Ong Chengsi, Lee Jan Hau, Leow Melvin K S, Puthucheary Zudin A
Nutrition and Dietetics, KK Women's and Children's Hospital, Singapore, Singapore.
Children's Intensive Care Unit, KK Women's Children's Hospital, Singapore, Singapore.
Transl Pediatr. 2021 Oct;10(10):2763-2777. doi: 10.21037/tp-20-298.
Muscle wasting is now recognized as a growing, debilitating problem in critically ill adults, resulting in long-term deficits in function and an impaired quality of life. Ultrasonography has demonstrated decreases in skeletal muscle size during pediatric critical illness, although variations exist. However, muscle protein turnover patterns during pediatric critical illness are unclear. Understanding muscle protein turnover during critical illness is important in guiding interventions to reduce muscle wasting. The aim of this review was to explore the possible protein synthesis and breakdown patterns in pediatric critical illness. Muscle protein turnover studies in critically ill children are lacking, with the exception of those with burn injuries. Children with burn injuries demonstrate an elevation in both muscle protein breakdown (MPB) and synthesis during critical illness. Extrapolations from animal models and whole-body protein turnover studies in children suggest that children may be more dependent on anabolic factors (e.g., nutrition and growth factors), and may experience greater muscle degradation in response to insults than adults. Yet, children, particularly the younger ones, are more responsive to anabolic agents, suggesting modifiable muscle wasting during critical illness. There is a lack of evidence for muscle wasting in critically ill children and its correlation with outcomes, possibly due to current available methods to study muscle protein turnover in children-most of which are invasive or tedious. In summary, children may experience muscle wasting during critical illness, which may be more reversible by the appropriate anabolic agents than adults. Age appears an important determinant of skeletal muscle turnover. Less invasive methods to study muscle protein turnover and associations with long-term outcome would strengthen the evidence for muscle wasting in critically ill children.
肌肉萎缩如今被认为是危重症成年患者中一个日益严重且使人衰弱的问题，会导致长期的功能缺陷和生活质量受损。超声检查已显示小儿危重症期间骨骼肌大小会减小，不过存在个体差异。然而，小儿危重症期间的肌肉蛋白质周转模式尚不清楚。了解危重症期间的肌肉蛋白质周转对于指导减少肌肉萎缩的干预措施很重要。本综述的目的是探讨小儿危重症中可能的蛋白质合成和分解模式。除烧伤患儿外，针对危重症儿童的肌肉蛋白质周转研究较少。烧伤患儿在危重症期间肌肉蛋白质分解（MPB）和合成均增加。从动物模型和儿童全身蛋白质周转研究推断，儿童可能更依赖合成代谢因子（如营养和生长因子），并且与成人相比，在受到损伤时可能会经历更大程度的肌肉降解。然而，儿童，尤其是年幼的儿童，对合成代谢药物反应更敏感，这表明危重症期间肌肉萎缩是可改变的。目前缺乏关于危重症儿童肌肉萎缩及其与预后相关性的证据，这可能是由于当前用于研究儿童肌肉蛋白质周转的方法——其中大多数具有侵入性或操作繁琐。总之，儿童在危重症期间可能会出现肌肉萎缩，与成人相比，适当的合成代谢药物可能使其更易逆转。年龄似乎是骨骼肌周转的一个重要决定因素。采用侵入性较小的方法研究肌肉蛋白质周转及其与长期预后的关联，将为危重症儿童肌肉萎缩提供更有力的证据。
