Correlation between renal function and pharmacokinetic parameters of inorganic fluoride following sevoflurane anesthesia

We studied the correlation between renal function and pharmacokinetic parameters of inorganic fluoride following sevoflurane anesthesia. In 30 neurosurgical patients aged 40–70 years, anesthesia was induced with midazolam and sevoflurane and maintained with sevoflurane and nitrous oxide in oxygen. Serum and urine inorganic fluoride (F⁻) levels and β₂-microglobulin (BMG), blood urea nitrogen (BUN), and serum creatinine (Cr) were measured during and after anesthesia. The decrease rate of serum F⁻ level and the area under the curve (AUC) of serum F⁻ were calculated. Correlations among sevoflurane dosage, duration of administration, peak serum F⁻ level, AUC, the decrease rate of serum F⁻ level, and the maximum values in BUN, Cr, and urine BMG during the study were investigated. Urine BMG increased significantly after surgery but returned to the preoperative level in a week. BUN, Cr, and serum BMG remained within normal ranges during the study. Sevoflurane dosage and duration of administration were significantly correlated with AUC and the maximum value of urine BMG, but not with the peak serum F⁻ level or the decrease rate of serum F⁻. AUC was significantly correlated with the maximum value of urine BMG. In sevoflurane anesthesia, sevoflurane dosage, duration of administration, and AUC affected urine BMG level, but not peak serum F⁻.