CA-2 here. As a general rule, I do not read in the OR. Now, once in a while, I might check my work e-mail or skim an article someone gave me or open up the little Anesthesia Handbook a drug that I'm using. But I do not sit there with textbooks ever for a variety of reasons.
1. You're taking care of a patient. Think about what kind of anesthesiologist you would want taking care of you if you or your family member were that patient.
2. At this point in my training, I'm still perfecting my technique of timing and learning what to expect with different types of surgeries and surgeons, esp. now that I'm on peds. I can't 100% predict the surgery, and I need to pay attention.
3. Unless you just have one long case in your OR, there's generally stuff to be doing to get things moving faster later in the day like drawing up your reversal agents, drawing up your zofran, getting tubes and blades ready for the next case, etc.
4. If the patient moves or coughs during surgical stimulation and the surgery team looks over and sees you reading, you look really unprofessional. These things happen sometimes, esp. if you're running someone on the lighter side for whatever reason. But it's much more forgivable if you're actively engaged in the case.
5. Your anesthesia attending should be coming in and out of the room frequently at this stage in the game. You really want them to catch you reading something else?