The PCA is an infusion pump that connects to an access port (normally in the back of your hand) that will have been sited prior to surgery for delivery of medication during your operation. This system allows a pain relieving drug, normally an opiate such as morphine, to be effectively dosed and delivered directly to the vascular system for rapid effect. We use it in tandem with a Patient Controlled Epidural Analgesia (PCEA) which is discussed further here.

The PCA can be seen above with the main control panel, syringe driver and ‘top-up’ button clearly visible. The opiate is appropriately dosed within the syringe and the PCA programmed to deliver a set volume. We can deliver this drug in two ways: 

 

1) Background doseage - this is a low level continual dose that dampens down pain but may not be sufficient where activity such as physiotherapy is undertaken

2) Bolus - This is in essence a ‘topup’ if the backgroud dose is insufficient at any time

 

The real benefit to patient controlled pain delivery systems are that they allow you a degree of control over both your levels of pain and the amount of drug that you have. The bolus system is operated by a small hand held button that you can see at the top in the picture above. When depressed, a pre-set doseage of morphine will be given and the effects felt within a few minutes. A lock out time is always set to prevent any overdosing which when using such potent drugs can have significant implications. Opiate drugs work on a specific receptors found in the brain and on the spinal cord that control pain. It is what we call an antagonostic drug, that is, it sits in the receptor site and blocks other chemicals which stimulate or heighten the pain response. Because of this the relief is felt as a total effect, that is everywhere will be effectively pain surpressed. This is different to the PCEA where the area of relief can be controlled by varying placement within the spinal canal.

Many people are adverse to the use of opiates, commonly Morphine, when addressing their pain. Many are worried about the side effects and the risks of addiction. All drugs possess side effects and the most common for Opiates are nausea, vomiting, itchiness and drowsiness. If you do experience these please do tell the staff as a simple medicines such as anti-emetics (anti sickness) can be administered and are generally very effective. The issues of addiction in these situations are very over exaggerated. If you have real acute pain for which you are taking the Morphine, the potential for addiction is minimal and its benefits far out way this risk.

Simple methods will be regularly used to measure your levels of pain. The most common is that of a 0-10 pain scale. You will be asked to represent your levels of pain with ‘0′ indicating no pain and ‘10′ the worst pain you can imagine. The anaesthetists can then titrate (change proportionally to your pain) the doses of drug that are given. You should aim to have a pain level of no more than around 0-4 prior too ,and during, light mobilisation.

Your anaesthetist will normally run through the workings of the PCA during your pre-op checks, enabling you time to absorb the information and ask any questions should they arise. Any variations specifically intiated by your anaesthetist will supercede any of the above information, and should be strictly adhered to.