Renal safety of postoperative short-term use of flurbiprofen axetil in well-controlled hypertensive patients: a prospective multicenter cohort study

Background: Currently, postoperative nonsteroidal anti-inflammatory drugs-associated kidney damage in hypertensive patients remains undetermined. This study aimed to examine renal safety of short-term post-surgery use of flurbiprofen axetil (FA) in well-controlled hypertensive patients. Methods: Data were collected from January 2020 to March 2021 at four major hospitals on patients who had undergone total knee replacement surgery (TKA). Patients were divided into well-controlled hypertensive and normotensive groups, and received short-term intravenous FA postoperatively. The primary outcomes were trajectory changes of postoperative renal injury biomarkers. Second outcomes included acute kidney injury (AKI), pain intensity and other complications. Results: A total of 120 patients were enrolled. Post-surgery FA significantly reduced pain in both groups. The results of repeated measures analysis of variance (ANOVA) demonstrated that the main effects of group, time and the group-by-time interaction on blood urea nitrogen (BUN), serum creatine (SCr) and Cystatin C (Cys C) levels were not statistically significant on postoperative day 2 and 5 (POD2 and POD5) (all P > 0.05). Urine N-acetyl-beta-glucosaminidase (NAG) levels were significantly higher on POD2 and POD5 in both groups [preoperative: (6.66 ± 4.87) U/L, POD2: (10.07 ± 6.88) U/L, POD5: (10.25 ± 7.68) U/L in normotensive group; preoperative: (7.39 ± 4.07) U/L, POD2: (12.34 ± 7.1) U/L, POD5: (15.57 ± 12.34) U/L in well-controlled hypertensive group; all P < 0.001] compared with baseline. However, only the well-controlled hypertensive group showed a continued increase in NAG levels on POD5 (P = 0.039). AKI occurred in 7.0% (4/57) and 3.2% (2/63) of well-controlled hypertensive and normotensive patients (P = 0.335), and all the AKI patients were at stage 1. After adjusting for confounding factors, hypertension had no impact on AKI (OR = 0.733, 95%CI: 0.074-7.222, P = 0.790). No significant differences in other complications were observed between the groups. Conclusion: The current FA regimen after surgery is effective, and it does not increase AKI incidence in well-controlled hypertensive TKA patients, thought posing a risk of tubular damage.