PREOP - Anaesthetic Information For Caesarean Section

It is important to read this information carefully before going into labour, even if you don't expect to require a caesarean section. The purpose of this information sheet is to help you understand your anaesthetic for caesarean section. If you have any questions you should talk to your obstetrician or anaesthetist.

Currently over 25% of births are by caesarean section. Just under half of the caesarean sections performed are planned during the pregnancy; the decision to perform a caesarean section in the remainder is made during labour. The rate of caesarean section has been steadily increasing over the past 20 years and this has been associated with improved outcomes for mother and baby.

WHAT TYPES OF ANAESTHETIC ARE AVAILABLE

The purpose of the anaesthetic is to remove the pain or awareness of the caesarean section operation. This can be achieved using a general anaesthetic, a spinal anaesthetic or an epidural anaesthetic. There are times when these techniques may be used together.

GENERAL ANAESTHETIC

A general anaesthetic is given using a combination of drugs that are injected into you and gases that you breathe. It is used to make you unconscious in a carefully controlled way. Your anaesthetist closely monitors and adjusts your anaesthetic throughout the operation. General anaesthesia has been shown to be very safe for caesarean section. Although less commonly performed than epidural or spinal anaesthetics for caesarean section, it may be more suitable for patients who are very anxious, are not able to have an epidural or spinal anaesthetic or for whom a spinal or epidural is not working well. In particular, a general anaesthetic may be chosen when a caesarean section operation is of an urgent nature and time is important.

Although the mother is made unconscious, the baby absorbs only a small amount of the anaesthetic drugs and is not put to sleep by the drugs.

General anaesthetics for caesarean section are different to general anaesthetics for other types of operation. Your anaesthetist will not give you a drug to relax you before the operation, as these drugs may affect the baby. Before being put to sleep, an intravenous drip is inserted, the mother is taken into the operating theatre and given oxygen to breathe through a mask. As well, your obstetrician may prepare your skin with an antiseptic wash and put sterile drapes on and around you, before you are put to sleep.

The anaesthetic will be started by giving you an injection of special anaesthetic drugs into a vein. Your anaesthetist routinely uses an intravenous line (drip), a pulse oximeter, blood pressure monitor and an ECG during your anaesthetic.

Intravenous Line. An intravenous line or drip is a small plastic tube or cannula that is inserted into a vein. A vein is a blood vessel that carries blood back to the heart. Your anaesthetist uses the drip to give you drugs or fluids during and after your anaesthetic. Risks associated with an intravenous drip include pain and bruising at the insertion site that usually resolves in a few days and infection.

Pulse Oximeter. A pulse oximeter is a small peg that your anaesthetist places on your finger, toe or earlobe to monitor your pulse and the oxygen level in your blood.

Blood Pressure Monitor. Your blood pressure is monitored via a cuff placed around your upper arm. The cuff can be inflated either manually or automatically in order to measure your blood pressure .

ECG. An ECG, or electrocardiograph, monitors the electrical activity of your heart. It is not invasive and small electrodes or leads are connected to sticky patches that are placed on your chest and limbs. Your anaesthetist uses the ECG to monitor the rate and rhythm of your heart. An ECG also provides information about whether enough oxygen is getting to the heart, past damage to the heart and how well your heart is functioning. The only side effect of an ECG may be some skin irritation from the sticky patches.

Your anaesthetist understands the importance of looking after your wellbeing very carefully during your procedure and remains with you during your whole anaesthetic. In Australia an aneasthetist only cares for one patient at a time. Your anaesthetist uses sophistocated equipment to monitor you during your anaesthetic. This equipment is used to measure your breathing, oxygen level, blood pressure, heart rate, heart rhythm and the level of anaesthetic. Your anaesthetist adjusts your anaesthetic according to your needs.

Compared to general anaesthetics for other operations, there is a smaller range of anaesthetic drugs available for use during caesarean section. This is because some anaesthetic drugs, especially those related to ether or chloroform, prevent the uterus from contracting. Other drugs, such as morphine or pethidine, used for pain relief are not given to the mother until after the birth as these may slow the baby's breathing. Drugs given for the general anaesthetic and postoperative pain relief are only present in small quantities in breast milk and so do not cause problems with breast feeding.

All needles, syringes, drugs for injection, intravenous equipment and fluids are sterile items that are used for one patient only. Other items of anaesthetic equipment are either single patient use, are sterilized before each use in accordance with Australian Standards, or are protected by viral and bacterial filters. These measures have been shown to be extremely effective in preventing cross-infection.

SIDE EFFECTS OF GENERAL ANAESTHETICS

Dizziness, drowsiness, headache and blurred vision are common and usually wear off quickly. Occasionally muscle weakness can be noticed immediately after the anaesthetic, and may cause difficulty with breathing. Occasionally patients wake up feeling agitated or teary. These problems recover quickly. Swelling and bruising at injection sites are common and recover within a few days.

Short-term memory loss is common. Most patients do not remember being awake in the Post Anaesthetic Care Unit. Short-term memory loss usually recovers by the next day.

Nausea and vomiting are the most common side effects of a general anaesthetic and post operative pain relief. Up to 30% of patients experience nausea or vomiting. There is a lot of individual variation, with some patients more likely to experience these side effects. If you have had problems with nausea and vomiting after anaesthetics, or following morphine or pethidine injections in the past, tell your anaesthetist, as there are ways to tackle this problem.

It is usual for your anaesthetist to place a tube in your airway to help maintain your breathing while you are anaesthetized. This may cause a sore throat or hoarse voice, which usually recovers within 24 hours.

Muscle aches and pains are common. This is caused by a muscle-relaxing drug called suxamethonium and is expected to recover within three days. The usual pain relief following a caesarean section controls these aches and pains.

RISKS AND COMPLICATIONS OF GENERAL ANAESTHETICS

Anaesthetics in Australia are among the safest in the world. For a fit and healthy person, general anaesthetics are no more hazardous than a couple of short trips in the car. This level of safety is because, in addition to being a medical practitioner, your anaesthetist has completed a high level of specialist anaesthetic training and uses modern drugs and modern anaesthetic equipment.

However, as with driving a car, it is not possible to totally eliminate risk. Although very uncommon, anaesthetic complications do occur and these complications may be serious.

Awareness. During a general anaesthetic, it is possible to be awake, unable to move and aware of what is happening around you. This is called awareness and occurs during general anaesthetics where muscle-relaxing drugs are used. These drugs need to be used during a general anaesthetic for caesarean section. It is also possible to dream of being aware, without it actually happening. During caesarean section, awareness may occur in up to 2% of patients.

Death or serious complication. This may include conditions such as: heart attack; stroke; brain damage; blindness; fitting; pneumonia; DVT (blood clot in the leg) and pulmonary embolus (blood clot in the lungs); major allergic reaction; irregular heart beat; kidney, lung or liver failure; permanent nerve damage; permanent damage to voice; eye damage; and infections or reactions to blood transfusions. Even though many patients are worried about this, the chance of dying or having a serious complication because of an anaesthetic for caesarean section is very low. For a young healthy person, the chance is so low that it is difficult to measure it accurately. These risks may be higher for people who are less healthy, especially for those with heart or lung disease. Although general anaesthetics are very safe, there are specific risks related to DVT and pulmonary embolus, or vomiting which can cause pneumonia, which are higher for general anaesthetics for caesarean section operation than anaesthetics for other operations. Although a general anaesthetic for caesarean section is very safe, a spinal or epidural anaesthetic is safer again, up to 7 times as safe. You should discuss your individual risks and any concerns you may have with your anaesthetist.

Post operative pain. Your anaesthetist aims to have you as comfortable as possible following your operation. However, it is not always possible to have you totally free of any discomfort. Post operative pain relief can be better if an epidural or spinal anaesthetic is used compared to a general anaesthetic. Methods of pain relief include tablets, mixtures, suppositories (medicine via the back passage), injections into muscles or veins or combinations of these. If you have concerns about postoperative pain, you should discuss them with your anaesthetist.

Damage to teeth. Every care is taken by your anaesthetist not to damage teeth (including false teeth, capped teeth and bridges). Although dental damage is uncommon, it is important to understand that with any general anaesthetic there is a small risk that teeth may be damaged. Although very uncommon, injury may also occur to the larynx (voice box), vocal chords, lips, throat or tongue.

SPINAL AND EPIDURAL ANAESTHETICS

An epidural or spinal anaesthetic is an injection of local anaesthetic, often with an opiate drug, into the lower back, performed by an anaesthetist, to make part of the body go numb. Epidural and spinal anaesthetics do not make you sleepy and so allow you to experience the birth. They do not directly affect the baby. They are often recommended by the anaesthetist because they are associated with better safety, quicker recovery and better post operative pain relief.

Running down the middle of the backbones (spine) there is a sac of fluid called the dural sac. A spinal anaesthetic is an injection of local anaesthetic into the fluid inside the dural sac. An epidural anaesthetic is an injection of local anaesthetic around the outside of the dural sac. Nerves travel both inside and outside the dural sac and the local anaesthetic blocks these nerves and makes parts of the body go numb.

Epidural anaesthetics are usually used in labour, because a plastic tube, called an epidural catheter, can be threaded into the epidural space and left there for ongoing doses of local anaesthetic until pain relief is no longer required. You may have an epidural inserted during labour that can be topped up to provide anaesthetic for a caesarean section if required.

Spinal anaesthetics are usually used as a single injection of local anaesthetic for an operation. The single injection lasts for 2-3 hours Spinal anaesthetics are more commonly chosen for caesarean section, because they block the nerves more completely and more rapidly than an epidural.

Sometimes a combined epidural/spinal technique is used and can offer the benefits of both techniques.

WHAT DOES YOUR ANAESTHETIST DO?

An intravenous drip will be inserted prior to the spinal or epidural injection. This is done for safety reasons and to reduce the fall in blood pressure that is the most common side effect of an epidural or spinal injection.

You may be sitting up or lying on your side to have the spinal or epidural injection. Your anaesthetist will need your co-operation and may require you to curl up as this helps to open up the spaces between the bones in your spine and makes it possible to put in the injection. You will also need to try to stay still.

After preparing your back with an antiseptic wash and drapes, your anaesthetist will inject a small amount of local anaesthetic under the skin to make the skin on your lower back numb. It is usual for local anaesthetic to sting at first and it is normal to feel pressure as the spinal or epidural needle is inserted.

For a spinal anaesthetic a long, fine needle is inserted through the numbed skin, between the bones of the spine and into the fluid of the dural sac. This needle is a similar width to the needles your dentist would use to make your mouth numb. Local anaesthetic, with or without opiates, is then injected into the fluid. This is done as a one off procedure and the needle is removed straight away.

For an epidural, a thicker needle is inserted into the epidural space and local anaesthetic, with or without opiates, is injected into this space. A catheter (fine plastic tube) is often threaded through the epidural needle. The needle can be removed leaving one end of the catheter in the epidural space. Local anaesthetic, again with or without opioids, can be then injected via the catheter into the epidural space to provide anaesthesia or pain relief. The epidural catheter can be taped to your back and further doses of local anaesthetic given. The epidural catheter remains in place until you have no further need for epidural pain relief.

SIDE EFFECTS OF SPINAL AND EPIDURAL ANAESTHETICS

Numbness and muscle weakness. The most noticeable side effect is numbness and weakness of the lower half of the body. This is the desired effect of the local anesthetic block in order for your operation to be comfortable.

Drop in blood pressure. Although usually not noticed by the patient, the use of an epidural or spinal anaesthetic causes blood pressure to drop. Low blood pressure is usually controlled by giving fluids and/or drugs via the intravenous drip. .

Nausea and vomiting. Nausea and vomiting can occur with spinal and epidural anaesthesia during the operation and can be treated by the anaesthetist at the time. Nausea and vomiting can occur post operatively, this is most commonly due to the post operative pain relieving drugs and is less common than following a general anaesthetic.

Shivering. This is common with an epidural anaesthetic and sometimes occurs with a spinal anaesthetic. Shivering is of no medical concern and it stops when the epidural or spinal anaesthetic wears off.

Itching. Itching of the face, chest and arms can occur when epidural or spinal opioid drugs (such as morphine or pethidine) are given. These drugs significantly improve for postoperative pain relief, but at the risk of causing this nuisance side effect. If itching occurs, giving an antidote drug called naloxone (Narcan) with the intravenous fluids can treat itching very effectively. Naloxone does not reverse the pain relieving effects of the epidural or spinal opiate drugs.

RISKS AND COMPLICATIONS OF SPINAL AND EPIDURAL ANAESTHETICS

Inadequate block. It is normal to feel pressure and pulling during a caesarean section operation. You should not feel pain. However, epidural and spinal anaesthetics are often temperamental. They can be patchy, may only block one side, may block too high or too low, can miss blocking individual nerves and as epidural catheters are only held in by tape, these can leak or fall out. In some cases, the block can be inadequate. There are several ways of managing these problems. A spinal or epidural anaesthetic can sometimes be reinserted or, if an epidural catheter is in place, extra doses can be given via this. The obstetrician can also give extra local anaesthetic drugs. It is important to understand that there is the possibility of needing to have a general anaesthetic if an epidural or spinal anaesthetic is inadequate.

There is a lot of individual variation in people's size and shape and requirements for local anaesthetic. It is not always possible for the anaesthetist to put in an epidural or spinal. This can also result in the need to have a general anaesthetic.

Pain at injection site. Low back pain is common after epidural or spinal injection, but is expected to resolve within 2 weeks. After this time, there is no difference in the rate of low back pain for women who have had an epidural compared to women who have not.

Post spinal headache. A specific type of headache, called a post spinal headache, can occur after spinal or epidural injection in up to 1% of healthy young people and is far less common in older age groups. This headache can be mild or severe and usually resolves spontaneously over 1-3 weeks. It can be cured more quickly using an epidural injection of the patient's own blood. If you have a persistent headache, you should contact your anaesthetist. It is also important to understand that there are many other causes of headache that are more common. It is also possible to experience temporary deafness following spinal anaesthetic.

Nerve Damage. Nerve damage is uncommon and usually only temporary, but rarely may be permanent. Nerve damage may range from causing a very small area of numbness or weakness to, in extremely rare cases, paraplegia or quadriplegia. It is important to understand that nerve damage is five times more likely to occur just as a result of the delivery, than because of the epidural or spinal.

Infection. Infections are extremely rare, so rare that it is not possible to give an accurate incidence. All of the epidural and spinal needles, catheters, local anaesthetics, intravenous drips, syringes, tubing and fluids are sterile and used for one patient only. Your anaesthetist uses a sterile technique to insert the epidural or spinal. However, it is not possible to totally eliminate the risk of infection at the injection site or around the spinal cord (causing meningitis or an abscess). Infection may require antibiotic treatment, or very rarely surgery.

Death or serious complications. Although these risks are often lower with a local anaesthetic block than with general anaesthesia, they still exist and cannot be totally eliminated. Serious complications may include conditions such as: heart attack; stroke; brain damage; respiratory failure; fitting; high spinal anaesthetic block; DVT (blood clot in the leg); pulmonary embolus (blood clot in the lungs); major allergic reaction; and, irregular or slow heart beat. Even though many patients are worried about this, the chance of dying or having a serious complication because of an anaesthetic is extremely low. For a young healthy person, the chance is so low that it is not possible to measure it accurately. For those with poor general health, especially heart or lung disease, the risks may be greater. You should discuss your individual risks with your anaesthetist.

Incidental injury. Very rarely, a patient who is unconscious or drowsy is injured accidentally. For example, falls from operating table, eye damage, pressure injury, stretching injury, back injury associated with being moved, or unintentional burns. Nerve damage may occur despite the best positioning or padding of pressure points, resulting in an area or region of numbness or weakness.

Risks for the baby. The epidural or spinal anaesthetic has no direct effect on the baby. At the usual doses of local anaesthetic and opiates used for epidural and spinal anaesthetic, the baby only absorbs a very small amount of drug.

However, a prolonged drop in maternal blood pressure has the potential to reduce blood flow to the baby. During the epidural or spinal anaesthetic the blood pressure is monitored carefully by the anaesthetist and treated readily to prevent potential problems for the baby.

WILL YOU NEED TO SEE YOUR ANAESTHETIST BEFORE YOUR DELIVERY?

If you expect to have an elective caesarean section and if you have serious heart or lung disease or previous back surgery you should see your anaesthetist. If you have a bleeding or clotting disorder or if you are taking blood-thinning drugs (anticoagulants) such as fragmin or clexane, you need to talk to your obstetrician or anaesthetist about whether you need to alter these medications before the delivery. Your obstetrician can arrange for you to talk to an anaesthetist if required.

WHAT ELSE SHOULD YOU DO?

Stop smoking and stop taking herbal and alternative products, as some of these products may interfere with the wellbeing of the baby, anaesthetic drugs, blood clotting and blood pressure.

WHAT DO YOU NEED TO TELL YOUR ANAESTHETIST?

You need to tell your anaesthetist about any problems with your health, especially bleeding or clotting disorders or heart and lung disease, any medications you take, including herbal and alternative products, any allergies, any past history or family history of problems with anaesthetics or past back surgery.

OUT OF POCKET COSTS

If you are treated as a private patient, there will be an out of pocket cost with most anaesthetic services. There are no standard charges, each anaesthetist sets his or her own fees. The level of the ‘gap' or out of pocket cost will also depend on whether or not you have Private Health Insurance, the type of insurance you have, the type of procedure you are undergoing and how long the procedure takes. You should ask your obstetrician or anaesthetist about the cost of your anaesthetic.

This information was prepared by Dr G Eastaugh MBBS, FANZCA and Dr L Eastaugh MBBS, MBA and is provided to give you a better understanding of anaesthesia for caesarean section.. It cannot replace professional advice regarding your individual circumstances. It is important that you are satisfied that you understand this information If you are unsure or concerned about any of this information you should talk to your anaesthetist. Your anaesthetist can assess you and discuss your risks during your pregnancy, if required.

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ANAESTHETIC INFORMATION FOR CAESAREAN SECTION