Effect of norepinephrine on ventricular systolic function during septic shock: the ENESySS study

To determine whether norepinephrine improves the left ventricle systolic function in early septic shock patients. Single-center, prospective, observational study in critically ill patients over a 2-year period in Italy. Hypotensive patients were included within 24 hours from the diagnosis of septic shock; preload responsiveness was excluded by a passive leg raising test. The main objective was the augmentation of the left ventricular outflow tract velocity time integral (LVOT-VTI) induced by the increase of norepinephrine infusion dosage. Thirty patients were included in the final analysis, with a median age and SAPS II score of 67 (51–77) years and 49 (41–65), respectively. All patients were mechanically ventilated, 25 (83%) invasively and 5 (17%) non-invasively. The time elapsed between septic shock diagnosis and inclusion was 8 (3–17) hours. The norepinephrine infusion dose was increased from 0.3 (0.2–0.6) to 0.6 (0.4–0.9) µg kg −1 min −1 , p < 0.01. The LVOT-VTI improved from 14 (11–17) to 17 (13–20) cm, p < 0.01. Conversely, the left ventricle ejection fraction (LVEF) did not change ( p = 0.54). The end-systolic left ventricle elastance and the arterial elastance augmented from 1.02 (0.64–1.78) to 1.64 (0.98–2.22) mmHg ml −1 — p < 0.01—and from 1.71 (1.28–2.03) to 2.01 (1.71–2.82) mmHg ml −1 — p < 0.01, respectively; hence, the ventriculoarterial coupling decreased from 1.75 (1.15–2.29) to 1.29 (0.99–1.78), p < 0.01. An improvement of the left ventricle systolic indices was recorded also in the 15 (50%) patients with baseline depressed LVEF. Norepinephrine improved the left ventricle systolic function and the ventriculoarterial coupling in septic shock patients.