Early administration of norepinephrine increases cardiac preload and cardiac output in septic patients with life-threatening hypotension

Abstract

IntroductionWe sought to examine the cardiac consequences of early administration of norepinephrine in severely hypotensive sepsis patients hospitalized in a medical intensive care unit of a university hospital.MethodsWe included 105 septic-shock patients who already had received volume resuscitation. All received norepinephrine early because of life-threatening hypotension and the need to achieve a sufficient perfusion pressure rapidly and to maintain adequate flow. We analyzed the changes in transpulmonary thermodilution variables associated with the increase in mean arterial pressure (MAP) induced by norepinephrine when the achieved MAP was ≥65 mm Hg.ResultsNorepinephrine significantly increased MAP from 54 ± 8 to 76 ± 9 mm Hg, cardiac index (CI) from 3.2 ± 1.0 to 3.6 ± 1.1 L/min/m2, stroke volume index (SVI) from 34 ± 12 to 39 ± 13 ml/m2, global end-diastolic volume index (GEDVI) from 694 ± 148 to 742 ± 168 ml/m2, and cardiac function index (CFI) from 4.7 ± 1.5 to 5.0 ± 1.6 per min. Beneficial hemodynamic effects on CI, SVI, GEDVI, and CFI were observed in the group of 71 patients with a baseline echocardiographic left ventricular ejection fraction (LVEF) >45%, as well as in the group of 34 patients with a baseline LVEF ≤45%. No change in CI, SVI, GEDVI, or CFI was observed in the 17 patients with baseline LVEF ≤45% for whom values of MAP ≥75 mm Hg were achieved with norepinephrine.ConclusionsEarly administration of norepinephrine aimed at rapidly achieving a sufficient perfusion pressure in severely hypotensive septic-shock patients is able to increase cardiac output through an increase in cardiac preload and cardiac contractility. This effect remained in patients with poor cardiac contractility except when values of MAP ≥75 mm Hg were achieved.

Cardiac Output Response to Norepinephrine in Postoperative Cardiac Surgery Patients

“…HR changes in response to NE have been reported before, but the changes are variable. No decrease in HR was reported in septic shock patients treated with NE (5,8,10,28,29). In fact, HR increased during NE infusion in both septic shock patients (29) and septic pigs (13).…”

“…Both increases and decreases in CO can be seen in response to NE in patients with both septic shock (4-10) and without (11,12). Cardiovascular mechanisms used to explain these effects include increases in cardiac contractility, cardiac preload, coronary perfusion and afterload (5,13,14) as recently described in humans with septic shock (10). Central to these arguments is that changes in effective circulating blood and venous return occur independent of changes in contractility.…”

Echocardiography in the sepsis syndromes

“…Epinephrine infusion [0.01 mcg/ (kg min)] restores adequate pressures and flows, increasing LVOT VTI to 12.7 cm, SV to 49 ml (3.90 cm 2 9 12.7 cm), heart rate to 120 bpm and CO to 5.83 L/min (c). LVOT left ventricular outflow tract, VTI Doppler velocity-time integral, CO cardiac output index, and that it does not necessarily equate to the need for fluid infusion (absolute hypovolemia correction); also recruitment of unstressed volume from the venous reservoir (relative hypovolemia correction) may increase cardiac output [45,46]: when an upward titration of vasoconstrictors determines an increase in stroke volume, this may be the preferred choice toward limiting harmful positive fluid balance [47].…”

Early Management of Severe Sepsis

“…99 , 100 The early use of norepinephrine restores BP and organ blood fl ow with a significant fl uid sparing effect. Hamzaoui and colleagues 101 demonstrated that the early administration of norepinephrine largely reverses the hemodynamic abnormalities of severe vasodilatory shock. Abid and colleagues 102 demonstrated that the early use of norepinephrine in patients with septic shock was a strong predictor of survival.…”