Can calf circumference be a viable option for nutritional assessment in the PICU?

Abstract

Children admitted to paediatric intensive care units (PICUs) often need specialised nutritional intervention. Nutritional assessments provide specific data to support such interventions. Body composition measures, such as mid-upper arm circumference (MUAC), can complement nutritional assessment. However, MUAC has limitations. Calf circumference (CC) is an easy and common measure of muscle loss in the elderly; however, there are still very few studies on CC in children. To evaluate the viability of using CC for nutritional monitoring of children under intensive care, compared with MUAC and weight. Patients aged 2-10 years admitted to the PICU between December 2018 and August 2019 were included in the study. Two MUAC, CC, and weight measurements were performed: one in the first 24h after PICU admission and another after 7 days. As there are no reference values for CC in children, this measure was used solely to observe the patient's individual progress. The nutritional status, both according to body mass index and MUAC, was used to characterise samples. Percentage changes in these measures were compared using the Wilcoxon signed-rank test for comparison between medians and Spearman's correlation test. Information from medical records regarding hospitalisation was also collected and analysed. Thirty patients were included in the study. During hospitalisation week 1, CC decreased significantly (p=0.001), whereas MUAC (p=0.427) and weight (p=0.315) did not change significantly. Percentage changes in CC and MUAC were statistically different (p=0.0449), with a positive correlation between the changes in both measures (p=0.0333; r=0.3896); conversely, although the percentage changes in CC and weight significantly differed (p=0.0066), no correlation was found between them (p=0.9382; r=0.0148). The percentage changes in MUAC and weight were not different (p=0.1880) or correlated (p=0.1691; r=0.2577). No statistically significant relationship was found between percentage changes in CC and clinical outcomes (length of stay, fasting time, and mechanical ventilation time). CC appears to be a viable measure for use in PICUs. Although positively correlated with MUAC, a measure proven useful in critically ill children, CC decreased significantly in the first week of intensive care, whereas MUAC remained unchanged, indicating that CC may show signs of depletion earlier than MUAC in these patients. Our study reinforces the importance of alternative measures for anthropometric assessment of critically ill children.