Complete blood count before and after total hip or knee arthroplasty

To validate our transfusion protocol based on pre- and post-operative complete blood count (CBC) data in patients undergoing primary total hip or knee arthroplasty (THA or TKA).

Records of 113 men and 205 women aged 32 to 94 (mean, 70) years who underwent primary uncemented THA (n=123) or cemented TKA (n=195) for osteoarthritis by 2 senior surgeons were reviewed. A post-surgical drain was used in 29 THA patients and 74 TKA patients, based on the surgeon's preference. CBC was assessed preoperatively, during postanaesthesia care, and at the beginning of postoperative days 1, 2, and 3 to determine their predictive power for transfusion rate. According to our transfusion protocol, blood was transfused when the haemoglobin (Hb) level was <80 g/l, or when hypotension, tachycardia, light-headedness, dizziness, or syncope occurred.

Respectively in 123 and 195 patients who underwent THA and TKA, the transfusion rates within 3 days were 31.7% (n=39) and 25.6% (n=50). No patient required transfusion during postanaesthesia care; the transfusion rates of all patients during day 1 to day 2 and day 2 to day 3 were 15.1% (n=48) and 12.9% (n=41), respectively. The transfusion rate was higher in women than men (36.6% vs. 12.4%, p<0.001), but did not differ significantly in patients with or without a post-surgical drain (29.1% vs. 27.4%, p=0.754). Respectively for the Hb level of <130 g/l, 130-150 g/l, and >150 g/l, the overall transfusion rates were 48.5%, 22.0%, and 4.3% based on the preoperative level; 32.6%, 7.6%, and 0% based on the postanaesthesia care level; and 28.9%, 8.3%, and 0% based on the day 1 level. The predictive power of the preoperative Hb level was highest, followed by that during postanaesthesia care and the on day 1.

CBC during postanaesthesia care is no more predictive than preoperative CBC. Preoperative optimisation and close monitoring of the Hb level from day 1 to day 3 is recommended.