Anaesthesia Information

 

This page provides useful information for patients who are to undergo surgical procedures requiring anaesthesia.

The word “anaesthesia” is derived from two Greek words “an” meaning “without” and “aesthesis” meaning “sensation”.  Anaesthesia is a pharmacologically induced and reversible state of amnesia, analgesia and loss of responsiveness.  It is achieved using a combination of drugs like analgesics, hypnotics, sedatives and paralytics.


What is the difference between an anaesthetist and an anaesthesiologist?
Any qualified medical doctor can administer an anaesthetic – this is where the term anaesthetist comes from.
An anaesthesiologist is a medical doctor who has spent at least 4 years after completing medical school specialising in giving anaesthetics.
This means that an anaesthesiologist has had far more training and has passed a series of examinations to improve their skills and abilities when performing an anaesthetic.


Types of Anaesthesia

All types of anaesthesia can be used individually or in combination to achieve the best and safest anaesthetic for each individual patient

    1. General Anaesthesia

This is often called a “GA”. You will be put into a state of controlled unconsciousness so that you are not aware of your procedure. This is done using drugs injected into a vein, gases that you inhale or a combination thereof.
These agents inhibit feeling, movement and nerve transmission at the level of the brain.

    1. Local Anaesthesia

Often called “Local”. Using either drops, spray, ointment or an injection of local anaesthetic a small part of the body is numbed so that you do not feel anything in that area, but remain conscious but unable to feel.

      1. Regional Anaesthesia – blocks, spinal, epidural

Local anaesthetic drugs are injected near the bundles of nerves which carry signals from that part of the body to the brain.  Whole body parts are made numb. You remain conscious but pain free. These are divided into spinals, epidurals and specific limb blocks.

      1. Spinal and epidural blocks:

Injections into the lower back are used to temporarily paralyse the nerves of the spinal cord producing numbness of the lower half of the body.

      1. Nerve blocks:

Local anaesthetic is injected around a nerve or group of nerves making a single limb numb.

    1.  
    2. Sedation/Conscious Sedation

Injected drugs or gases are used to keep you calm and slightly sleepy but rousable. This is usually combined with local or regional block for a procedure. Eye surgery (cataracts), hand surgery, gastroscopies and colonoscopies are often done under sedation.


How you can prepare for an anaesthetic
Medical History

You will be required to complete a medical questionnaire to highlight potential problems while you are undergoing surgery and anaesthesia. Try and do this in peace and quiet at home before you come to the hospital. A medical questionnaire can be printed here.Please bring information on any medical conditions you may have to the hospital with you when you are admitted for your operation.

Medication
      • Bring your current medication to the hospital if there is any chance that you will be staying overnight or need to take this medication while in the hospital.
      • Bring a list of any medication that you are currently on, or have taken in the past 3 months (including homeopathic and natural products).
      • Bring a list of any allergies you may have.
      • Take your routine medication as normal. (If you are taking Warfarin, Aspirin, Plavix or any other blood thinners please ask the surgeon when you should stop these before the operation).

 

Starvation prior to Anaesthesia

 

YOU NEED TO BE STARVED FOR ALL ANAESTHETICS AND SEDATION.

All patients including children must have no food or milk products from 6 hours before admission, but may have clear fluids (water, black tea, clear apple juice or clear energy drinks) up to 2 hours before you report to the hospital on the day of your operation. Failure to adhere to these guidelines significantly increases the risks of aspirating and suffocating during the procedure which can have dire consequences.

      • Morning surgery – No food or milk products after midnight! Clear fluids up to 5am.
      • Afternoon surgery – No food or milk products after an early light breakfast (before 7am)! Clear fluids up to 10am

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Timing of Surgery

Although an operating list is scheduled to start at a particular time, only one patient can be anaesthetised and operated on at a time. This means that your surgery may be hours after the scheduled start time of the list. You will be given a rough estimate of the start time for your procedure. If the surgeon offers you an admission time after the start time of a list, you may only see the anaesthesiologist in the theatre waiting area. If you have a medical condition or anything else to discuss with the anaesthesiologist please either make contact before the day of surgery (this is highly recommended – please obtain contact details from your surgeon’s rooms or via the specific associate’s page) or ensure you are admitted to the ward at least one hour before the start time of the list.

What to expect during an anaesthetic
Preoperative consult (Premed Visit)

The anaesthesiologist will conduct a preoperative visit on the morning of your planned surgery to ensure that you are fit to undergo surgery based on your history, examination and results of any investigations. At this time the anaesthesiologist will also decide on and discuss the type of anaesthesia that is optimal for your surgery and medical history. This is the best time to discuss concerns about the anaesthetic and other techniques that may be employed with your anaesthesiologist.

The anaesthesiologist will try to see you in the ward for the preoperative visit, BUT is it is NOT always possible and you may only be seen by the anaesthesiologist in the theatre reception area.

      1. History

You will need to know about your medical history and may be asked about:

        • Current and previous medical conditions e.g. hypertension, diabetes, cholesterol, cardiac disease, asthma, epilepsy and thyroid conditions.
        • If you have a family history of medical conditions especially those that may be anaesthetic related e.g. porphyria, scoline apnoea and malignant hyperthermia.
        • Problems with previous anaesthetics
        • Allergies
        • Current medication including homeopathic meds and supplements

It is useful to bring along the actual medication or a list of the medications you are taking. This includes prescribed and over-the-counter drugs.
You should continue taking your chronic medication up to and including the day of surgery (with a small sip of water) unless your anaesthesiologist or surgeon has asked you not to e.g., diabetic meds, blood thinning meds and some herbal remedies.

      1. Examination

You will have a medical examination by the anaesthesiologist, looking in particular at your:

        • General condition
        • Airway. (Most anaesthetics require that a breathing tube be inserted.)
        • Cardiovascular system (heart)
        • Lungs and chest
        • Any weakness or numbness, especially if you are having a regional block, local anaesthesia or lines inserted.
      1. Investigations

Further investigations may have to be ordered guided by your history and examination. (These may entail additional costs and delays that prevent surgery being done at the time planned). At times another specialist may be required to assess your condition further.

        • Blood tests e.g. full blood counts, haemoglobin, infection markers, kidney, liver and thyroid function.
        • X rays (chest or other)
        • Heart examination (ECG or an ECHO)

Using the above information the anaesthesiologist will discuss the best anaesthetic options available to you for the planned surgical procedure.

At times your anaesthesiologist might have to postpone your surgery based on the preoperative consultation and investigations. This is done to optimise your condition in an attempt to decrease the risks of anaesthesia and surgery. This delay is usually until the problem is corrected or brought under control.

      1. Premedication

Medication may need to be given to you before the operation in an attempt to make you less anxious, decrease nausea, or for pain control. These may not be routinely used and are guided by the surgery and patient medical history. In the case of short day surgery they may keep you drowsy after the operation and delay your discharge home.

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During the operation

During the operation the anaesthesiologist is present throughout the procedure and monitors your vital signs constantly while adjusting the amount of anaesthetic to meet the requirements of the operation.

What are some of the monitors you may have?
      • Your heart (using an ECG) through 3 stickers on your chest.
      • Your blood pressure, using a cuff on one of your arms. This squeezes your arm firmly while it is taking your blood pressure.
      • The oxygen level in your blood
      • Other specialised monitors depending on the patient and type of surgery.

 

What can I expect to happen during my anaesthetic?
      1. Before you go to sleep an intravenous line (drip) will be put up either in one of your hands, forearms or cubital fossa.  It may sometimes take more than one attempt to get the drip in.
      2. Induction of anaesthetic. You will be given oxygen to breathe and anaesthetised in one of two ways.
        1. Through an injection into your drip. This is the commonest way.
        2. You may be given gas to breathe through a mask. This is usually used when anaesthetising a child.
      3. A breathing tube will then be inserted to help you breathe during the anaesthetic. A variety of techniques and equipment may be used depending on the surgery and patient. These tubes can be associated with sore throats, damage to the tissues and structures of the airway, bruising, bleeding, hoarseness, damage to the nerves in the airway and failure to insert the tube.
      4. Once you become unconscious the anaesthesiologist will continue giving you drugs, either intravenously or gases to keep you anaesthetised.
      5. The anaesthesiologist monitors the depth of your anaesthetic to keep it both safe and effective.
      6. The anaesthetist is trained to observe you, detect and then manage any complications that may arise during the procedure. (E.g. give you blood if you are bleeding excessively)
      7. They manage your pain to in an attempt to keep you pain free during the operation and once you emerge from the anaesthetic.
      8. Depending on the procedure, length of surgery and your preoperative risk profile, the anaesthesiologist may have to make use of additional monitoring techniques such as:
        • Arterial line – to monitor blood pressure via an artery.
        • CVP (central venous line) – used to give drugs via a large central blood vessel.
        • Temperature
        • Urinary catheter
        • Cerebral monitoring – to monitor brain function.

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After the Operation

At the end of the procedure the anaesthesiologist wakes you up and assesses your condition during which they will see if  your pain is under control, you are not nauseous, you can breathe on your own, and you are ready to be transferred to the recovery room.

You will spend about 20-30 minutes in the recovery room for further monitoring until the team are completely satisfied with your condition before you go back to the ward.

Occasionally you will be transferred to a high care or ICU after your operation. This may be planned before the operation starts (based on your medical condition or the surgery to be performed) or unplanned if a complication (surgical or anaesthetic) develops during the procedure.

 

Going home after Anaesthesia and Sedation

The time to discharge after surgery and recovery varies according to the type of surgery, the type of anaesthesia and your individual recovery. If you have had same day surgery you may be discharged within a few hours of your procedure. Even if you feel absolutely fine you will not be allowed to drive (arrange for a lift home), operate dangerous machinery or make important decisions for 24 hours after your anaesthesia.

DO NOT CONSUME ALCOHOL post anaesthesia and until you have stopped all your post-operative prescribed medication (i.e. pain killers, anti-inflammatories, antibiotics etc). This is critical and cannot be emphasised enough.

 

For information for parents of children undergoing anaesthesia please click here.

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Complications of Anaesthesia

No one can guarantee an incident free anaesthetic. Complications and unpleasant effects following an anaesthetic are fairly common and can occur even after previous uneventful procedures. The complications that occur may be related to the surgery, the anaesthetic, procedures done for pain relief or monitoring or underlying conditions that the patient may have. These complications may range from trivial to brain damage and death. The following list covers some of the complications that may occur under anaesthesia or after an operation.

 

Common complications (1-10%)
Minimal treatment usually required
Rare complications (<1:1000)
May require further treatment
Very rare complications (1:10000-200000)
Often serious with longterm sequelae
Brain damage or death (<1:250000)
  • Nausea and Vomiting
  • Sore throat
  • Shivering or feeling cold
  • Headache
  • Dizziness
  • Itching
  • Pain during drug injection
  • Swelling/bruising at drip site
  • Confusion/memory loss (esp in elderly)
  • Injuries to teeth, crowns, tongue, lips, mouth
  • Hoarseness, vocal cord damage
  • Muscle pains
  • Difficulty urinating
  • Difficulty breathing
  • Visual disturbances
  • Worsening of underlying medical condition
  • Side effects of post op medications
  • Eye injuries
  • Nerve injuries causing paralysis
  • Lung infection
  • Awareness
  • Bleeding
  • Stroke
  • Allergic reactions
  • Unexpected drug reactions
  • Inherited reactions to drugs (Malignant hyperthermia, Scoline apnoea, porphyria)
  • Due to any other complication getting more severe
  • Heart attacks
  • Emboli (clots)
  • Lack of oxygen

 

Complications of procedures which may be performed during your anaesthetic

Procedure Complication
Intravenous line Pain, swelling, repeated insertions, inflammation, infection
Central Line for specialised monitoring/therapy Pain, swelling, bleeding, inflammation, infection, repeated insertions, puncture of lung, artery or nerve.
Arterial Line for specialised monitoring Pain, swelling, bleeding, inflammation, infection, repeated insertions, loss of blood flow to the hand leading to death of fingers
Airway management Damage to lips, teeth, tongue, palate, throat, vocal cords, hoarseness, inhalation of stomach contents (aspiration), pneumonia, obstruction of breathing, failure to manage the airway which may require an emergency operative procedure.
Nerve block, spinal or epidural injection Nerve damage, paralysis, backache, headache, nausea, vomiting, dizziness, shortness of breath, pain, bleeding, inadequate pain control.

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Links to other anaesthesia information