I'm a student nurse--
Recently there was a patient who was only a few hours post-op with a major surgery. The health issue was chronic in nature and I'm thinking the patient had built a tolerance for the pain meds. She had a PCA pump and was in a lot of pain in spite of pushing it every time she could. In fact she had pushed it over 100 times at shift change when it was being checked, and had emptied the entire syringe and was still in a lot of pain. I felt the pain was genuine, especially since the nature of the surgery was a very painful one, and she was not a drug seeker or anything. I noticed that the pt had an order for 2mg morphine IV push every hour PRN for breakthrough pain.
The nurse did not give the pt her PRN morphine. I asked the nurse what was her rationale (politely of course, in the spirit of learning) I was told that the pt had used the PCA so much that she was at risk for depressed respiration with any more morphine. The pt had rapid shallow respirations from the pain, normal HB, slightly elevated bp from her normal, and was mostly alert and oriented except for complaining of pain, had very tense muscles, was sweating, and was unable to ambulate or do cough deep breathe or anything else. I felt like if I were the nurse I would give the PRN morphine as ordered. I don't want to question this very experienced nurse, but I would like to know more about the guidelines of when to hold PRN pain meds and when to give.
I have been taught that resp rate lower than 12 to hold, but this pt was nowhere near that.