This piece was written by one of our contributors; consultant anaesthetist – Anna Williams.
You couldn’t fail to be alarmed at times by the representation of labour and delivery so often depicted in the media, television drama series or documentaries. For many women, the delivery suite is likely to be their first encounter with the medical speciality of the anaesthetist. Our role on a delivery suite is to provide advice and our practical skills to facilitate effective analgesia, provide anaesthesia for any obstetric cases that require theatre intervention, or provide additional medical advice and management for any women on the delivery suite requiring an extra level of medical input.
One of the most common interventions an anaesthetist carries out on the delivery suite is inserting an epidural for labour analgesia. An epidural is a type of regional anaesthetic whereby a very thin, flexible plastic tube is inserted in between the bones in your spine towards the bottom of your back, where pain killing drugs can be given. The plastic tube lies very close to the nerves in your back and blocks the nerve messages associated with pain. Most often on the delivery suite a combination of an opioid analgesic called fentanyl and a local anaesthetic agent.
The epidural can be put in once your labour has started, and the key to insertion is often getting you in the best possible position. The anaesthetist will work around your contractions, as these won’t conveniently stop whilst the epidural is being put in! If one hasn’t already been inserted, you will need a drip (cannula) inserted, before getting into the correct position. This is either with you sat up curled over a pillow, and your bump! Or lying on your side with your legs pulled up to your chest.
The epidural needs to be inserted under sterile conditions, so the anaesthetist will often be wearing a gown, gloves, hat and mask, and will clean your back with an antiseptic before placing a clean drape over the area. After the antiseptic has dried, the anaesthetist will inject a small amount of local anaesthetic to numb the skin surface. A different, longer needle is used to place the plastic tube into the epidural space in your back, the needle is then removed, and the plastic tube is left behind. This is can then be connected, via a sterile filter to the infusion bag containing the local anaesthetic. In some units this will be continuously and safely injected into the tubing. Other places use a device called a PCEA which is a ‘patient controlled epidural analgesia’, whereby you press the button to administer the local anaesthetic.
The aim of the epidural is not to make you entirely numb, often women still feel the sensation of the tightenings and contractions, but not to the same extent or intensity as without the epidural. Often you will have a catheter put into your bladder to drain away your urine. Despite these often being low dose infusion bags, sometimes your legs may feel heavy, your midwife will keep monitoring you throughout your labour and delivery.
Most commonly, epidurals are inserted for analgesia based on maternal request, but there are other circumstances when epidurals are preferred for medical reasons, this can include if you have a diagnosis of pre-eclampsia, multiple pregnancy (twins or triplets) or if you need to be induced for your labour to start. There are reasons when epidurals may not be the right choice, these would include:
- if you have abnormal blood clotting, or having been on certain medications to thin your blood or prevent blood clots
- if you have a local infection or sepsis, then the anaesthetist, with yourself and the rest of the team would have to weigh up the risks and benefits of inserting the epidural
- it may be that an alternative form of analgesia needs to be offered
Sometimes the epidural may not work as well as we would like it to, and in those cases the anaesthetist will try a number of manoeuvres to improve it, however there a group of patients for whom we never get it working optimally. A side effect that can occur is a headache, this is often quite severe in nature. It is called a post-dural puncture headache and can occur in between 1 in 100 and 1 in 500 procedures.
Injury to nerves in the back is a rare complication of an epidural injection, any nerve damage is usually temporary and improve over days, weeks or months. Only very rarely is there permanent injury, in the region of 1 in 23,500 to 50,500.
For some women, they may have to visit the operating theatre as part of their pregnancy and delivery, whether that is:
- for an elective or emergency caesarean section
- after delivery for a repair of a tear
- for manual removal of a retained placenta
Most often, these operations are done under a ‘spinal anaesthetic’, another type of regional anaesthetic. Occasionally, because of contraindications to a spinal anaesthetic, or due to the emergency of the situation, you may have to go off to sleep and have a general anaesthetic.
A spinal anaesthetic is one where we do an injection into your back, into the fluid that bathes your brain and spinal cord, which then leaves your lower half of your body numb, but you stay awake for the procedure. The benefit of this is your birthing partner can also be present if you are having the spinal for a caesarean section, and you will be awake to see and hold your baby straight away, if you wish too. It also means you avoid the side effects of a general anaesthetic, and the spinal provides excellent pain relief for a good number of hours after the caesarean section.
To site the spinal anaesthetic, the anaesthetist will get you into the same position as for an epidural. Once the injection is done, often people describe pins and needles and a warm sensation in their feet, this is entirely normal. After a few minutes, your legs will get increasingly heavy and feel numb to touch. Once the injection is fully working, you will be unable to lift your legs up and will not feel any pain in the lower part of your body. You will likely still feel the sensation of touch and pressure, but no pain associated with that. Lots of women have said to me, ‘it feels a though someone is washing up inside me’, but it should not be an unpleasant sensation. The anaesthetist will do a range of tests so check how high up the numbness has gone, before they let the surgeons start.
There are side effects and potential complications, as with all medical interventions. Very common side effects include low blood pressure, which may make you feel dizzy or sick, the anaesthetist will treat this with fluid or a drug to increase your blood pressure. Sometimes people can feel very itchy, and often that’s because of the type of pain-killing drug that is added to the mix injected into your back. As with an epidural, a post-dural puncture headache is a risk.
If during the siting of the spinal anaesthetic you experience pain other than where the needle is, such as shooting pains travelling down a leg, you should voice this to your anaesthetist, if may be because the needle is close to a nerve. Those sensations will then pass, when the needle is repositioned.
Occasionally, if you had an epidural sited for labour pain relief, and it has been working well, the epidural can be topped up with a more concentrated version of the local anaesthetic, should you require an intervention in theatre such as an emergency caesarean section or a post-delivery procedure. The anaesthetist will carry out the same checks, as they would with a spinal anaesthetic, ensuring the pain relief is adequate before allowing the surgeons to start. If the epidural top up is not adequate to continue to start the operation, the epidural can either be pulled out, and a spinal anaesthetic given, or you will be put to sleep and receive a general anaesthetic.
For a group of patients, a regional anaesthetic technique such as the epidural is contra-indicated. For those women, that want something more than the Entonox, ‘gas and air’, many units offer a Remifentanil PCA. A PCA is a Patient Controlled Analgesia device, whereby a syringe of a drug is connected to a cannula and you administer the pain relief when required by pressing a button. These devices have the options of a lockout time or ability for a background infusion and so are very safe.
Remifentanil is a very short acting opioid type analgesic drugs which can provide effective and rapid labour analgesia. Remifentanil has rapid onset time and rapid offset time, therefore can match the timings of contractions. As with other opioids such as the intramuscular pethidine injection, it may cause you to be a little sleepy, may have a depressant effect on your breathing system, make you feel itchy, or experience nausea or vomiting. The remifentanil crosses the placenta, but evidence has shown that it is not harmful to babies. In most units, you can only have the remifentanil PCA with a dedicated midwife, and you will need to have oxygen administered whilst you have the PCA set up, your observations will be taken regularly.
For lots of women, they choose to do other routes and methods to assist their labour, including Entonox (gas and air), other analgesia such as paracetamol or pethidine, or entirely different strategies such as hypno-birthing or breathing techniques.
What’s important to remember is doing what is best for you and your delivery. No one gets a medal for doing it without any anaesthetic intervention, but also remember it’s ok if you decide to tear up your birthing plan and choose other options in the full pelt of labour!