US EPA

700487 

Journal Article 

The group pharmacology of anaesthetic agents. I. The absorption-elimination of inhaled drugs 

Hunter, A 

1956 

Yes 

British Journal of Anaesthesia
ISSN: 0007-0912
EISSN: 1471-6771 

NIOSH/00134869 

28 

6 

244-250 

English 

13329287 

The absorption and elimination of inhalation anesthetics are reviewed. The first step in the absorption of a volatile anesthetic into the body is its entry into the lung alveoli. This phase requires about 2 minutes in persons with healthy lungs, regardless of the anesthetic agent used. Anesthetics then cross the alveolar membrane and enter into solution in the blood stream. The rate of entry into the blood stream depends on the partial pressure of the anesthetic vapor and its solubility in water and blood. Substances are grouped according to solubility: highly soluble anesthetics including diethyl-ether (60297) and divinyl ether (109933); moderately soluble anesthetics including nitrous-oxide (10024972) and ethylene (74851); and anesthetics with low solubility, such as chloroform (67663), trichlorethylene (79016), and cyclopropane (75194). Anesthetics are carried through the pulmonary capillaries first to the brain, where they exert their specific action, and ultimately into all body tissues. The rate of uptake by an individual body structure depends on its blood supply and the solubility of the anesthetic drug. Anesthetic agents are eliminated from the body by a reversal of the uptake processes, except that the central nervous system is slow to recover because of its high vascularization. The absorption and elimination characteristics of the anesthetics are discussed in terms of their practical applications in clinical anesthesia.