ObjectiveTo assess the hemodynamic effects of fluid loading in patients with acute circulatory failure caused by acute massive pulmonary embolism (AMPE).DesignProspective study.SettingRespiratory critical care unit of a university hospital.PatientsThirteen patients free of previous cardiopulmonary disease with angiographically proven AMPE (Miller index = 24 +/- 1), with acute circulatory failure defined by a cardiac index (CI) lower than 2.5 L/min/m2.InterventionInfusion of 500 mL of dextran 40 over 20 mins.Measurements and Main ResultsFluid loading induced a substantial increase in right atrial pressure from 9 +/- 1 mm Hg to 17 +/- 1 mm Hg and in right ventricular end-diastolic volume index from 123 +/- 14 mL/m2to 150 +/- 11 mL/m2(p < .05 for both comparisons). The increase in right ventricular preload was associated with an increase in CI from 1.6 +/- 0.1 to 2.0 +/- 0.1 L/min/m2(p < .05), whereas right ventricular ejection fraction (15 +/- 3% at baseline vs. 16 +/- 3% after fluid loading) and total pulmonary vascular resistance index (1689 +/- 187 dyne[center dot]sec/cm5[center dot]m2at baseline vs. 1492 +/- 166 dyne[center dot]sec/cm (5) [center dot]m2after fluid loading) remained unchanged. The increase in CI induced by fluid loading was inversely correlated to baseline right ventricular end-diastolic volume index (r = -.89; p < .05).ConclusionsThese results suggest that fluid loading can improve hemodynamic status in patients with acute circulatory failure caused by AMPE. (Crit Care Med 1999; 27:540-544)