Slight variants of the schemes were applied in two patients of group S (in one patient 0.5 litres min ā1 was used, and the vaporizer was set to 8 vol% in another) and in six patients of group F (4 vol% during stage 1 and 0.5 litres min ā1 during stage 2; Table 3). Recovery from the anaesthetic was uneventful in all patients..