Pain can also occur due to bursal inflammation, swelling or fracture at the base of the tumor stalk. Some of the clinical signs and symptoms of malignant osteochondroma are pain, swelling, and mass enlargement. Mechanism
Osteochondromas are long and slender, pedunculated on a stalk often taking the shape of a cauliflower. The cartilage cap is covered by fibrous perichondrium and continues with the periosteum of the underlying bone. The cartilage cap is less than 2 cm thick and the thickness decreases with age. A cap more than 2 cm thick, indicates malignant transformation of a tumor. The cartilage cap merges with the epiphyseal area of the long bones called spongiosa. In the spongiosa, the chondrocytes are arranged in accordance with the epiphyseal growth plate. The spongiosa of the stalk continues with the underlying cancellous bone. Fractures within the stalk causes fibroblastic proliferation and formation of a new bone. Development of bursa takes place over the osteochondroma, which is attached to the perichondrium of the cap. Inflammation of the bone is indicated by the bursal wall lined by the synovium. As a result, patients may have swelling for years related to the location and site of the lesion indicative of mechanical obstruction, nerve impingement, pseudoaneurysm of the overlying vessel, fracture at the stalk of the lesion, or formation of bursa over the osteochondroma. Heparan sulphate (HS) are glycosaminoglycans which are involved in the formation of proteoglycans.
The CO2 absorbent Baralyme, when dried, is most culpable for the production of carbon monoxide from desflurane degradation, although it is also seen with soda lime absorbent as well. Dry conditions in the carbon dioxide absorbent are conducive to this phenomenon, such as those resulting from high fresh gas flows. Pharmacology
As of 2005 the exact mechanism of the action of general anaesthetics has not been delineated. Desflurane is known to act as a positive allosteric modulator of the GABAA and glycine receptors, and as a negative allosteric modulator of the nicotinic acetylcholine receptor, as well as affecting other ligand-gated ion channels. Stereochemistry
Desflurane medications are a racemate of two enantiomers. Physical properties
Global-warming potential
Desflurane is a greenhouse gas. The twenty-year global-warming potential, GWP(20), for desflurane is 3714, meaning that one tonne of desflurane emitted is equivalent to 3714 tonnes of carbon dioxide in the atmosphere, much higher than sevoflurane or isoflurane. In addition to global warming potentials, drug potency and fresh gas flow rates must be considered for meaningful comparisons between anesthetic gases. When a steady state hourly amount of anesthetic necessary for 1 minimum alveolar concentration (MAC) at 2 liters per minute (LPM) for Sevoflurane, and 1 LPM for Desflurane and Isoflurane is weighted by the GWP, the clinically relevant quantities of each anesthetic can then be compared. On a per-MAC-hour basis, the total life cycle GHG impact of desflurane is more than 20 times higher than Isoflurane and Sevoflurane (1 minimal alveolar concentration-hour).