Extreme thrombocytosis in admissions to paediatric intensive care: no requirement for treatment.

Extreme thrombocytosis (ExtThr; platelet count > or =1000x10(9)/l) is uncommon but may have an increased occurrence in critically ill children. The incidence of ExtThr for children on the Paediatric Intensive Care Unit at Bristol Royal Hospital for Children between January 2001 and December 2004 was calculated, and the notes of children identified with ExtThr were reviewed for possible common aetiological factors, potential treatment regimes and outcome.