors is to marvel at their everyday accomplishments. To watch their patients, many of whom are nonchalant about gang violence, is to appreciate life more than ever.

“Chicago Trauma” is an outstanding documentary series. It’s just that watching the horrors of real life may be too much to endure.