Patient-controlled analgesia (PCA) is a method of pain management that allows you to decide when you will get a dose of pain medication. In some situations, PCA may be a better way of providing pain relief than calling for someone — typically a nurse — to administer pain medication. You don't need to wait for a nurse, and you can get smaller doses of pain medicine more frequently.
With this type of pain treatment, a needle attached to an intravenous (IV) line is placed into one of your veins. A computerized pump attached to the IV allows you to release pain medication by pressing a hand-held button.
PCA can be used in the hospital for pain after surgery or for painful conditions like pancreatitis or sickle cell disease. PCA is also effective for people who cannot take medications by mouth. PCA can also be used at home by people who are in hospice or who have moderate to severe pain caused by cancer. Children as young as age 7 can benefit from PCA if they understand the concept behind the PCA and can follow instructions. But people who are confused, disoriented, or unresponsive cannot use PCA.
How PCA works
If your doctor prescribes PCA for you, the pain reliever delivered through the pump will most likely be an opioid, such as morphine or hydromorphone (Dilaudid).
This is what you may expect if a PCA is prescribed for you:
Your doctor will decide on a starting dose of the pain medication. He or she will also figure out how much medicine you will get each time you press the button, how much time there should be between doses, and the total amount of medication you will get over a certain period of time, all to keep you from getting an overdose. A low dose of pain medication may also be injected continuously to establish a base level of pain control. All these specifics will be programmed into the pump, and the pump will record all the times you press the button and how much pain reliever you are given.
A nurse will make sure you understand how to use the PCA machine.
Between doses of pain medication, IV fluid may flow into your vein to keep it open and keep you well hydrated.
Your vital signs and oxygen levels may be checked by monitors at your bedside.
When your pain lessens, you may be switched to a pain medication taken by mouth.
Risks of PCA
PCA is safe and effective. The main risk is having a reaction to the opioid medication. Side effects from opioid include an allergic reaction, nausea or vomiting, low blood pressure, sleepiness, constipation, or difficulty breathing. Difficulty breathing, called respiratory depression, is the biggest danger. People who are elderly, have asthma or other lung problems, are obese, or have sleep apnea should be monitored carefully for difficulty breathing, as should people who are not used to opioids or who require high doses for pain relief.
If used properly, PCA may actually reduce the risks associated with opioids because you are less likely to be over- or undertreated. Make sure that you are the only one who pushes the button for pain relief. If friends or family members also push the button in an effort to help, there is the danger that you might get over-sedated and have trouble breathing. Also, your medical team should explain to everyone that you do not have to push the button as often as permitted: You only need to press it if you need pain relief.