Background: Suboptimal ventricular arterial coupling (VAC) is one of the pivotal determinants of inefficient heart performance despite appropriate administration of fluids or vasopressors in shocks. Here, we investigate the performance of VAC in patients who are unresponsive to fluid administration in septic shock.
Methods: This is a retrospective observational study of septic shock patients (n = 35). VAC was evaluated by effective arterial elastance (EaI), left ventricular end-systolic elastance (EesI), and EaI/EesI. Septic shock patients successfully fluid resuscitated after pulse indicator continuous cardiac output (PiCCO) monitoring, defined as an increase in general end-diastolic ventricular volume (GEDVI) more than 10%, were divided into volume responsive (VVr), and volume unresponsive (VVur) groups based on a cardiac index increase above 10%. We hypothesize that two groups of patients will exhibit dissimilarities of VAC variation, defined as EaI/EesI variation (ΔEaI/EesI).
Results: Variations of EaI (ΔEaI), and EaI/EesI (ΔEaI/EesI), and systemic vascular resistance index (ΔSVRI) were significantly lower in the VVr group than those in the VVur group (P < 0.05). Variations of cardiac index (ΔCI), stroke volume index (ΔSVI), and EesI (ΔEesI) were significantly higher in patients with ΔEaI/EesI ≤ 0. Concomitantly, ΔEaI and ΔSVRI were significantly diminished as compared with patients with ΔEaI/EesI > 0 (P < 0.05). ΔCI has an inverse relationship with both ΔEaI (r = -0.46, P = 0.006), ΔEaI/EesI (r = -0.65, P < 0.001), and ΔSVRI (r = -0.59, P < 0.001). We observed more patients who were fluid responsive in the ΔEaI/EesI ≤ 0 group than in the group with ΔEaI/EesI > 0 (88.89% vs. 26.92%, P = 0.01).
Conclusions: Variation of VAC is often related to suboptimal ventricular volume responsiveness among patients with septic shock.