In a patient with hereditary hemochromatosis undergoing therapeutic phlebotomy, what hematocrit range should prompt holding or continuing the procedure?

Hematocrit Parameters for Holding Phlebotomy in Hereditary Hemochromatosis

Hold phlebotomy when hemoglobin falls below 11 g/dL, and reduce frequency or volume when hemoglobin is below 12 g/dL. 1

Pre-Procedure Monitoring Requirements

• Check hemoglobin or hematocrit before every single phlebotomy session during both induction and maintenance phases 1, 2
• This mandatory pre-procedure check prevents excessive anemia and ensures safe iron removal 2

Specific Hemoglobin Thresholds

Discontinue Phlebotomy

• Hemoglobin <11 g/dL: Stop all phlebotomy procedures immediately and reassess the patient's clinical status at a later time 1, 2

Reduce Frequency or Volume

• Hemoglobin <12 g/dL: Decrease the frequency of phlebotomy sessions, and in specific cases consider reducing the volume removed per session 1, 2
• This threshold allows for continued treatment while preventing progression to more severe anemia 1

Hematocrit-Based Parameters

• Do not allow hematocrit to fall by more than 20% of the baseline starting value 1, 2
• The older AASLD guideline specified maintaining hematocrit at ≥80% of the starting value, which is equivalent to the 20% maximum drop rule 1

Clinical Context and Rationale

The 2022 EASL guidelines provide the most current and specific hemoglobin-based thresholds, superseding the older hematocrit-based approach from the 2011 AASLD guidelines. 1 The hemoglobin thresholds are more practical for clinical use because:

• Hemoglobin measurements are more standardized across laboratories than hematocrit 1
• The 11 g/dL and 12 g/dL cutoffs provide clear action points that prevent both over-treatment (iron deficiency) and under-treatment 1
• These thresholds apply to both the induction phase (weekly/biweekly phlebotomy) and maintenance phase (every 1-4 months) 1

Common Pitfalls to Avoid

Overtreatment leading to iron deficiency: Sustained iron deficiency can develop if hemoglobin monitoring is infrequent or incorrectly interpreted, resulting in symptomatic anemia, microcytosis, and hypochromia that may persist for months. 3 This complication is entirely preventable with proper adherence to pre-phlebotomy hemoglobin checks. 3

Cardiac complications: Patients with pre-existing cardiac arrhythmias or cardiomyopathy face increased risk of sudden death with rapid iron mobilization, requiring more conservative hemoglobin thresholds and slower phlebotomy schedules. 1, 2