Evaluation of Regional Pulmonary Ventilation in Spontaneously Breathing Patients with Idiopathic Pulmonary Fibrosis (IPF) Employing Electrical Impedance Tomography (EIT): A Pilot Study from the European IPF Registry (eurIPFreg)

Ekaterina Krauss; Daniel van der Beck; Isabel Schmalz; Jochen Wilhelm; Silke Tello; Ruth C Dartsch; Poornima Mahavadi; Martina Korfei; Eckhard Teschner; Werner Seeger; Andreas Guenther

doi:10.3390/jcm10020192

Evaluation of Regional Pulmonary Ventilation in Spontaneously Breathing Patients with Idiopathic Pulmonary Fibrosis (IPF) Employing Electrical Impedance Tomography (EIT): A Pilot Study from the European IPF Registry (eurIPFreg)

J Clin Med. 2021 Jan 7;10(2):192. doi: 10.3390/jcm10020192.

Authors

Ekaterina Krauss^{1

2}, Daniel van der Beck¹, Isabel Schmalz^{1

2}, Jochen Wilhelm^{1

3

4}, Silke Tello^{1

2}, Ruth C Dartsch^{1

2}, Poornima Mahavadi^{1

2}, Martina Korfei^{1

2}, Eckhard Teschner⁵, Werner Seeger^{1

2

5}, Andreas Guenther^{1

2

4

6}

Affiliations

¹ Member of the German Center for Lung Research (DZL), Universities of Giessen and Marburg Lung Center (UGMLC), Klinikstr. 33, 35392 Giessen, Germany.
² European IPF Registry & Biobank (eurIPFreg), 35392 Giessen, Germany.
³ Institute of Lung Health (ILH), 35392 Giessen, Germany.
⁴ Cardio-Pulmonary Institute (CPI) Klinikstr. 33, 35392 Giessen, Germany.
⁵ Draegerwerk AG & Co. KGaA, 23558 Luebeck, Germany.
⁶ Agaplesion Lung Clinic Waldhof-Elgershausen, 35753 Greifenstein, Germany.

Abstract

Objectives: In idiopathic pulmonary fibrosis (IPF), alterations in the pulmonary surfactant system result in an increased alveolar surface tension and favor repetitive alveolar collapse. This study aimed to assess the usefulness of electrical impedance tomography (EIT) in characterization of regional ventilation in IPF.

Materials and methods: We investigated 17 patients with IPF and 15 healthy controls from the University of Giessen and Marburg Lung Center (UGMLC), Germany, for differences in the following EIT parameters: distribution of ventilation (TID), global inhomogeneity index (GI), regional impedance differences through the delta of end-expiratory lung impedance (dEELI), differences in surface of ventilated area (SURF), as well as center of ventilation (CG) and intratidal gas distribution (ITV). These parameters were assessed under spontaneous breathing and following a predefined escalation protocol of the positive end-expiratory pressure (PEEP), applied through a face mask by an intensive care respirator (EVITA, Draeger, Germany).

Results: Individual slopes of dEELI over the PEEP increment protocol were found to be highly significantly increased in both groups (p < 0.001) but were not found to be significantly different between groups. Similarly, dTID slopes were increasing in response to PEEP, but this did not reach statistical significance within or between groups. Individual breathing patterns were very heterogeneous. There were no relevant differences of SURF, GI or CGVD over the PEEP escalation range. A correlation of dEELI to FVC, BMI, age, or weight did not forward significant results.

Conclusions: In this study, we did see a significant increase in dEELI and a non-significant increase in dTID in IPF patients as well as in healthy controls in response to an increase of PEEP under spontaneous breathing. We propose the combined measurements of EIT and lung function to assess regional lung ventilation in spontaneously breathing subjects.

Keywords: European Registry for idiopathic pulmonary fibrosis (eurIPFreg); electrical impedance tomography (EIT); idiopathic pulmonary fibrosis (IPF); interstitial lung diseases (ILD).