Splenic Doppler Velocity-Time Integral as a Dynamic Marker of Visceral Perfusion in Septic Shock: A Prospective Pilot Feasibility Study

Background In septic shock, macrocirculatory targets may not ensure tissue perfusion. Capillary refill time (CRT) is a simple, guideline-endorsed bedside marker, but its reliability can be affected by edema, temperature, skin factors, and vasoactive drugs. Traditional splenic Doppler indices, resistive index (RI) and pulsatility index (PI), often change little under vasodilated states and provide limited directional information. By contrast, the velocity–time integral (VTI) summarizes forward velocity over time. We therefore assessed whether splenic VTI (s-VTI) could serve as a directional, organ-level flow signal at the bedside. Methods Prospective case series with a structured within-patient paired analysis in a single tertiary ICU. Adults with septic shock (n = 9) underwent paired splenic pulsed-wave Doppler at two clinically adjudicated states (worse vs better by pre-specified bedside hierarchy: CRT→norepinephrine→MAP). Doppler metrics were not used for adjudication. The primary outcome was the paired change Δ s-VTI = s-VTI_better − s-VTI_worse (cm), tested with an exact sign test (one-sided directional hypothesis; two-sided reported). Secondary: directional behavior of CRT and state-paired behavior of splenic RI/PI. Analyses were descriptive and hypothesis-generating. Results Δ s-VTI > 0 in 9/9 pairs (exact sign test one-sided p = 0.002, two-sided p = 0.004). Median s-VTI_worsewas 15.8 cm (IQR 13.0–17.8) vs s-VTI_better 31.0 cm (IQR 21.55–35.0); the median paired change was + 15.25 cm(IQR 7.60–19.0), + 96.6% from the worse state (IQR 54.7–192.1%). CRT moved in the expected direction (median 7.0 → 2.1 s; Δ − 4.9 s, IQR − 7.9 to − 3.4), with normalization < 3 s in 5/7 recoveries. RI/PI showed limited and variable directional behavior: RI concordant in 5/9; PI concordant in 4/9, with overlapping distributions between states. Conclusions In this prospective, within-patient case series, s-VTI rose in the clinically adjudicated better vs worse state in all pairs (9/9; exact sign test one-sided p = 0.002), nearly doubling in the median. s-VTI behaved as a directional, organ-level flow signal that may complement capillary refill time (CRT) at the bedside, whereas RI/PI provided limited directional information under vasoplegic sepsis. These hypothesis-generating findings require prospective validation to establish reproducibility and actionable thresholds.