对行心内直视手术的患者吸入氟化麻醉药（如：氟烷、甲氧氟烷、恩氟醚和异氟醚中的一种）后，血清无机氟离子（F-）浓度升高，最高峰值为甲氧氟烷组（20.6μmol/L）恩氟醚组（8.0μmol/L)异氟醚组（4.3μmol/L)氟烷组（4.0μmol/L）。与常温手术相比，其排列顺序相同，但峰值要低。本文讨论了体外循环对血清F-浓度的影响以及预防血清F-浓度升高所致肾损害的关键措施。

Volatile anaesthetics are often used during cardiopulmonary bypass (CPB). To understand the kinetics of inhaled anaesthetics during CPB, anaesthetists should understand changes in blood solubility caused by fluid use. We set out to predict the solubility of three volatile anaesthetics, desflurane. isoflurane and halothane, during CPB by determining; (i) their solubility in fresh whole blood and eight CPB priming fluids at 37℃; (ii) the effect of temperature on the solubility of these anaesthetics in lactated Ringer's, gelofusin, banked blood and plasma; (iii) their solubilith in different mbotures of these four priming fluids at different temperatures; and (iv) their estimated and actual solubility in blood during hypothermic CPB, We calculated solubilith using a concept of volume fraction partition coefficient and compared estimated and measured solubilities. For the three anaesthetics tested, solubilities are in the order. fresh whole blood=plasma＞banked blood＞normal saline=lactated Ringer's=gelofusin=Haemaccel=hydroxyethyl starch＞mannitol. The solubilities of the anaestheties in all priming fluids increased logarithmically at lower temperatures (p＜0.05). The volume-fraction estimates of the partition coefficients were within approximately ±20% of the measured values for all values of solubility. The corresponding estimates of solubility for CPB blood sampies were between-36% and +24% of the measured values. During normothermic CPB, blood solubility of volatile anaesthetics would be unchanged when using plasma, slightly reduced when using banked blood and markedly reduced when using crystalloids and coiloids.

Neither lipophilicity nor vapor pressure of larger n-al-kanes appear to correlate with their anesthetizing partial pressures in inspired gas. Such results suggest that the Meyer-Overton hypothesis and Ferguson's rule may not apply to these compounnds. An alternative explanation might be that a large difference in inspiredto-arterial partial pressure exists, i.e., that the inspired partial pressure misrepresents the effective partial pressure. To test this explanation, we investigated the kinetics of five consecutive even-numbered n-alkanes (C2H6 to C10H22) in rats. The ratio of end-tidal-to-inspired (PA/P1), arterial-to-end-tidal (Pa/PA), and arterial-to-inspired (Pa/P1) pressures decreased with increasing carbon chain length, consistent with our separate finding that blood solubility increased. Using Pe/P1 and the minimum inspired concentration (MIC) obtaihed previously, we calculated the true effective potency, minimum alveolar anesthetic concentration (MAC); of these n-alkanes as (Pa/P1)(MIC). This markedly improved, but did not perfectly correct, the correlation of MAC with lipid solubility (the Meyer. Overton hypothesis) and vapor pressure (Ferguson's rule). A coefficient of variation of 76.7% was found for the product of MAC and the olive oil/gas partition coefficient. More importantly, the correlation of the logarithm of MAC and oil solubility had a slope of 0.724(i.e., deviated from-1.0), whereas the slope for eight conventional anesthetics was-1.046 (approached-1.0). These data imply that olive oil does not adequatelv mimic the nature of the anesthetic site of action of n-alkanes.