This case report showed that chronic polycythemia could be associated with peripheral shunting that might reduce patient’s tolerance to acute isovolemic hemodilution.

– P. Van der Linden.

The authors have seen the deleterious effects of diluting a patient from an initial hematocrit (Hct) of 59% down to a Hct of 30%. This information is very important. However, I was surprised to read that the authors did not find in the literature any report on the effects of acute isovolemic hemodilution in polycythemic individuals. Isovolemic hemodilution has long been performed in polycythemic patients (see, for example, Saumarez RC et al. Bibl Haematol 1975;(41):278-93). So far, it has been suggested in the literature to reduce the hematocrit of polycythemic patients in the range of normal hematocrit values but not down to 30%.

– K. Messmer.