Inhalation anaesthetics: types, mechanism of action and adverse effects

Abstract

Inhalational anesthetics have been used to induce and maintain general anaesthesia for more than 150 years. These anaesthetic agents are commonly used in the surgical and clinical practice solely and as a conjugant with other anaesthetics. Since inhalational anaesthetic agents develop amnesia, loss of awareness, and reduce reactions to painful surgical stimuli, they are an essential part of general anaesthesia. The choice of anaesthetic agent is based on the procedure's duration and type, patient characteristics, the attending anaesthesiologist’s preferences, and occasionally on institutional protocols. These medications are administered to the patient through the anesthetic circuit using a special vaporizer. The purpose of this research is to review the available information about inhalation anaesthetics: types, mechanism of action and adverse effects. Nitrous oxide is one of the earliest anaesthetic agents while isoflurane, sevoflurane, and desflurane are three commonly used inhalational anaesthetics. The low-solubility inhalation anaesthetics desflurane and sevoflurane have several clinical advantages over isoflurane, including rapid induction and faster recovery after prolonged treatment. However, isoflurane can sometimes be used effectively enough to match the induction and recovery times of other drugs. Inhalation anaesthetics work by suppressing inhibitory signals such as chloride channels and potassium channels and enhancing excitatory signals such as acetylcholine, muscarinic and nicotinic receptors, glutamate and serotonin in the central nervous system. Certain side effects including nausea, vomiting, malignant hyperthermia, post-operative cognitive impairment is associated with their use. More research is needed to further enhance the safety profile of available inhalation anaesthetics and can further lead to discovery of new, safe anaesthetics.