12_1_2
Volume 12, Number 1, 29 - 33
Predicting methanol clearance during hemodialysis when direct measurement is not available
Margo McMurray, RN, CNeph(C), Diane Carty, RN, and Edwin B. Toffelmire, MDCM, FRCPC, FACP
Abstract
The appropriate treatment of a patient with methanol intoxication includes the use of a competitive inhibitor of alcohol dehydrogenase (ethanol, PO or IV, or fomepizole) to prevent the metabolism of methanol to formaldehyde and formic acid. Where available, dialysis can be added to this therapy, since methanol is cleared well by hemodialysis. The ability to predict the time course of methanol elimination in any given patient is an essential factor in planning his or her care. Where the availability of ethanol, bicarbonate, nursing time, or dialysis machines is limited, such predictions can be used to allocate these resources quite accurately within a couple of hours of starting treatment.
Even when direct measurement of methanol by gas chromatography is not readily available, its level can be estimated indirectly by a quick and easy method, using available laboratory values. The length of time necessary to clear the methanol below a toxic level can be predicted accurately. Careful interpretation of laboratory values can result in early treatment, correct treatment time, and a positive patient outcome.
Author Affiliation(s): Margo McMurray, Burr Satellite Dialysis Unit, Kingston General Hospital, in Kingston, Ontario. Diane Carty, Burr Satellite Dialysis Unit. Edwin B. Toffelmire, Department of Medicine, Queen's University, Kingston, Ontario, and Medical Director, Hemodialysis, at Kingston General Hospital.