Pediatric Postoperative Acute Kidney Injury After Noncardiac Surgery: A Systematic Review and Meta-Analysis.

BACKGROUND

Postoperative acute kidney injury (AKI) is associated with substantial morbidity and mortality. Reliable estimates of AKI after surgery in children are lacking. To address this gap, we aimed to synthesize the available evidence on the incidence of AKI after pediatric noncardiac surgery.

METHODS

We searched PubMed, Cochrane and Web of Science for studies reporting the incidence of AKI, defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria, within 7 postoperative days. Observational studies and clinical trials including patients aged < 18 years were eligible. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Twenty-seven studies (n = 21 908) were included. Considerable heterogeneity (I2 = 98.7%) and likely overrepresentation of clinically distinct high-risk populations limited the interpretability of a single overall pooled incidence estimate. The incidence was 22.3% (95% CI, 11.2-39.3) after neonatal surgery, 30.1% (95% CI, 21.4-40.6) after pediatric liver transplantation, and 9.2% (95% CI, 3.3-23.6) in mixed pediatric surgical populations. The certainty of evidence was rated low to very low. In mixed pediatric surgical populations, AKI incidence increased from 2.4% in American Society of Anesthesiologists (ASA) class 1-2 to 7.5% in ASA 3 (p < 0.001) and 18.9% in ASA 4-5 (p < 0.001), and decreased from 9.8% at 0-2 years to 4.0% at 12-18 years (p < 0.001).

CONCLUSION

The reported incidence of postoperative AKI in children undergoing noncardiac surgery remains uncertain due to substantial heterogeneity and overrepresentation of high-risk populations. AKI incidence was high in neonates and liver transplant recipients and was associated with younger age and higher ASA class, although data were limited. Further prospective studies in broader pediatric surgical populations are needed to better assess the risk of postoperative AKI in children.

TRIAL REGISTRATION: PROSPERO registration no.: CRD42024518832.