Search results
Results from the WOW.Com Content Network
General anaesthetics can be administered either as gases or vapours (inhalational anaesthetics), or as injections (intravenous or even intramuscular).All of these agents share the property of being quite hydrophobic (i.e., as liquids, they are not freely miscible—or mixable—in water, and as gases they dissolve in oils better than in water).
Prior to administration of a general anaesthetic, the anaesthetist may administer one or more drugs that complement or improve the quality or safety of the anaesthetic or simply provide anxiolysis. Premedication also often has mild sedative effects and may reduce the amount of anaesthetic agent required during the case. [6]
The Meyer-Overton correlation for anaesthetics. A nonspecific mechanism of general anaesthetic action was first proposed by Emil Harless and Ernst von Bibra in 1847. [9] They suggested that general anaesthetics may act by dissolving in the fatty fraction of brain cells and removing fatty constituents from them, thus changing activity of brain cells and inducing anaesthesia.
Drug-induced amnesia is amnesia caused by drugs. Amnesia may be therapeutic for medical treatment or for medical procedures, or it may be a side-effect of a drug, such as alcohol, or certain medications for psychiatric disorders, such as benzodiazepines. [1] It is seen also with slow acting parenteral general anaesthetics. [citation needed]
Halothane, an agent introduced in the 1950s, has been almost completely replaced in modern anesthesia practice by newer agents because of its shortcomings. [10] Partly because of its side effects, enflurane never gained widespread popularity. [10] In theory, any inhaled anesthetic agent can be used for induction of general anesthesia.
In the 1930s, physicians started to augment inhaled general anesthetics with intravenous general anesthetics. The drugs used in combination offered a better risk profile to the subject under anesthesia and a quicker recovery. A combination of drugs was later shown to result in lower odds of dying in the first seven days after anesthetic.
Emetogenic drugs commonly used in anaesthesia include nitrous oxide, physostigmine, and opioids. The intravenous anaesthetic propofol is currently the least emetogenic general anaesthetic. These medications are thought to stimulate the chemoreceptor trigger zone.
All of these agents share the property of being quite hydrophobic (i.e., as liquids, they are not freely miscible with water, and as gases they dissolve in oils better than in water). [3] The ideal volatile anaesthetic agent offers smooth and reliable induction and maintenance of general anaesthesia with minimal effects on non-target organ systems.