RT Book, Section A1 Jaksic, Tom A1 Shew, Stephen B. A1 Gutierrez, Ivan M. A2 Ziegler, Moritz M. A2 Azizkhan, Richard G. A2 Allmen, Daniel von A2 Weber, Thomas R. SR Print(0) ID 1100430967 T1 Metabolic Response to Illness and Operation T2 Operative Pediatric Surgery, 2e YR 2014 FD 2014 PB McGraw-Hill Education PP New York, NY SN 978-0-07-162723-8 LK accesssurgery.mhmedical.com/content.aspx?aid=1100430967 RD 2024/03/28 AB Children have reduced metabolic reserves and are particularly susceptible to the adverse effects associated with the catabolic response to critical illness.The metabolic response to injury is proportional to the degree of stress.Both protein degradation and protein synthesis increase during illness; however, quantitatively the former predominates. Hence, net negative protein balance ensues.Adequate supplementation of protein is the most important nutritional intervention in children during illness.In illness the breakdown of existing skeletal muscle stores and consequent release of amino acids is driven by increased requirements. These needs include amino acids to synthesize new proteins and the conversion of these amino acids to form glucose through the process of gluconeogenesis. During the metabolic stress state, this catabolic process is refractory to inhibition by the supplementation of dietary glucose.Energy expenditure can be measured either directly or indirectly. Direct calorimetry is very precise but not practical as a method to use in sick children. Indirect calorimetry requires a leak-free system, which can be difficult to achieve in children with uncuffed endotracheal tubes or not breathing calmly. Other indirect methods include deuterated water and 13C-labeled bicarbonate, which have been shown to correlate with indirect calorimetry.In neonates and children, the increase in resting energy expenditure associated with surgery is very brief and is measured in hours.Free fatty acids are the primary source of energy in stressed patients. In neonates, with limited stores, this makes them more susceptible to develop essential fatty acid deficiency. The quantity of lipid necessary to obviate fatty acid deficiency is relatively limited. Newer experimental data support the use of lipid-limited omega-3 formulas, in highly selected patients with cholestasis and a long-term requirement for parenteral nutrition.During illness neural pathways, hormones, and inflammatory mediators mediate the prolonged metabolic response. The ability to effectively modulate these responses could result in an amelioration of the net negative protein balance that exists during stress states. Neural pathway modulation is achieved with adequate sedation and analgesia and has been shown to decrease the hypercatabolic state in ill neonates. Hormonal and inflammatory mediator modulation remains experimental at this time.