MULTIPLE FREQUENCY BIOIMPEDANCE - A BED-SIDE TECHNIQUE FOR ASSESSMENTOF FLUID SHIFT PATTERNS IN A PATIENT WITH SEVERE DEHYDRATION

This report describes the use of multiple frequency bioimpedance analy sis (MFBIA) to monitor fluid changes in a patient who developed severe dehydration and recovered. Initially, the patient weighed 53.2 kg, hi s total body water (TEW; D2O dilution) was 33.5 L, his extracellular w ater (ECW; Br dilution) was 19.5 L, and hydration of the fat-free mass (FFM; dual-energy X-ray absorptiometry) was normal (73%). The resista nces at infinite and 0 frequency were R-inf = 454 and R-0 = 580 ohm re spectively, which predicted TEW = 33.1 L and ECW = 16.6 L. On day 7, w hen the weight loss was 7.2 kg, FFM had decreased by 7.4 kg, and R-inf and R-0 had increased to 662 and 902 ohm respectively, predicting dec reases of 5.8 L in TEW and 3.7 L in ECW. On recovery (day 14), all par ameters had returned to baseline values. This study encourages the use of MFBIA as a bed-side technique for the serial assessment of body wa ter compartments in patients with disturbances in fluid balance.