I liked Marie as a character. I enjoyed learning more about anethesiology as a career - it's much more complex and interesting than I imagined it was. It's also interesting to read about the workings of a hospital when it comes to malpractice. I believe as a doctor, Cassella must know these situations fairly well, even if she's never been sued herself (or maybe she has, I don't know), so I took this part of the story pretty literally. Being sued seems like a somewhat lonely position for a doctor, however you're also part of a "club" because so many doctors get sued at some point in their life. I also liked the side story of Marie's sister and father.
However, I'd say the book is just OK. I felt it was a little too long, a little too much about the case (the reader could get the idea in half as many words, I think). The book was also fairly predictable. I figured out the ending after reading just a few pages, and it just wasn't that satisfying of an ending, really. It all kind of added up to an episode or two of ER, which isn't bad necessarily, just not completely fulfilling or all that compelling.