Utility of postoperative hemoglobin testing following total shoulder arthroplasty

BACKGROUND: Identifying areas of excess cost for shoulder arthroplasty patients can play a role in effective health care spending. The purpose of this study was to assess the utility of postoperative complete blood count (CBC) testing after total shoulder arthroplasty (TSA) and identify which patients benefit from routine CBC testing. METHODS: We performed a retrospective review of a cohort of patients who underwent primary TSA from January 2018 through January 2019. All patients in this cohort received tranexamic acid. Patient demographic characteristics and patient-specific risk factors such as American Society of Anesthesiologists score, Elixhauser index, body mass index, smoking status, and coagulopathy history were obtained. Perioperative values including length of surgery, preoperative and postoperative hemoglobin (Hgb) levels, and need for transfusion were also obtained. RESULTS: This study included 387 TSA patients in the final analysis. Comparison between the cohort requiring transfusion and the cohort undergoing no intervention revealed no statistically significant differences in age, sex, body mass index, American Society of Anesthesiologists score, or Elixhauser index. The group receiving transfusions was found to have significantly lower levels of preoperative Hgb (11.3 g/dL) and postoperative Hgb (8.1 g/dL) (P < .0001). Additionally, the percentages of patients with abnormal preoperative Hgb levels (<12 g/dL) (72.3%) and postoperative day 1 Hgb levels < 9 g/dL (81.8%) were significantly higher in the group receiving transfusions (P < .0001). A multivariate regression model identified an abnormal preoperative Hgb level (<12 g/dL), with an odds ratio of 3.8 (95% confidence interval, 1.5-6.2; P < .001), and postoperative day 1 Hgb level < 9 g/dL, with an odds ratio of 3.3 (95% confidence interval, 0.4-6.1; P < .03), as significant predictors of the risk of transfusion with a sensitivity of 64% and specificity of 96.2% with an area under the curve of 0.87. CONCLUSION: Routine CBC testing may not be necessary for patients who receive tranexamic acid and have preoperative Hgb levels > 12 mg/dL and first postoperative Hgb levels > 9 mg/dL. This translates to potential health care cost savings and improves current evidence-based perioperative management in shoulder arthroplasty.