Anaesthesia, general Health Dictionary

Anaesthesia, General: From 1 Different Sources


Loss of sensation and consciousness induced to prevent the perception of pain throughout the body during surgery. General anaesthesia is usually induced by intravenous injection of a barbiturate drug and maintained by inhalation of anaesthetic gases such as halothane, which may be introduced into the lungs via an endotracheal tube. During the anaesthetic, the pulse, blood pressure, and other vital signs are continuously monitored.

General anaesthetics have become much safer, and serious complications are rare.

However, severe pre-existing diseases such as lung or heart disorders increase the risks.

Minor after effects such as nausea and vomiting are usually controlled effectively with antiemetic drugs.

Health Source: BMA Medical Dictionary
Author: The British Medical Association

Anaesthesia

The loss or absence of sensation or feeling. Commonly used to describe a reversible process which allows operations and painful or unpleasant procedures to be performed without distress to the patient.

The speciality of anaesthesia broadly covers its provision for SURGERY, intensive therapy (intensive care), chronic pain management, acute pain management and obstetric analgesia. Anaesthetists in Britain are trained specialists with a medical degree, but in many countries some anaesthetists may be nurse practitioners working under the supervision of a medical anaesthetist.

The anaesthetist will assess the patient’s ?tness for anaesthesia, choose and perform the appropriate type of anaesthetic while monitoring and caring for the patient’s well-being, and, after the anaesthetic, supervise recovery and the provision of post-operative pain relief.

Anaesthesia may be broadly divided into general and local anaesthesia. Quite commonly the two are combined to allow continued relief of pain at the operation site after the patient awakens.

General anaesthesia is most often produced by using a combination of drugs to induce a state of reversible UNCONSCIOUSNESS. ‘Balanced’ anaesthesia uses a combination of drugs to provide unconsciousness, analgesia, and a greater or lesser degree of muscle relaxation.

A general anaesthetic comprises induction, maintenance and recovery. Historically, anaesthesia has been divided into four stages (see below), but these are only clearly seen during induction and maintenance of anaesthesia using inhalational agents alone.

(1) Onset of induction to unconsciousness

(2) Stage of excitement

(3) Surgical anaesthesia

(4) Overdosage

Induction involves the initial production of unconsciousness. Most often this is by INTRAVENOUS injection of a short-acting anaesthetic agent such as PROPOFOL, THIOPENTONE or ETOMIDATE, often accompanied by additional drugs such as ANALGESICS to smooth the process. Alternatively an inhalational technique may be used.

Maintenance of anaesthesia may be provided by continuous or intermittent use of intravenous drugs, but is commonly provided by administration of OXYGEN and NITROUS OXIDE or air containing a volatile anaesthetic agent. Anaesthetic machines are capable of providing a constant concentration of these, and have fail-safe mechanisms and monitors which guard against the patient’s receiving a gas mixture with inadequate oxygen (see HYPOXIC). The gases are adminstered to the patient via a breathing circuit either through a mask, a laryngeal mask or via ENDOTRACHEAL INTUBATION. In recent years, concerns about side-effects and pollution caused by volatile agents have led to increased popularity of total intravenous anaesthesia (TIVA).

For some types of surgery the patient is paralysed using muscle relaxants and then arti?cially ventilated by machine (see VENTILATOR). Patients are closely monitored during anaesthesia by the anaesthetist using a variety of devices. Minimal monitoring includes ELECTROCARDIOGRAM (ECG), blood pressure, PULSE OXIMETRY, inspired oxygen and end-tidal carbon-dioxide concentration – the amount of carbon dioxide breathed out when the lungs are at the ‘empty’ stage of the breathing cycle. Analgesic drugs (pain relievers) and local or regional anaesthetic blocks are often given to supplement general anaesthesia.

Volatile anaesthetics are either halogenated hydrocarbons (see HALOTHANE) or halogenated ethers (iso?urane, en?urane, des?urane and sevo?urane). The latter two are the most recently introduced agents, and produce the most rapid induction and recovery – though on a worldwide basis halothane, ether and chloroform are still widely used.

Despite several theories, the mode of action of these agents is not fully understood. Their e?cacy is related to how well they dissolve into the LIPID substances in nerve cells, and it is thought that they act at more than one site within brain cells – probably at the cell membrane. By whatever method, they reversibly depress the conduction of impulses within the CENTRAL NERVOUS SYSTEM and thereby produce unconsciousness.

At the end of surgery any muscle relaxant still in the patient’s body is reversed, the volatile agent is turned o? and the patient breathes oxygen or oxygen-enriched air. This is the reversal or recovery phase of anaesthesia. Once the anaesthetist is satis?ed with the degree of recovery, patients are transferred to a recovery area within the operating-theatre complex where they are cared for by specialist sta?, under the supervision of an anaesthetist, until they are ready to return to the ward. (See also ARTIFICIAL VENTILATION OF THE LUNGS.) Local anaesthetics are drugs which reversibly block the conduction of impulses in nerves. They therefore produce anaesthesia (and muscle relaxation) only in those areas of the body served by the nerve(s) affected by these drugs. Many drugs have some local anaesthetic action but the drugs used speci?cally for this purpose are all amide or ester derivatives of aromatic acids. Variations in the basic structure produce drugs with di?erent speeds of onset, duration of action and preferential SENSORY rather than MOTOR blockade (stopping the activity in the sensory or motor nerves respectively).

The use of local rather than general anaesthesia will depend on the type of surgery and in some cases the unsuitability of the patient for general anaesthesia. It is also used to supplement general anaesthesia, relieve pain in labour (see under PREGNANCY AND LABOUR) and in the treatment of pain in persons not undergoing surgery. Several commonly used techniques are listed below:

LOCAL INFILTRATION An area of anaesthetised skin or tissue is produced by injecting local anaesthetic around it. This technique is used for removing small super?cial lesions or anaesthetising surgical incisions.

NERVE BLOCKS Local anaesthetic is injected close to a nerve or nerve plexus, often using a peripheral nerve stimulator to identify the correct point. The anaesthetic di?uses into the nerve, blocking it and producing anaesthesia in the area supplied by it.

SPINAL ANAESTHESIA Small volumes of local anaesthetic are injected into the cerebrospinal ?uid through a small-bore needle which has been inserted through the tissues of the back and the dura mater (the outer membrane surrounding the spinal cord). A dense motor and sensory blockade is produced in the lower half of the body. How high up in the body it reaches is dependent on the volume and dose of anaesthetic, the patient’s position and individual variation. If the block is too high, then respiratory-muscle paralysis and therefore respiratory arrest may occur. HYPOTENSION (low blood pressure) may occur because of peripheral vasodilation caused by sympathetic-nerve blockade. Occasionally spinal anaesthesia is complicated by a headache, perhaps caused by continuing leakage of cerebrospinal ?uid from the dural puncture point.

EPIDURAL ANAESTHESIA Spinal nerves are blocked in the epidural space with local anaesthetic injected through a ?ne plastic tube (catheter) which is introduced into the space using a special needle (Tuohy needle). It can be used as a continuous technique either by intermittent injections, an infusion or by patient-controlled pump. This makes it ideal for surgery in the lower part of the body, the relief of pain in labour and for post-operative analgesia. Complications include hypotension, spinal headache (less than 1:100), poor e?cacy, nerve damage (1:12,000) and spinal-cord compression from CLOT or ABSCESS (extremely rare).... anaesthesia

Epidural Anaesthesia

See ANAESTHESIA.... epidural anaesthesia

General Paralysis Of The Insane

An outdated term for the tertiary stage of SYPHILIS.... general paralysis of the insane

General Dental Council

A statutory body set up by the Dentists Act which maintains a register of dentists (see DENTAL SURGEON), promotes high standards of dental education, and oversees the professional conduct of dentists. Membership comprises elected and appointed dentists and appointed lay members. Like other councils responsible for registering health professionals, the General Dental Council now comes under the umbrella of the new Council for Regulatory Excellence, a statutory body. (See APPENDIX 7: STATUTORY ORGANISATIONS.)... general dental council

General Dental Services

See DENTAL SURGEON.... general dental services

General Practice

A form of practice in which medical practitioners provide a wide range of primary health care services to people.... general practice

Spinal Anaesthesia

See under ANAESTHESIA.... spinal anaesthesia

Generalized Anxiety Disorder

A psychiatric illness characterized by chronic and persistent apprehension and tension that has no particular focus. There may also be physical symptoms such as trembling, sweating, lightheadedness, and irritability. The condition can be treated with psychotherapy or with drugs such as beta blockers, sedatives or tranquillizers that relieve symptoms but do not treat the underlying condition.

(See anxiety; anxiety disorders.)... generalized anxiety disorder

General Hospital

A hospital providing a variety of services, including medicine and surgery, to meet the general medical needs of the community it serves.... general hospital

General Liability Insurance

Insurance which covers the risk of loss for most accidents and injuries to third parties (the insured and its employees are not covered) which arise from the actions or negligence of the insured, and for which the insured may have legal liability, except those injuries directly related to the provision of professional health care services (the latter risks are covered by professional liability insurance).... general liability insurance

General Medical Council (gmc)

A statutory body of elected and appointed medical practitioners and appointed lay members with the responsibility of protecting patients and guiding doctors in their professional practice. Set up by parliament in 1858 – at the request of the medical profession, which was concerned by the large numbers of untrained people practising as doctors – the GMC is responsible for setting educational and professional standards; maintaining a register of quali?ed practitioners; and disciplining doctors who fail to maintain appropriate professional standards, cautioning them or temporarily or permanently removing them from the Medical Register if they are judged un?t to practise.

The Council is funded by doctors’ annual fees and is responsible to the Privy Council. Substantial reforms of the GMC’s structure and functions have been and are still being undertaken to ensure that it operates e?ectively in today’s rapidly evolving medical and social environment. In particular, the Council has strengthened its supervisory and disciplinary functions, and among many changes has proposed the regular revalidation of doctors’ professional abilities on a periodic basis. The Medical Register, maintained by the GMC, is intended to enable the public to identify whom it is safe to approach to obtain medical services. Entry on the Register shows that the doctor holds a recognised primary medical quali?cation and is committed to upholding the profession’s values. Under revalidation requirements being ?nalised, in addition to holding an initial quali?cation, doctors wishing to stay on the Register will have to show their continuing ?tness to practise according to the professional attributes laid down by the GMC.

Once revalidation is fully established, there will be four categories of doctor:

Those on the Register who successfully show their ?tness to practise on a regular basis.

Those whose registration is limited, suspended or removed as a result of the Council’s disciplinary procedures.

Those who do not wish to stay on the Register or retain any links with the GMC.

Those, placed on a supplementary list, who do not wish to stay on the main Register but who want to retain a formal link with the medical profession through the Council. Such doctors will not be able to practise or prescribe.... general medical council (gmc)

General Optical Council

The statutory body that regulates the professions of ophthalmic OPTICIAN (optometrist) and dispensing optician. It promotes high standards of education and professional conduct and was set up by the Opticians Act 1958.... general optical council

Local Anaesthesia

Loss of sensation produced in a part of the body to stop pain while a person is examined, investigated or treated (see also ANAESTHESIA). The anaesthesia is e?ected by giving drugs in a local area temporarily to stop the action of pain-carrying nerve ?bres. To anaesthetise a large area, a nerve block is done. Various drugs are used, depending on the depth and length of local anaesthesia required.... local anaesthesia

Mainstream Housing / General Needs Housing

Housing not specifically designed for a particular user group.... mainstream housing / general needs housing

Regional Anaesthesia

See ANAESTHESIA – Local anaesthetics.... regional anaesthesia

Anaesthesia, Dental

Loss of sensation induced in a patient to prevent pain during dental treatment.

For minor procedures, a local anaesthetic (see anaesthesia, local) is injected either into the gum at the site being treated or into the nerve a short distance away (called a peripheral nerve block).

In addition, topical anaesthetics are often used on the gums.

For more complicated procedures, such as periodontal (gum) surgery and multiple tooth extractions, general anaesthesia is carried out (see anaesthesia, general).... anaesthesia, dental

They Generally Heal Without Treatment Child Abuse

The maltreatment of children.

Child abuse may take the form of physical injury, sexual abuse, emotional mistreatment, and/or neglect; it occurs at all levels of society.

Being deprived or ill-treated in childhood may predispose people to repeat the pattern of abuse with their own children.

Children who are abused or at risk of abuse may be placed in care while the health and social services decide on the best course of action.... they generally heal without treatment child abuse

General Practitioner (gp)

A general practitioner (‘family doctor’; ‘family practitioner’) is a doctor working in primary care, acting as the ?rst port of professional contact for most patients in the NHS. There are approximately 35,000 GPs in the UK and their services are accessed by registering with a GP practice – usually called a surgery or health centre. Patients should be able to see a GP within 48 hours, and practices have systems to try to ensure that urgent problems are dealt with immediately. GPs generally have few diagnostic or treatment facilities themselves, but can use local hospital diagnostic services (X-rays, blood analysis, etc.) and can refer or admit their patients to hospital, where they come under the supervision of a CONSULTANT. GPs can prescribe nearly all available medicines directly to their patients, so that they treat 90 per cent of illnesses without involving specialist or hospital services.

Most GPs work in groups of self-employed individuals, who contract their services to the local Primary Care Trust (PCT) – see below. Those in full partnership are called principals, but an increasing number now work as non-principals – that is, they are employees rather than partners in a practice. Alternatively, they might be salaried employees of a PCT. The average number of patients looked after by a full-time GP is 1,800 and the average duration of consultation about 10 minutes. GPs need to be able to deal with all common medical conditions and be able to recognise conditions that require specialist help, especially those requiring urgent action.

Until the new General Medical Services Contract was introduced in 2004, GPs had to take individual responsibility for providing ‘all necessary medical services’ at all times to their patient list. Now, practices rather than individuals share this responsibility. Moreover, the contract now applies only to the hours between

8.00 a.m. and 6.30 p.m., Mondays to Fridays; out-of-hours primary care has become the responsibility of PCTs. GPs still have an obligation to visit patients at home on weekdays in case of medical need, but home-visiting as a proportion of GP work has declined steadily since the NHS began. By contrast, the amount of time spent attending to preventive care and organisational issues has steadily increased. The 2004 contract for the ?rst time introduced payment for speci?c indicators of good clinical care in a limited range of conditions.

A telephone advice service, NHS Direct, was launched in 2000 to give an opportunity for patients to ‘consult’ a trained nurse who guides the caller on whether the symptoms indicate that self-care, a visit to a GP or a hospital Accident & Emergency department, or an ambulance callout is required. The aim of this service is to give the patient prompt advice and to reduce misuse of the skills of GPs, ambulance sta? and hospital facilities.

Training of GPs Training for NHS general practice after quali?cation and registration as a doctor requires a minimum of two years’ post-registration work in hospital jobs covering a variety of areas, including PAEDIATRICS, OBSTETRICS, care of the elderly and PSYCHIATRY. This is followed by a year or more working as a ‘registrar’ in general practice. This ?nal year exposes registrars to life as a GP, where they start to look after their own patients, while still closely supervised by a GP who has him- or herself been trained in educational techniques. Successful completion of ‘summative assessment’ – regular assessments during training – quali?es registrars to become GPs in their own right, and many newly quali?ed GPs also sit the membership exam set by the Royal College of General Practitioners (see APPENDIX 8: PROFESSIONAL ORGANISATIONS).

A growing number of GP practices o?er educational attachments to medical students. These attachments provide experience of the range of medical and social problems commonly found in the community, while also o?ering them allocated time to learn clinical skills away from the more specialist environment of the hospital.

In addition to teaching commitments, many GPs are also choosing to spend one or two sessions away from their practices each week, doing other kinds of work. Most will work in, for example, at least one of the following: a hospital specialist clinic; a hospice; occupational medicine (see under OCCUPATIONAL HEALTH, MEDICINE AND DISEASES); family-planning clinics; the police or prison services. Some also become involved in medical administration, representative medicopolitics or journalism. To help them keep up to date with advances and changes in medicine, GPs are required to produce personal-development plans that outline any educational activities they have completed or intend to pursue during the forthcoming year.

NHS GPs are allowed to see private patients, though this activity is not widespread (see PRIVATE HEALTH CARE).

Primary Care Trusts (PCTs) Groups of GPs (whether working alone, or in partnership with others) are now obliged by the NHS to link communally with a number of other GPs in the locality, to form Primary Care Trusts (PCTs). Most have a membership of about 30 GPs, working within a de?ned geographical area, in addition to the community nurses and practice counsellors working in the same area; links are also made to local council social services so that health and social needs are addressed together. Some PCTs also run ambulance services.

One of the roles of PCTs is to develop primary-care services that are appropriate to the needs of the local population, while also occupying a powerful position to in?uence the scope and quality of secondary-care services. They are also designed to ensure equity of resources between di?erent GP surgeries, so that all patients living in the locality have access to a high quality and uniform standard of service.

One way in which this is beginning to happen is through the introduction of more overt CLINICAL GOVERNANCE. PCTs devise and help their member practices to conduct CLINICAL AUDIT programmes and also encourage them to participate in prescribing incentive schemes. In return, practices receive payment for this work, and the funds are used to improve the services they o?er their patients.... general practitioner (gp)

Acute Generalized Exanthematous Pustulosis

(toxic pustuloderma) a reaction to a medication, resulting in the appearance of fine sterile *pustules on inflamed skin; the pustules may easily be overlooked. Common causes include penicillins, and pustular psoriasis must be excluded from the diagnosis.... acute generalized exanthematous pustulosis

Diet - General

It is sometimes not possible to achieve worthwhile results from herbal medicine without due regard to the quality and type of food that enters the body. Suggested foods are those which experience has shown to assist recovery and conserve body energies that might otherwise be diverted towards elimination of metabolic wastes.

“A good and proper diet in disease is worth a hundred medicines and no amount of medication can do good to a patient who does not observe a strict regimen of diet.” (Charaka Samhita 300AD)

A healthy diet helps maintain the immune system, builds up reserves and hastens recovery from illness.

A good general diet includes foods low in fat, salt and high in fibre. All white sugar and white sugar products (chocolates, sweets, etc) should be replaced with natural sugars (honey, dates, figs, molasses, raisins etc). It should contain plenty of raw fresh fruit and vegetables; best prepared in a juice-press.

Vegetables should be conservatively cooked in very little water with little salt in a covered vessel. At least one mixed raw vegetable salad should be taken daily. Bread can be replaced by jacket potato, Soya- bean flour products or ripe bananas. Puddings, pastry and suety meals should be avoided.

Lean meat should be restricted to two or three parts a week with liberal inclusion of oily fish. Tofu, a Soya bean product, is an excellent alternative to meat. Three or four eggs, only, should be taken weekly.

Dairy produce (milk, butter, cream) contain cholesterol which thickens the blood, blocks arteries and increases resistance against the heart and major blood vessels, and should be taken sparingly.

Accept: Garlic, Onions, Lecithin, Muesli or Oatmeal porridge for breakfast or at other times during the day, yoghurt, honey.

Reject: fried foods, biscuits, confectionery.

Salt: replace with powdered Garlic, Celery or Kelp.

Alcohol: replace with fresh fruit or raw vegetable juices. Coffee is a risk factor raising cholesterol concentration; Dandelion coffee, Rutin or any one of many herbal teas available offer alternatives.

Avoid over-eating and meals when tired. Foods should be well masticated without liquid drinks; dry- feed. Plenty of liquid drinks, water etc should be taken between meals.

Supplements: Vitamin C 200mg, Vitamin E 200iu, morning and evening. Evening Primrose oil. Efamol produce a combined Evening Primrose and Fish oil capsule.

Dietary fibre can prevent certain colonic diseases. Treatment of disease by diet is preferred to drugs because it has the advantage of being free from side-effects. ... diet - general

Neuralgia, General

 Pain along a nerve, i.e. pain in the shoulders from pressure on a spinal nerve serving the neck.

Alternatives. Black Cohosh, Cactus, Chamomile, Lady’s Slipper, Ginseng, Hops, Jamaica Dogwood, White Willow, Wild Lettuce, Valerian.

Chamomile tea (mild analgesic).

Tablets/capsules. Any of the above.

Formula. Ginseng 4; Black Cohosh 2; Skullcap 2; Mistletoe 1; Motherwort 1. Dose: Liquid Extracts: 1 teaspoon. Tinctures: 2 teaspoons. Powders: 500mg (two 00 capsules or one-third teaspoon). Thrice daily. Children: see: DOSAGE. Cayenne pepper (Capsicum) sometimes successful.

Topical. Poultice: Chamomile, Hops, Linseed or Bran. Acute cases (cold), chronic cases (hot). Grated or bruised Horseradish root. Evening Primrose oil. Hot Cider vinegar, Tincture Arnica or Hypericum. Aromatherapy. 2 drops each: Juniper, Lavender, Chamomile to 2 teaspoons vegetable oil. Light massage. Diet. High protein. Calcium-rich foods.

Supplements. Vitamin B-complex, B6, B12, Niacin, Magnesium, Dolomite, Zinc.

See: FACIAL and INTERCOSTAL NEURALGIA; DYSMENORRHOEA (neuralgia of the womb). ANTISPASMODICS. ... neuralgia, general

Anaesthesia, Local

Loss of sensation induced in a limited region of the body to prevent pain during examinations, diagnostic or treatment procedures, and surgical operations. Local anaesthesia is produced by the administration of drugs that temporarily interrupt the action of pain-carrying nerve fibres.

Local anaesthetics applied topically before injections or blood tests include sprays and skin creams and ointments.

These are often used for children.

For minor surgical procedures, such as stitching of small wounds, local anaesthesia is usually produced by direct injection into the area to be treated.

To anaesthetize a large area, or when local injection would not penetrate deeply enough into body tissues, a nerve block may be used.

Nerves can also be blocked where they branch off from the spinal cord, as in epidural anaesthesia, which is widely used in childbirth, and spinal anaesthesia, which is used for surgery on the lower limbs and abdomen.

Serious reactions to local anaesthetics are uncommon.

Repeated use of topical preparations may cause allergic rashes.... anaesthesia, local

General Health Questionnaire

(GHQ) a reliable screening tool published in 1978 for identifying minor psychiatric disorders, still frequently used for research in the general population. The 28-question version (GHQ28) is most commonly used, but the GHQ is available in lengths from 12 to 60 questions.... general health questionnaire

General Household Survey

a rolling survey carried out annually (1971–2007) in Great Britain by the *Office for National Statistics. It included questions about the household and questions to be completed by all individuals aged over 16 within the household. It covered a wide variety of topics, such as health, employment, pensions, education, and income. It was succeeded (2007–12) by the general lifestyle survey. See also census.... general household survey

Generalized Anxiety Disorder Questionnaire

see GAD-7.

/// ... generalized anxiety disorder questionnaire

General Practitioner With Special Interest

(GPwSI, GPSI) see general practitioner.... general practitioner with special interest

General Medical Council

(GMC) the regulatory body of the medical profession in the UK, which was established in 1858 by the Medical Act and has statutory powers. It licenses doctors to practise medicine and has the power to revoke licences or place restrictions on practice. The governing body of the GMC, its Council, comprises 12 members, 6 of which are medically qualified and 6 of which are not. Its purpose is to protect, promote, and maintain the health and safety of the public by ensuring proper standards in the practice of medicine and medical education and training. Following various high-profile cases involving malpractice, there has been a shift in the role of the GMC from one of simple registration to that of *revalidation of doctors.

GMC website: includes the Council’s guide to Good Medical Practice... general medical council

General Practitioner

(GP) a doctor working in the community who provides family health services to a local area. General practitioners (also known as family doctors or family practitioners) may work on their own or in a group practice in which they share premises and other resources with one or more other doctors. GPs are usually the first port of call for most patients with concerns about their health. They look after patients with wide-ranging medical conditions and can refer patients with more complex problems to specialists, such as hospital consultants. Some GPs with additional training and experience in a specific clinical area take referrals for assessment and treatment that may otherwise have been referred directly to hospital consultants; these are known as GPs with a special interest (GPwSI or GPSI). Most GPs work solely within the *National Health Service but a few work completely privately. The current model of general practice allows for GPs to provide general medical services (GMS), the terms and conditions of which are governed by a national contract which is usually negotiated on an annual basis, or personal medical services (PMS), the terms and conditions of which are governed by locally negotiated contracts within a broad framework. The new primary care contract (nGMS contract) came into force in April 2004, allowing GPs to opt out of weekend and night (*out-of-hours) service provision for patients registered with their practice. In this period, patient care is usually provided by an out-of-hours cooperative or deputizing service. At the same time the government also introduced the *Quality and Outcomes Framework (QOF) as a means to improve the quality of care provided. Most GPs are *independent contractors although more recently there has been an increase in the number of salaried GPs. GPs may employ a variety of staff, including *practice nurses, *nurse practitioners, and counsellors.... general practitioner



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