Patient education: Patient-controlled analgesia (The Basics)

What is patient-controlled analgesia? — The word "analgesia" refers to pain relief. Patient-controlled analgesia ("PCA") is way to let a person give themselves certain pain medicines when they need them.

With PCA:

●The pain medicine is in a computerized pump connected to an IV (a thin tube that goes into a vein). When you push a button, a dose of medicine is given to you through your IV (figure 1).

●Sometimes, the pump is connected to an epidural catheter, which is a tube that goes into the lower back. This is called patient-controlled epidural analgesia ("PCEA").

Who might use PCA? — PCA can be used to treat many kinds of pain. Doctors often give a PCA pump to a person when they are in the hospital and have pain:

●After surgery

●Related to cancer

●Related to sickle cell disease

How does a PCA pump work? — The doctor orders the type and dose of pain medicine based on the cause of your pain. This also depends on any health conditions you have, other medicines you take, your age, and your weight. The pump is programmed based on the doctor's orders. Then, it is connected to your IV or epidural catheter.

The pump is set to:

●Give a specific dose of medicine when the button is pressed

●Have time limits for how often it will give a dose

When you are feeling pain, press the button. Then, the pump releases a safe dose of medicine that your doctor has prescribed. Most of the time, doctors prescribe medicines called "opioids" through a PCA. These are strong pain medicines that include morphine and hydromorphone. The medicine begins working quickly, usually within minutes.

Tell your doctor or nurse if you have trouble pushing the button.

How often can I have a dose of pain medicine? — You can push the button whenever you feel like you need pain medicine. But the pain medicine can only be released from the pump as often as your doctor programmed. This is called a "lockout" period. For example, if the time limit between doses is set for 10 minutes and you press the button less than 10 minutes after your last dose, no pain medicine is given. This is a safety measure to keep you from overdosing on pain medicine.

What are the benefits of using PCA? — People who use PCA like having better control over their pain. There is often less of a wait time from when you start to feel pain and when you get the medicine. You do not have to wait for a nurse to give the medicine. It's also less likely that you will get the wrong dose.

The pump also keeps track of how much medicine was given and how often. There are programmed safeguards so that you won't overdose.

What are the risks of using PCA? — Using a PCA pump is a generally safe way to get pain medicines. But the kinds of medicines used for PCA can still have side effects. For example, they can slow your breathing. This risk is higher in people who already have a breathing problem such as COPD or sleep apnea. To prevent problems, the doctors and nurses will check your vital signs often while you are using PCA. Vital signs include your blood pressure, heart rate, and blood oxygen level.

Other common side effects of opioid pain medicines include:

●Feeling dizzy or sleepy, or having trouble thinking clearly

●Feeling itchy

●Nausea and vomiting

●Constipation

●Urinary retention

Tell your doctor if the PCA is not relieving your pain or if you are having any side effects. They will treat your side effects and might adjust the pain medicine.

How long will I need to use PCA? — This depends on how much pain you have and why you are having it. When you need less pain medicine, your doctor will usually give you a different medicine that you can take by mouth.

Your doctor or nurse will work with you to make sure that your pain is treated properly.

More on this topic

Patient education: Managing pain after surgery (The Basics)
Patient education: Managing acute pain at home (The Basics)
Patient education: Anesthesia (The Basics)
Patient education: Questions to ask if you are having surgery or a procedure (The Basics)