Blood management in total hip arthroplasty: a nationwide trend analysis from 2011 to 2018.

PURPOSE: With the advent of practice changes surrounding preoperative patient optimization and postoperative protocols, a marked reduction has been reported in blood transfusion rates following total hip arthroplasty (THA). Thus, the purpose of this study was to examine differences in the prevalence of preoperative anemia, thrombocytopenia, elevated international normalized ratio (INR), bleeding disorders, and pre- and postoperative blood transfusions over the last decade.

METHODS: From 2011 to 2018, the American College of Surgeons National Quality Improvement Program database was queried for all primary THA procedures (n = 208,796). The following continuous variables were examined using analysis of variance: preoperative hematocrit (HCT), platelet count, and INR. The following categorical variables were analyzed by chi-squared tests: anemia (HCT < 35.5% for females and < 38.5% for males), thrombocytopenia (platelet count < 150,000/µL), INR > 2.0, bleeding disorders, preoperative transfusions, and postoperative transfusions.

RESULTS: There were decreases in preoperative anemia (2011: 16.2%; 2018: 11.4%, p < 0.001) and postoperative transfusions (2011: high = 22.2%; 2018: low = 1.3%, p < 0.001). Statistically significant but clinically irrelevant changes were observed in preoperative HCT (2011: low = 40.3, 2018: high = 41.1, p < 0.001), platelet count (2011: low = 248,700; 2018: high = 250,100, p < 0.001), thrombocytopenia (2011: high = 4.9%; 2018: low = 4.3%, p = 0.036), INR > 2.0 (2011: high = 1.1%; 2018: low = 0.7%, p = 0.001), bleeding disorders (2011: high = 2.9%; 2018: low = 2.0%, p < 0.001), and preoperative transfusions (2011: high = 0.2%; 2018: low = 0.1%, p = 0.007).

CONCLUSION: Large decreases in the number of patients with preoperative anemia and those receiving postoperative blood transfusion were observed during the study period. Future investigation is needed to ascertain whether this is due to patient optimization, practice changes, "cherry-picking" of healthy patients, or a combination of these factors.

LEVEL OF EVIDENCE: III.