Fluoride metabolism in smokers and non-smokers following enflurane anaesthesia.
BACKGROUND
Inorganic fluoride is released by the metabolism of enflurane and the increased serum fluoride concentrations may impair renal function. Tobacco smoke consists of numerous reactive compounds that can either induce or inhibit drug metabolism. Studies on the interaction of smoking with anaesthetic drug metabolism and possible toxicity are warranted.


METHODS
Sixteen non-smoking and 17 smoking (>10 cigarettes day(-1)) generally healthy women undergoing elective gynaecological surgery were given 1 MAC (minimum alveolar concentration)-hour standardized anaesthesia with enflurane in oxygen-air mixture. The serum inorganic fluoride and renal function markers beta(2)-microglobulin, tumour-associated trypsin inhibitor (TATI) and serum creatinine were measured for 48 h.


RESULTS
The greatest inorganic fluoride concentration was between 8.4 and 21.0 (mean 13.8 (SD 3.4)) micromol litre(-1) in the non-smokers and between 8.6 and 38.0 (18.7 (7.0)) micromol litre(-1) in the smokers; the mean difference was 4.9 micromol litre(-1) (95% confidence interval (CI) 1.0-8.8, P<0.05). Serum beta(2)-microglobulin, TATI and creatinine were not increased. Serum inorganic fluoride concentrations were significantly greater in the smokers compared with the non- smokers 1, 2, 3 and 6 h after 1 MAC-hour inhalation with enflurane (P<0.05). Inorganic fluoride concentrations were still increased 24 h after anaesthesia in both groups. Urine beta(2)-microglobulin and TATI creatinine ratio remained at low values during the whole 48-h period in both groups.


CONCLUSIONS
Regular smoking is associated with an increase in serum inorganic fluoride concentration after anaesthesia with enflurane, but there are no signs of renal damage.
Laisalmi
M
M
Department of Anaesthesia and Intensive Care Medicine, Helsinki University Hospital, Helsinki, Finland. merja.laisalmi@kuh.fi
Soikkeli
A
A
Kokki
H
H
Markkanen
H
H
Yli-Hankala
A
A
Rosenberg
P
P
Lindgren
L
L
D000328:Adult; D018685:Anesthetics, Inhalation / Q000009:adverse effects / Q000378:metabolism*; D003404:Creatinine / Q000097:blood; D004737:Enflurane / Q000009:adverse effects / Q000378:metabolism*; D005260:Female; D005459:Fluorides / Q000097:blood*; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000503:physiopathology; D008875:Middle Aged; D011446:Prospective Studies; D012907:Smoking / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D018709:Statistics, Nonparametric; D014359:Trypsin Inhibitor, Kazal Pancreatic / Q000097:blood; D001613:beta 2-Microglobulin / Q000097:blood
D018685:Anesthetics, Inhalation; D001613:beta 2-Microglobulin; D014359:Trypsin Inhibitor, Kazal Pancreatic; D004737:Enflurane; D003404:Creatinine; D005459:Fluorides