Preoperative Platelet and International Normalized Ratio Thresholds and Risk of Complications After Primary Hip Fracture Surgery.

BACKGROUND A paucity of data exists on safe platelet and international normalized ratio (INR) thresholds for hip fracture surgery. Recent work has called into question the safety of preoperative INRs 1.0 to 1.5, >1.5 to 2.0, and >2.0, respectively). Multivariable logistic regressions were used to assess the independent association between platelet count and INR on bleeding complications requiring transfusion, wound complications, reoperations, readmissions, and deaths. RESULTS A total of 72,306 and 56,027 patients were included for analysis of preoperative platelet and INR levels, respectively. In reference to platelet levels ≥150 k/μL, a notably increased risk of bleeding events was observed for patients with platelet counts ≥100 k to 150 k/μL (odds ratio [OR] 1.21, 95% confidence interval 1.15 to 1.27), ≥50 to 100 k/μL (OR 1.85, 1.69 to 2.03), and 1.5. DISCUSSION The results of this study suggest that preoperative platelet thresholds of <100,000/μL and INR thresholds of 1.5 serve as an important risk factor for complications after hip fracture surgery. Future work is warranted to determine whether preoperative platelet transfusions and/or INR reversal will improve outcomes for these patients. LEVEL OF EVIDENCE Prognostic Level III.