Purpose The incidence, patient features, risk factors and outcomes of surgery-associated postoperative acute kidney injury (PO-AKI) across different countries and health care systems is unclear. Methods We conducted an international prospective, observational, multi-center study in 30 countries in patients undergoing major surgery (> 2-h duration and postoperative intensive care unit (ICU) or high dependency unit admission). The primary endpoint was the occurrence of PO-AKI within 72 h of surgery defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Secondary endpoints included PO-AKI severity and duration, use of renal replacement therapy (RRT), mortality, and ICU and hospital length of stay. Results We studied 10,568 patients and 1945 (18.4%) developed PO-AKI (1236 (63.5%) KDIGO stage 1500 (25.7%) KDIGO stage 2209 (10.7%) KDIGO stage 3). In 33.8% PO-AKI was persistent, and 170/1945 (8.7%) of patients with PO-AKI received RRT in the ICU. Patients with PO-AKI had greater ICU (6.3% vs. 0.7%) and hospital (8.6% vs. 1.4%) mortality, and longer ICU (median 2 (Q1-Q3, 1–3) days vs. 3 (Q1-Q3, 1–6) days) and hospital length of stay (median 14 (Q1-Q3, 9–24) days vs. 10 (Q1-Q3, 7–17) days). Risk factors for PO-AKI included older age, comorbidities (hypertension, diabetes, chronic kidney disease), type, duration and urgency of surgery as well as intraoperative vasopressors, and aminoglycosides administration. Conclusion In a comprehensive multinational study, approximately one in five patients develop PO-AKI after major surgery. Increasing severity of PO-AKI is associated with a progressive increase in adverse outcomes. Our findings indicate that PO-AKI represents a significant burden for health care worldwide. Supplementary Information The online version contains supplementary material available at 10.1007/s00134-023-07169-7.

Background: Spontaneous muscle hematomas (SMH) are rare but potentially life-threatening. We report three patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia who developed hemorrhagic shock, due to large SMHs, during their intensive care unit stay. Case Presentation: All the patients were receiving mechanical ventilation and anticoagulation therapy with enoxaparin. The bleeding was located in the gluteal muscles in two of the patients and in the iliopsoas muscle with retroperitoneal extension in the other. Anemia and hemodynamic instability were the main signs; however, because of their gradual onset, they were initially confused with the anemia of the critically ill patient and sepsis related to secondary infections. All received conservative medical treatment, but unfortunately one patient died within hours of diagnosis. Conclusion: This report highlights that clinicians should also be alert to major spontaneous hemorrhage in patients with SARSCoV- 2 infection. Since it is a novel disease, a possible association with bleeding events cannot be disregarded and, on the contrary, should be considered, particularly to determine the appropriate use of anticoagulation in this type of patients.