Global End-Diastolic Volume as an Indicator of Cardiac Preload in Patients With Septic Shock.

Study objective: To assess the value of the global end-diastolic volume (GEDV) evaluated by transpulmonary thermodilution as an indicator of cardiac preload. Design: Prospective clinical study. Setting: Medical ICU of a university hospital (20 beds). Patients: Thirty-six patients with septic shock. Interventions: Volume loading and dobutamine infusion. Measurements and results: Hemodynamic parameters were evaluated in triplicate by the transpulmonary thermodilution technique: (1) before and after 66 fluid challenges in 27 patients, and (2) before and after 28 increases in dobutamine infusion rate in 9 patients. Volume loading induced a significant (p < 0.001) increase in central venous pressure (CVP) from 10 ± 4 to 13 ± 4 mm Hg, in GEDV index from 711 ± 164 to 769 ± 144 mL/m², in stroke volume index (SVI) from 36 ± 12 to 42 ± 12 mL/m², and in cardiac index (CI) from 3.4 ± 1.1 to 3.9 ± 1.2 L/min/m² (mean ± SD). Changes in GEDV index were correlated (r = 0.72, p < 0.001) with changes in SVI, while changes in CVP were not. The increase in SVI was > 15% in 32 of 66 instances (positive response). The preinfusion GEDV index was lower (637 ± 134 mL/m² vs 781 ± 161 mL/m², p < 0.001) in the eases of positive response, and was negatively correlated with the percentage increase in GEDV index (r = -0.65, p < 0.001) and in SVI (r = -0.5, p < 0.001). Dobutamine infusion induced an increase in SVI (32 ± 11 mL/m² vs 35 ± 12 mL/m², p < 0.05) and in CI (2.8 ± 0.6 L/min/m² vs 3.2 ± 0.6 L/min/m², p < 0.001) but no significant change in CVP (13 ± 3 mm Hg vs 13 ± 3 mm Hg) and in GEDV index (823 ± 221 mL/m² vs 817 ± 202 mL/m²). Conclusion: In patients with septic shock, our findings demonstrate that, in contrast to CVP, the transpulmonary thermodilution GEDV index behaves as an indicator of cardiac preload. [ABSTRACT FROM AUTHOR]