Right ventricular dysfunction in patients with septic shock.

Using a rapid computerized thermodilution method, we examined the evolution of right ventricular performance in 23 patients with septic shock. Nine survived the episode of septic shock. The other 14 patients died of refractory circulatory shock. Significant right ventricular systolic dysfunction, defined as decreased ejection fraction (-39%) and right ventricular dilation (+38%) was observed in all patients with septic shock. However, in the survivors, increased right ventricular preload may prevent hemodynamic evidence of right ventricular pump failure by utilizing the Frank-Starling mechanism to maintain stroke volume. Conversely, in the nonsurvivors, right ventricular dysfunction was more prononced two days after the onset of septic shock, leading to a fall in stroke. In the last patients, a decrease in contractility appears to be the major factor accounting for decreased right ventricular performance, as evidenced by the marked increase in end-systolic volume (+27%) without significant change in pulmonary artery pressure, during the later stage of septic shock. The observed right ventricular pump failure then appears associated with an alteration in diastolic mechanical properties of this ventricle, as suggested by a leftward displacement of the individual pressure-volume curves.

Bedside evaluation of right ventricular performance using a rapid computerized thermodilution method.

In 34 patients, we assessed the reproducibility and accuracy of a new, computerized, thermodilution method that determines right ventricular ejection fraction (RVEF). We compared the results from this new algorithm with simultaneous results from the conventional plateau thermodilution method and from both first-pass and gated nuclear techniques. Using this new method improved the reproducibility of thermal determinations of RVEF. Although the thermal values were lower, the correlations between thermal and nuclear measurements were close [r = .92 (first-pass technique), r = .81 (gated technique)]. This new method seems particularly appropriate for serial monitoring of RV performance.