Acute kidney injury (AKI) is a common complication in patients undergoing major abdominal surgery. Various recent studies using modern standardized classifications for AKI reported a variable incidence of AKI after major abdominal surgery ranging from 3 to 35%. Several patient-related, procedure-related factors and postoperative complications were identified as risk factors for AKI in this setting. AKI following major abdominal surgery has been shown to be associated with poor short- and long-term outcomes. Herein, we provide a contemporary and critical review of AKI after major abdominal surgery focusing on its incidence, risk factors, pathogeny and outcomes.

Acute kidney injury (AKI) is characterized by an acute decrease in renal function that can be multifactorial in its origin and is associated with complex pathophysiological mechanisms. In the short term, AKI is associated with an increased length of hospital stay, health care costs, and in-hospital mortality, and its impact extends into the long term, with AKI being associated with increased risks of cardiovascular events, progression to chronic kidney disease (CKD), and long-term mortality. Given the impact of the prognosis of AKI, it is important to recognize at-risk patients and improve preventive, diagnostic, and therapy strategies. The authors provide a comprehensive review on available diagnostic, preventive, and treatment strategies for AKI.

Acute kidney injury (AKI) is a complex syndrome characterized by a decrease in renal function and associated with numerous etiologies and pathophysiological mechanisms. It is a common diagnosis in hospitalized patients, with increasing incidence in recent decades, and associated with poorer short- and long-term outcomes and increased health care costs. Considering its impact on patient prognosis, research has focused on methods to assess patients at risk of developing AKI and diagnose subclinical AKI, as well as prevention and treatment strategies, for which an understanding of the epidemiology of AKI is crucial. In this review, we discuss the evolving definition and classification of AKI, and novel diagnostic methods.

Surgery is one of the leading causes of acute kidney injury (AKI) in hospitalized patients. Major abdominal surgery has the second higher incidences of AKI, after cardiac surgery. AKI results from a complex interaction between hemodynamic, toxic and inflammatory factors. The pathogenesis of AKI following major abdominal surgery is distinct from cardiac and vascular surgery. The neutrophil, lymphocytes and platelets (N/LP) ratio has been demonstrated as an inflammatory marker and an independent predictor for AKI and mortality after cardiovascular surgery. The aim of this study was to evaluate the prognostic ability of the post-operative N/LP ratio after major abdominal surgery. We cross-examined data of a retrospective analysis of 450 patients who underwent elective or urgent major nonvascular abdominal surgery at the Department of Surgery II of Centro Hospitalar Lisboa Norte from January 2010 to February 2011. N/LP ratio was determined using maximal neutrophil counts and minimal lymphocyte and platelet counts in the first 12 h after surgery. AKI was considered when developed within 48 h after surgery. One-hundred and one patients (22.4%) developed AKI. Patients with higher N/LP ratio had an increased risk of developing postoperative AKI (6.36 ± 7.34 vs 4.33 ± 3.36, p < 0.001; unadjusted OR 1.1 (95% CI 1.04–1.16), p = 0.001; adjusted OR 1.05 (95% CI 1.00–1.10), p = 0.048). Twenty-nine patients died (6.44%). AKI was an independent predictor of mortality (20.8 vs 2.3%, p < 0.0001; unadjusted OR 11.2, 95% CI 4. 8-26.2, p < 0.0001; adjusted OR 3.56, 95% CI 1.0 2-12.43, p = 0.046). In a multivariate analysis higher N/LP ratio was not associated with increased in-hospital mortality. Postoperative N/LP ratio was independently associated with AKI after major abdominal surgery, although there was no association with in-hospital mortality.

Acute kidney injury (AKI) is a frequent occurrence following major abdominal surgery and is independently associated with both in-hospital and long-term mortality, as well as with a higher risk of progressing to chronic kidney disease (CKD) and cardiovascular events. Postoperative AKI can account for up to 40% of in-hospital AKI cases. Given the differences in patient characteristics and the pathophysiology of postoperative AKI, it is inappropriate to assume that the management after noncardiac and nonvascular surgery are the same as those after cardiac and vascular surgery. This article provides a comprehensive review on the available evidence on the management of postoperative AKI in the setting of major abdominal surgery.

Background: The incidence of AKI in coronavirus disease 2019 (COVID-19) patients is variable and has been associated with worse prognosis. A significant number of patients develop persistent kidney damage defined as Acute Kidney Disease (AKD). There is a lack of evidence on the real impact of AKD on COVID-19 patients. We aim to identify risk factors for the development of AKD and its impact on mortality in COVID-19 patients. Methods: Retrospective analysis of COVID-19 patients with AKI admitted at the Centro Hospitalar Universitário Lisboa Norte between March and August of 2020. The Kidney Disease Improving Global Outcomes (KDIGO) classification was used to define AKI. AKD was defined by presenting at least KDIGO Stage 1 criteria for >7 days after an AKI initiating event. Results: In 339 COVID-19 patients with AKI, 25.7% patients developed AKD (n = 87). The mean age was 71.7 ± 17.0 years, baseline SCr was 1.03 ± 0.44 mg/dL, and the majority of patients were classified as KDIGO stage 3 AKI (54.3%). The in-hospital mortality was 18.0% (n = 61). Presence of hypertension (p = 0.006), CKD (p < 0.001), lower hemoglobin (p = 0.034) and lower CRP (p = 0.004) at the hospital admission and nephrotoxin exposure (p < 0.001) were independent risk factors for the development of AKD. Older age (p = 0.003), higher serum ferritin at admission (p = 0.008) and development of AKD (p = 0.029) were independent predictors of in-hospital mortality in COVID-19-AKI patients. Conclusions: AKD was significantly associated with in-hospital mortality in this population of COVID-19-AKI patients. Considering the significant risk of mortality in AKI patients, it is of paramount importance to identify the subset of higher risk patients.