Anesthesiology
Anesthesiology, anaesthesiology or anaesthesia is the medical specialty concerned with the total perioperative care of patients before, during and after surgery. It encompasses anesthesia, intensive care medicine, critical emergency medicine, and pain medicine. A physician specialized in anesthesiology is called an anesthesiologist, anaesthesiologist, or anaesthetist, [|depending on the country]. In some countries, the terms are synonymous, while in other countries, they refer to different positions and anesthetist is only used for non-physicians, such as nurse anesthetists.
The core element of the specialty is the prevention and mitigation of pain and distress using various anesthetic agents, as well as the monitoring and maintenance of a patient's vital functions throughout the perioperative period. Since the 19th century, anesthesiology has developed from an experimental area with non-specialist practitioners using novel, untested drugs and techniques into what is now a highly refined, safe and effective field of medicine. In some countries anesthesiologists comprise the largest single cohort of doctors in hospitals, and their role can extend far beyond the traditional role of anesthesia care in the operating room, including fields such as providing pre-hospital emergency medicine, running intensive care units, transporting critically ill patients between facilities, management of hospice and palliative care units, and prehabilitation programs to optimize patients for surgery.
Scope
As a specialty, the core element of anesthesiology is the practice of anesthesia. This comprises the use of various injected and inhaled medications to produce a loss of sensation in patients, making it possible to carry out procedures that would otherwise cause intolerable pain or be technically unfeasible. Safe anesthesia requires in-depth knowledge of various invasive and non-invasive organ support techniques that are used to control patients' vital functions while under the effects of anaesthetic drugs; these include advanced airway management, invasive and non-invasive hemodynamic monitors, and diagnostic techniques like ultrasonography and echocardiography. Anesthesiologists are expected to have expert knowledge of human physiology, medical physics, and pharmacology as well as a broad general knowledge of all areas of medicine and surgery in all ages of patients, with a particular focus on those aspects which may impact on a surgical procedure. In recent decades, the role of anesthesiologists has broadened to focus not just on administering anesthetics during the surgical procedure itself, but also beforehand in order to identify high-risk patients and optimize their fitness, during the procedure to maintain situational awareness of the surgery itself so as to improve safety, and afterwards to promote and enhance recovery. This has been termed "perioperative medicine".The concept of intensive care medicine arose in the 1950s and 1960s, with anesthesiologists taking organ support techniques that had traditionally been used only for short periods during surgical procedures and applying these therapies to patients with organ failure, who might require vital function support for extended periods until the effects of the illness could be reversed. The first intensive care unit was opened by Bjørn Aage Ibsen in Copenhagen in 1953, prompted by a polio epidemic during which many patients required prolonged artificial ventilation. In many countries, intensive care medicine is considered to be a subspecialty of anesthesiology, and anesthesiologists often rotate between duties in the operating room and the intensive care unit. This allows continuity of care when patients are admitted to the ICU after their surgery, and it also means that anesthesiologists can maintain their expertise at invasive procedures and vital function support in the controlled setting of the operating room, while then applying those skills in the more dangerous setting of the critically ill patient. In other countries, intensive care medicine has evolved further to become a separate medical specialty in its own right, or has become a "supra-specialty" which may be practiced by doctors from various base specialties such as anesthesiology, emergency medicine, general medicine, surgery or neurology.
Anesthesiologists have key roles in major trauma, resuscitation, airway management, and caring for other patients outside the operating theatre who have critical emergencies that pose an immediate threat to life, again reflecting transferable skills from the operating room, and allowing continuity of care when patients are brought for surgery or intensive care. This branch of anesthesiology is collectively termed critical emergency medicine, and includes provision of pre-hospital emergency medicine as part of air ambulance or emergency medical services, as well as safe transfer of critically ill patients from one part of a hospital to another, or between healthcare facilities. Anesthesiologists commonly form part of cardiac arrest teams and rapid response teams composed of senior clinicians that are immediately summoned when a patient's heart stops beating, or when they deteriorate acutely while in hospital. Different models for emergency medicine exist internationally: in the Anglo-American model, the patient is rapidly transported by non-physician providers to definitive care such as an emergency department in a hospital. Conversely, the Franco-German approach has a physician, often an anesthesiologist, come to the patient and provide stabilizing care in the field. The patient is then triaged directly to the appropriate department of a hospital.
The role of anesthesiologists in ensuring adequate pain relief for patients in the immediate postoperative period as well as their expertise in regional anesthesia and nerve blocks has led to the development of pain medicine as a subspecialty in its own right. The field comprises individualized strategies for all forms of analgesia, including pain management during childbirth, neuromodulatory technological methods such as transcutaneous electrical nerve stimulation or implanted spinal cord stimulators, and specialized pharmacological regimens.
Anesthesiologists often perform interhospital transfers of critically ill patients, both on short range helicopter or ground based missions, as well as longer range national transports to specialized centra or international missions to retrieve citizens injured abroad. Ambulance services employ units staffed by anesthesiologists that can be called out to provide advanced airway management, blood transfusion, thoracotomy, ECMO, and ultrasound capabilities outside the hospital. Anesthesiologists often make up part of military medical teams to provide anesthesia and intensive care to trauma victims during armed conflicts.
Terminology
Various names and spellings are used to describe this specialty and the individuals who practice it in different parts of the world. In North America, the specialty is referred to as anesthesiology, and a physician of that specialty is therefore called an anesthesiologist. In these countries, the term anesthestist is used to refer to non-physician providers of anesthesia services such as certified registered nurse anesthetists and anesthesiologist assistants. In other countries – such as United Kingdom, Australia, New Zealand, and South Africa – the medical specialty is referred to as anaesthesia or anaesthetics, with the "ae" diphthong. Contrary to the terminology in North America, anaesthetist is used only to refer to a physician practicing in the field; non-physicians use other titles such as physician assistant. At this time, the spelling anaesthesiology is most commonly used in written English, and a physician practicing in the field is termed an anaesthesiologist. This is the spelling adopted by the World Federation of Societies of Anaesthesiologists and the European Society of Anaesthesiology, as well as the majority of their member societies. It is the also the most commonly used spelling found in the titles of medical journals. In fact, many countries, such as Ireland and Hong Kong, which formerly used anaesthesia and anaesthetist have now transitioned to anaesthesiology and anaesthesiologist.History
Throughout human history, efforts have been made by almost every civilization to mitigate pain associated with surgical procedures, ranging from techniques such as acupuncture or phlebotomy to administration of substances such as mandrake, opium, or alcohol. However, by the mid-nineteenth century the study and administration of anesthesia had become far more complex as physicians began experimenting with compounds such as chloroform and nitrous oxide, albeit with mixed results. On October 16, 1846, a day that would thereafter be referred to as "Ether Day", in the Bullfinch Auditorium at Massachusetts General Hospital, which would later be nicknamed the "Ether Dome", New England Dentist William Morton successfully demonstrated the use of diethyl ether using an inhaler of his own design to induce general anesthesia for a patient undergoing removal of a neck tumor. Reportedly, following the quick procedure, operating surgeon John Warren affirmed to the audience that had gathered to watch the exhibition, "Gentlemen, this is no humbug!", although this report has been disputed.The term Anaesthesia was first used by the Greek philosopher Dioscorides, derived from the Ancient Greek roots ἀν- an-, "not", αἴσθησις aísthēsis, "sensation" to describe the insensibility that accompanied the narcotic-like effect produced by the mandrake plant. However, following Morton's successful exhibition, Oliver Wendell Holmes Sr. sent a letter to Morton in which he first to suggested anesthesia to denote the medically induced state of amnesia, insensibility, and stupor that enabled physicians to operate with minimal pain or trauma to the patient. The original term had simply been "etherization" because at the time this was the only agent discovered that was capable of inducing such a state.
Over the next one hundred-plus years the specialty of anesthesiology developed rapidly as further scientific advancements meant that physicians' means of controlling peri-operative pain and monitoring patients' vital functions grew more sophisticated. With the isolation of cocaine in the mid-nineteenth century there began to be drugs available for local anesthesia. By the end of the nineteenth century, the number of pharmacological options had increased and had begun to be applied both peripherally and neuraxially. Then in the twentieth century neuromuscular blockade allowed the anesthesiologist to completely paralyze the patient pharmacologically and breathe for him or her via mechanical ventilation. With these new tools, the anesthetist could intensively manage the patient's physiology, bringing about critical care medicine, which, in many countries, is intimately connected to anesthesiology.
Historically anesthesia providers were almost solely utilized during surgery to administer general anesthesia in which a person is placed in a pharmacologic coma. This is performed to permit surgery without the individual responding to pain during surgery or remembering the surgery.