Anaesthesia Information Page

Frequently Asked Questions

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Why do I need to have a drip?

An intravenous line or drip as it's commonly referred to is used in almost all anaesthetics. The reason it is used is that it provides the most direct route for administration of drugs and fluids to the person undergoing the anaesthetic. Having a rapid way of giving drugs gives us the ability to induce anaesthesia in the most rapid and smooth means, and for further administration of drugs as required during the operation. It also provides the most rapid means of giving important drugs during emergencies that may arise. Finally preoperative fasting and fluid and blood losses during the operation mean fluids need to be given during the operation to compensate and intravenous fluids are the only practical means of doing this. There are some situations where a compromise may have to be reached in terms of safety versus person's comfort. If a needle phobia is the biggest fear of the person and other safety factors are adequately met the anaesthetic can be started by a gas mask. Children often have their anaesthetic started in this manner. The pain of having an drip put in is usually slightly more than that of having blood taken. When an IV needs to be put into children some local anaesthetic cream is applied to the hand and left there for one hour and then the IV doesn't hurt when it's put in.

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Why do I need to fast before an operation?

Fasting - which is not eating, drinking or chewing anything for a set period of time - is part of every safe anaesthetic technique. It is performed to improve the safety of someone undergoing general anesthesia. When some one is given a general anaesthetic many of the normal reflexes of the body are lost. One of these is the one that keeps food in the stomach and prevents it coming back up and into the lungs - or "going down the wrong way" as it is commonly known. When someone experiences this in the normal state the body can cough and protect the lungs from food and fluid going down. Under anaesthesia this does not occur to the same degree and the consequences of food going into the lungs can be very severe. The normal fasting period is from midnight if you are having an operation on the morning operating list and from 7 am (after only a light breakfast) if you are having an afternoon operation. This is the normal period people go between meals so has little effect on the body. Do not fast for longer periods, this causes unnecessary stress on the body. Children are given specific instructions according to their age and every attempt will be made to minimise the time they are fasted.

Why is fasting needed if I'm not going to have a general anaesthetic?

Any anaesthetic has the potential for complications and there is the possibility that some other form of anaesthetic may be inadequate for the operation and the anaesthetic may have to be converted to a general anaesthetic at any time.

What about emergencies when I haven't fasted?

Good question. When someone is not fasted and there is an urgent need to perform surgery the anaesthetic technique can be modified to minimise the risks associated with not fasting. As this is a less satisfactory option than adequate fasting it will be up to your anaesthetist to decide whether the urgency of your operation outweighs the increased risk of inadequate fasting.

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Why is my history of smoking so important?

Smoking causes numerous short and long term health problems which may influence anaesthesia. In the long term it increases the risks of heart disease, breathing problems, blood clots, stroke, blood vessel disease, kidney disease, all forms of cancer and numerous others. The number of cigarettes smoked needs to be assessed to determine whether you have increased risk of these problems and what further precautions need to be taken. In the short term smoking impairs the ability of blood to carry oxygen and literally starves your body of oxygen the more you smoke. Under anaesthesia this contributes to the risk of complications further. The longer you don't smoke prior to an operation the better. Ideally give it up as soon as possible for your overrall health but if you simply cannot quit then abstaining as long as possible prior to an operation is desirable. The absolute minimum you should not smoke is the period you are fasting for prior to the operation.

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Alcohol and drugs
How does my alcohol intake or drug use affect my anaesthetic?

Moderate intake of alcohol has not been shown to be detrimental to your health. It may in fact be helpful. Moderate is defined as 2-3 glasses 2-3 times per week for an adult male and 1-2 glasses 1-2 times per week for females. Drinking alcohol in excess of this quantity can lead to short and long term health problems, both of which must be taken into consideration when an anaesthetic is given. For your own health don't drink in excess but you should at least not drink alcohol for two days prior to an anaesthetic. The effects of other drug use on anaesthesia are complicated and it is best, if possible, to avoid using them around the time of the anaesthetic. It is vital your anaesthetist knows about any drug and alcohol history.

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Am I going to die?

The short answer is no. The risk of dying from the actual anaesthetic is extremely low. If you have no medical problems and are not elderly your risk of death from just having an anaesthetic and then being woken up without having any operation is probably less than the risk of dying from crossing the road. Modern anaesthesia with today's anaesthetic techniques, training, equipment and monitoring is extremely safe in Australia and the rest of the western world. Your risk of dying during an operation is more related to the illness for which you are having an operation, the operation type and your background medical state. A healthy 30 year old having a knee operation is not the same as an 80 year old with heart, kidney and lung diseases having a quadruple heart bypass for example.

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Will I wake up?

This is actually three different questions.

  • Will I wake up during a general anaesthetic?
  • Will I wake up at the end of the anaesthetic?
  • Will I be awake during the operation?

Will I wake up during a general anaesthetic?

Unfortunately the media has a habit of sensationalising rare events. Modern anaesthetic techniques with routine monitoring and experienced anaesthetists means waking up during an operation is extremely unlikely. We have numerous indirect ways to tell how "deep" an anaesthetic is and new monitoring equipment may decrease the incidence further. Waking up unable to do anything is also less likely today as more anaesthetic techniques involve allowing the person to have full muscle strength so if you are awake you can move and open your eyes and talk. When "awareness" has occurred during a general anaesthetic it almost always occurs in specific settings. There are certain operations that have a higher risk of awareness. The reason for this is that a "light" anaesthetic may be required for safety because the severity of illness means the person's body cannot tolerate much anaesthetic as it interferes with their heart too much - this occurs in major heart operations or in people who have catastrophic injuries from accidents. The other scenario is a caesarean section where any anaesthetic given to the mother also goes across to the baby and the baby needs to be as awake as possible when it is delivered to breath properly so a balance has to be struck. A major concern people have is how do you know if you've given me enough anaesthetic to last the operation or too much? Most anaesthetic drugs we give only last a short time. For this reason we don't just give one shot of anaesthetic. We actually continually give anaesthetic drugs either by a continuous infusion into the drip or by giving anaesthetic gas to the air the person is breathing. The anaesthetic drug is only stopped when the operation is over. Then any drug left over wears off as the body gets rid of it and the person wakes up. Usually the person wakes up within 5 minutes of the end of the operation regardless of how long the operation takes. There is no "wake up" medicine required, the sleep medicine simply wears off.

Will I wake up at the end of the anaesthetic?

The short answer is yes. As explained in the previous section anaesthetic drugs wear off quite rapidly when they have stopped being administered. For a person to not wake up at the end of the anaesthetic they will have had to have suffered some major complication such as a stroke or brain damage. Your risk of suffering these complications is extremely rare during an operation and not much more likely than if you hadn't had an anaesthetic. If you are already at high risk of having a stroke then your risk increases further if you are having an operation, and more so if you are having brain surgery or surgery on the blood supply to the brain. Feeling drowsy on the other hand is very common. Partly this is residual effect of anaesthetic drugs in your body, partly it is strong pain-killers you may have received as part of the anaesthetic (they tend to make you sleepy), and part of it is the fact that you've had some sort of surgery and stress to the body. The bigger the operation, the drowsier you will feel.

Will I be awake during the operation?

While most people think of having an anaesthetic as being asleep, there are numerous operations that can be performed without a general anaesthetic. In the same way as having work done at the dentist with local anaesthetic, many operations can be performed under regional anaesthesia. Regional anaesthesia does not require the person to be asleep and so how awake you are during the operation is dependent on the compromise chosen by yourself and your anaesthetist on how much sedation you are given during the operation. You can be wide awake, calm and drowsy or completely asleep. Often the sedation given to you during this sort of anaesthetic makes you forget most of the operation even though you were awake.

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Why is my anaesthetic so different this time?

People who have had at least one previous anaesthetic may have had completely different experiences and expectations of their anaesthetic. Every single anaesthetic administered is uniquely tailored to the person and the operation. Changes in the type of operation, your health status and your anaesthetist mean there may be enormous differences between anaesthetics. There are also numerous occasions when procedures are done for your anaesthetic while you are sedated. When this occurs, you may have no memory of the procedure even though you were awake for it the first time. The final decision is also made by your anaesthetist and in the same way no two people drive cars the same way but will get you safely to your destination, no two anaesthetists give the same anaesthetic.

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Residual effects
Will I be left with any long term effects from anaesthesia?

Most of today's anaesthetic drugs are very short acting. From the moment the anaesthetic is no longer being administered, 90% of the anaesthetic drug is gone within 10 minutes. Furthermore within 12-16 hours there is no trace of them. The effects of anaesthetic drugs appear to purely occur when the drug is in your body and have no long term effects. Regardless of how long an operation you have or how many anaesthetics you have, if you do not have a problem during the operation, there is no evidence to suggest that you could have a late effect. No link between any diseases (like cancer) and anaesthesia has ever been shown. Pregnancy is of special concern but as long as it is known someone is pregnant, safe drugs can be used. It is recommended you take it easy and not drive a car for 24 hours.

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Will I suffer from nausea and vomiting?

Nausea in relation to an operation is due to numerous factors. The type of surgery you are having is by far the most important factor. Second is the person's own predisposition to nausea and third is the anaesthetic. Most anaesthetics today tend not to cause nausea by themselves, but as anaesthetists we certainly try to reduce the rate of nausea further. Most anaesthetics usually include drugs to decrease nausea. If you have a history of motion sickness or past nausea with operations there are some options. First you must tell your anaesthetist so they can tailor the anaesthetic and pain relief accordingly. You can also have the operation under regional anaesthesia which avoids general anaesthetic drugs and minimises strong pain killers as the strong pain killers tend to cause nausea. Even if you do get nauseated after an operation there are still strong anti-nausea drugs that can be given to you. The majority of patients leave the recovery room free of nausea these days.

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Child awaiting surgery (Click for larger image)

  Back to Top Site created by Con Kolivas Jan 2001

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