Pain Relief for Surgery:
Anaesthetists play a major role in your post-operative pain control. It is essential for your pain to be adequately controlled. By doing so we can help prevent certain post-operative complications such as blood clots (eg DVT’s), chest infections and heart attacks. With adequate pain relief, certain simple things like deep breathing exercises and early mobilisation can result in a speedier recovery – getting you home sooner.
There are many forms and modalities of pain relief. These vary from simple painkillers, to intravenous medication, to epidurals, spinals and nerve blocks. These are briefly discussed below.
Your anaesthetist will cater your pain relief to your individual needs depending on your procedure, your pre-existing health and their personal experiences.
If you have any further questions about any of these topics, please discuss with your anaesthetist.
(1) Tablets/”Simple” painkillers.
There are multiple forms and types of tablet/capsule painkillers currently available. Sometimes these have only one “ingredient” (eg panadol contains only paracetamol), or they are in combinations (eg panadeine forte contains paracetamol and codeine). Often patients will be prescribed a combination of painkillers to take post-operatively – for example paracetamol and ibuprofen taken regularly, with oxycodone (AKA endone) to be taken as required. Combination therapy often works better than a single medication. Of course, every individual case (by definition) is different, so please be guided by your anaesthetist.
Every different “class” of painkiller has a unique action and side effect profile. The following are only potential side effects, and not all possible side effects are listed, so please enquire further if you need more information.
Possible side effects:
- Anti-inflammatory medication: stomach irritation, worsening asthma, worsening kidney problems
- Opioids like codeine and oxycodone: drowsiness, itching, constipation
- Tramadol: delirium, nausea and vomiting
(2) Morphine and related opiates.
There are various opiate medications used for your pain relief during and after your surgical procedure. They work on similar pain ‘receptors’ but have slightly different properties. Morphine, pethidine, fentanyl, alfentanil, hydromorphone – are all members of this group. They are very strong and effective painkillers, but have a number of side effects. These side effects include nausea, confusion, drowsiness, altered breathing patterns, itching and constipation. Due to these side effects, patients receiving these medications must be monitored closely during their hospital stay.
A common way these medications are administered to patients post-operatively is a technique called Patient Controlled Analgesia or PCA. You are given a button, which is connected to a pump, which in turn is attached to your intravenous (IV) drip. The pump contains the pain medication (eg morphine in solution). When you press the button (when you are in pain), you receive a small IV dose of prescribed painkiller from the pump. You cannot receive ‘too much’ medication, as the pump locks-out for a set amount of time (usually 5 minutes). This is a very effective way of controlling your own pain.
At other times your dose of opiate is administered on a ‘as required’ basis. Again, this is a decision made by your anaesthetist, so feel free to discuss these topics prior to surgery.
(3) Epidural and Spinal Anaesthesia
Occasionally, your anaesthetist will offer you an epidural or spinal for your pain relief. A spinal involves a single injection between the bones of your lower back. Once the right space has been found (the space containing spinal fluid surrounding the nerves) a small dose of medication is injected rendering those nerves numb for a period of about 2-3 hours. An epidural involves inserting a fine plastic tube via a needle in the back into a space called the epidural space. Pain killing medication (usually a combination of local anaesthetic and an opioid eg fentanyl) is injected through the catheter to bathe the nerves making them numb. Epidurals effectively numb the nerves at their origin from the spinal cord to provide you with excellent pain relief. However, there are a number of side effects that are important to know about:
- Low blood pressure, usually treated with intravenous fluids.
- Weakness of the legs rendering it difficult, but not impossible, to walk (with epidurals only).
- Severe headache can occur with a risk of approximately 1 in 200.
- Damage to nerves: This individual nerve fibre damage can be temporary (1 in 1,000) or permanent (1 in 10,000). Temporary nerve damage recovers within a period of months. Potential of paralysis is extremely rare (1 in 100-200,000) but has been described.
(4) Nerve blocks
Anaesthetists can ‘block’ or ‘make numb’ individual nerves or groups of nerves to create a painless field prior to an operation. It involves an injection of local anaesthetic near the nerves to be blocked. An ultrasound machine is often used to improve accuracy, but is not essential. Nerve blocks are commonly used for operations on arms, hands, shoulders, knees, hips and feet.
Nerve blocks can provide excellent pain relief, but they also render the limb completely numb and weak. This usually lasts from 4 to 24 hours depending on the medication used.
Risks involved with this form of pain relief include damage to the nerve from direct trauma, infection or blood clot – but all these risks are relatively rare. Permanent nerve damage can occur in these circumstances.
If you have any further questions regarding pain relief, please browse the patient information sheets on the website and please, discuss your queries with your anaesthetist.