Progression of chronic kidney disease after non-cardiac surgery: A retrospective cohort study.

Background: Chronic-kidney-disease (CKD) is prevalent among adults undergoing noncardiac surgery, with surgery-related factors potentially worsening CKD or triggering acute kidney injury (AKI). We hypothesized that CKD patients experience more kidney function decline within one to two years post-surgery than those without CKD, particularly if they develop AKI.

Methods: We conducted a single-center retrospective cohort study, including noncardiac surgery patients with documented creatinine preoperative and between 1 and 2 years after surgery. The primary outcome was long-term course of kidney function, defined as the change in estimated glomerular filtration rate (eGFR) in mL/min/1.73m.

Results: Of 58,175 included cases, 17 % had preoperative CKD. Mean eGFR changed from 90.1 ± 16.7 to 92.0 ± 18.8 in non-CKD patients and from 45.6 ± 11.9 to 55.6 ± 20.1 in patients with CKD, with an estimated difference in means of 8.9 (95 % CI: 8.5, 9.3; P < 0.0001). There was a significant interaction between CKD-dependent eGFR change from baseline to follow-up and postoperative AKI (P = 0.001). For cases with preoperative CKD, eGFR increase from baseline to follow-up was 11.7 ± 18.0 with no AKI, 7.7 ± 17.9 with AKI stage 1, 2.4 ± 15.0 with AKI stage 2, and 7.3 ± 25.8 with AKI stage 3. For non-CKD patients, eGFR increased from baseline by 2.3 ± 13.7 with no AKI but decreased by 5.5 ± 19.0 with AKI stage 1, 7.7 ± 21.8 with AKI stage 2, and 9.3 ± 21.3 with AKI stage 3.

Conclusions: Contrary to expectations, patients with preoperative CKD experienced a significant improvement in eGFR postoperatively. Patients without CKD exhibited minimal change. Postoperative AKI negated the eGFR improvement in CKD patients and exacerbated the decline in non-CKD patients.