Postoperative Acetaminophen Use and Acute Kidney Injury in Abdominal Surgery: A MIMIC-IV Analysis

Acute kidney injury (AKI) is a significant postoperative complication, particularly following abdominal surgery. Although acetaminophen is widely used for postoperative pain management, its impact on AKI risk in this context remains underexplored. This study investigates the association between postoperative acetaminophen use and AKI incidence in abdominal surgery patients.

A retrospective cohort study was conducted using the MIMIC-IV database, including 8696 abdominal surgery patients. Multivariable logistic regression and Cox proportional hazards models were used to assess the relationship between acetaminophen administration within 48 h postsurgery and AKI occurrence within 7 days. Subgroup analyses were performed to evaluate effects based on anemia severity, sodium levels, surgery type, and gender.

Acetaminophen use within 48 h postsurgery was associated with a 40% reduction in AKI risk (odds ratio = 0.60, 95% confidence interval: 0.54-0.67; hazard ratio [HR] = 0.57, 95% confidence interval: 0.53-0.62). Greater protective effects were observed in females (HR = 0.51 versus males = 0.62), patients with severe anemia (HR = 0.44), hyponatremia (HR = 0.47), and those undergoing open surgery (HR = 0.50). Time-dependent analysis revealed that delayed acetaminophen administration (18-48 h postsurgery) provided stronger protection, with odds ratio values declining from 0.8 to 0.4.

Postoperative acetaminophen use is associated with a reduced risk of AKI in abdominal surgery patients, particularly in high-risk subgroups such as females, anemic patients, and those with hyponatremia or undergoing open surgery. These findings suggest that acetaminophen may serve as a safer alternative to nonsteroidal anti-inflammatory drugs for postoperative pain management. Further prospective studies are needed to optimize dosing and timing strategies.