Electrical impedance tomography in the assessment of extravascular lung water in noncardiogenic acute respiratory failure

Peter W.A. Kunst*, Anton Vonk Noordegraaf, Esther Raaijmakers, Jan Bakker, A. B. Johan Groeneveld, Piet E. Postmus, Peter M.J.M. De Vries

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Study objectives: To establish the value of electrical impedance tomography (EIT) in assessing pulmonary edema in noncardiogenic acute respiratory failure (ARF), as compared to the thermal dye double indicator dilution technique (TDD). Design: Prospective clinical study. Setting: ICU of a general hospital. Patients: Fourteen ARF patients. Interventions: In order to use the TDD to determine the amount of extravascular lung water (EVLW), a fiberoptic catheter was placed in the femoral artery. Measurements and main results: Fourteen consecutive ARF patients receiving mechanical ventilation were measured by EIT and TDD. EIT visualizes the impedance changes caused by the ventilation in two-dimensional image planes. An impedance ratio (IR) of the ventilation-induced impedance changes of a posterior and an anterior part of the lungs was used to indicate the amount of EVLW. For the 29 measurements in 14 patients, a significant correlation between EIT and TDD (r = 0.85; p< 0.001) was found. The EIT reproducibility was good. The diagnostic value of the method was tested by receiver operator characteristic analysis, with 10 mL/kg of EVLW considered as the upper limit of normal. At a cutoff level of the IR of 0.64, the IR had a sensitivity of 93%, a specificity of 87%, and a positive predictive value of 87% for a supranormal amount of EVLW. Follow-up measurements were performed in 11 patients. A significant correlation was found between the changes in EVLW measured with EIT and TDD (r = 0.85; p < 0.005). Conclusion: We conclude that EIT is a noninvasive technique for reasonably estimating the amount of EVLW in noncardiogenic ARF.

Original languageEnglish
Pages (from-to)1695-1702
Number of pages8
JournalChest
Volume116
Issue number6
DOIs
Publication statusPublished - 1 Jan 1999

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