Interventions and Randomization
The patients receiving different
dosing schedules of rhEPO were randomly divided into three groups. The
patients in group A received 10,000 IU of subcutaneous rhEPO (1 ml)
daily from preoperative day 5 to postoperative day 3 (9 doses); the
patients in group B received 1 ml of subcutaneous normal saline daily
from preoperative day 5 to day 3 and then 10,000 IU of subcutaneous
rhEPO daily until postoperative day 3 (6 doses); and the patients in
group C received 1 ml of subcutaneous normal saline daily from
preoperative day 5 to the day before surgery and then 10,000 IU of
subcutaneous rhEPO daily from the surgery day to postoperative day 3 (4
doses). If the Hb level exceeded 150 g/L, rhEPO was stopped. All
patients received a daily dose of 100 mg intravenous ferric
carboxymaltose when given subcutaneous rhEPO, which has been widely
accepted as an effective partner with rhEPO for autologous blood
donation in patients undergoing arthroplasty (9).
A random allocation sequence was computer-generated and concealed in
consecutively numbered, opaque, sealed envelopes by a research
statistician who was not involved in the data analysis. One experienced
surgeon enrolled the patients, and another recorded the basic details.
The envelope was opened after the patients were enrolled, and the study
medication and placebo were prepared by a dedicated nurse who was not
involved in daily patient care or outcome measurement. Patients,
surgeons, anaesthesiologists, care providers, and data collectors were
blinded to the allocation sequence. The placebo (normal saline) has the
same appearance (colourless and clear liquid) as rhEPO.