general anaesthetic is given using a combination of drugs that are injected into your child and gases that your child breathes. It is used to make your child unconscious in a carefully controlled way. Your child’s body has a number of reflex responses to the painful stimulus caused by the surgery, even when your child is not aware of the pain. These responses include changes in blood pressure, raising or lowering of heart rate and alteration of breathing. As well as making your child unconscious, the anaesthetist also controls changes in your child’s blood pressure, heart rate and breathing that are caused by the surgery. For some larger operations, drugs are used to weaken your child’s muscles and a machine called a ventilator is used to do the beathing for your child. Muscle relaxing drugs are used in long procedures or to make it possible for the surgeon to do a particular operation. For most procedures, your child is asleep and able to breathe alone without the assistance of a machine.

Sedation is the use of drugs to make your child sleepy, but not as deeply asleep as a general anaesthetic. Sedation is usually used for shorter, less painful procedures in adults and less frequently in children. It may be used in combination with a local anaesthetic block. It has advantages over a general anaesthetic in that it may be safer, causes less nausea or vomiting, and allows quicker recovery. It is not unusual for patients receiving sedation to wake up during the procedure and to be aware of what is going on around them. After the procedure, most patients do not remember being awake, but some patients do recall what has happened. This is not an unpleasant experience and should not be of concern. If you have any concerns about this, you should talk to your anaesthetist.

Local anaesthetic blocks involve the injection of special drugs that make specific parts of the body go numb. This can range from making a single finger go numb to making half of your body numb. These blocks are particularly safe when small parts of the body are made numb. Larger blocks, such as epidural or spinal anaesthetic, can also be safer than a general anaesthetic. Local anaesthetic blocks provide better pain relief following surgery and are often combined with a general anaesthetic. They can also be used with sedation.

TYPES OF LOCAL ANAESTHETIC BLOCKS

Local anaesthetics may be injected directly at the site of surgery, or to block a single nerve or even whole groups of nerves to make parts of the body go numb and prevent pain.

Intravenous limb block.
Although this type of block is commonly used in adults, it requires the cooperation of the patient and is less frequently used in children. For this type of block, your child’s anaesthetist puts a tourniquet around your child’s upper arm or leg and injects a local anaesthetic drug into a vein in your child’s hand or foot. This is a very reliable block for making the arm numb, particularly for short procedures and is less commonly used in the leg. However, there can be some discomfort from the tourniquet and for this reason it is common for the anaesthetist to give sedation as well.

Nerve plexus blocks.
Nerves are grouped together in some parts of the body. Such a group of nerves is called a plexus. The whole upper limb and parts of the lower limb can be made numb by injecting a local anaesthetic drug near the groups of nerves that supply the limbs. For the upper limb, this is most commonly done by injecting the local anaesthetic into the armpit. For the lower limb, this can be done in the upper thigh or behind the knee. It is usual in children to give a general anaesthetic or sedation when the block is put in. This technique is best used for longer, larger operations on the limbs.

Individual nerve blocks.
Individual nerves in the face, mouth and limbs can be blocked by injecting the local anaesthetic near the individual nerve that supplies the area of the body where the procedure will take place. These blocks are particularly safe. Because smaller doses of local anaesthetic are required there are less potential complications. This type of block is most useful for dentistry or surgery on the hand or fingers.

Spinal and epidural anaesthetics.
An epidural or spinal anaesthetic is an injection of local anaesthetic, often with other pain-relieving drugs, into the lower back. Your child’s anaesthetist uses this type of block to make a large region of your child’s body go numb. Your anaesthetist may recommend this type of block, because it may provide better safety, quicker recovery and better postoperative pain relief than a general anaesthetic alone. 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 through the back, into the fluid inside the dural sac. An epidural anaesthetic is an injection of local anaesthetic through the back, into the area outside of the dural sac. Nerves travel both inside and outside the dural sac and the local anaesthetic is used to block these nerves and make parts of the body go numb.

Epidural anaesthetics are usually used for treating postoperative pain following large operations. Epidurals can also be used to treat long-term pain. This is 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. An epidural may be used for several days. Spinal anaesthetics are usually used as a single injection of local anaesthetic for an operation. The single injection lasts for 2-3 hours

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

Another common local anaesthetic block is a caudal anaesthetic. This is like an epidural anaesthetic, but given lower down in the back. Caudal anaesthetics have been shown to be particularly safe and useful in children.

This information has been prepared by Dr G Eastaugh, Dr L Eastaugh and Dr J Waters to give you a better understanding of your child’s anaesthetic, but cannot replace professional advice regarding your child’s individual circumstances. It is important that you are satisfied that you understand the information regarding both your child’s procedure and the anaesthetic. If you are unsure or concerned about any of this information you should talk to your anaesthetist. Your anaesthetist can assess your child and discuss your child’s risks at the pre anaesthetic visit or earlier if required.

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