Feasibility of impedance cardiography to assess hemodynamic changes and fluid loss related to pleural drainage

This work aims to verify if impedance cardiography (ICG) as a non-invasive measurement method for hemodynamic parameters is feasible for the detection of hemodynamic changes and fluid loss due to pleural drainage in heart failure (HF) patients with pleural effusion. Thus, stroke volume (SV) and thoracic fluid content (TFC) before and after pleural drainage were compared. 6 patients with pleural effusion as implication were treated and by the insertion of an intercostal drain, between 1 and 2 liters of fluid were removed from the pleural space in sitting position. ICG measurements were made before and after the drainage by injecting a sinusoidal current of 1.5 mA at a frequency of 85 kHz into the body. SV was calculated according to Kubicek, Sramek and Bernstein. TFC was calculated using the static base impedance (Z₀). A paired-sample t-test was made at 5 % significance level. The calculated SV difference varies between 45 ml and 17 ml, whereas Z₀ changes between 0.9 Ω and 2 Ω. The t-tests showed significant changes of SV (p ≤ 0.0035) and TFC (p ≤ 0.0014). All measured and calculated values show significant changes before and after pleural drainage.