George is correct, FVC is forced vital capacity. I think the "-Med" suffix is being used in the Spanish ST to designate the measured or observed FVC, as opposed to the predicted FVC, based on the patient's age, height, weight, ethnicity, & for some published studies, other factors such as smoking history.
So the patient's FVC-Med here is 0.85, for which the standard unit is litres. This is a very low value, basically off the charts low. "FVC-%" is normally the patient's measured FVC divided by the predicted FVC, times 100. For the case cited, the predicted FVC would be calculated to be about 1.25 litres; this is in the neighborhood of the range for a very elderly, slight individual - but just barely.