BACKGROUND: Sepsis is a major contributor to global morbidity and mortality. Effective fluid resuscitation is essential for managing septic shock, but it must be carefully monitored to avoid fluid overload and related complications. Recent studies have demonstrated that both inadequate and excessive fluid resuscitation are linked to poor outcomes. METHODS: This observational study was conducted over 18 months, including spontaneously breathing patients aged 18 to 65 with sepsis-related acute circulatory failure. Patients were enrolled through convenience sampling. Baseline vital signs and point-of-care ultrasound (POCUS) parameters were recorded. A volume expansion test (VET) was performed, administering 500 ml of normal saline over 15 minutes, followed by reassessment of vital signs and POCUS parameters. Patients were classified as responders or non-responders. The study evaluated the left ventricular outflow tract velocity time integral (LVOT VTI) as a predictor of fluid responsiveness. RESULTS: The study enrolled 113 patients with a mean age of 48.69 years (SD: ±16.81). The most common age group was 61-70 years (24 patients
21.2%), and there was a male predominance (73 patients
64.6%). Forty-eight patients (42.5%) had no comorbidities, with hypertension being the most prevalent (17 patients
15.0%). Pneumonia was the most common source of sepsis (50 patients
44.2%), and 16 patients (14.2%) died. The percentage change in LVOT VTI following the VET demonstrated a sensitivity of 96.0% and specificity of 100%, with an area under the receiver operating characteristic (ROC) curve of 0.992. A percentage change of ≥15.19% indicated high fluid responsiveness, although a single VTI measurement alone was not a reliable predictor. CONCLUSION: LVOT VTI measurements play a critical role in assessing fluid responsiveness in sepsis-related acute circulatory failure. While a single VTI measurement is unreliable, the percentage change in LVOT VTI after a VET offers excellent diagnostic performance. A cutoff of ≥15.19% post-expansion indicates a high likelihood of fluid responsiveness.