T Bluth1, T Kiss1, M Kircher2, A Braune1, C Bozsak3, R Huhle1, M Scharffenberg1, M Herzog1, J Roegner1, P Herzog1, L Vivona4, M Millone5, O Dössel2, M Andreeff6, T Koch1, J Kotzerke6, B Stender3, M Gama de Abreu7. 1. Pulmonary Engineering Group Dresden, Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany. 2. Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany. 3. Drägerwerk AG & Co. KGaA, Lübeck, Germany. 4. Pulmonary Engineering Group Dresden, Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples, Italy. 5. Pulmonary Engineering Group Dresden, Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; IRCCS AOU San Martino IST, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy. 6. Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Dresden, Germany. 7. Pulmonary Engineering Group Dresden, Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany. Electronic address: mgabreu@uniklinikum-dresden.de.
Abstract
BACKGROUND: Electrical impedance tomography (EIT) with indicator dilution may be clinically useful to measure relative lung perfusion, but there is limited information on the performance of this technique. METHODS: Thirteen pigs (50-66 kg) were anaesthetised and mechanically ventilated. Sequential changes in ventilation were made: (i) right-lung ventilation with left-lung collapse, (ii) two-lung ventilation with optimised PEEP, (iii) two-lung ventilation with zero PEEP after saline lung lavage, (iv) two-lung ventilation with maximum PEEP (20/25 cm H2O to achieve peak airway pressure 45 cm H2O), and (v) two-lung ventilation under unilateral pulmonary artery occlusion. Relative lung perfusion was assessed with EIT and central venous injection of saline 3%, 5%, and 10% (10 ml) during breath holds. Relative perfusion was determined by positron emission tomography (PET) using 68Gallium-labelled microspheres. EIT and PET were compared in eight regions of equal ventro-dorsal height (right, left, ventral, mid-ventral, mid-dorsal, and dorsal), and directional changes in regional perfusion were determined. RESULTS: Differences between methods were relatively small (95% of values differed by less than 8.7%, 8.9%, and 9.5% for saline 10%, 5%, and 3%, respectively). Compared with PET, EIT underestimated relative perfusion in dependent, and overestimated it in non-dependent, regions. EIT and PET detected the same direction of change in relative lung perfusion in 68.9-95.9% of measurements. CONCLUSIONS: The agreement between EIT and PET for measuring and tracking changes of relative lung perfusion was satisfactory for clinical purposes. Indicator-based EIT may prove useful for measuring pulmonary perfusion at bedside.
BACKGROUND: Electrical impedance tomography (EIT) with indicator dilution may be clinically useful to measure relative lung perfusion, but there is limited information on the performance of this technique. METHODS: Thirteen pigs (50-66 kg) were anaesthetised and mechanically ventilated. Sequential changes in ventilation were made: (i) right-lung ventilation with left-lung collapse, (ii) two-lung ventilation with optimised PEEP, (iii) two-lung ventilation with zero PEEP after saline lung lavage, (iv) two-lung ventilation with maximum PEEP (20/25 cm H2O to achieve peak airway pressure 45 cm H2O), and (v) two-lung ventilation under unilateral pulmonary artery occlusion. Relative lung perfusion was assessed with EIT and central venous injection of saline 3%, 5%, and 10% (10 ml) during breath holds. Relative perfusion was determined by positron emission tomography (PET) using 68Gallium-labelled microspheres. EIT and PET were compared in eight regions of equal ventro-dorsal height (right, left, ventral, mid-ventral, mid-dorsal, and dorsal), and directional changes in regional perfusion were determined. RESULTS: Differences between methods were relatively small (95% of values differed by less than 8.7%, 8.9%, and 9.5% for saline 10%, 5%, and 3%, respectively). Compared with PET, EIT underestimated relative perfusion in dependent, and overestimated it in non-dependent, regions. EIT and PET detected the same direction of change in relative lung perfusion in 68.9-95.9% of measurements. CONCLUSIONS: The agreement between EIT and PET for measuring and tracking changes of relative lung perfusion was satisfactory for clinical purposes. Indicator-based EIT may prove useful for measuring pulmonary perfusion at bedside.
Authors: Elena Spinelli; Michael Kircher; Birgit Stender; Irene Ottaviani; Maria C Basile; Ines Marongiu; Giulia Colussi; Giacomo Grasselli; Antonio Pesenti; Tommaso Mauri Journal: Crit Care Date: 2021-06-03 Impact factor: 9.097
Authors: Olivia A Brabant; David P Byrne; Muriel Sacks; Fernando Moreno Martinez; Anthea L Raisis; Joaquin B Araos; Andreas D Waldmann; Johannes P Schramel; Aline Ambrosio; Giselle Hosgood; Christina Braun; Ulrike Auer; Ulrike Bleul; Nicolas Herteman; Cristy J Secombe; Angelika Schoster; Joao Soares; Shannon Beazley; Carolina Meira; Andy Adler; Martina Mosing Journal: Front Vet Sci Date: 2022-07-22
Authors: Kaspar Felix Bachmann; Rakesh Vasireddy; Paul Philipp Heinisch; Hansjörg Jenni; Andreas Vogt; David Berger Journal: Sci Rep Date: 2021-06-01 Impact factor: 4.379