title: Plasma inorganic fluoride concentrations after sevoflurane anesthesia in children.
abstract: BACKGROUND
  Sevoflurane is degraded in vivo in adults yielding plasma concentrations of inorganic fluoride [F-] that, in some patients, approach or exceed the 50- micron theoretical threshold for nephrotoxicity. To determine whether the plasma concentration of inorganic fluoride [F-] after 1-5 MAC x h sevoflurane approaches a similar concentration in children, the following study in 120 children scheduled for elective surgery was undertaken.
  
  
  METHODS
  Children were randomly assigned to one of three treatment groups before induction of anesthesia: group 1 received sevoflurane in air/oxygen 30% (n = 40), group 2 received sevoflurane in 70% N2O/30% O2 (n = 40), and group 3 received halothane in 70% N2O/30% O2 (n = 40). Mapleson D or F circuits with fresh gas flows between 3 and 61/min were used Whole blood was collected at induction and termination of anesthesia and at 1, 4, 6, 12, and 18 or 24 h postoperatively for determination of the [F-]. Plasma urea and creatinine concentrations were determined at induction of anesthesia and 18 or 24 h postoperatively.
  
  
  RESULTS
  The mean (+/- SD) duration of sevoflurane anesthesia, 2.7 +/- 1.6 MAC x h (range 1.1-8.9 MAC x h), was similar to that of halothane, 2.5 +/- 1.1 MAC x h. The peak [F-] after sevoflurane was recorded at 1 h after termination of the anesthetic in all but three children (whose peak values were recorded between 4 and 6 h postanesthesia). The mean peak [F-] after sevoflurane was 15.8 +/- 4.6 microns. The [F-] decreased to <6.2 microns b 24 h postanesthesia. Both the peak [F-] (r2 = 0.50) and the area under the plasma concentration of inorganic fluoride-time curve (r2 = 0.57) increased in parallel with the MAC x h of sevoflurane. The peak [F-] after halothane, 2.0 +/- 1.2 microns, was significantly less than that after sevoflurane (P<0.00012) and did not correlate with the duration of halothane anesthesia (MAC x h; r2 = 0.007). Plasma urea concentrations decreased 24 h after surgery compared with preoperative values for both anesthetics (P<0.01), whereas plasma creatinine concentrations did not change significantly with either anesthetic.
  
  
  CONCLUSIONS
  It was concluded that, during the 24 h after 2.7 +/- 1.6 MAC x h sevoflurane, the peak recorded [F-] is low (15.8 microns), F- is eliminated rapidly, and children are unlikely to be at risk of nephrotoxicity from high [F-].
authors.affiliation: Department of Anaesthesia, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: M F
authors.initials: MF
authors.lastname: Levine
authors.forename: J
authors.initials: J
authors.lastname: Sarner
authors.forename: J
authors.initials: J
authors.lastname: Lerman
authors.forename: P
authors.initials: P
authors.lastname: Davis
authors.forename: N
authors.initials: N
authors.lastname: Sikich
authors.forename: K
authors.initials: K
authors.lastname: Maloney
authors.forename: E
authors.initials: E
authors.lastname: Motoyama
authors.forename: D R
authors.initials: DR
authors.lastname: Cook
mesh_terms: D018685:Anesthetics, Inhalation / Q000493:pharmacokinetics*; D002648:Child; D002675:Child, Preschool; D004987:Ethers / Q000009:adverse effects / Q000493:pharmacokinetics*; D005459:Fluorides / Q000097:blood*; D006221:Halothane / Q000009:adverse effects / Q000493:pharmacokinetics; D006801:Humans; D007223:Infant; D007668:Kidney / Q000187:drug effects; D008738:Methyl Ethers; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D004987:Ethers; D008738:Methyl Ethers; D000077149:Sevoflurane; D005459:Fluorides; D006221:Halothane