Biomaterial Database

Age-related iso-MAC charts for isoflurane, sevoflurane and desflurane in man. 2003

R W D Nickalls, and W W Mapleson

Department of Anaesthesia, City Hospital, Nottingham, UK. dicknickalls@compuserve.com

BACKGROUND The motivation for this study was the current difficulty in estimating the total age-related MAC for a patient in a clinical setting. METHODS Age-related iso-MAC charts for isoflurane, sevoflurane and desflurane were developed for the clinically useful MAC range (0.6-1.6), age range 5-95 yr, and put in a convenient form for use by practising anaesthetists. The charts are based on Mapleson's meta-analysis (1996) of the available MAC data and can be used to allow for the contribution of nitrous oxide to the total MAC. RESULTS The charts indicate the influence of age on anaesthetic requirements, showing, for example, that a total MAC of 1.2 using isoflurane and nitrous oxide 67% in oxygen requires an end-expired isoflurane concentration of only 0.25% in a patient of 95 yr vs 1% in a 5-yr-old patient. Colleagues found the charts to be helpful and simple to use clinically. CONCLUSIONS The iso-MAC charts show clearly how patient age can be used to guide the choice of end-expired agent concentration. They also allow a consistent total MAC to be maintained when changing the inspired nitrous oxide concentration, thereby reducing the chance of inadvertent awareness, particularly at the extremes of age.

UI	MeSH Term	Description	Entries
D007530	Isoflurane	A stable, non-explosive inhalation anesthetic, relatively free from significant side effects.
D008738	Methyl Ethers	A group of compounds that contain the general formula R-OCH3.	Ethers, Methyl
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D011650	Pulmonary Alveoli	Small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place.	Alveoli, Pulmonary,Alveolus, Pulmonary,Pulmonary Alveolus
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D002675	Child, Preschool	A child between the ages of 2 and 5.	Children, Preschool,Preschool Child,Preschool Children
D004334	Drug Administration Schedule	Time schedule for administration of a drug in order to achieve optimum effectiveness and convenience.	Administration Schedule, Drug,Administration Schedules, Drug,Drug Administration Schedules,Schedule, Drug Administration,Schedules, Drug Administration
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000077149	Sevoflurane	A non-explosive inhalation anesthetic used in the induction and maintenance of general anesthesia. It does not cause respiratory irritation and may also prevent PLATELET AGGREGATION.	BAX 3084,Fluoromethyl Hexafluoroisopropyl Ether,Fluoromethyl-2,2,2-trifluoro-1-(trifluoromethyl)ethyl Ether,Sevorane,Ultane