In this study, we explore the effects of flurbiprofen on postoperative acute kidney injury (AKI). While previous research has indicated an association between nonsteroidal anti-inflammatory drugs (NSAIDs) and an increased risk of AKI, our findings demonstrate that the perioperative use of low-dose Flurbiprofen in spinal surgeries is associated with a reduced risk of AKI.

Observational studies present conflicting results concerning the relationship between NSAID usage and AKI (Chiu et al. 2015; Zhan et al. 2020; Drugs and (NSAID) administration and acute kidney injury (AKI) in major gastrointestinal surgery: a prospective, multicenter, propensity matched cohort study. 2020; Aboul-Hassan et al. 2020). For instance, a study involving over 12,000 patients with rheumatoid arthritis (RA) found an association between NSAID use and increased risk of chronic kidney disease (CKD) (Chiu et al. 2015). However, recent findings indicate that short-term use of NSAIDs early in the postoperative period does not correlate with increased AKI risk within the first seven days postoperatively (Drugs and (NSAID) administration and acute kidney injury (AKI) in major gastrointestinal surgery: a prospective, multicenter, propensity matched cohort study. 2020). Additionally, the use of ibuprofen has been linked to a reduced risk of AKI, consistent with the results of our current investigation (Drugs and (NSAID) administration and acute kidney injury (AKI) in major gastrointestinal surgery: a prospective, multicenter, propensity matched cohort study. 2020). In addition, according to a recent study, continuation of aspirin administration after coronary artery bypass grafting was linked to a lower risk of acute kidney injury (AKI) than the interruption of aspirin 24 to 48 h before surgery (Aboul-Hassan et al. 2020). In a retrospective observational study with 913 patients who underwent laparoscopic or robot-assisted laparoscopic renal resection, no correlation was observed between NSAID use for PCA and the incidence of postoperative renal impairment (Han et al. 2020).

While it remains unclear how Flurbiprofen reduces the risk of postoperative AKI, inflammation may play a contributory role. Epidemiological studies have shown that chronic inflammation significantly contributes to the progression of AKI to CKD (Sato and Yanagita 2018). Furthermore, research indicates that inflammation predicts postoperative AKI in non-cardiac surgeries and that anti-inflammatory treatments could improve AKI prognosis (Murashima et al. 2019). Flurbiprofen reduces both local and systemic inflammatory cytokines during the postoperative period (Zhao et al. 2021; Esme et al. 2011).

The use of NSAIDs as adjunct analgesics in the postoperative setting may offer significant benefits (Wattchow et al. 2009; Coloma et al. 2000). Although opioids are effective in pain management, they are associated with risks such as long-term dependence, respiratory depression, upregulation of pro-inflammatory signals, and delayed recovery of bowel function (postoperative ileus). NSAIDs have opioid-sparing effects, which could mitigate some of the adverse effects associated with opioids (Martinez et al. 2017). Additionally, the anti-inflammatory properties of NSAIDs may be beneficial throughout the recovery period (Fang et al. 2013) as surgical stimulation increases systemic inflammatory responses, potentially linked with increased short-term and long-term adverse events (Neal et al. 2014; Kalff et al. 2003).

The study has certain limitations that merit discussion. Notably, it employs a retrospective design which inherently suffers from recall bias due to its reliance on past events. Furthermore, the accuracy and completeness of the medical records system serving as the data source may lend an element of uncertainty to the results. Crucial variables such as BMI, intraoperative hypotension, and vasoactive drug usage were unattainable due to the retrospective design, potentially impacting our analysis. Despite efforts to address these factors in data interpretation, the observational nature introduces potential confounding variables. A notable limitation in our study arises from the inability to confirm several typical independent preoperative risk factors for postoperative AKI, partially attributable to data loss affecting the comprehensive assessment of certain variables. However, the introduction of propensity score matching, while capable of reducing bias and confounding variables, also brings forth new sources of bias. It is crucial to underscore that our study establishes an association, not a causal relationship, between AKI incidence and flurbiprofen use. While other studies have looked at low-dose (50–100 mg), medium-dose (100–250 mg), and high-dose (≥ 250 mg) flurbiprofen treatment, our analysis focused solely on the low-dose group. This limitation may affect the comprehensive assessment of treatment effects across different dosage levels. Future research could broaden the analysis to include additional dosage ranges and explore dose-dependent effects further.