EFFECT OF PARTIAL-PRESSURE ON SOLUBILITY OF ISOFLURANE IN BLOOD

The effect of partial pressure of isoflurane on its solubility in bloo d of different haematocrit was determined at different isoflurane part ial pressures, using a syringe-flask method and gas chromatography wit h blood from one donor. The solubility of isoflurane decreased with in creasing blood haematocrit (39.5%, 51.9% and 61.9%) and isoflurane par tial pressure from 1 MAC to 4 MAC. The solubility in 50% and 60% haema tocrit blood at 2, 3 and 4 MAC was significantly different from the so lubility in normal blood at 1 MAC (P<0.05). We conclude that the solut ion of isoflurane in blood (especially in high haematocrit blood) does not obey Henry's law.