Brachial artery reactivity in sepsis and septic shock patients in the intensive care unit: a prospective exploratory study in an Indian population.

BACKGROUND: Sepsis is increasingly recognized as a state of profound endothelial dysfunction triggered by infection, leading to microvascular injury and multi-organ failure. Non-invasive assessment of brachial artery reactivity using ultrasound following transient ischemia provides an indirect yet practical tool for evaluating endothelial dysfunction. This study aimed to determine the association between brachial artery reactivity indices and intensive care unit (ICU) mortality in sepsis and septic shock patients. METHODS: In this prospective analysis, 120 participants were enrolled, with 40 in each group (sepsis, septic shock, and healthy controls). Within 24 hours of ICU admission, baseline and post-deflation arterial diameters and velocity time integral (VTI) were measured using ultrasonography after three minutes of cuff occlusion at 50 mm Hg above systolic pressure and compared. Subgroup analysis was performed to compare survivors and non-survivors, correlating with Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) scores. RESULTS: Flow mediated dilation (FMD), hyperemic VTI, and change in VTI (ΔVTI) were significantly reduced (P<0.001) in sepsis and septic shock compared with controls. Non-survivors (n=38) had significantly lower hyperemic VTI (53.40 cm/cardiac cycle [interquartile range, 40.28-65.95] vs. 61.30 [48.18-84.85], P=0.041) and lower ΔVTI (35.80 [20.3-43.66] vs. 44.65 [30.95-57.23], P=0.011) than survivors. Receiver operating characteristic analysis showed ΔVTI (cutoff, 43.07 cm/cardiac cycle) had higher specificity (59.5% vs. 54.8%) than hyperemic VTI (cutoff, 60.15), while both showed equal sensitivity (71.1%) for discriminating ICU mortality. CONCLUSIONS: Brachial artery reactivity indices were impaired in sepsis and septic shock. Hyperemic VTI and ΔVTI may have potential as complementary bedside prognostic markers requiring further validation in larger multicenter studies.