Abstract Body (Do not enter title and authors here): Background
Sepsis and septic shock are life-threatening conditions driven by dysregulated host responses to infection, resulting in multi-organ dysfunction. While early fluid resuscitation is essential, both fluid overload and under-resuscitation can worsen outcomes. Left Ventricular Outflow Tract Velocity Time Integral (LVOT VTI) has emerged as a non-invasive echocardiographic tool to assess fluid responsiveness. This systematic review evaluates the diagnostic performance, cutoff values, and limitations of LVOT VTI as a tool for assessing fluid responsiveness in adult patients with sepsis or septic shock.
Methods
A systematic search of PubMed, Cochrane, Scopus, Web of Science, EMBASE, and CINAHL was conducted through April 13, 2025, following PRISMA 2020 guidelines (PROSPERO ID: CRD420251036927). Eligible studies used transthoracic or transesophageal echocardiography to measure LVOT VTI and assessed changes following passive leg raise (PLR) or volume expansion tests (VET). Fluid responsiveness was defined as a ≥10–15% increase in VTI.
Results
From 6,942 articles, three observational studies, including 199 adult patients (20 with sepsis, 179 with septic shock), met the inclusion criteria. Two studies used VET (500 mL saline), and one used PLR. Optimal reported LVOT VTI cut-offs ranged from >7% to 16%, with sensitivities from 78% to 96% and specificities from 91% to 100%. AUCs ranged from 0.84 to 0.992. Fluid responsiveness definitions varied across studies. Based on the Newcastle-Ottawa Scale, two studies were rated good quality, and one was fair.
Conclusions
LVOT VTI is a reliable, non-invasive parameter for assessing fluid responsiveness in sepsis and septic shock. Although limited data, this review supports its integration into bedside fluid management protocols to guide individualized resuscitation strategies.