Efficacy of Repeated High-Dose Versus Intermediate-Dose Intravenous Dexamethasone in Reducing Pain After Bilateral Total Knee Arthroplasty: A Randomized Clinical Trial.

Background: The optimal dose of intravenous (IV) dexamethasone for bilateral one-stage total knee arthroplasty (BTKA) remains controversial. Therefore, this study aimed to evaluate the efficacy of administering repeated high-dose IV dexamethasone compared to repeated intermediate-dose dexamethasone for BTKA. Methods: In this randomized, triple-blinded, clinical trial of 46 patients who underwent BTKA were randomly divided into 2 groups. The high-dose group received 16 mg of IV dexamethasone before surgical incision and a repeated dose at 24 hours postoperatively. The intermediate-dose group received 8 mg of dexamethasone at the same time points. The outcomes measured included visual analog scale (VAS) for pain intensity during motion and at rest, morphine consumption (MC), knee flexion angle, knee strength, knee circumference, timed up and go, frequency of postoperative nausea and vomiting, high-sensitivity C-reactive protein, blood glucose levels, and complications. Results: No significant differences were found between groups regarding VAS, except the high-dose group reporting lower VAS during motion only at 24 hours postoperatively (mean difference: -0.9, P < .001). The high-dose group had lower overall MC during the hospital stay (mean difference: -2.22 mg, P = .030) and smaller knee circumference at 24 and 72 hours (P < .05). However, the difference in VAS and MC did not reach the minimal clinically important difference (1.8 points and 10 mg, respectively). No significant differences were found between groups regarding functional recovery outcomes and biomarkers. Conclusions: Repeated high-dose IV dexamethasone provides comparable clinical outcomes to the intermediate-dose IV dexamethasone. Therefore, intermediate-dose IV dexamethasone may be sufficient for controlling pain and inflammatory response in BTKA setting.