Body fluid status assessment by bio-impedance analysis in patients presenting to the emergency department with dyspnea

Korean J Intern Med. 2018 Sep;33(5):911-921. doi: 10.3904/kjim.2016.358. Epub 2017 Dec 18.

Abstract

Background/aims: Fluid retention occurs in patients with heart failure, accounting for dyspnea. We investigated the diagnostic implication of body fluid status, assessed by bio-impedance analysis (BIA), in acute heart failure (AHF) among patients who presented with dyspnea.

Methods: A total of 100 patients who presented with dyspnea and suspected with AHF were analyzed in this study. We enrolled 50 AHF and 50 non-AHF patients discriminated through echocardiographic analysis and Framingham criteria and were matched by age and sex. Body composition was analyzed using a multifrequency BIA.

Results: AHF patients demonstrated higher extracellular water (ECW)/total body water (TBW) compared with non-AHF patients (0.412 ± 0.017 vs. 0.388 ± 0.023, p < 0.001). A significant difference of ECW/TBW between AHF patients and nonAHF patients was noted when the upper extremities, trunk, and lower extremities were analyzed (all p < 0.001, respectively). ECW/TBW was not different between patients with reduced ejection fraction (EF) and preserved EF along body compartments. The best cut-off value to predict AHF was > 0.412 at lower extremities with sensitivity and specificity of 0.780 and 0.960. The ECW/TBW of the lower extremities (ECW/TBWL) was correlated with log B-type natriuretic peptide (BNP) levels (r = 0.603, p < 0.001) and also improved the net reclassification improvement and integrated discriminated improvement when added to log BNP level. Multivariate analysis revealed that ECW/TBWL > 0.412 had an independent association with AHF patients (p = 0.011).

Conclusion: The ECW/TBWL was higher in patients with dyspnea caused by AHF than their counterparts and demonstrated an independent diagnostic implication. It may be a promising marker to diagnose AHF at bedside.

Keywords: Dyspnea; Electric impedance; Heart failure; Natriuretic peptide, brain.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Body Fluids*
  • Body Water
  • Dyspnea* / diagnosis
  • Dyspnea* / etiology
  • Electric Impedance*
  • Emergency Service, Hospital
  • Female
  • Heart Failure* / complications
  • Heart Failure* / diagnosis
  • Humans
  • Male
  • Middle Aged
  • Seoul