A series of studies of inhalation anesthetics distribution coefficient
|School||Peking Union Medical College , China|
|Keywords||Anesthetics, volatile Blood/gas partition coefficient Normal saline/gas partition coefficient Anesthetics, Volatile Blood/gas partition coefficient Equilibrated concentration Age Hypothermia Hemodilution Cardiopulmonary bypass Enflurane Liquid/gas partition coefficient Tissue/gas partition coefficient Tissue/blood partition coefficient Temperature|
Objective: To establish syringe-syringe double equilibrated method and to determine the reliability of this method for measuring liquid/gas partition coefficients of several volatile anesthetics simultaneously. Method: Standard gases were prepared as follows, 1) 0.76% desflurane; 2) 0.69% enflurane; 3) 0.38% halothane; and 4) mixture of 0.90% desflurane, 0.54% enflurane and 0.43% halothane. Blood/gas (B/G) and normal saline/gas (S/G) partition coefficients of desflurane, enflurane, and halothane were measured at 37℃, 1 atm separately and simultaneously using syringe-syringe double equilibration method by gas chromatography. Result: The B/Gs of desflurane, enflurane, and halothane measured separately were 0.523±0.040, 1.751±0.087, and 1.992±0.192, respectively; the respective S/Gs were 0.357±0.004, 0.760±0.014, and 0.754±0.013. The B/Gs of these three volatile anesthetics measured simultaneously were 0.501±0.045, 1.717±0.150, and 1.910±0.150 respectively; the respective S/Gs were 0.355±0.008, 0.768±0.004, and 0.759±0.003. For the B/G or S/G of desflurane, enflurane, and halothane, no significant difference was found between measured separately and simultaneously (P>0.05). Conclusion: It is reliable to measure the liquid/gas partition coefficients of several volatile anesthetics simultaneously.