A Single Preoperative Low Dose of Dexamethasone Is Efficacious in Improving Early Postoperative Pain, Function, Nausea, and Vomiting After Primary Total Knee Arthroplasty: A Randomized, Double-Blind, Placebo-Controlled Trial.

Background: The primary objective was to evaluate a single preoperative low-dose (8 mg) dexamethasone (DXM) efficacy in relieving postoperative pain in patients undergoing total knee arthroplasty (TKA). The secondary objectives were to assess its effect on postoperative nausea and vomiting (PONV), C-reactive protein (CRP) levels, and early wound complications incidence.

Methods: This was a single-center, double-blind, randomized controlled trial. We included 86 unilateral primary TKA divided equally into two groups (placebo [Group A] and DXM [Group B], as a single intravenous dose given after anesthesia). Postoperative pain was assessed as the primary outcome at rest and while walking using a visual analog scale (VAS). Secondary outcomes included PONV evaluated using VAS for postoperative nausea. The following variables were evaluated: the Time Up and Go test, serum CRP, quadriceps muscle power, and wound complications. All outcomes were reported in the first three days and at 14 days follow-up visit.

Results: Both groups' baseline data were comparable. Group B reported significantly less pain at rest and walking throughout all time points (P < 0.001). Group B had fewer vomiting episodes on postoperative days one and two (P = 0.195 and 0.747, respectively) and no difference in PONV VAS score. Group B had significantly lower Time Up and Go test scores for postoperative days one and two (P = 0.029 and 0.016, respectively) and significantly better quadriceps muscle power on postoperative days two and three (P = 0.042 and 0.019, respectively). The Serum CRP levels were significantly less in Group B throughout all follow-up time points (P < 0.001) except on day three (P = 0.302). No wound complications were reported in any patient.

Conclusions: Preoperative single low dose (eight mg) DXM intravenous in patients undergoing unilateral TKA is safe (early postoperatively) and effective for reducing postoperative pain scores, improving early mobility, and reducing inflammatory markers. However, the effect on PONV was less evident.