From the Journals

Preop IV dexamethasone conveys relief after total knee surgery



Patients given a single preoperative dose of intravenous dexamethasone had significantly less pain after total knee arthroplasty than did those given a placebo in a randomized controlled study of 100 adults.

“Corticosteroids were introduced several years ago for relieving postoperative pain in total joint replacement but, unfortunately, are not widely used due to surgeons’ concerns and the limited supporting evidence,” wrote Nattapol Tammachote, MD, of Thammasat University, Khlong Luang, Pathumthani, Thailand, and colleagues.

In a study published in the Journal of Arthroplasty, the researchers randomized 50 adults undergoing unilateral total knee surgery to a preoperative IV dexamethasone dose of 0.15 mg/kg diluted with normal saline or saline placebo. Patients, who were aged 50-85 years, were assessed every 3 hours after surgery, up to 48 hours; the primary outcomes were pain level, using the visual analog pain scale (VAS), and morphine use.

Overall, patients in the treatment group reported significant reductions on the VAS in mean pain scores of 11 points at rest and 15 points with knee movement. No significant differences in morphine use were noted between groups overall or at 12-hour intervals post-surgery.

In the first 24-48 hours after surgery dexamethasone was associated with a significantly lower rate of nausea and vomiting vs. placebo (58% vs. 84%), and a lower average C-reactive protein level (89 mg/L vs. 167 mg/L) at 48 hours after surgery. Hospital stays averaged 3 days for both groups, and no wound infections were reported.

Scores on tests of knee function using the modified Western Ontario and McMaster University Osteoarthritis Index scores and range of motion of the knee at three months were similar between the groups.

The study findings were limited by several factors, including the small sample size and use of multimodal pain control that may have impacted morphine use, a lack of data on hyperglycemia, and variation in doses of ketorolac given to patients in both groups, the researchers noted.

The results nevertheless support the potential of preoperative dexamethasone as “a promising approach in postoperative pain management and may be suitable for patients with contraindication to multimodal pain regimens,” they concluded.

The researchers reported no financial conflicts.

SOURCE: Tammachote N et al. J Arthroplasty. 2019. doi: j.arth.2019.09.002.

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