Anaesthetics for local or general surgery

Following surgery many become confused. ICU psychosis is a term commonly used by Healthcare Professionals. Several papers can be found discussing this. However we need to make family members aware a sudden onset of psychosis can emerge some days after the surgery, following discharge from hospital.

Intrusive memories of hallucinations and delusions in traumatized intensive care patients - interview study.


The Royal College of Anaesthetists produced a pamplet  'Becoming confused after an operation' as one of a series of booklets for patients 'Risks associated with your anaesthetic'

More information about confusion


A UK study of Adverse Drug Reactions in Children (ADRIC) found the following in regard to anaesthesia and drugs used around surgery:

The most surprising findings were from the study of ADRs in hospital. First, we found that the incidence of ADRs in children is much greater than in adults.

We also observed that the risk of experiencing an ADR was increased over six times in children who had a general anaesthetic during their admission and over half of the drugs implicated in all ADRs were used either perianaesthetic or post anaesthetic.

These drug groups have been under-represented in previous studies and our findings have important implications for all clinicians concerned with the perioperative and postoperative management of children, in particular in view of the recent moves to ambulatory surgery in the UK and elsewhere.


  • IMPORTANT -  Check the Liver and kidney function of patients suffering psychiatric disturbance following surgery.

An anaesthetic drug that brings about a reversible loss of consciousness. These drugs are generally administered by an anesthesia provider in order to induce or maintain general anaesthesia to facilitate surgery 

Drugs given to induce or maintain general anaesthesia are either given as:

  • Gases or vapors (inhalational anaesthetics)
  • Injections (intravenous anaesthetics)

Inhalational anaesthetic substances are either volatile liquids or gases and are usually delivered using an anaesthesia machine. An anaesthesia machine allows composing a mixture of oxygen, anaesthetics and ambient air, delivering it to the patient and monitoring patient and machine parameters. Liquid anaesthetics are vaporized in the machine.

Many compounds have been used for inhalation anaesthesia, but only a few are still in widespread use. Desflurane, isoflurane and sevoflurane are the most widely used volatile anaesthetics today. They are often combined with nitrous oxide. Older, less popular, volatile anesthetics, include halothane, enflurane, and methoxyflurane. Researchers are also actively exploring the use of xenon as an anaesthetic.

Injection anaesthetics are used for induction and maintenance of a state of unconsciousness. Anaesthetists prefer to use intravenous injections as they are faster, generally less painful and more reliable than intramuscular or subcutaneous injections. Among the most widely used drugs are:

  • Propofol
  • Etomidate
  • Barbiturates such as methohexital and thiopentone/thiopental
  • Benzodiazepines such as midazolam and diazepam
  • Ketamine is used in the UK as "field anaesthesia", for instance at a road traffic incident, and is more frequently used in the operative setting in the US.


Where can we find the required information to enable us to make informed choices?

Decisions by patients to go ahead with, as in this case, unnecessary surgery, or where a local anaesthetic would be an alternative, should be made on the basis of informed choice.

Research is needed to ascertain which drugs are less likely to cause problems for mentally vulnerable patients of all ages.

This is a matter of utmost urgency. There is too little attention paid to this problem, by the colleges, conferences and professionals involved in anaesthesia.

Warning to patients taking trycyclic antidepressants:

There is a higher risk of side effects from the drugs used during surgery or dental or emergency treatments, so the doctors must be informed that you are taking this medicine.

Related links and information
Anaesthetic's effect on women

Adverse effects of anaesthetics

Reporting Adverse Drug Reactions (ADRs)

It is well known that serious side effects of medicines are under reported and the UK regulatory body the Medicines and Healthcare Regulatory Agency (MHRA) estimate less than 10% of serious ADRs are reported.

If you are, for no apparent reason, feeling mentally distressed, it may be caused by starting or stopping medication, due to a changed dose, withdrawal effects, interactions with other drugs, or following surgery. You can request a list of drugs used pre surgery and during surgery and those for pain or infection to be taken later.

Some drugs must not be stopped suddenly

If you have suffered psychiatric, neurological or physical adverse drug reactions (ADRs) please report them. There may be adverse effects not mentioned on the patient leaflets (PILs) or data sheets. (SPCs)

You should be given a patient information leaflet (PIL) for all drugs prescribed, either as you are discharged from hospital, or if the pharmacy supplies you from a bulk supply of pills. (EU Directive 1997)

Please report Adverse Drug Reactions (ADRs) to:

UK - Yellow Card Reporting for Patient and Health Professional reports of Adverse Drug Reactions you can report to the MHRA using the link above or call them 0808 100 3352 10am - 2pm Monday to Friday

USA and worldwide - to the Food and Drug Administration for Patients and Healthcare Professionals

Universal free, independent drug safety website - Rxisk


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