Anaesthetic Information

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 muscle relaxants.

Types of Anaesthesia

  1. General Anaesthesia (GA)
  • Medication is given via a drip into your vein or anaesthetic gases are inhaled into your lungs to induce a controlled loss of consciousness.
  • These agents will keep you asleep, completely unaware and pain-free during your surgery.
  • A breathing tube or mask will be used to protect your airway and assist your breathing whilst asleep.
  • A GA may result in a slightly longer time spent in the postoperative ward before discharge home in order to allow for recovery.
  1. Spinal / Epidural Anaesthesia
  • This involves the injection of local anaesthetic and other medications close to the spinal cord to temporarily produce paralysis and numbness of the lower half of the body.
  • With an Epidural, a tiny plastic tube is placed in the epidural space of the back in order to allow continued administration of anaesthesia for the surgical area for a longer post-operative period.
  1. Regional Anaesthesia
  • Local anaesthetic drugs are injected near to nerves to produce numbness to a specific part of the body or limb.
  • Safe and correct placement of the injection may entail usage of an ultrasound machine or a nerve stimulator.
  • A small plastic tube may be placed near to the nerve in order to continue to administer anaesthesia to the surgical area for a longer post-operative period.
  • This may be accompanied by sedation for the duration of the surgery.
  1. Local Anaesthesia
  • Local anaesthetic medication, either drops, spray, ointment or an injection is used on a small part of the body around the site of surgery in order to numb the area.
  • This may be accompanied by sedation for the duration of the surgery.
  1. Procedural Sedation & Analgesia (PSA)
  • Medication is given via a drip into your vein or orally as a tablet.
  • This will help you to relax, stay calm, alleviate anxiety, keep you comfortable and often reduces pain.
  • You are awake but not fully aware during conscious sedation and may not remember the surgery or anaesthetic.
  • The depth of sedation is determined by your requirements to maintain spontaneous breathing and comfort during surgery.

Complications Associated with Anaesthesia

Anaesthesia is associated with risks, side effects and complications, as are all types of medical treatments.

  • No one can guarantee an incident free anaesthetic. Adverse events can occur during any anaesthetic.
  • Complications that occur may be related to the surgery, the anaesthetic and drugs administered, procedures done for pain relief or monitoring or due to underlying medical conditions that the patient may have.
  • Anaesthesiologists are trained to manage these complications and all necessary precautions will be taken to ensure that you receive the safest and most appropriate anaesthetic possible.
  • If a complication persists for more than 48-hours please inform your anaesthesiologist.


Complications that may occur under anaesthesia or post operatively:

Very rare
Brain damage or Death

(1 to 10% of cases)

Minimal treatment usually

(Less than  1 in 1000 cases)

May require further treatment

(1 in 10,000 to 1 in 200,000 cases)

Often serious with long-term damage

(Less than 1 in 250,000 cases)

Nausea & vomiting

Sore throat

Shivering or feeling cold




Pain during injection of drugs

Swelling or bruising at the infusion site.

Confusion or memory loss (common if elderly)

Injuries to teeth, crowns, lips, tongue and mouth

Painful muscles

Difficulty in urinating

Difficulty breathing

Visual disturbances

Worsening of underlying medical conditions like diabetes, asthma or heart disease

Hoarse voice, vocal cord injuries

Pressure related injuries

Eye injuries

Nerve injuries causing paralysis of nerves / numbness

Lung infection

Awareness of the operation



Allergic reactions / anaphylaxis

Unexpected reactions to anaesthetic drugs

Inherited reactions to drugs (Malignant hyperthermia, Scoline apnoea, Porphyria)

Due to any other complication becoming more severe

Heart attacks

Emboli (clots)

Lack of oxygen





Complications that may occur due to procedures that may be performed during your anaesthetic:


Intravenous line (IV)
Pain, swelling, bleeding, inflammation, infection, clots, repeated insertions if IV not working adequately
Central line for monitoring or therapy
Pain, swelling, bleeding, inflammation, infection, repeated insertions, puncture of lung, artery or nerve, clots
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 maintain the airway requiring an operative procedure.
Nerve blocks, spinal or epidural injection
Back pain, non-resolving headache, nerve damage, paralysis, headache, nausea, vomiting, infection, dizziness, shortness of breath, chest pain, pneumothorax, seizures, drug toxicity.

Preparing for your Anaesthetic

Fasting Guidelines:

One must remain nil by mouth for a specified period before undergoing anaesthesia. Failure to adhere to these guidelines significantly increases the risk of aspiration during the procedure which can have dire consequences.

The recommendations are as follows:

1. All patients (including children)

  • No solid food or milk products (including formula) from 6hrs before surgery
  • Clear fluids (water, black tea, clear apple juice or clear energy drinks) may be taken up to 2hrs prior to undergoing anaesthesia.
    • Clear fluids are those fluids which, when held to the light, are transparent. They do not include juice with pulp, carbonated drinks such as Coca Cola, milk-based products or jelly.

2. Infants

  • May receive breast milk up to 4hrs before surgery.
  • Clear fluids may be taken up to 1hr prior to undergoing anaesthesia

3. In general

  • 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.

Medications / Drugs:

  • Please bring a list of all the medications you are currently taking with you to hospital.
    • Including Traumeel/Arnica, herbal, homeopathic, traditional or alternative medicines or therapies, cannabis or cannabis oil, gym supplements, performance enhancers, pre-workouts/post workouts, testosterone/testosterone boosters, EPO, growth hormone, fat burners or diet tablets, recreational drugs of any sort, cigarettes, pipe tobacco, snuff or chewing tobacco
  • Most chronic medication should be taken on the day of surgery and pre-operative fasting is not a contra-indication.
  • Drugs may be taken with a small amount of water (50ml).
  • Medication to be TAKEN:
  • All “cardiac” or blood pressure drugs
  • EXCEPT ACE inhibitors, AT2 antagonists and diuretics (see below)
    • All epilepsy or Parkinsons’ drugs
    • All asthma drugs or inhalers
    • All tablets which reduce gastric acid (omeprazole, lansoprazole, pantaloc, ranitidine)
    • All thyroid drugs (eltroxin, Euthyrox)
    • All major and minor tranquilisers, which are taken regularly at home
    • Also antidepressants and nicotine patches, EXCEPT for Lithium (Camcolit) + Moclobemide (Depnil)
    • All steroids taken regularly, including inhalers
    • All immunosuppressants and cancer drugs (eg. azathioprine, tamoxifen)
    • All analgesics can be given before surgery – EXCEPT NSAID’S (see below)
  • Medication to be OMITED:
    • ACE inhibitors: ramipril (Ramiwin, Titrace), enalapril (Enap-co), perindopril (Coversyl, Coveram, Prexum), captopril (Capoten), lisinopril (Zestril, Zestoretic)
    • Angiotensin 2 antagonists: candesartan (Atacand), losartan (Cozaar)
    • All diuretics (water tablets): furosemide (Lasix), amiloride (Dapamax), spironolactone (Spiractin)
    • Diabetic treatment: omit on the morning of surgery
    • Anticoagulants (blood thinners): Aspirin, Ecotrin, clopidogrel (Plavix, Clopiwin), rivaroxiban (Xarelto), warfarin, clexane.
    • Please inform the surgeon of the fact that you are taking “blood thinning” medication prior to hospital admission.
    • Drugs which are not essential in the short term: eg. vitamins, iron, laxatives, osteoporosis treatment, liquid antacid medicines (eg gaviscon), hormone replacement therapy, anti- histamines, herbal remedies or homeopathic medicines.
    • Lithium (Camcolit) and Moclobemide (Depnil) should be omitted.
    • Non-steroidal anti-inflammatory drugs: diclofenac (voltaren), indomethacin (Indocid), ibuprofen (Brufen).
    • Viagra (Sildenafil), Cialis (Tadalafil) and Levitra (Vardenafil) should be omitted 24hrs prior to surgery.


If you or your child are ill before your elective surgery (i.e.. significant cough, fever, diarrhoea, vomiting) please inform your surgeon or contact your anaesthesiologist before hospital admission as the surgery may need to be postponed until you are well enough.


Pregnancy / Breastfeeding:

  • Please inform your surgeon and anaesthesiologist.
  • Your anaesthesiologist will try use medications that are to be the safest available for you and your baby.
  • General anaesthetics do not normally have an effect on breastfed babies.
    • It is recommended that you breastfeed up until the operation and to continue breastfeeding as soon as you are awake and feel ready to do so afterwards.
    • Very small amounts of anaesthetic medication may pass into breast milk, however there is no need to ‘pump and dump’.
  • It is also important that you are not the primary carer for your child for the first 24 hours post surgery and it is recommended that other arrangements are made.


  • Post anaesthetic or after sedative medication, one may not be able to think clearly for up to 24 hours.
  • During this time, one should not:
    • supervise children or other people
    • drive a vehicle or ride a bicycle
    • cook or use any machinery
    • make any important decisions, even if you feel fine
    • post anything on social media
    • drink alcohol
  • 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.
  • No patient is permitted to drive themselves home after a day case procedure, even if they have only received sedation, so please arrange transport prior to your hospital discharge.
  • 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.

Sedation Information

Pre-sedation instructions for patients / carers / guardians

  • If you are unable to comply with, or have any concerns regarding the instructions listed on this page, please contact your anaesthesiologist, so that we can discuss how to best make adjustments for your particular requirements or circumstances.
  • If you feel sick or unwell, please liaise with your doctor / dentist whether to postpone the treatment.
  • Do not eat anything for at least 6 hours before the procedure / operation.
  • Clear fluids (black tea/ black coffee/ apple juice) may be taken up to 2 hours before the procedure.
  • Smoking and alcohol intake should be avoided for 24 hours before your appointment.
  • The use of recreational drugs is not permitted for 48 hours prior to treatment.
  • Please wear comfortable clothes with loose-fitting sleeves in order to be able to apply an electronic blood pressure cuff to your upper arm.
  • Avoid wearing heavy make-up, nail varnish and jewellery.
  • Wear flat shoes, as you may be slightly unsteady for a short while afterwards.
  • Take any chronic medication, on the day of the procedure / operation, as ordered by your doctor / dentist. If taken, it must be taken at the usual times, along with a small amount of water, regardless of the restrictions on fluid intake noted above.
  • Asthma sufferers should bring their inhalers.
  • Diabetic patients should bring their blood glucose monitoring devices and take their blood glucose level the morning before the sedation. A low blood glucose level must be reported to the anaesthesiologist.
  • Patients with Obstructive Sleep Apnoea who use CPAP should bring their CPAP devices.
  • Depending on the nature and duration of the surgery, contact lens wearers may have to remove their lenses. So, bring a contact lens container along, or wear spectacles if possible.
  • Please arrive in good time for your appointment, at least 30 minutes beforehand. In some cases, your doctor/ dentist may feel that you will benefit from premedication to reduce your anxiety and make you feel relaxed. In this case, you may have to come earlier in order to take the premedication.
  • Please empty your bladder before the procedure / operation.
  • You must have an adult escort to accompany you home. The escort may remain with you until the sedation is underway and the procedure / operation is about to start. The escort will then be requested to leave the procedure/operation room.
  • If the sedation ends late in the day, it is advised that the escort remains with the patient until the following morning. Guidelines do not allow us to send you home on your own. If there is nobody to accompany you home we will unfortunately not be able to provide sedation.
  • There must be arrangements in place for you and the responsible escort to travel home by private car or taxi rather than public transport.

Post-sedation instructions (aftercare) for patients / carers / guardians

  • A responsible adult must take you home after the sedation, and you must remain in the company of a responsible adult for the remainder of the day. Sedation will not proceed if you arrive without an escort.
  • It can take up to 24 hours for the sedative drugs to be eliminated from your body and for you to recover from the effects of sedation (drowsiness, loss of memory, lack of awareness and coordination).
  • Therefore, for east 24 hours following the procedure/ operation, you must not: drive a vehicle (insurance will be void), use electrical equipment, cook, or operate machinery, climb heights (e.g. ladders, scaffolding), participate in any other activities that require alertness or coordination (e.g. swimming, cycling, etc.), be in charge of children or dependent adults, make important decisions, or sign legal documents, use alcohol, sleeping tablets, tobacco, or recreational drugs, perform any complicated tasks, go back to work on the day of your sedation.
  • After the sedation you may continue your acute and chronic medication as ordered by your doctor/ dentist.
  • Discuss post-sedation breastfeeding with your doctor/dentist.
  • You should not experience nausea or vomiting after sedation. If vomiting occurs more than once, please contact your doctor / dentist.
  • Do not eat or drink if you are nauseous. Introduce any fluids or foods slowly after sedation. If you tolerate clear fluids, you may then progress to solids. Do not consume any alcoholic drinks for the remainder of the day.
  • If you have not passed urine within 6–8 hours of being discharged, please contact the doctor / dentist at the telephone numbers provided.
  • The sedation may result in amnesia (loss of memory). This is temporary, sometimes lasting for a few hours.
  • We trust that the enclosed information will answer all your questions. However, please phone your anaesthesiologist or the practice if you are unsure about any information.