Introduction:Sepsis often leads to acute kidney injury (AKI), presenting significant challenges in fluid management. This study explores the potential of analyzing intrarenal venous flow (IRVF) patterns to guide tailored fluid therapy, aiming to improve patient outcomes.Patient concerns:A patient was admitted to the intensive care unit with symptoms of septic shock, including fever, severe hypotension, and altered mental status, secondary to a perforated ascending colon adenocarcinoma.Diagnosis:The patient was diagnosed with perforated ascending colon adenocarcinoma, septic shock, and AKI. Clinical findings included elevated inflammatory markers and impaired renal function.Interventions:The primary therapeutic interventions included surgical resection of the perforated colon, administration of broad-spectrum antibiotics, and fluid resuscitation. Fluid management was guided by continuous monitoring of IRVF, which facilitated precise adjustments to optimize fluid balance and renal perfusion.Outcomes:By utilizing IRVF patterns to guide fluid therapy, the patient's circulatory status and renal function significantly improved. The individualized fluid management approach contributed to better stabilization of the patient's condition.Lessons:This case underscores the potential utility of IRVF patterns in guiding fluid management strategies for patients with sepsis and AKI. The main is the benefit of IRVF-guided fluid therapy in improving patient outcomes. Further research is warranted to validate the efficacy and safety of this approach, with the aim of enhancing clinical outcomes in critically ill patients.