A commentary on ‘Preoperative renal insufficiency predicts postoperative adverse outcomes in a mixed surgical population: a retrospective matched cohort study using the NSQIP database’

Dear Editor,

Chronic kidney disease (CKD) is a condition characterized by a progressive decrease of renal function and is frequently associated with a higher risk of postoperative complications, including cardiovascular adverse events, infections, and mortality^1–3. Liao et al.⁴ conducted a retrospective matched cohort analysis on patients with preoperative renal insufficiency (RI) who had undergone surgery. It seems an enhanced care strategy should be implemented for patients with preoperative RI.

This retrospective cohort study included 502 281 patients which was based on data from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) that were acquired between 2013 and 2018. After propensity score matching, 1 729 517 patients were in the non-RI group, and 691 769 patients were in the RI group. The study’s findings indicated that compared to the non-RI group, the RI group had a greater risk of 30-day in-hospital mortality (odds ratio: 1.54, 95% CI: 1.49–1.58). Postoperative problems such as myocardial infarction, stroke, pneumonia, septic shock, and bleeding after surgery were linked to an increased risk in the RI group. Additionally, there was a correlation seen between the RI group and a higher chance of readmission, reoperation, and extended ventilator use exceeding 48 h.

The research also sheds light on the risk of postoperative mortality associated with preoperative RI by a stratified analysis. Analysis results, stratified by surgical specialty, showed that when undergoing general surgery, orthopedic surgery, or vascular surgery, the RI group had a higher risk of postoperative death than the non-RI group. Furthermore, compared to non-RI patients, RI patients with diabetes, hypertension, chronic obstructive pulmonary disease, and dialysis had a marginally higher chance of dying. However, there were still a lot of restrictions. First, some residual confounding factors may not have been considered. Second, since this is a retrospective study, there may be potential bias. Finally, the bias exists due to a lack of patient information, such as estimated glomerular filtration rate (eGFR) value⁵.

More detailed and multicenter research is required to confirm this result. Furthermore, deeper prospective research, clinical trials, and examination of indications and risk factors in various patient subgroups are required to identify the best course of action. Future research designs can take into account the following factors: Initially, carry out a comprehensive multicenter investigation to confirm the present conclusions and investigate indications and risk factors in other patient subgroups. Secondly, renal dysfunction reasons should be meticulously documented throughout the design of clinical trials in order to distinguish between patients with acute episodes of CKD, individuals with CKD, and patients with acute kidney injury episodes. Finally, a larger number of individuals with a wider range of eGFR are included to make the results applicable to all patient populations.

This study delves into whether preoperative RI predicts postoperative unfavorable outcomes in a heterogeneous surgical group. This issue has enormous ramifications for clinical practice. This retrospective cohort study with a large population provides early evidence that patients with preoperative RI have a higher risk of postoperative 30-day mortality and comorbidities, laying the framework for larger, multicenter trials. The factors that could influence the preoperative RI are also discussed. This forward-thinking approach provides valuable guidance and inspiration for the continued development of this area of research. To summarize, this study offers preliminary evidence that patients with preoperative RI have an increased risk of postoperative 30-day mortality and complications. Further investigation and research should be conducted to improve the care plan for patients with preoperative RI.

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Author contribution

W.G.: study concept or design, data collection, data analysis or interpretation, writing, and revising the paper; S.L. and Y.Z.: data collection.

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Guarantor

Wei Guo.

Data availability statement

This manuscript is a comment. Don’t need a Data availability statement. However, all the data from the current study are publicly available.

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