Haematological Response to Therapeutic Phlebotomy in Patients with Erythrocytosis: A Retrospective Cohort Study Of 134 Patients at a Tertiary Care Centre

Abstract

Background: Therapeutic phlebotomy is used to manage selected conditions associated with erythrocytosis and iron overload. Although its clinical role is established in specific indications, the magnitude of haematological response and treatment patterns in routine tertiary-care practice require evaluation in appropriately characterised patient cohorts.

Objective: To evaluate changes in haemoglobin and haematocrit following therapeutic phlebotomy and to describe treatment characteristics and associated changes in blood volume and plasma volume among patients treated at a tertiary-care centre.

Methods: This retrospective cohort study included 134 patients who underwent therapeutic phlebotomy between January 2022 and December 2023. Clinical records were reviewed for patient characteristics, indications for treatment, number of procedures, volume of blood removed, and available pre- and post-treatment laboratory measurements. Paired outcome comparisons were performed using appropriate statistical methods. The study was reported in accordance with the STROBE recommendations for observational research.

Results: The mean haemoglobin decreased from 17.6 ± 1.6 to 17.2 ± 1.7 g/dL, while mean haematocrit decreased from 54.2 ± 4.6% to 52.6 ± 4.7%. Mean blood volume decreased from 69.4 ± 4.0 to 66.6 ± 4.5 mL/kg, and mean plasma volume changed from 31.6 ± 3.5 to 31.5 ± 3.9 mL/kg. Paired statistical analyses, effect estimates and confidence intervals are required to establish the precision and statistical significance of these changes.

Conclusion: The observed pre- and post-treatment differences suggest a reduction in haemoglobin, haematocrit and estimated or measured blood volume following therapeutic phlebotomy. The clinical significance of these changes and their relationship to diagnosis-specific treatment targets require further evaluation.