title: Isoflurane sedation for patients undergoing mechanical ventilation: metabolism to inorganic fluoride and renal effects.
abstract: The metabolism and renal effects of isoflurane sedation were studied for 24 h in patients undergoing mechanical ventilation. Forty-six patients admitted to our intensive therapy unit were allocated randomly to receive either 0.1-0.6% isoflurane or midazolam 0.01-0.2 mg kg-1 h-1 for sedation. In 26 patients sedated with isoflurane, plasma inorganic fluoride increased from a mean concentration of 4.03 mumol litre-1 to 13.57 mumol litre-1 12 h after stopping sedation. Plasma inorganic fluoride concentrations in 20 patients sedated with midazolam were unchanged from baseline values (mean 5.32 mumol litre-1). Serum electrolyte, urea and creatinine concentrations, and urine output rates during and after sedation in patients who received isoflurane were similar to those who received midazolam. We conclude that, following isoflurane sedation for up to 24 h, metabolism to inorganic fluoride is insufficient to cause clinical renal dysfunction.
authors.affiliation: Sir Humphry Davy Department of Anaesthesia, Bristol Royal Infirmary.
authors.forename: K L
authors.initials: KL
authors.lastname: Kong
authors.forename: J E
authors.initials: JE
authors.lastname: Tyler
authors.forename: S M
authors.initials: SM
authors.lastname: Willatts
authors.forename: C
authors.initials: C
authors.lastname: Prys-Roberts
mesh_terms: D000368:Aged; D003404:Creatinine / Q000097:blood; D004573:Electrolytes / Q000097:blood; D005260:Female; D005459:Fluorides / Q000097:blood*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000378:metabolism* / Q000494:pharmacology; D007530:Isoflurane / Q000378:metabolism* / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects*; D008297:Male; D008874:Midazolam / Q000378:metabolism / Q000494:pharmacology; D012121:Respiration, Artificial; D013997:Time Factors; D014508:Urea / Q000097:blood
chemical_list: D004573:Electrolytes; D006993:Hypnotics and Sedatives; D014508:Urea; D003404:Creatinine; D007530:Isoflurane; D005459:Fluorides; D008874:Midazolam