BackgroundDuring general anesthesia, a heated breathing circuit (HBC) is used to replace the heat and moisture exchange function of the upper airway. One HBC uses an air dryer filter that employs silica gel (SG) as a desiccant. SG is capable of adsorbing many organic compounds. Therefore, we undertook an in vitro study of the adsorption of desflurane by SG filters.MethodsAn HBC was connected to an anesthesia machine, and a test lung was connected to the circuit. The test lung was mechanically ventilated with 2 or 4 L/min of fresh gas flow, with and without the air dryer filter. Desflurane was administered at a 6 vol% on the vaporizer dial setting. The experiment was repeated 15 times in each group. The end-tidal concentrations were measured during the experiments. The air dryer filter weights were measured before and after the experiments, and the times required to achieve the specific end-tidal desflurane concentrations were determined.ResultsSignificant differences in the end-tidal concentrations of desflurane were observed between the control and filter groups (P < 0.001). The filter weights increased significantly after the experiments (P < 0.001). The times required to achieve the same end-tidal desflurane concentrations were different with the application of the air dryer filter (P < 0.001).ConclusionsThe adsorption of desflurane with the use of an air dryer filter was verified in this in vitro study. Careful attention is needed when using air dryer gel filters during general anesthesia.

A review of the literature regarding combined liver-kidney transplantation (CLKT) does not provide adequate central venous pressure (CVP) values that would allow for unimpaired hepatic venous outflow and early renal allograft diuresis during the procedure. We report a case of fluid management of CLKT based on the limited literature available in a 59-year-old male with liver cirrhosis and end-stage renal disease. During the preanhepatic phase, CVP was maintained at 5 mmHg. Following portal vein clamping, CVP was reduced to below 5 mmHg until venovenous bypass was initiated. From the neohepatic phase to 1 hour before renal allograft reperfusion, CVP was slowly increased to 10 mmHg. Within an hour before renal allograft reperfusion, maximal crystalloid hydration was used to increase CVP to 15 mmHg. The urine output was replaced to maintain CVP at 8 to 10 mmHg until the end of the surgery. The postoperative course was uneventful. In conclusion, fluid management tailored to each phase yielded beneficial results in a patient with CLKT.