Nutrition support in critical care: How does a South African unit measure up against the suggested guidelines and against the world?

Both the European Society for Clinical Nutrition and Metabolism (ESPEN) and the American Society of Parenteral and Enteral Nutrition (ASPEN) in their published guidelines agreed that indirect calorimetry (IC) should be used to determine energy requirements in the critically ill patients, where feasible and available. 3 However, ESPEN advocated a progressive implementation of energy provision. In this approach, hypocaloric nutrition not exceeding 70% of energy expenditure, in the early phase of acute illness was recommended. Provision of 80–100% of requirements should only be implemented after 72 hours following admission. In the absence of IC, ASPEN and ESPEN suggest that simple weight-based equations be used. 3 The ASPEN 2016 guidelines gave a range of 25–30 kCal/kg/day. ESPEN however suggested that hypocaloric nutrition support, below 70% of estimated needs, should be continued for the first week of ICU stay when weight-based equations are being used. The reasoning behind progressively increasing energy provision in the critical care setting by ESPEN is based on earlier data (Tappy et al. 1998), which showed that exogenous glucose provision does not suppress endogenous glucose production. Endogenous energy production, which occurs in the early phase of critical illness, can provide 500–1 400 kCal/day. 4 Currently, it is not possible to measure this endogenous production at the point-of-care, however providing full measured or calculated requirements during this stage would result in overfeeding. 4