Local anesthesia
The local anesthesia (from Latin locus , place ' , and " anesthesia " from ancient Greek ἀν- not' and ancient Greek αἴσθησις , perception ' ) or local anesthesia is the local anesthesia in the area of nerve endings or pathways without affecting consciousness. Through the targeted administration of anesthetics , mostly local anesthetics , it causes the temporary, reversible function inhibition of selected nerves and leads to insensitivity and freedom from pain, sometimes also to inhibition of active mobility in parts of the body.
As an alternative to general anesthesia ( general anesthesia), local anesthesia enables medical procedures, such as operations or certain examinations, for the implementation of which the merely local elimination of pain and the restriction of movements are necessary, but sufficient to this extent.
Objectives of local anesthesia
Local anesthesia is primarily aimed at eliminating pain by interrupting the nerve conduction function ( afferent fibers ). The interruption of the function of certain A-fibers results in a switch-off of sensations (sensation of touch and vibration, also afferent fibers). In some procedures, the disruption of the function of motor ( efferent ) nerve fibers causes the active mobility of the muscles concerned to be switched off.
Damage to nerve structures (such as the trigeminal nerve ) causes neuropathic pain . The first specific treatment measure used here is therapeutic local anesthesia (also known as “curative anesthesia”). The preparation used for this must be free of vasoconstrictor (such as adrenaline ). In some of the patients a pain relief is achieved that lasts well beyond the duration of the anesthesia and ideally leads to the complete disappearance of the symptoms.
Systematics
A distinction is made between the following versions of local anesthesia:
- Surface anesthesia : The local anesthetic is applied to the surface of the body, whereby the sensitive nerve endings are reached by diffusion . Typical areas of application are corneal anesthesia and mucous membrane anesthesia, as the local anesthetics can easily penetrate these tissues. Surface anesthesia of the skin is only possible to a very limited extent using special creams (EMLA) or electrophoresis . The use of cold for surface stunning is also practiced.
- Infiltration anesthesia: The local anesthetic is injected directly into the tissue in the operating area. The effect is based on the blockade of sensitive nerve endings and terminal nerve tracts. Infiltration anesthesia also changes the properties of the tissue to be operated on, and relatively large amounts of local anesthetic are required. A special form is intradermal anesthesia ("skin wheal"). The tumescent anesthesia is a special process in which the local anesthetic is a solvent in the subcutaneous fatty tissue is introduced in a large volume and is there distributed over a large area. It is mainly used in cosmetic surgery for liposuction, but it is viewed critically.
- Regional anesthesia : Regional anesthesia is the term used to describe conduction anesthesia of peripheral nerve trunks (peripheral regional anesthesia )or nerve roots near the spinal cord (regional anesthesia near the spinal cordsuch as spinal or epidural anesthesia ). Another variant is the intravenous regional anesthesia according to Bier , in which the anesthetic is injected into emptied veins and diffuses from there into nerve tracts and nerve ends.
For historical and pharmacological reasons, the term local anesthesia takes precedence over regional anesthesia . However, the nomenclature of the classification is not uniform: Sometimes only surface anesthesia and infiltration anesthesia are summarized under the term local anesthesia and regional anesthesia is managed separately.
Local anesthesia in dentistry
history
Dominique Jean Larrey (1766-1842) was a French military doctor and surgeon in the "Great Army" of Napoleon Bonaparte and also his personal physician. Larrey was one of the first doctors to observe the local anesthetic effects of cold. After the battle of Preussisch Eylau, which was fought in grim cold on February 7th and 8th, 1807, he performed amputations without some of the injured uttering painful sounds. As a result of the sub-zero temperatures, the peripheral nerves of Larrey's patients were numb , i.e. largely insensitive to pain.
In a self-experiment with the later psychoanalyst Sigmund Freud , the ophthalmologist Carl Koller (1857–1944) discovered in 1884 that cocaine numbs the tongue when tasted. After successful animal experiments, he first used the agent in 1884 for eye operations on humans: he dripped cocaine solution onto the eye, which numbed the cornea of the eye (surface anesthesia). Koller is therefore considered the father of local anesthesia. He called it local anesthesia .
From 1885 onwards, William Stewart Halsted (1852–1922) used cocaine for infiltration anesthesia in dental operations, in 1888 Maximilian Oberst developed conduction anesthesia of the finger ( Oberst block ) .
The German doctor Carl Ludwig Schleich (1859–1922) introduced infiltration anesthesia in 1892. By injecting an anesthetic into areas to be anesthetized, skin-covered areas could now also be treated for the first time.
As the first regional anesthesia method , August Bier (1861–1949) introduced spinal anesthesia in 1898 and intravenous regional anesthesia in 1908.
Ropivacaine ( Naropin ), introduced in 1997, is one of the more modern local anesthetics for local or regional anesthesia .
Individual evidence
- ↑ a b c H. A. Adams, E. Kochs, C. Krier: Today's anesthesia methods - attempt at a system. In: Anästhesiol Intensivmed Emergency Med Schmerzther, 2001, 36, pp. 262–267. doi: 10.1055 / s-2001-14470 PMID 11413694
- ↑ Tumescent local anesthesia. Statement of the Scientific Working Group on Regional Anesthesia of the DGAI . In: Anästh. Intensivmed. , 41, 2000, pp. 114–115 (PDF; 82 kB)
- ^ MA Rauschmann: The pain and its therapy in the mirror of the time. In: Der Orthopäde 37, Oct. 2008, pp. 1007-1015
- ↑ Guido Kluxen: Sigmund Freud: About Coca Missed Discovery . In: Deutsches Ärzteblatt . tape 88 , no. 45 . Deutscher Ärzte-Verlag, November 7, 1991, p. A-3870 .
- ↑ C. Koller: Preliminary information on local anesthesia on the eye. Supplement to the clinical weekly papers for ophthalmology, 1884, 22, pp. 60–63
- ↑ C.-L. Schleich: Infiltration anesthesia (local anesthesia) and its relationship to general anesthesia (inhalation anesthesia) . Conditional German Ges. Chir. 1892; 1: 121-127
- ↑ A. Bier: Experiments on the cocainization of the spinal cord. In: Deutsche Zeitschrift für Chirurgie 51 (1899): 361–368
- ↑ A. Bier: About a new way of producing local anesthesia on the limbs. In: Archive for Clinical Surgery 1908; 86: 1007-1016
- ↑ Michael Heck, Michael Fresenius: Repetitorium Anaesthesiologie. Preparation for the anesthesiological specialist examination and the European diploma in anesthesiology. 3rd, completely revised edition. Springer, Berlin / Heidelberg / New York et al. 2001, ISBN 3-540-67331-8 , p. 804.
