Anaesthesia for Cardiac Surgery

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The following contains some information for parents of children who are going to have cardiac surgery at the Children's Hospital at Westmead. It is designed to give basic information and often the details may vary from patient to patient. An anaesthetist will see you and your child prior to the surgery and you will be able to ask questions about your child's anaesthetic management.

Fasting and Premedication

Prior to surgery children need to be fasted for 6 hours for milk and solids, 4 hours for breast milk and 2 to 3 hours for clear fluids. Sometimes a premedication might be given (usually by mouth) about an hour before the anaesthetic is due to start.


The child is usually anaesthetised by holding a mask in front of their face, and allowing them to breathe the anaesthetic gases. Sometimes an injection will be given to send them to "sleep". Once they are "asleep", various monitoring lines are inserted. The number and types of monitoring lines depend on the type of surgery and how sick or otherwise the child is expected to be after the surgery.

A cannula might be inserted into an artery, often at the wrist, but sometimes in the groin - to monitor their blood pressure. A larger cannula might be inserted into a vein in the side of the neck - to monitor the way the heart pumps and to allow medications to be given close to the heart. These cannulas are put in while the child is "asleep" and so they feel no pain or discomfort.

It is necessary to "breathe" for the child during the operation (and often afterwards in the intensive care unit), so a tube will be placed into the airway, through their nose, or occasionally through the mouth, which allows them to be connected to a ventilator, or "breathing machine". A catheter is also commonly inserted into the bladder, to measure the urine and therefore to monitor the way the kidneys are working. An ultrasound probe might be placed in the oesophagus (or "gullet") to enable the heart to be monitored during the surgery.

Preparing the child for the surgery can take an hour or more, before the actual operation takes place. Cardiac operations often take three or four hours, or even more, so it is possible that it will be four or five hours at least before you see your child again in the intensive care unit. They will go straight to the intensive care unit from the operating room, at the completion of the operation.


Your child's surgeon will explain the surgery to you. Open-heart surgery usually involves placing the child on a heart-lung machine to provide blood to your child's vital organs while the heart is being repaired. An anaesthetist and a cardiac perfusionist work as a team to manage this machine during the operation.

Intensive Care

After the operation, your child will be looked after in the intensive care unit. Apart from the monitoring lines placed by the anaesthetist at the start of the operation, you might see other tubes and wires placed by the surgeon. These include drainage tubes, which drain blood and fluid from the chest, pacing wires which can be used to stimulate the heart, if necessary, and fine tubes which pass through the chest wall and monitor the pressures in different parts of the heart. All these tubes and wires will gradually be removed as they are no longer required to monitor your child's progress.

Your child will usually be heavily sedated for a while after the surgery. How long they need this heavy sedation depends on the type of surgery and the amount of medication they need to support their heart after the operation. Your surgeon and the intensive care doctors and nurses will keep you advised about your child's progress. Once your child's condition is stable, they will gradually decrease the sedation and allow your child to wake up. As they wake, they will breathe more and more for themselves and the ventilator can be turned down until they are breathing entirely for themselves.

Risks of anaesthesia

The risk of anaesthesia is very small, especially when compared to the risk of undergoing open-heart surgery, although it is not zero. Complications can occur when inserting the monitoring lines, such as damage to blood vessels and nerves, although this is very uncommon. Reactions to anaesthetic agents can also occur, but again this is rare, and the anaesthetists are trained to deal with this.

Your surgeon will talk to you about the risks of the surgery, as this varies depending on the type of operation. He will also tell you that there is a (small) risk of brain damage. This could result in a stroke, or even death.

Often your child will require a blood transfusion during or after the operation. Although there is a risk of transmitting an infection, which might cause an illness such as hepatitis, this is extremely rare.


  • Although this all sounds a bit frightening, it is important that you realise that the vast majority of patients undergo these big operations without any problems.
  • While open-heart surgery is potentially dangerous, usually the risk of not having the surgery is greater. The anaesthetic team is skilled and experienced, and they undertake this sort of surgery frequently. They are part of a large team of surgeons, nurses and technicians who are all committed to looking after your child as if he or she were their own.
The Children's Hospital at Westmead

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