Figure 2.

Frequency histogram showing the number of units of red cells produced by washed post-operative cell salvage per case of total hip arthroplasty on data from 75 patients. One unit of packed red blood cells contains 200 mL of red cell mass. Cases with red cell mass <200 mL was considered to be 0 Units, 200–400 mL was 1 Unit, 400–600 mL was 2 Units, 600–800 mL was 3 units, and 800–1000 mL was 4 units.