Anesthesia

From WikiMD's Health & Wellness Encyclopedia



Editor-In-Chief: Prab R. Tumpati M.D.
Obesity, Sleep & Internal medicine
Founder, WikiMD Wellnesspedia &
W8MD weight loss and sleep centers


Anesthesia or anaesthesia (see spelling differences), from the Greek roots an-, meaning "not, without" and aesthētos, meaning "perceptible, able to feel", refers to the medical practice of blocking the perception of pain and other sensations. This concept is central to modern medicine as it allows patients to undergo surgery and other procedures without experiencing the associated pain and distress. The term was first coined by Oliver Wendell Holmes, Sr. in 1846.

Understanding Anesthesia

The essence of anesthesia lies in its ability to create a state where the patient does not feel pain and other sensations. It is essentially achieved through a combination of five key elements:

  • Analgesia: This component involves blocking the conscious perception of pain.
  • Hypnosis: It involves inducing a state of unconsciousness.
  • Amnesia: This refers to the inhibition of memory formation.
  • Relaxation: This component ensures the prevention of unwanted movement or muscle tone.
  • Homeostasis: This involves the preservation of normal body functioning such as maintaining blood pressure within the normal physiological range.

Types of Anesthesia

Anaesthesia can be administered in several forms, each serving a unique purpose:

  1. General anaesthesia: This involves a reversible loss of consciousness and memory of unpleasant events. It is typically used for major surgeries.
  2. Local anaesthesia: This form of anesthesia causes a reversible loss of sensation in a specific part of the body. It is achieved by localized administration of anaesthetic drugs at the affected site.
  3. Regional anaesthesia: This type of anesthesia causes a reversible loss of sensation and, possibly, movement in a larger region of the body. It is achieved by selectively blocking certain sections of the spinal cord or nerves that supply the region.

Sedation, although not a form of anesthesia, is also a practice that is associated with it. Sedation involves administering drugs to make a patient more comfortable or less anxious during a procedure, but without necessarily inducing anesthesia.

Historical Overview

The use of anesthesia dates back to the classical age. For instance, Dioscorides, an ancient physician, documented potions prepared from opium and mandragora that served as surgical anesthetics. There is also an account in the biblical Book of Genesis (2:20) where God puts Adam into a deep sleep, during which one of his ribs was extracted and formed into Eve.

In the Eastern world, references to anesthesia can be found in the 10th-century work Shahnama. The author describes a Caesarean section performed on Rudaba during childbirth, in which a special wine concoction was prepared by a Zoroastrian priest and used to induce unconsciousness for the operation. Despite the largely mythical content of the passage, it does provide some indication of knowledge of anesthesia in ancient Persia.

Non-Pharmacological Methods

Hypnotism and acupuncture have a long history of use as anaesthetic techniques. In China, Taoist medical practitioners developed anesthesia through acupuncture. Additionally, the application of cold (e.g., with ice) can temporarily halt nerve fibres (axons) from conducting sensation, while hyperventilation can cause a brief alteration in the conscious perception of stimuli, including pain (as seen in Lamaze techniques). However, these techniques are seldom employed in modern anesthetic practice.

Use of Herbal Derivatives

The use of herbal anesthesia can be traced back to prehistory. Opium and Cannabis were two of the most crucial herbs used. They were either ingested or burned, and the smoke was inhaled. Alcohol was also utilized, though its vasodilatory properties were unknown at the time. In early America, preparations from datura (containing scopolamine) were used, as was coca. In Medieval Europe, various preparations of mandrake and henbane (hyoscyamine) were tried.

Advent of Gases and Vapours

In 1804, the world's first general anaesthesia for a surgical procedure was performed by the Japanese surgeon Hanaoka Seishū. He operated on a patient with breast cancer (mastectomy) by combining Chinese herbal medicine and Western surgery techniques learnt through "Rangaku", or "Dutch studies". His pioneering work, which involved using a compound called Tsusensan (based on the plants Datura metel and Aconitum among others), was performed 40 years before the more recognized Western innovations of Long, Wells, and Morton.

Development of Modern Anesthesia

As medical knowledge progressed into the 19th and 20th centuries, new advancements in anesthesia came into light. The introduction of inhaled anesthetics such as ether and chloroform revolutionized surgical practices by making procedures more tolerable and safe for patients. These agents were first used by Long, Wells, and Morton, who are recognized for their significant contributions to the field of anesthesia.

The 20th century saw further advancements with the development of intravenous anesthetics and muscle relaxants. This allowed for a more profound state of anesthesia, making more complex surgeries feasible. The discovery and application of regional anesthesia techniques also advanced during this period.

Anesthesia in Modern Medicine

Today, anesthesia is a specialized field in medicine, with professionals (anesthesiologists) trained in the administration and management of anesthetics. Anesthesiologists are involved in a wide range of procedures beyond surgery, including pain management, critical care, and obstetrics.

Modern anesthetic techniques provide not only pain relief but also amnesia (to prevent memory formation during surgery), immobility, and maintenance of physiological homeostasis. Patient safety is of utmost importance, and anesthesiologists monitor and manage vital signs such as heart rate, blood pressure, and oxygen levels throughout the procedure.

Anesthesia in the current era is highly patient-centric, with the type and level of anesthesia tailored to the individual's needs and the nature of the procedure. Patient comfort, safety, and outcomes are continuously improved through ongoing research and technological advancements in the field.

frequently asked questions

  1. What shouldn't you do before undergoing anesthesia? Before anesthesia, you must abstain from eating and drinking for a specified amount of time, often 6 to 8 hours before to operation. Additionally, you should avoid smoking, consuming alcohol, and taking certain drugs, such as blood thinners, without seeing your anesthesiologist or surgeon.
  2. What should be avoided following anesthesia? You should avoid driving, operating heavy machinery, and making significant judgments for 24 hours after anesthesia. Additionally, you should avoid ingesting alcohol and some drugs without consulting your doctor.
  3. How long does the body require to recover from anesthesia? The time required for the body to recover from anesthesia varies depending on the type of anaesthetic administered and the patient's medical history. Recovery timeframes typically range from a few hours to several days.
  4. What is the most common anesthetic complication? The most frequent side effects of anesthesia include nausea, vomiting, sore throat, and tiredness. These symptoms are typically transient and treatable with medicine.
  5. Why should you not use deodorant prior to surgery? You should not use deodorant before to surgery due to the possibility that it contains metals that could interfere with the imaging equipment.
  6. How does one recover from anesthesia? Anesthesiologists employ a combination of medicines, oxygen, and other methods to rouse patients from anesthesia. Before being discharged, the process is closely watched to verify that you are alert and steady.
  7. Does stress influence anesthesia? Anxiety can influence how the body reacts to anesthesia. It is essential to inform your healthcare professional of any concerns you may have regarding the surgery and anesthesia.
  8. Why do you behave strangely after anesthesia? Anesthesia can result in confusion, disorientation, and loss of memory. Typically, these effects are transient and will subside as the drug wears off.
  9. What are the adverse consequences of anesthesia? Anesthetic side effects can include nausea, vomiting, sore throat, drowsiness, and disorientation. Rarely, anesthesia can also result in more severe complications, including as allergic reactions, heart or lung difficulties, and blood clots.
  10. Do you dream while sedated? Some individuals may dream while under anesthesia, however the specific causes are unknown.
  11. Does anesthetic affect the brain? The effects of anesthesia on the brain include confusion, disorientation, and memory loss. However, the symptoms are often transient and disappear when the drug wears off.

Journals

Some of the most popular journals in the field of Anesthesia include:

See also

External links

References

Resources

Latest articles - Anesthesia

PubMed
Clinical trials
Up To Date
UpToDate
Medline
Medline plus
You Tube
YouTube videos
About
Apple bitten.svg

WikiMD is the world's largest, free medical and wellness encyclopedia edited only by professionals.


Medicine - Specialties and subspecialties
Surgery

Cardiac surgery / Cardiothoracic surgery / Colorectal surgery / Ophthalmology / General surgery / Neurosurgery / Oral and maxillofacial surgery / Orthopedic surgery / Hand surgery / Otolaryngology / ENT / Pediatric surgery / Plastic surgery / Reproductive surgery / Surgical oncology / Transplant surgery / Trauma surgery / Urology / Andrology / Vascular surgery

Medicine Internal medicine / Allergy / Immunology / Angiology / Cardiology / Endocrinology / Gastroenterology / Hepatology / Geriatrics / Hematology / Hospital medicine / Infectious disease / Nephrology / Oncology / Pulmonology / Rheumatology
Obstetrics and gynaecology Gynaecology / Gynecologic oncology / Maternal–fetal medicine / Obstetrics / Reproductive endocrinology and infertility / Urogynecology
Diagnostic Radiology / Interventional radiology / Nuclear medicine / Pathology / Anatomical / Clinical pathology / Clinical chemistry / Cytopathology / Medical microbiology / Transfusion medicine
Other specialties Addiction medicine / Adolescent medicine / Anesthesiology / Dermatology / Disaster medicine / Diving medicine / Emergency medicine / Mass gathering medicine / Family medicine / General practice / Hospital medicine / Intensive care medicine / Medical genetics / Narcology / Neurology / Clinical neurophysiology / Occupational medicine / Ophthalmology / Oral medicine / Pain management / Palliative care / Pediatrics / Neonatology / Physical medicine and rehabilitation (PM&R) / Preventive medicine / Psychiatry /Addiction psychiatry / Radiation oncology / Reproductive medicine / Sexual medicine / Sleep medicine / Sports medicine / Transplantation medicine / Tropical medicine / Travel medicine / Venereology
Medical education Medical school / USMLE / Bachelor of Medicine, Bachelor of Surgery / Bachelor of Medical Sciences / Master of Medicine / Master of Surgery / Doctor of Medicine / Doctor of Osteopathic Medicine / Alternative medicine / Allied health / Dentistry / Podiatry / Pharmacy / Physiotherapy / Molecular oncology / Nanomedicine / Personalized medicine / Public health / Rural health / Therapy / Traditional medicine / Veterinary medicine / Physician / Chief physician / History of medicine
Misc. topics Health topics A-Z / Rare diseases / Drugs / Diet / Medicine portal / First Aid / Glossary of medicine / Health insurance / Glossary of health topics / Drug classes / Medicines / Dentistry portal / Pharmacology and Medications/Medications portal / Pharmacology portal / Psychiatry portal
Wiki.png

Navigation: Wellness - Encyclopedia - Health topics - Disease Index‏‎ - Drugs - Rare diseases - Gray's Anatomy - USMLE - Hospitals

Ad: Tired of being Overweight? Try W8MD's insurance physician weight loss
Philadelphia medical weight loss & NYC medical weight loss.

WikiMD is not a substitute for professional medical advice. See full disclaimer.

Credits:Most images are courtesy of Wikimedia commons, and templates Wikipedia, licensed under CC BY SA or similar.