A Guytonian Atlas of Venous Return in Septic Shock: Reconstruction of Hemodynamic States

Objectives: To reconstruct venous return physiology across published studies of septic shock and characterize the distribution of circulatory states represented in the literature. Design: Exploratory physiologic reconstruction study. Setting: Secondary analysis of published hemodynamic observations. Patients: Adult patients with septic shock reported in studies containing sufficient information for reconstruction of mean circulatory filling pressure analogue (Pmca) and related parameters including venous return driving pressure (VRdP) and resistance to venous return (RVR). Interventions: None. Measurements and Main Results: A total of 150 observations were available. Median Pmca, central venous pressure (CVP), VRdP, and RVR were 17.3 mm Hg, 9.0 mm Hg, 7.9 mm Hg, and 1.04 mm Hg/min/L, respectively. Empirical quartiles identified four recurrent circulatory phenotypes: reduced filling pressure/gradient, preserved venous return, elevated venous pressure, and high-resistance venous return. The preserved venous return pattern demonstrated the highest median cardiac output (CO), whereas the high-resistance pattern exhibited the lowest flow despite comparable filling pressures. In exploratory adjusted analyses incorporating available vasopressor exposure and fluid-therapy context, VRdP remained strongly associated with CO (β, 1.03 L/min/mm Hg; 95% CI, 0.80–1.25; p < 0.001). When Pmca and CVP were entered separately, Pmca was positively associated with CO (β, 1.02; 95% CI, 0.79–1.25; p < 0.001), whereas CVP was inversely associated with CO (β, –1.03; 95% CI, –1.26 to –0.80; p < 0.001). Conclusions: Published hemodynamic observations in septic shock occupy distinct Guytonian phenotypes characterized by different combinations of circulatory filling pressure, venous pressure, and RVR. Reconstruction of venous return geometry may provide a physiologic framework for interpreting circulatory heterogeneity in septic shock.