The search for a less toxic and less addictive substitute led to the development of the aminoester local anesthetics stovaine in 1903 and procaine in 1904. Since then, several synthetic local anesthetic drugs have been developed and put into clinical use, notably lidocaine in 1943, bupivacaine in 1957, and prilocaine in 1959. The invention of clinical use of local anaesthesia is credited to the Vienna School which included Sigmund Freud (1856-1939), Carl Koller (1857-1944) and Leopold Konigstein (1850-1942). They introduced local anaesthesia, using cocaine, through self-experimation on their oral mucosa before introducing it to animal or human experimentation. The Vienna school first started using cocaine as local anaesthesia in ophthalmology and it was later incorporated into ophthalmologic practice. Dr. Halsted and Dr. Hall, in the United States in 1885 described an intraoral anaesthetic technique of blocking the inferior alveolar nerve and the antero-superior dental nerve using 4% cocaine. {Shortly after the first use of cocaine for topical anesthesia, blocks on peripheral nerves were described. Brachial plexus anesthesia by percutaneous injection through axillary and supraclavicular approaches was developed in the early 20th century. The search for the most effective and least traumatic approach for plexus anesthesia and peripheral nerve blocks continues to this day. In recent decades, continuous regional anesthesia using catheters and automatic pumps has evolved as a method of pain therapy. Intravenous regional anesthesia was first described by August Bier in 1908. This technique is still in use and is remarkably safe when drugs of low systemic toxicity such as prilocaine are used.
Hypochloremia (or Hypochloraemia) is an electrolyte disturbance in which there is an abnormally low level of the chloride ion in the blood. The normal serum range for chloride is 97 to 107 mEq/L. It rarely occurs in the absence of other abnormalities. It is sometimes associated with hypoventilation. It can be associated with chronic respiratory acidosis. If it occurs together with metabolic alkalosis (decreased blood acidity) it is often due to vomiting. It is usually the result of hyponatremia or elevated bicarbonate concentration. It occurs in cystic fibrosis. References


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