Bio-Electrical Impedance Analysis in Patients with Critical Illnesses

There is a new technique to measure total body water named bio-electrical impedance analysis (BIA), used in healthy subjects and patients. BIA determines the total body water (TBW), fat-free mass (FFM), body cell mass (BCM), extra cellular water (ECW), and intra cellular water (ICW) in subjects without significant fluid and electrolyte imbalance. There are several methods such as segmental BIA, multi-frequency BIA, and bio-electrical spectroscopy to perform a BIA. The positive fluid balance has effects on morbidity and mortality in patients with critical illnesses. In such patients, monitoring fluid status and fluid overload is an important issue. The current study aims at discussing parameters of BIA and whether they can control fluid imbalance of patients with critical illnesses admitted in intensive care units.