Changes in perioperative hemoglobin and hematocrit in patients undergoing total knee arthroplasty: a prospective observational study of optimal timing of measurement

Abstract

Objective This study was performed to depict the patterns of change in the perioperative hemoglobin (Hb) concentration and hematocrit (Hct) and to identify the optimal timing of Hb and Hct measurement in patients undergoing total knee arthroplasty (TKA). Methods This prospective observational study involved 302 consecutive patients who underwent TKA. The patients were kept in hospital for 1 full week postoperatively. Hb and Hct measurements were performed preoperatively and on days 1 to 7 postoperatively and then during clinic visits at 1, 3, and 6 months postoperatively. Results The Hb concentration and Hct decreased during the first few days postoperatively and reached a nadir on postoperative day 4 and 3, respectively; they then recovered in the following days. Significant differences in the Hb concentration and Hct were detected between the preoperative period and day 1, between days 1 and 2, between days 2 and 3, between day 7 and 1 month, and between 1 and 3 months. A significant difference in the Hct was also detected between 3 and 6 months. Conclusion The optimal timing of Hb and Hct measurement is on postoperative day 3 or 4. This timing accurately reflects ongoing hidden blood loss to better guide blood transfusions.

Comparing the Efficacy of Articulating Spacers in Two-Stage Revision for Periprosthetic Joint Infection Following Total Knee Arthroplasty: All-Cement Spacers vs Sterilized Replanted Metal-Polyethylene Spacers

“…Blood loss was calculated as follow according to previously reported: blood loss = [(preoperative HCT - HCT on the second day after operation)/preoperative HCT] × weight × 7% × 1000 + intraoperative blood transfusion. 21 Restricted flexion function is defined as the inability to reach 90° when the knee is flexed (a goniometer is used for measurement). In brief, the patient is asked to lay in a supine position; the fixed arm of the goniometer was parallel to the midline of the femur, the moving arm was parallel to the midline of the tibia, and the axis was located outside the center of the knee joint for measurement.…”

Postoperative Intravenous Iron Supplementation Increases Hemoglobin Level in Total Knee Arthroplasty

“…Transfusion is usually done within 3 days of TKA surgery in the presence of serious bleeding. 20 However, since iron supplementation is known to take effect approximately a week after administration, this may not be helpful to prevent transfusion in those in acute need of it. 21 Precision medicine, which concentrates on identifying the right patient in prescribing medicine, is currently an important concept for treating patients with osteoarthritis.…”

Are Risk Factors for Postoperative Significant Hemorrhage following Total Knee Arthroplasty Potentially Modifiable? A Retrospective Cohort Study

“…We defined a hemoglobin (Hb) drop as the difference between the preoperative Hb value and the lowest recorded postoperative Hb value, which was recorded at the third postoperative day as in previous studies [ 30 , 31 ] on TKA. As in previous studies [ 25 , 26 , 27 , 28 ], we divided our patients into two groups according to the Hb drop.…”