Cardiogenic shock and nutrition: safe?

Abstract

Cardiogenic shock is a common diagnosis in patients in the intensive care unit (ICU), and is characterized by a decreased cardiac output in the presence of adequate intravascular volume associated with an inadequate tissue perfusion including a physiological reduction in the splanchnic territory. It may occur in isolation as a reflection of cardiac pathology, or it may be part of a shock syndrome involving other pathogenic mechanisms. As the use of enteral nutrition (EN) is associated with an increase in mesenteric arterial output, EN could be deleterious by overwhelming the mechanisms of mesenteric adaptation. Accordingly, EN has been suspected to increase the risk of mesenteric ischaemia, bacterial translocation and sepsis in ICU patients with cardiogenic shock. International guidelines recommend a cautious use of EN within 72 h following cardiogenic shock. Recent evidence indicates that mesenteric arterial output may decrease during parenteral nutrition administration, suggesting that parenteral nutrition could have a protective effect on splanchnic organs in ICU patients with cardiogenic shock. Contrary to former beliefs, several meta-analyses have shown that parenteral nutrition is not associated with increased mortality. Exclusive EN is associated with negative energy balance and the combination of EN with supplemental parenteral nutrition during the first days following ICU admission has been proposed to prevent negative energy balance. Such a nutritional strategy could also be beneficial for the mesenteric circulation in cardiogenic shock, and consequently may improve the clinical outcome of patients with cardiogenic shock. Clinical trials are warranted to verify these hypotheses.

Nutrition support during extracorporeal membrane oxygenation (ECMO) in adults

“…Although controversial, we also consider that EN is also feasible in cardiac surgery patients with hemodynamic failure [5]. More studies are clearly warranted to confirm these findings.…”

Early Enteral Nutrition in Postoperative Cardiac Surgery Patients with Severe Hemodynamic Failure and Venoarterial (VA) Extracorporeal Membrane Oxygenation (ECMO)

“…As discussed above, EN is associated with an increase in mesenteric arterial output that may be insufficient to cover demands in patients in shock and thus possibly lead to ischemia. Early EN may be possible in similar situations to post cardiac surgery, such as in patients with cardiogenic (Thibault et al 2011) or septic shock (Macl and Muzevich 2013). In general, EN has been noted to be safe and well tolerated in patients with sepsis.…”

“…Mesenteric blood flow accounts for 10-15 % of cardiac output under fasting conditions (Thibault et al 2011). In response to normal feeding, cardiac output increases, the mesenteric arteries dilate, and peripheral vascular resistance is reduced.…”

“…In response to normal feeding, cardiac output increases, the mesenteric arteries dilate, and peripheral vascular resistance is reduced. The consequence of this is postprandial hyperemia, in which blood flow and metabolic activity are increased twofold (Gatt et al 2009;Thibault et al 2011). When perfusion pressure in the small intestine is reduced, ischemia and the buildup of metabolites induce vasodilatation mediated by myogenic and metabolic responses (Reilly et al 2001).…”

Optimal timing, dose and route of early nutrition therapy in critical illness and shock: the quest for the Holy Grail

“…Both conditions have been shown to be associated with poor outcome. Thus, whether EEN may have beneficial or deleterious effects in patients with shock, remains highly controversial [5].…”