Protein and energy requirements: effect of clinical state

ESPEN practical and partially revised guideline: Clinical nutrition in the intensive care unit

Following the new ESPEN Standard Operating Procedures, the previous 2019 guideline to provide best medical nutritional therapy to critically ill patients has been shortened and partially revised. Following this update, we propose this publication as a practical guideline based on the published scientific guideline, but shortened and illustrated by flow charts. The main goal of this practical guideline is to increase understanding and allow the practitioner to implement the Nutrition in the ICU guidelines. All the items discussed in the previous guidelines are included as well as special conditions.

Low nutritional quality of unconventional tropical crop seeds in rats

As the search for alternative sources of food to alleviate hunger continues, this study was undertaken to determine the biological value in growing rats (BV) of proteins of some lesser known tropical seeds gathered in Nigeria. Antinutritional factors (trypsin inhibitors, phytic acid, oxalate, tannin, alkaloids) and amino acid compositions were also determined, and protein digestibility-corrected amino acid score (PDCAAS) was calculated using the amino acid requirement pattern of the preschool child and individual seed-specific correction factors for crude protein. A rat growth and balance study was conducted to determine digestibility, nitrogen-, and energy balance by feeding as the only unsupplemented protein source milled and heat-treated seeds of Adansonia digitata (Bombacaceae) and Prosopis africana, Lonchocarpus sericeus, Enterolobium cyclocarpium, Sesbania pachycarpa and Pterocarpus osun (Leguminosae) in comparison to casein fortified with methionine (control). Diets containing P. africana and L. sericeus seeds caused poor feed intake and weight loss in rats and were excluded from the nitrogen-balance test. Among the seed samples, S. pachycarpa followed by A. digitata showed the most advantageous nutritional quality [amino acid composition, digestibility, BV and net protein utilization (NPU)]. True digestibility was 82.9 and 74.5 vs. 98.5, BV was 64.6 and 70.0 vs. 90.4, and NPU was 53.5 and 52.1 vs. 89.0 for S. pachycarpa and A. digitata vs. casein (control), respectively. In terms of PDCAAS, lysine was the first limiting amino acid for S. pachycarpa (88%) and for A. digitata (58%). The PDCAAS of all essential amino acids was below 100% for E. cyclocarpium (e.g., cysteine + methionine: 37%) and for P. africana (e.g., threonine: 46%, except valine and a very high content of cysteine and methionine). In conclusion, all seeds tested in the rat balance trial were of inferior quality compared to casein. Before these tropical seeds could be used as food components or feed supplements, safety studies and proper processing to remove antinutritional factors and possible toxic constituents were required.

[Consequences of surgery on nutritional status]

Trauma and surgery induce extensive physiological changes, commonly denominated the acute phase reaction (APR). This APR is activated by various kinds of stimuli, namely nociceptive stimulations, tissue injury, tissue ischaemia and reperfusion as well as by haemodynamic disturbances which occur commonly in such patients. APR is mainly characterised by the release of counter-regulatory hormones, complex metabolic changes and by the hepatic synthesis of numerous acute phase factors (C-reactive protein, haptoglobin, complement protein, etc). In addition, fever is typically present and there is a resistance to the nutritional support. The intensity of APR is variable, according to the extent of surgery, the subsequent course, occurrence of complications and to various factors related to the patient and its treatment. In patients with non complicated surgery and low or moderate severity trauma, the metabolic changes are minor and self-limited. In such a condition, there is no need for nutritional support. Conservely, in patients with complicated surgery or major trauma, there is an extensive APR, which can be very prolonged. This results in important and sustained metabolic changes, leading to extensive catabolism and progressive loss of body cell mass. The latter is amplified by the decreased body ability to adapt to starvation and by the resistance to the nutritional support that typically occur in complicated postoperative and trauma patients. Total parenteral nutrition does not prevent from metabolic changes occurring in surgical patients. By contrast, several experimental and human studies have shown that early enteral nutrition may alleviate both the endocrine and metabolic responses in such conditions. Regional anaesthesia, particularly by the epidural route, may also decrease but not abolish the extent of APR.