Measurement of relative lung perfusion with electrical impedance and positron emission tomography: an experimental comparative study in pigs

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

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.

Details

Original languageEnglish
Pages (from-to)246-254
Number of pages9
JournalBritish journal of anaesthesia
Volume123
Issue number2
Publication statusPublished - Aug 2019
Peer-reviewedYes

External IDs

PubMedCentral PMC6676171
Scopus 85066334480
ORCID /0000-0002-5385-9607/work/141544721
ORCID /0000-0003-2185-1819/work/142245093
ORCID /0000-0002-0676-6926/work/149082341

Keywords

Keywords

  • Animals, Disease Models, Animal, Electric Impedance, Lung/diagnostic imaging, Positron-Emission Tomography, Pulmonary Ventilation/physiology, Respiration, Artificial, Swine