الملخص

Objectives: (1) To assess the prevalence of primary and secondary polycythaemia in our locality and their detailed clinical and haematological parameters. (2) To determine causes of secondary polycythaemia. (3) To establish a working formula for determining packed cell volume reduction after a given number of blood units donated. Methods: A prospective clinico- haematological case series study, done in Mosul teaching hospitals and central blood bank, including seventy two patients with raised packed cell volume. The patients were assessed by clinical evaluation, complete blood picture, coagulation tests, chemical tests, chest x-ray, echocardiography, ultrasound, in addition to arterial O2 saturation and pulmonary function tests. Results: The most common clinical features were headache, dizziness and plethora. The pruritus was present only in polycythaemia vera. Thrombotic complications present more in secondary polycythaemia. Raised packed cell volume and haemoglobin above normal value has been found in all patients. Leucocytosis and thrombocytosis was present in 12/42 patients with polycythaemia vera. Majority of patients with secondary polycythaemia (86.7%) have ventilatory defects. The effect of number of blood units donated and it’s frequency (in weeks) on the degree of packed cell volume reduction in patients treated with venesection was expressed by equations. Conclusions: Polycythaemia vera patients were younger than those with secondary polycythaemia and found mainly to affect males. All cases of secondary polycythaemia were due either to chronic lung disease or congenital heart disease. We have established an equation when applied to patients with polycythaemia can predict value of packed cell volume reduction after donating a given number of blood units. Keyword: Polycythaemia.