[Pseudohypoxemia and a myeloproliferative syndrome]

In the interval between the sampling of blood and analysis of the blood gas composition, the partial pressure of oxygen falls. The rate of fall depends on the temperature, initial level of partial pressure of oxygen in arterial blood, white cell and platelet count. Pseudohypoxaemia secondary to leukaemia and thrombocytosis can be recognized if the arterial blood sample is kept in ice until analysis can be carried out.