Neonatale polycytemie: Voorbeelden uit de praktijk en overzicht van de literatuur

Neonatal polycythaemia is defined as a complex of symptoms in association with a venous haematocrit higher than 65%. The incidence is reported as 1-5% of all neonates. The pathophysiology is characterised by an increased number of red blood cells resulting in increased blood viscosity causing malperfusion of various organs, with a diversity of symptoms. Several factors, known to be associated with neonatal polycythaemia, will be discussed. Haematocrit rises in the first hours after birth, explaining why symptoms may not be present directly after birth, but become severe a couple of hours after birth. As guidelines to perform a partial plasma exchange transfusion a haematocrit of more than 70%, without symptoms, or between 65-70%, with symptoms, can be used. Crystalloids are now preferred for partial plasma exchange transfusion, usually causing direct relief of symptoms. We report data of eight newborn infants with polycythaemia in the presence of various predisposing factors, presenting with symptoms of relative hypoxia. A symptomatic index case is described, in which symptoms disappeared after partial plasma exchange transfusion. The literature on the subject is discussed. If a new-born infant presents with symptoms consistent with possible polycythaemia, we advise to determine the haematocrit and, if polycythaemia is diagnosed, perform a physiologic saline partial plasma exchange transfusion without delay.