Nutrition support in intensive care unit: Septic shock

Major stress such as severe trauma, infection or postoperative state, is frequently associated with increased catabolism and energy expenditure. These contribute to fat-free mass loss. The increase of energy debt in the first week of intensive care unit (ICU) stay is associated with an increase in infectious complications and length of mechanical ventilation and ICU stay. When oral intake is insufficient to cover nutritional needs after the three first days of ICU stay, enteral nutrition (EN) is the first choice and should be started within 24 hours. The volume of daily EN should be gradually increased to reach the target within 48 hours (20-25 kcal/kg/day). Protein provision must be 1.2-1.5 g/kg/day. However, enteral feeding could be poorly tolerated by ICU patients due to impaired gastrointestinal motility. In case of gastroparesis, prokinetics can be administered according to previously established protocol. Nevertheless, the use of supplemental parenteral nutrition (PN) or jejunal EN could be necessary in case of failure or insufficient gastric EN. In the ICU, enteral immunonutrition is not indicated because of the absence of additional benefits. Undemutrition prior to admission is likely to worsen during the ICU stay. In case of preexisting undernutrition, the risk of refeeding syndrome is high. EN must be increased very cautiously under tight monitoring of plasma electrolytes, including phosphates, potassium, sodium, calcium, and magnesium. An electrolyte supplementation is warranted in case of plasma deficiencies, along with vitamins and trace elements. Nutrition support is taking part of the management of the ICU patient, as ventilation and hemodynamics. Specific nutritional monitoring is essential to prevent any risk of over- or undernutrition, and to optimize clinical outcome. (C) 2015 Elsevier Masson SAS. All rights reserved.