Korean J Blood Transfus.  2016 Dec;27(3):220-228. 10.17945/kjbt.2016.27.3.220.

Optimal Phlebotomy Interval to Change Hematocrit Levels in Patients with Polycythemia

• Lee HJ
• Shin KH
• Song D
• Lee SM
• Kim HH

• KMID: 2368784
• DOI: http://doi.org/10.17945/kjbt.2016.27.3.220

Abstract

BACKGROUND
Phlebotomy is used to maintain hematocrit levels <45% to prevent polycythemia-related thrombotic events. However, guidelines for the phlebotomy intervals are lacking. Therefore, we analyzed post-phlebotomy changes in hematocrit and determined the optimal phlebotomy intervals for patients with polycythemia.
METHODS
Between March 2009 and August 2016, we performed 441 phlebotomies for 48 patients with polycythemia. Patients with high-risk polycythemia vera (PV) or secondary polycythemia with hypertension or arrhythmia were medicated with hydroxyurea. We divided the patients into three groups based on phlebotomy interval: <2 weeks, 2~4 weeks, and >4 weeks.
RESULTS
No patients with secondary polycythemia and 25.8% of the patients with PV had thrombotic events pre-phlebotomy. Post-phlebotomy, none of the patients experienced a thrombotic event. The average decrease in hematocrit level was significantly different between the three groups, being 1.98±1.90% (<2 weeks), 0.73±2.53% (2~4 weeks), and −0.46±4.80% (>4 weeks).
CONCLUSION
To prevent thrombotic events, phlebotomy is a safe and effective treatment to reduce hematocrit levels in patients with polycythemia, regardless of medication. For the maximum effect, a <2-week phlebotomy interval to reduce and <4-week phlebotomy interval to maintain hematocrit levels could be effective.

Keyword

Polycythemia; Thrombosis; Phlebotomy

MeSH Terms

Arrhythmias, Cardiac
Hematocrit*
Humans
Hydroxyurea
Hypertension
Phlebotomy*
Polycythemia Vera
Polycythemia*
Thrombosis
Hydroxyurea