Peak systolic pressure/end-systolic volume ratio, a load-independent measure of ventricular function, is reversibly decreased in human septic shock

Abstract

Objective: To evaluate left ventricular performance in patients with septic shock, using a load-independent measure of left ventricular systolic function, the peak systolic pressure/ end-systolic volume index ratio. Setting: National Institutes of Health research facility. Design: Prospective study with retrospective analysis of data. Patients: Twenty-seven patients with septic shock, 13 critically ill, nonseptic control patients, and nine normal volunteers. Measurements: Hemodynamic measurements from indwelling arterial and pulmonary artery catheters and radionuclide-determined ejection fraction measurements. These data were used to calculate the peak systolic pressure/end-systolic volume index ratio in each patient group. The survivors and nonsurvivors of septic shock were evaluated on admission to the intensive care unit and at recovery in the survivors or within 24 hrs of death in the nonsurvivors. The ratio in each group was compared with the ratio in the critically ill, nonseptic patients and the normal volunteers. Main Results: Both survivors and non-survivors of septic shock had a decreased peak systolic pressure/end-systolic volume index ratio (1.2 ± 0.1 and 1.7 ± 0.2 mm Hg/mL/m2, respectively) compared with critically ill, nonseptic patients (3.5 ± 0.7 mm Hg/mL/m2; bothp< .05) and normal volunteers (4.3 ± 0.4 mm Hg/mL/m2; bothp< .05). The differences between the groups were highly significant (p< .001) by analysis of variance. The survivors had a lower initial peak systolic pressure/end-systolic volume index ratio than the nonsurvivors (p< .05). In the survivors, the peak systolic pressure/end-systolic volume index ratio increased significantly (p< .05) with recovery to 2.4 ± 0.3 mm Hg/mL/m2. Serial determinations of peak systolic pressure/end-systolic volume index ratio in the nonsurvivors did not show any significant change. Conclusions: This study confirms that survivors and nonsurvivors of septic shock have significant depression of myocardial performance as measured by a load-independent technique. Survivors have greater depression of myocardial performance than nonsurvivors, and, with recovery, the ventricular performance in survivors increases toward normal values. (Crit Care Med 1994; 22:1955–1959)