• Rodrigo Cornejo, Pablo Iturrieta, Tayran M M Olegário, Carolina Kajiyama, Daniel Arellano, Dannette Guiñez, María A Cerda, Roberto Brito, Abraham I J Gajardo, Marioli Lazo, Lorena López, MoraisCaio C ACCADivisao de Pneumologia, Faculdade de Medicina, Instituto do Coracao, Hospital das Clinicas HCFMUSP, Universidade de Sao Paulo, Sao Paulo, Brazil., Sedric González, Miguel Zavala, Verónica Rojas, Juan N Medel, Daniel E Hurtado, Alejandro Bruhn, Cristobal Ramos, and Nivia Estuardo.
• Unidad de Pacientes Críticos, Departamento de Medicina, Hospital Clínico Universidad de Chile, Santiago, Chile.
• Acta Anaesthesiol Scand. 2021 Feb 1; 65 (2): 228-235.

RationaleCyclic strain may be a determinant of ventilator-induced lung injury. The standard for strain assessment is the computed tomography (CT), which does not allow continuous monitoring and exposes to radiation. Electrical impedance tomography (EIT) is able to monitor changes in regional lung ventilation. In addition, there is a correlation between mechanical deformation of materials and detectable changes in its electrical impedance, making EIT a potential surrogate for cyclic lung strain measured by CT (StrainCT ).ObjectivesTo compare the global StrainCT with the change in electrical impedance (ΔZ).MethodsAcute respiratory distress syndrome patients under mechanical ventilation (VT 6 mL/kg ideal body weight with positive end-expiratory pressure 5 [PEEP 5] and best PEEP according to EIT) underwent whole-lung CT at end-inspiration and end-expiration. Biomechanical analysis was used to construct 3D maps and determine StrainCT at different levels of PEEP. CT and EIT acquisitions were performed simultaneously. Multilevel analysis was employed to determine the causal association between StrainCT and ΔZ. Linear regression models were used to predict the change in lung StrainCT between different PEEP levels based on the change in ΔZ.Main ResultsStrainCT was positively and independently associated with ΔZ at global level (P < .01). Furthermore, the change in StrainCT (between PEEP 5 and Best PEEP) was accurately predicted by the change in ΔZ (R2 0.855, P < .001 at global level) with a high agreement between predicted and measured StrainCT .ConclusionsThe change in electrical impedance may provide a noninvasive assessment of global cyclic strain, without radiation at bedside.© 2020 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

13 keywords...

hide…