Surgery Guide

Anesthesia technicians are specially trained biomedical technicians who assist anesthesiologists, nurse anesthetists, and anesthesiologist assistants with monitoring equipment, supplies, and patient care procedures in the operating room. * Anesthesia Technician

In New Zealand, anaesthetic technicians complete a course of study recognized by the New Zealand Association of Anaesthetic Technicians and Nurses.

In the United Kingdom, personnel known as ODPs (Operating Department Practitioners) or anaesthetic nurses provide support to the physician anaesthetist (anaesthesiologist). They can also assist with Surgical procedures alongside the Surgeon and provide Post-Operative Care to patients emerging from Anaesthesia. ODPs can be found in the Operating Department, Accident and Emergency (providing advanced airway assistance), Intensive Care Unit, High Dependancy Unit and for specialist MRI scanners which require Anaesthetic cover.

In the US, anesthesiologist assistants (AAs) are graduate-level trained specialists who have undertaken specialized education and training to provide anesthesia care under the direction of an Anesthesiologist. AAs typically hold a masters degree and practice under Anesthesiologist supervision in 18 states through licensing, certification or physician delegation.[17]

In the UK, a similar group of assistants are currently being evaluated. They are named Physician’s Assistant (Anaesthesia) (PAAs). Their background can be nursing, Operating Department Practice or another profession allied to medicine or a science graduate. Training is in the form of a post-graduate diploma and takes 27 months to complete. Once finished, a masters degree can be undertaken.

In the United States, advance practice nurses specializing in the provision of anesthesia care are known as Certified Registered Nurse Anesthetists (CRNAs). According to the American Association of Nurse Anesthetists, the 36,000 CRNAs in the US administer approximately 27 million anesthetics each year, roughly two thirds of the US total.[14] Thirty-four percent of nurse anesthetists practice in communities of less than 50,000. CRNAs start school with a bachelors degree and at least 1 year of acute care nursing experience,[15] and gain a masters degree in nurse anesthesia before passing the mandatory Certification Exam. Masters-level CRNA training programs range in length from 27 to 36 months.

CRNAs may work with podiatrists, dentists, anesthesiologists, surgeons, obstetricians and other professionals requiring their services. CRNAs administer anesthesia in all types of surgical cases, and are able to apply all the accepted anesthetic techniques – general, regional, local, or sedation. CRNAs do not require Anesthesiologist supervision in any state and only require surgeon/dentist/podiatrists to sign the chart for medicare billing in all but 16 states.[16]

In the US, medical doctors who specialize in anesthesiology are called anesthesiologists, and dentists who specialize in anesthesiology are called dental anesthesiologists. Such physicians in the UK, Canada and Australia are called anaesthetists or anaesthesiologists.

In the US, a physician specializing in anesthesiology completes 4 years of college, 4 years of medical school, 1 year of internship, and 3 years of residency. According to the American Society of Anesthesiologists, anesthesiologists provide or participate in more than 90 percent of the 40 million anesthetics delivered annually.[12]

In the UK, this training lasts a minimum of seven years after the awarding of a medical degree and two years of basic residency, and takes place under the supervision of the Royal College of Anaesthetists. In Australia and New Zealand, it lasts five years after the awarding of a medical degree and two years of basic residency, under the supervision of the Australian and New Zealand College of Anaesthetists. Other countries have similar systems, including Ireland (the Faculty of Anaesthetists of the Royal College of Surgeons in Ireland), Canada and South Africa (the College of Anaesthetists of South Africa).

In the UK, Fellowship of the Royal College of Anaesthetists (FRCA), is conferred upon medical doctors following completion of the written and oral parts of the Royal College’s examination. In the US, completion of the written and oral Board examinations by a physician anesthesiologist allows one to be called “Board Certified” or a “Diplomate” of the American Board of Anesthesiology (or of the American Osteopathic Board of Anesthesiology, for osteopathic physicians).

Other specialties within medicine are closely affiliated to anaesthetics. These include intensive care medicine and pain medicine. Specialists in these disciplines have usually done some training in anaesthetics. The role of the anaesthetist is changing. It is no longer limited to the operation itself. Many anaesthetists perform well as peri-operative physicians, and will involve themselves in optimizing the patient’s health before surgery (colloquially called “work-up”), performing the anaesthetic,including specialized intraoperative monitoring (like[13] transesophageal echocardiography), following up the patient in the post anesthesia care unit and post-operative wards, and ensuring optimal analgesia throughout.

It is important to note that the term anesthetist in the United States usually refers to registered nurses who have completed specialized education and training in nurse anesthesia to become certified registered nurse anesthetists (CRNAs). As noted above, the term anaesthetist in the UK and Canada refers to medical doctors who specialize in anesthesiology.

Physicians specialising in peri-operative care, development of an anesthetic plan, and the administration of anesthetics are known in the United States as anesthesiologists and in the UK and Canada as anaesthetists or anaesthesiologists. All anaesthetics in the UK, Australia, New Zealand and Japan are administered by physicians. Nurse anesthetists also administer anesthesia in 109 nations.[6] In the US, 35% of anesthetics are provided by physicians in solo practice, about 55% are provided by ACTs with anesthesiologists medically directing Anesthesiologist Assistants or CRNAs, and about 10% are provided by CRNAs in solo practice.[7][8][9] -[10] -[11]

The first effective local anesthetic was cocaine. Isolated in 1859, it was first used by Carl Koller, at the suggestion of Sigmund Freud, in ophthalmic surgery in 1884. Before that doctors had used a salt and ice mix for the numbing effects of cold, which could only have limited application. Similar numbing was also induced by a spray of ether or ethyl chloride. A number of cocaine derivatives and safer replacements were soon produced, including procaine (1905), Eucaine (1900), Stovaine (1904), and lidocaine (1943).

Opioids were first used by Racoviceanu-Piteşti, who reported his work in 1901.

The works of Greek authors such as Dioscorides were well-known among physicians in the Islamic Empire, and Arab and Persian physicians such as Muhammad ibn Zakarīya Rāzi (Rhazes), Avicenna (Ibn Sina) and Abu al-Qasim al-Zahrawi wrote medical textbooks of great importance in the development of medicine in Europe and the Middle East. Arabic and Iranian anesthesiologists were the first to utilize oral as well as inhalant anesthetics. In Islamic Spain, Abulcasis and Ibn Zuhr (Avenzoar), among other Muslim surgeons, performed hundreds of surgeries under inhalant anesthesia with the use of narcotic-soaked sponges. Abulcasis and Avicenna wrote about anesthesia in their influential medical encyclopaedias, the Al-Tasrif and The Canon of Medicine.[4][5] These were the precursors to the true narcotic derivatives, now known as general anesthesia or general anesthetics, which were not produced until Dr. Janssen developed narcotics, except morphine, in the past 50 years.

Contemporary re-enactment of Morton’s October 16, 1846, ether operation; daguerrotype by Southworth & Hawes.

In the West, the development of effective anesthetics in the 19th century was, with Listerian techniques, one of the keys to successful surgery. Henry Hill Hickman experimented with carbon dioxide in the 1820s. The anesthetic qualities of nitrous oxide (isolated in 1773 by Joseph Priestley) were discovered by the British chemist Humphry Davy about 1799 when he was an assistant to Thomas Beddoes, and reported in a paper in 1800. But initially the medical uses of this so-called “laughing gas” were limited — its main role was in entertainment. It was used on 30 September 1846 for painless tooth extraction upon patient Eben Frost by American dentist William Thomas Green Morton. Horace Wells of Connecticut, a traveling dentist, had demonstrated it the previous year 1845 at Massachusetts General Hospital. Wells made a mistake in choosing a particularly sturdy male volunteer, and the patient suffered considerable pain. This lost the colorful Wells any support. Later the patient told Wells he screamed in shock and not in pain. A subsequently drunk Wells died in jail, by cutting his femoral artery, after allegedly assaulting a prostitute with sulfuric acid.

Another dentist, William E. Clarke, performed an extraction in January 1842 using a different chemical, diethyl ether (discovered by Valerius Cordus in 1540). In March 1842 in Danielsville, Georgia, Dr. Crawford Long was the first to use anaesthesia during an operation, giving it to his friend, who was also a school teacher (James M. Venable) before excising a cyst from his neck. Long got the idea to do this from his observations at ether frolics. He noted that participants experienced bumps and bruises but afterward had no recall of what had happened. He did not publicize this information until 1849.

On October 16, 1846, dentist William Thomas Green Morton, invited to the Massachusetts General Hospital, performed the first public demonstration of diethyl ether (then called sulfuric ether) as an anesthetic agent, for a patient (Edward Gilbert Abbott) undergoing an excision of a vascular tumor from his neck. In a letter to Morton shortly thereafter, Oliver Wendell Holmes, Sr. proposed naming the procedure anæsthesia.

Anesthesia pioneer Crawford W. Long

Despite Morton’s efforts to keep “his” compound a secret, which he named “Letheon” and for which he received a US patent, the news of the discovery and the nature of the compound spread very quickly to Europe in late 1846. Here, respected surgeons—including Liston, Dieffenbach, Pirogoff, and Syme—undertook numerous operations with ether. An American-born physician, Boott—who had traveled to London—encouraged a leading dentist, Mr James Robinson, to perform a dental procedure on a Miss Lonsdale. This was the first case of an operator-anesthetist. On the same day, 19 December 1846 in Dumfries Royal Infirmary, Scotland, a Dr. Scott used ether for a surgical procedure. The first use of anesthesia in the Southern Hemisphere took place in Launceston, Tasmania, that same year. Ether has a number of drawbacks, such as its tendency to induce vomiting and its flammability. In England it was quickly replaced with chloroform.

Discovered in 1831, the use of chloroform in anesthesia is usually linked to James Young Simpson, who, in a wide-ranging study of organic compounds, found chloroform’s efficacy on 4 November 1847. Its use spread quickly and gained royal approval in 1853 when John Snow gave it to Queen Victoria during the birth of Prince Leopold. Unfortunately, chloroform is not as safe an agent as ether, especially when administered by an untrained practitioner (medical students, nurses, and occasionally members of the public were often pressed into giving anesthetics at this time). This led to many deaths from the use of chloroform that (with hindsight) might have been preventable. The first fatality directly attributed to chloroform anesthesia (Hannah Greener) was recorded on 28 January 1848.

John Snow of London published articles from May 1848 onwards ‘On Narcotism by the Inhalation of Vapours’ in the London Medical Gazette. Snow also involved himself in the production of equipment needed for inhalational anesthesia.

The surgical amphitheatre at Massachusetts General Hospital, or “ether dome,” still exists today, although it is used for lectures and not surgery. The public can visit the amphitheater on weekdays when it is not in use.

Hypnotism have a long history of use as anesthetic techniques. I Chilling tissue (e.g. with ice) can temporarily cause nerve fibers (axons) to stop conducting sensation, while hyperventilation can cause brief alteration in conscious perception of stimuli including pain (see Lamaze).

In modern anesthetic practice, these techniques are seldom employed.

Herbal derivatives

The first anesthesia (a herbal remedy) was administered in prehistory. Opium poppy capsules were collected in 4200 BC, and opium poppies were farmed in Sumeria and succeeding empires. The use of opium-like preparations in anaesthesia is recorded in the Ebers Papyrus of 1500 BC. By 1100 BC poppies were scored for opium collection in Cyprus by methods similar to those used in the present day, and simple apparatus for smoking of opium were found in a Minoan temple. Opium was not introduced to India and China until 330 BC and 600–1200 AD respectively, but these nations pioneered the use of cannabis incense and aconitum. In the second century, according to the Book of Later Han, the physician Hua Tuo performed abdominal surgery using an anesthetic substance called mafeisan (麻沸散 “cannabis boil powder”) dissolved in wine. Throughout Europe, Asia, and the Americas a variety of Solanum species containing potent tropane alkaloids were used, such as mandrake, henbane, Datura metel, and Datura inoxia. Classic Greek and Roman medical texts by Hippocrates, Theophrastus, Aulus Cornelius Celsus, Pedanius Dioscorides, and Pliny the Elder discussed the use of opium and Solanum species. In 13th century Italy Theodoric Borgognoni used similar mixtures along with opiates to induce unconsciousness, and treatment with the combined alkaloids proved a mainstay of anaesthesia until the nineteenth century. In the Americas coca was also an important anaesthetic used in trephining operations. Incan shamans chewed coca leaves and performed operations on the skull while spitting into the wounds they had inflicted to anaesthetize the site.[citation needed] Alcohol was also used, its vasodilatory properties being unknown. Ancient herbal anaesthetics have variously been called soporifics, anodynes, and narcotics, depending on whether the emphasis is on producing unconsciousness or relieving pain.

In the famous 10th century Persian work, the Shahnameh, the author, Ferdowsi, describes a caesarean section performed on Rudabeh when giving birth, in which a special wine agent was prepared as an anesthetic[2] by a Zoroastrian priest in Persia, and used to produce unconsciousness for the operation. Although largely mythical in content, the passage does at least illustrate knowledge of anesthesia in ancient Persia.

The use of herbal anaesthesia had a crucial drawback compared to modern practice — as lamented by Fallopius, “When soporifics are weak, they are useless, and when strong, they kill.” To overcome this, production was typically standardized as much as feasible, with production occurring from specific famous locations (such as opium from the fields of Thebes in ancient Egypt). Anaesthetics were sometimes administered in the spongia somnifera, a sponge into which a large quantity of drug was allowed to dry, from which a saturated solution could be trickled into the nose of the patient. At least in more recent centuries, trade was often highly standardized, with the drying and packing of opium in standard chests, for example. In the 19th century, varying aconitum alkaloids from a variety of species were standardized by testing with guinea pigs. Despite these refinements, the discovery of morphine, a purified alkaloid that soon afterward could be injected by hypodermic for a consistent dosage, was enthusiastically received and led to the foundation of the modern pharmaceutical industry.

Another factor affecting ancient anaesthesia is that drugs used systemically in modern times were often administered locally, reducing the risk to the patient. Opium used directly in a wound acts on peripheral opioid receptors to serve as an analgesic[citation needed], and a medicine containing willow leaves (salicylate, the predecessor of aspirin) would then be applied directly to the source of inflammation[citation needed].

In 1804, the Japanese surgeon Seishū Hanaoka performed general anaesthesia for the operation of a breast cancer (mastectomy), by combining Chinese herbal medicine know-how and Western surgery techniques learned through “Rangaku”, or “Dutch studies”. His patient was a 60-year-old woman named Kan Aiya.[3] He used a compound he called Tsusensan, based on the plants Datura metel, Aconitum and others.

Anesthesia, or anaesthesia (see spelling differences; from Greek αν-, an-, “without”; and αἲσθησις, aisthēsis, “sensation”), has traditionally meant the condition of having sensation (including the feeling of pain) blocked or temporarily taken away. This allows patients to undergo surgery and other procedures without the distress and pain they would otherwise experience. The word was coined by Oliver Wendell Holmes, Sr. in 1846. Another definition is a “reversible lack of awareness”, whether this is a total lack of awareness (e.g. a general anaesthestic) or a lack of awareness of a part of the body such as a spinal anaesthetic or another nerve block would cause. Anesthesia differs from analgesia in blocking all sensation, not only pain.

Today, the term general anesthesia in its most general form can include:[citation needed]
Analgesia: blocking the conscious sensation of pain;
Hypnosis: produces analgesia, even while wide awake;
Amnesia: preventing memory formation;
Relaxation: preventing unwanted movement or muscle tone;
Obtundation of reflexes, preventing exaggerated autonomic reflexes.

Patients undergoing anesthesia usually undergo preoperative evaluation. It includes gathering history of previous anesthetics, and any other medical problems, physical examination, ordering required blood work and consultations prior to surgery.

There are several forms of anesthesia. The following forms refer to states achieved by anesthetics working on the brain:
General anesthesia: “Drug-induced loss of consciousness during which patients are not arousable, even by painful stimulation.” Patients undergoing general anesthesia can often neither maintain their own airway nor breathe on their own. While usually administered with inhalational agents, general anesthesia can be achieved with intravenous agents, such as propofol.[1]
Deep sedation/analgesia: “Drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully following repeated or painful stimulation.” Patients may sometimes be unable to maintain their airway and breathe on their own.[1]
Moderate sedation/analgesia or conscious sedation: “Drug-induced depression of consciousness during which patients respond purposefully to verbal commands, either alone or accompanied by light tactile stimulation.” In this state, patients can breathe on their own and need no help maintaining an airway.[1]
Minimal sedation or anxiolysis[citation needed]: “Drug-induced state during which patients respond normally to verbal commands.” Though concentration, memory, and coordination may be impaired, patients need no help breathing or maintaining an airway.[1]

The level of anesthesia achieved ranges on a continuum of depth of consciousness from minimal sedation to general anesthesia. The depth of consciousness of a patient may change from one minute to the next.

The following refer to the states achieved by anesthetics working outside of the brain:
Regional anesthesia: Loss of pain sensation, with varying degrees of muscle relaxation, in certain regions of the body. Administered with local anesthesia to peripheral nerve bundles, such as the brachial plexus in the neck. Examples include the interscalene block for shoulder surgery, axillary block for wrist surgery, and femoral nerve block for leg surgery. While traditionally administered as a single injection, newer techniques involve placement of indwelling catheters for continuous or intermittent administration of local anesthetics.
Spinal anesthesia: also known as subarachnoid block. Refers to a Regional block resulting from a small volume of local anesthetics being injected into the spinal canal. The spinal canal is covered by the dura mater, through which the spinal needle enters. The spinal canal contains cerebrospinal fluid and the spinal cord. The sub arachnoid block is usually injected between the 4th and 5th lumbar vertebrae, because the spinal cord usually stops at the 1st lumbar vertebra, while the canal continues to the sacral vertebrae. It results in a loss of pain sensation and muscle strength, usually up to the level of the chest (nipple line or 4th thoracic dermatome).
Epidural anesthesia: Regional block resulting from an injection of a large volume of local anesthetic into the epidural space. The epidural space is a potential space that lies underneath the ligamenta flava, and outside the dura mater (outside layer of the spinal canal). This is basically an injection around the spinal canal.
Local anesthesia is similar to regional anesthesia, but exerts its effect on a smaller area of the body.