Renal concentrating function with prolonged sevoflurane or enflurane anesthesia in volunteers.
BACKGROUND
Sevoflurane, a new inhalational anesthetic, is biotransformed, producing peak plasma inorganic fluoride concentrations that may exceed 50 microM. We evaluated plasma inorganic fluoride concentrations with prolonged (> 9 MAC-h) sevoflurane or enflurane anesthesia in volunteers and compared renal concentrating function with desmopressin testing 1 and 5 days after anesthesia.


METHODS
Fourteen healthy male volunteers received either enflurane or sevoflurane (1-1.2 MAC) for more than 9 MAC-h. Each volunteer was administered three tests of renal concentrating function, with intranasal desmopressin and urine collections performed 1 week before anesthesia and 1 and 5 days after anesthesia. Venous blood samples were obtained for plasma fluoride concentrations during and after anesthesia. Creatinine clearance was determined by 24-h urine collections 7 days before and 4 days after anesthesia. Urine samples were obtained before and 1, 2, and 5 days after anesthesia for determination of n-acetyl-beta-glucosaminidase and creatinine concentrations.


RESULTS
Prolonged sevoflurane anesthesia (9.5 MAC-h) did not impair renal concentrating function on day 1 or 5 postanesthesia, as determined by desmopressin testing. Maximal urinary osmolality on day 1 postanesthesia was decreased (< 800 mOsm/kg) in two of seven enflurane-anesthetized volunteers; however, mean results did not differ from the those of the sevoflurane group. Mean peak plasma fluoride ion concentrations were 23 +/- 1 microM 6 h postanesthesia for enflurane and 47 +/- 3 microM at the end of anesthesia for sevoflurane (P < 0.01). There were no changes in creatinine clearance or urinary n-acetyl-beta-glucosaminidase concentration in either anesthetic group.


CONCLUSIONS
Prolonged sevoflurane anesthesia did not impair renal concentrating function, as evaluated with desmopressin testing 1 and 5 days postanesthesia in healthy volunteers. Although with prolonged enflurane anesthesia, mean maximal osmolality values on day 1 postanesthesia did not differ from sevoflurane values, there was evidence in two volunteers at this time point of impairment in renal concentrating function, which normalized 5 days postanesthesia. These results occurred despite a higher peak plasma fluoride ion concentration and greater total inorganic fluoride renal exposure with sevoflurane anesthesia.
Department of Anesthesiology, University of Arizona Health Sciences Center, Tucson 85724.
E J
EJ
Frink
T P
TP
Malan
R J
RJ
Isner
E A
EA
Brown
S E
SE
Morgan
B R
BR
Brown
D000118:Acetylglucosaminidase / Q000652:urine; D000328:Adult; D000769:Anesthesia, Inhalation; D000777:Anesthetics / Q000494:pharmacology*; D003404:Creatinine / Q000378:metabolism; D003894:Deamino Arginine Vasopressin; D004737:Enflurane / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D004987:Ethers / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D005459:Fluorides / Q000097:blood*; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008738:Methyl Ethers; D012016:Reference Values; D000077149:Sevoflurane; D013997:Time Factors
D000777:Anesthetics; D004987:Ethers; D008738:Methyl Ethers; D000077149:Sevoflurane; D004737:Enflurane; D003404:Creatinine; D000118:Acetylglucosaminidase; D003894:Deamino Arginine Vasopressin; D005459:Fluorides