WORLD ANESTHESIA DAY, 16 OCTOBER, BRIEF SUMMERY ABOUT ANESTHESIA.

WORLD  ANESTHESIA DAY,  Dear Readers, Today is October 16, World Anesthesia Day; So I  prepared a brief summary about Anesthesia on the occasion of this day. In some countries, this day is also known as National Anesthesia Day or Ether Day. The reason behind that to celebrate this day is for the first successful demonstration of Diethyl Ether Anesthesia on 16 October 1846.  

 WORLD  ANESTHESIA DAY 

Historical Aspects of Anesthesia  

The first recorded use of anesthesia goes back to the ancient Incas, shamans got cooked up chewing coca leaves and drilled holes in the heads of their patients( to let that bad spirits escape) while spitting into the wounds they had inflicted. The use of anesthesia dates back to 300 B.C. in the Alexandrian period when the juice from the mandrake plant was used. At the same time, unconsciousness was induced by compression of the carotid artery (by Egyptian). The first herbal anesthesia was observed in prehistory. Opium poppy capsules were collected in 4200 BC and opium poppies were framed in Sumeria and subsequent empires. Opium was not introduced to India and China until 330 BC and 600 to 1200 AD, but these Nations pioneered the use of Cannabis incense and aconitum. In Europe, Asia, and America a variety of Solanum species containing potent tropane alkaloid was used, such as mandrake, henbane, Datura metel, and Datura inoxia. Anesthetics were sometimes administered in the Spongia somnifera, a sponge into which a large quantity of drugs was allowed to dry, from which a saturated solution could be trickled into the nose of the patient.

History of Animal Anesthesia 

• Term anesthesia is given by Dr. Oliver Wendell Holmes (1886).
• Paracelsus (1540) produced ether and reported it to have a soporific effect on fowl.
• Sir Humphrey Davy (1800) suggested that N2O might have anesthetic property.
• Chloroform was discovered by Liebig in 1831.
• Dr. Horace Wells (1844) discovered the general anesthetic property of nitrous oxide.
• Ore (1875) published the first monograph on intravenous anesthetics using chloral hydrate.
• Rectal anesthesia attempted by Pirogoff  (1847).
• In 1884 Kolhler introduced cocaine for local anesthesia of the eye, its use in veterinary practice was popularized by Sir Fredrick Hobday.
• Conduction anesthesia by Halsted and Hall(1884).
• G.L. Corning (1885) induced spinal anesthesia in dogs using cocaine.
• Infiltration anesthesia by Reclus (1890) and Schleich (1892).
• Sendrail (1901) induced subarachnoid anesthesia in horses, cattle, dogs.
• Cathelin (1901) reported epidural anesthesia in dogs.
• Farquharson and Formston  (1940) Developed the paralumbar anesthesia technique in cattle.
• Carpentier (1950) introduced phenothiazine Derivatives as pre-anesthetic.
• Dr. C.P. Jackson (1953) a Boston Physician, was the first who employs Ether extensively in animals.

Terminologies Related to Anesthesia 

Local Anesthesia is a temporary loss of sensation in a limited body area without loss of consciousness.

Regional anesthesia is a loss of sensation or insensibility in larger, but limited, body area. It is produced by injection of a local analgesic solution into connective tissue around a sensory nerve trunk or intravenous injection distal to tourniquet.  

General anesthesia is a complete unconsciousness produced by controlled reversible intoxication of the central nervous system in which there is lowered sensitivity to environmental stimuli and diminished response to such stimuli.

Surgical anesthesia is the state of general anesthesia that provides unconsciousness, muscular relaxation, and analgesia sufficient for surgery so that surgery can be performed painlessly and without struggling on the part of the patient.

Balanced anesthesia is a state produced by a combination of drugs that is characterized by unconsciousness, analgesia, and muscle relaxation. Balanced anesthesia is induced by multiple drugs. Drugs are targeted to specially attenuate individual components of the anesthetic state; that is, consciousness, analgesia, muscle relaxation, and alteration of autonomic reflexes.

Dissociative anesthesia is induced by drugs (e.g., ketamine) that dissociate the thalamocortical and limbic systems, that cause interruption of information flow from the unconscious to the conscious part of the brain. Dissociative agents stimulate some brain centers rather than depress them. Dissociative anesthesia is characterized by a cataleptoid state in which the eyes remain open and swallowing reflexes remain intact. Skeletal muscle hypertonicity persists unless a peripheral or central muscle relaxant, strong sedative, or other concurrent medications are administered.

Basal anesthesia is a light level of anesthesia usually produced by preanesthetic agents( tranquilizers, sedatives ); it serves as a basis for deeper anesthesia on the administration of other agents.

Types of anesthesia

A.General anesthesia

1. Injectable anesthesia: Anesthesia is achieved by subcutaneous intramuscular and intravenous administration of anesthetics. Other routes include intrathoracic and intraperitoneal although not generally used.

2. Inhalational anesthetic: Anesthesia is achieved by inhalation of anesthetic gases or vapors in combination with oxygen.

B. Local anesthesia

Anesthetics solution is applied topically in the form of Gel, Solution, or aerosol on the eye and mucous membrane of the penis, vagina, rectum, urethra, etc. (Topical) or injected locally in the surgical site (Field block). Besides anesthetics are injected around the large nerve trunk (Regional nerve block) or in the epidural or subarachnoid space (Epidural) or in distal to the site of a tourniquet intravenously (Regional intravenously).

C. Other routes

1. Electronarcosis: Anesthesia is achieved by passing an electric current through the cerebrum to induce deep narcosis although the method is rarely used in veterinary practice.

2. Acupuncture: An ancient Chinese system that involves the insertion of specially designed in needles at specific points and their stimulation by various means to produce analgesia.

3. Hypothermia: The procedure involves decreasing the body temperature either locally or generally to minimize the anesthetic doses.