Kidney Week

Abstract: SA-PO0295

AKI After Major Surgery: A Retrospective Analysis of Nationwide Electronic Health Record Data

Session Information

• AKI: Epidemiology and Risk Factors
  October 24, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 101 AKI: Epidemiology, Risk Factors, and Prevention

Authors

• Yuan, Zhongyu, New York University Grossman School of Medicine, New York, New York, United States

Zhongyu Yuan, PhD

• Sang, Yingying, New York University Grossman School of Medicine, New York, New York, United States

Yingying Sang, MS

• Ballew, Shoshana, New York University Grossman School of Medicine, New York, New York, United States

Shoshana Ballew, PhD

• Grams, Morgan, New York University Grossman School of Medicine, New York, New York, United States

Morgan Grams, MD, PhD

Background

Acute Kidney Injury (AKI) is a common post-operative complication. The aim of this study was to leverage electronical health record (EHR) data to assess the incidence, characteristics, and prognosis of AKI in the post-operative setting, a commonly considered setting for AKI clinical trials.

Methods

We conducted a retrospective analysis of de-identified electronic health record (EHR) data in the Optum Labs Data Warehouse (OLDW), a nationwide database in the US containing more than 350 million patients. Adults who underwent inpatient major surgery (length of stay [LOS] ≥48 hours) between 2010 and 2023 were included. AKI within 7 days of surgery, defined by KDIGO creatinine-based criteria, was assessed. We evaluated the incidence, characteristics, and prognosis of post-operative AKI.

Results

AKI occurred in approximately 11% of 938,810 patients undergoing major surgery (stage 1, 78%; stage 2, 15%; stage 3, 7%). Urologic surgery had the highest risk of AKI, followed by cardiac and vascular surgery (Figure 1). Risk factors for AKI included older age, African American race, heart failure, liver disease, and lower estimated glomerular filtration (eGFR) when eGFR < 90 ml/min/1.73 m². Patients with post-operative AKI had longer LOS (4 days [3, 7] vs. 7 days [5, 11] in non-AKI) and a substantially higher risk of in-hospital mortality (4.2% vs. 0.6% in non-AKI). After discharge, patients with post-operative AKI had a consistently higher risk of end-stage kidney disease (ESKD) and death (Table 1). Post-operative AKI was associated with a over 2-fold higher risk of ESKD (adjusted HR=2.34, [2.23, 2.45]) and a 40% higher risk of all-cause mortality (adjusted HR=1.40 [1.38, 1.41]), with stronger associations observed for more severe AKI stage (Table 2).

Conclusion

AKI remains common after major surgery and is associated with not only adverse in-hospital outcomes but also inferior patient survival in the long run.

Funding

• Private Foundation Support