We don't have synonyms for hypoxaemia yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are hyperaemia, hypoxemia and hypohaemia.
(n) :
Alternative spelling of hypoxemia. [(medicine) An abnormal deficiency in the concentration of oxygen in the blood, be it the partial pressure of oxygen (mm Hg), the content of oxygen (ml oxygen per dl of blood) or the per cent saturation of the blood's hemoglobin, singly or in combination.]
(n) :
Alternative spelling of hypoxemia. [(medicine) An abnormal deficiency in the concentration of oxygen in the blood, be it the partial pressure of oxygen (mm Hg), the content of oxygen (ml oxygen per dl of blood) or the per cent saturation of the blood's hemoglobin, singly or in combination.]