Additional Dose of Intravenous Dexamethasone Can Replace Patient-Controlled Analgesia in Pain Control after Total Knee Arthroplasty while Reducing Opioid Complications.

Purpose The purpose of this study was to evaluate whether IV dexamethasone, within the current multimodal pain management protocol, (1) could maintain postoperative pain at a comparable level without IV PCA, (2) could reduce opioids-related side effects, and (3) whether an additional dose of dexamethasone on POD 2 would offer further pain-relieving effect without increasing the risk of complications. Methods A total of 178 patients (182 knees) who underwent total knee arthroplasty (TKA) for osteoarthritis were included in the study. The patients were divided into Dexa 2 & PCA and Dexa 3 & NoPCA group. From operative day to POD 5, pain visual analogue score (VAS), rescue opioids consumption, episodes of postoperative nausea and vomiting (PONV), antiemetics usage, and side effects of opioids such as postoperative urinary retention (POUR) and constipation were checked. For safety, wound complication and infection were checked. Results There was no difference in pain VAS between the two groups during all six perioperative days. Rescue opioids consumption was lower in Dexa 2 & PCA group. Total dosage of used opioids for six perioperative days was lower in Dexa 3 & NoPCA group. Dexa 3 & No PCA group had less PONV and POUR. There was a marked increase in pain VAS and the use of rescue opioids from POD 1 to POD 2 in the Dexa 2 & PCA. There were no wound problems or infections in either group. Conclusion Under the current multimodal pain management protocol, comparable level of postoperative pain could be achieved by dexamethasone without the need of IV PCA. By not using IV PCA, overall opioid usage was reduced, which could lead to a lower frequency of PONV and POUR. While there is still room for further research on the duration and frequency of administering dexamethasone, additional administration on POD 2 is believed to provide additional pain management benefits compared to administering only until POD 1.