Predictors of perioperative blood loss in total joint arthroplasty.

Update The print version of this article has errors that have been corrected in the online version of this article. In the Materials and Methods section, the sentence that reads as “During the study period, our institution offered preoperative autologous blood donation to all patients who were scheduling for total joint arthroplasty with a hemoglobin level of no less than 11 mg/dL or a hematocrit level of at least 33%.” in the print version now reads as “During the study period, our institution offered preoperative autologous blood donation to all patients who were scheduling for total joint arthroplasty with a hemoglobin level of no less than 11 g/dL or a hematocrit level of at least 33%.” in the online version. In Table III, the footnote that reads as “The values are given as the estimate and the standard error in milligrams per deciliter.” in the print version now reads as “The values are given as the estimate and the standard error in grams per deciliter.” in the online version. Background: Despite advances in surgical and anesthetic techniques, lower-extremity total joint arthroplasty is associated with considerable perioperative blood loss. As predictors of perioperative blood loss and allogenic blood transfusion have not yet been well defined, the purpose of this study was to identify clinical predictors for perioperative blood loss and allogenic blood transfusion in patients undergoing total joint arthroplasty. Methods: From 2000 to 2008, all patients undergoing unilateral primary total hip or knee arthroplasty who met the inclusion criteria were enrolled in the study. Perioperative blood loss was calculated with use of a previously validated formula. The predictors of perioperative blood loss and allogenic blood transfusion were identified in a multivariate analysis. Results: Eleven thousand three hundred and seventy-three patients who underwent total joint arthroplasty, including 4769 patients who underwent total knee arthroplasty and 6604 patients who underwent total hip arthroplasty, were evaluated. Multivariate analysis indicated that an increase in blood loss was associated with being male (263.59 mL in male patients who had undergone total hip arthroplasty and 233.60 mL in male patients who had undergone total knee arthroplasty), a Charlson Comorbidity Index of >3 (293.99 mL in patients who had undergone total hip arthroplasty and 167.96 mL in patients who had undergone total knee arthroplasty), and preoperative autologous blood donation (593.51 mL in patients who had undergone total hip arthroplasty and 592.30 mL in patients who had undergone total knee arthroplasty). In patients who underwent total hip arthroplasty, regional anesthesia compared with general anesthesia reduced the amount of blood loss. The risk of allogenic blood transfusion increased with the amount of blood loss in the patients who underwent total hip arthroplasty (odds ratio, 1.43 [95% confidence interval, 1.40 to 1.46]) and the patients who underwent total knee arthroplasty (odds ratio, 1.47 [95% confidence interval, 1.42 to 1.51]), but the risk of blood transfusion increased with the Charlson Comorbidity Index only in patients who underwent total knee arthroplasty (odds ratio, 3.2 [95% confidence interval, 1.99 to 5.15]). The risk of allogenic blood transfusion decreased with preoperative autologous blood donation in patients who underwent total hip arthroplasty (odds ratio, 0.01 [95% confidence interval, 0.01 to 0.02]) and patients who underwent total knee arthroplasty (odds ratio, 0.02 [95% confidence interval, 0.01 to 0.03]). Conclusions: This study identified some clinical predictors for blood loss in patients undergoing total joint arthroplasty that we believe can be used for implementing more effective blood conservation strategies. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.