Abstract
Introduction
Nutritional support is an essential component of caring for burn patients. Burns can induce a hypermetabolic state greater than twice the normal metabolic rate which can lead to higher rates of lean tissue mass breakdown. Despite its importance, there is no clear gold standard for monitoring nutritional status in the burn and critical care population. Many current methods of assessing body composition can be costly, labor-intensive, and inaccurate. Bioelectrical impedance analysis (BIA) is a promising new technology for assessing body composition that functions by sending a low-voltage current through the body and measuring the impedance to that current. Parameters derived from BIA have been demonstrated to reflect cellular health and correlate with nutritional status. The use of BIA to assess nutritional status in the critical care and burn population has not been well investigated. Thus, we have conducted a systematic review of the use of BIA to assess nutritional status in critically ill adults.
Methods
A search was conducted on Pubmed and Google Scholar in accordance with PRISMA guidelines between June 2020-August 2020 utilizing the keywords: bioelectrical impedance analysis, critical care, critical, nutrition, body composition, lean body mass, phase angle, water, fluid. Inclusion criteria were articles investigating the relationship between BIA and nutritional status in critically ill adults. Reviews, non-English articles, and studies involving pediatric patients were excluded.
Results
Our final study included 14 articles. BIA measured muscle mass was compared to a CT scan in two studies, with both reporting a statistically significant correlation. One article compared the ability of BIA and ultrasound to assess muscle mass, and this relationship was statistically significant. BIA derived phase angle was compared to NUTRIC and Subjective Global Assessment scores in four articles with all four reporting significant correlations. BIA was also compared to biochemical markers of nutrition such as albumin and two of three articles found significant correlations. One article compared BIA with gas exchange measured by indirect calorimetry and found that BIA could accurately assess body cell mass. No articles were found comparing BIA with other common nutritional markers such as prealbumin or nitrogen balance.
Conclusions
BIA shows promise as a method of assessing body composition and nutritional status in the critically ill patient population.
Assessing the reliability of FTIR spectroscopy measurements and validity of bioelectrical impedance analysis as a surrogate measure of body composition among children and adolescents aged 8–19 years attending schools in Kampala, Uganda
