The effect of intravenous tranexamic acid on visual clarity in arthroscopic shoulder surgery compared to epinephrine and a placebo: a double-blinded, randomized controlled trial

Background: The addition of epinephrine in irrigation fluid and the intravenous or local administration of tranexamic acid have independently been reported to decrease bleeding, thereby improving surgeons' visualization during arthroscopic shoulder procedures. No study has compared the effect of intravenous tranexamic acid, epinephrine in the irrigation fluid, or the combination of both tranexamic acid and epinephrine on visual clarity during shoulder arthroscopy with a placebo group. We hypothesized that intravenous tranexamic acid is more effective than epinephrine mixed in the irrigation fluid in improving visualization during shoulder arthroscopy, with no additive effect when both are used. Methods: Patients aged >= 18 years undergoing shoulder arthroscopy were randomized into one of 4 study arms: (1) saline irrigation fluid (placebo); (2) epinephrine (0.33 mL of 1:1000 per liter) mixed in irrigation fluid (EPI); (3) 1 g intravenous tranexamic acid (TXA); and (4) epinephrine and tranexamic acid combined (TXA + EPI). Visualization was rated intraoperatively on a scale from 0, indicating poor clarity, to 3, indicating excellent clarity, every 15 minutes and overall. The primary outcome measure was the overall rating of visualization. A stepwise linear regression was performed using visualization as the dependent variable and independent variables including presence or absence of epinephrine and tranexamic acid, surgery duration, complexity, mean arterial pressure, increase in pump pressure, and volume of irrigation fluid. Results: One hundred twenty-eight patients (mean age 56 years) were randomized. Mean visual clarity for the placebo, TXA, EPI, and TXA + EPI groups were 2.0 (+/- 0.6), 2.0 (+/- 0.6), 2.6 (+/- 0.5), and 2.7 (+/- 0.5), respectively (P < .001). The presence or absence of epinephrine was the most significant predictor of visual clarity (P < .001). Tranexamic acid presence or absence had no effect. No adverse events were recorded in any of the groups. Conclusion: Intravenous tranexamic acid is not an effective alternative to epinephrine in irrigation fluid to improve visualization during routine arthroscopic shoulder surgeries, and there is no additive effect when both are used.