Anaesthetic preconditioning and its role in protecting patients at risk of myocardial ischaemia

Ischaemic preconditioning is a phenomenon where prior minor ischaemic events allows organs to better withstand further episodes of ischaemia. Preconditioning downgrades the effects of ischaemia from necrosis to apoptosis to cell survival. It occurs in a wide variety of tissues, but it is most widely studied in the heart, and it occurs after a range of stimuli including hypoxia and the use of volatile anaesthetic agents. In this article, we look at the basic science, mechanisms, and potential uses of preconditioning.

The blood–gas partition coefficient

A partition coefficient (λ) describes the relative affinity of a volatile anaesthetic for two phases and how that anaesthetic distributes itself between the two phases when equilibrium has been achieved. The blood–gas partition coefficient (λb/g), or Ostwald coefficient for blood–gas, is a pharmacological term used to describe the solubility of a volatile anaesthetic agent. Volatile agents with a low blood–gas partition coefficient (less soluble) will exert a high partial pressure and produce a more rapid onset and offset of anaesthetic action.

Systemic sclerosis in an anaesthetist

Introduction Systemic sclerosis is a potentially devastating disease in which the aetiology and pathogenesis has not yet been fully understood. It has been associated with occupational exposure to silica, vinyl chloride, solvents and other chemical agents. Case summary In this paper, we present the case of an anaesthetist who developed scleroderma after an occupational exposure to volatile anaesthetic gases (halothane, sevoflurane, isoflurane and enflurane) in operating theatres with poor scavenging systems and we discuss the possible causal link between occupational exposure and the disease. Conclusions The case reported is the second that we are aware of in recent years. Reporting scleroderma cases in workers may be the first step in assessing the causal link between occupational exposure to anaesthetic gases and the disease.

Sevoflurane and its use in veterinary practice

In clinical practice die anaesthetist often faces die dilemma of choosing die best fitting agem from a wide variety of injectable and volatile anaesdietic drugs. Meanwhile, die continuous progress of anaesthesiology offers new drugs and modern Techniques, making die final choice even more difficult. Sevoflurane is a new volatile anaesthetic agent, which is nowadays increasingly used in veterinary anaesthesia. It is a fluorinated derivative of methyl- isopropyl-ether. At room temperature it is a non-flammable, non-explosive, colourless liquid, with a pleasant smell. The aim of this review article is to present the basic attributes of sevoflurane and its use in veterinary practice. Its most important physical and chemical properties and their clinical implications, as well as its pharmacokinetics, pharmacodynamics, metabolism and potential toxicity are presented. Furthermore, sevoflurane is compared with other commonly used volatile anaesthetic agents and its use in anaesthesia of various companion, large and laboratory animals is discussed. Examples of sevoflurane administration, and of possible combinations with other drugs used in veterinary anaesthesia, are also given.