- Morphine lowers the breathing rate in the brain’s respiratory center. This means the heart doesn’t have to work so hard to supply blood to the chest muscles for breathing. It reduces excessive breathing drive.
- Morphine widens blood vessels in the arms and legs. Pooling blood in the extremities reduces the amount of blood that returns to the heart. This means the heart doesn’t have to pump as often—it can rest more. When the heart doesn’t have to pump so hard, it also needs less oxygen—so the resident doesn’t have to breathe as hard.
- It eases anxiety, and when a resident is less anxious, he or she will breathe more calmly. If you breathe more slowly, you are less anxious.
- When we are in pain, we tend to breathe faster and harder. So relieving pain also reduces respiratory rate.
But if we don’t know how opioids like morphine, fentanyl, Vicodin or Dilaudid work, we may mistake initial responses. If an opiod is new to a person, he or she may be sleepy for the first 2 or 3 days—especially if they have not been sleeping well (maybe because of shortness of breath or pain). When symptoms are relieved, the resident may want to “catch up” on sleep. After a few days, the sleepiness wears off.
At the end of life, morphine is the most important medicine for providing comfort to heart patients. It reduces the breathless feeling that can be so frightening to people at the end of life.