Electrical impedance tomography (EIT) for quantification of pulmonary edema in acute lung injury

BackgroundAssessment of pulmonary edema is a key factor in monitoring and guidance of therapy in critically ill patients. To date, methods available at the bedside for estimating the physiologic correlate of pulmonary edema, extravascular lung water, often are unreliable or require invasive measurements. The aim of the present study was to develop a novel approach to reliably assess extravascular lung water by making use of the functional imaging capabilities of electrical impedance tomography.MethodsThirty domestic pigs were anesthetized and randomized to three different groups. Group 1 was a sham group with no lung injury. Group 2 had acute lung injury induced by saline lavage. Group 3 had vascular lung injury induced by intravenous injection of oleic acid. A novel, noninvasive technique using changes in thoracic electrical impedance with lateral body rotation was used to measure a new metric, the lung water ratioEIT, which reflects total extravascular lung water. The lung water ratioEIT was compared with postmortem gravimetric lung water analysis and transcardiopulmonary thermodilution measurements.ResultsA significant correlation was found between extravascular lung water as measured by postmortem gravimetric analysis and electrical impedance tomography (r = 0.80; p < 0.05). Significant changes after lung injury were found in groups 2 and 3 in extravascular lung water derived from transcardiopulmonary thermodilution as well as in measurements derived by lung water ratioEIT.ConclusionsExtravascular lung water could be determined noninvasively by assessing characteristic changes observed on electrical impedance tomograms during lateral body rotation. The novel lung water ratioEIT holds promise to become a noninvasive bedside measure of pulmonary edema.

[1]  M. Lamy,et al.  The American-European Consensus Conference on ARDS. Definitions, mechanisms, relevant outcomes, and clinical trial coordination. , 1994, American journal of respiratory and critical care medicine.

[2]  E. Weitzberg,et al.  Comparison of a single indicator and gravimetric technique for estimation of extravascular lung water in endotoxemic pigs , 2006, Critical care medicine.

[3]  Arthur S Slutsky,et al.  Acute Respiratory Distress Syndrome The Berlin Definition , 2012 .

[4]  R. Sherertz,et al.  Recognition and prevention of nosocomial vascular device and related bloodstream infections in the intensive care unit , 2010, Critical care medicine.

[5]  Robert E. Fromm,et al.  Guidelines for the inter- and intrahospital transport of critically ill patients* , 2004, Critical care medicine.

[6]  G. P. van Nieuw Amerongen,et al.  Predictors of pulmonary edema formation during fluid loading in the critically ill with presumed hypovolemia* , 2012, Critical care medicine.

[7]  V. Kuzkov,et al.  Extravascular lung water assessed by transpulmonary single thermodilution and postmortem gravimetry in sheep , 2004, Critical care.

[8]  B. Reichart,et al.  Reproducibility of double indicator dilution measurements of intrathoracic blood volume compartments, extravascular lung water, and liver function. , 1998, Chest.

[9]  Richard Bayford,et al.  Biomedical applications of electrical impedance tomography , 2004 .

[10]  G Hahn,et al.  Imaging pathologic pulmonary air and fluid accumulation by functional and absolute EIT , 2006, Physiological measurement.

[11]  B Lachmann,et al.  In Vivo Lung Lavage as an Experimental Model of the Respiratory Distress Syndrome , 1980, Acta anaesthesiologica Scandinavica.

[12]  S. Rasche,et al.  Effects of inhalation of perfluorocarbon aerosol on oxygenation and pulmonary function compared to PGI2 inhalation in a sheep model of oleic acid-induced lung injury , 2001, Intensive Care Medicine.

[13]  A. Pesenti,et al.  Measurement of pulmonary edema in patients with acute respiratory distress syndrome* , 2005, Critical care medicine.

[14]  M. Matthay,et al.  Measurement of extravascular lung water using the single indicator method in patients: research and potential clinical value. , 2009, American journal of physiology. Lung cellular and molecular physiology.

[15]  S. Leonhardt,et al.  Analysis of regional compliance in a porcine model of acute lung injury , 2012, Respiratory Physiology & Neurobiology.

[16]  J. Wright.  Immunomodulatory functions of surfactant. , 1997, Physiological reviews.

[17]  A Adler,et al.  Monitoring changes in lung air and liquid volumes with electrical impedance tomography. , 1997, Journal of applied physiology.

[18]  Gerardo Tusman,et al.  Regional lung perfusion estimated by electrical impedance tomography in a piglet model of lung collapse. , 2012, Journal of applied physiology.

[19]  V. Kuzkov,et al.  Radiographic lung density assessed by computed tomography is associated with extravascular lung water content , 2010, Acta anaesthesiologica Scandinavica.

[20]  I. Cuthill,et al.  Reporting : The ARRIVE Guidelines for Reporting Animal Research , 2010 .

[21]  T. Martin,et al.  Animal models of acute lung injury , 2008, American journal of physiology. Lung cellular and molecular physiology.

[22]  R. McAnulty,et al.  The radiographic detection of acute pulmonary oedema. A comparison of radiographic appearances, densitometry and lung water in dogs. , 1981, The British journal of radiology.

[23]  H. Necheles,et al.  Oleic Acid Toxicity and Fat Embolism.∗ , 1948, Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine.

[24]  David Isaacson,et al.  Biomedical Applications of Electrical Impedance Tomography , 2003 .

[25]  E. Raaijmakers,et al.  Electrical impedance tomography in the assessment of extravascular lung water in noncardiogenic acute respiratory failure. , 1999, Chest.

[26]  N. Hussain,et al.  Neutrophil apoptosis during the development and resolution of oleic acid-induced acute lung injury in the rat. , 1998, American journal of respiratory cell and molecular biology.

[27]  D. Kaminski,et al.  Comparison of double indicator thermodilution measurements of extravascular lung water (EVLW) with radiographic estimation of lung water in trauma patients. , 1982, The Journal of trauma.

[28]  R. Maharaj.  Extravascular Lung Water and Acute Lung Injury , 2011, Cardiology research and practice.

[29]  Marc Bodenstein,et al.  Principles of electrical impedance tomography and its clinical application , 2009, Critical care medicine.

[30]  First-time imaging of effects of inspired oxygen concentration on regional lung volumes and breathing pattern during hypergravity , 2015, European Journal of Applied Physiology.

[31]  O. Stenqvist,et al.  Monitoring pulmonary perfusion by electrical impedance tomography: an evaluation in a pig model , 2009, Acta anaesthesiologica Scandinavica.

[32]  Richard Beale,et al.  The Berlin definition of ARDS: an expanded rationale, justification, and supplementary material , 2012, Intensive Care Medicine.

[33]  V. Kuzkov,et al.  Extravascular lung water after pneumonectomy and one-lung ventilation in sheep , 2007, Critical care medicine.

[34]  M. Colmenero,et al.  How important is the measurement of extravascular lung water? , 2007, Current opinion in critical care.

[35]  I. Frerichs,et al.  Electrical impedance tomography in monitoring experimental lung injury , 1998, Intensive Care Medicine.

[36]  R. Brilli,et al.  Aerosolized soluble nitric oxide donor improves oxygenation and pulmonary hypertension in acute lung injury. , 1998, American journal of respiratory and critical care medicine.

[37]  G. Hedenstierna,et al.  Ventilation–perfusion distributions in different porcine lung injury models , 2001, Acta anaesthesiologica Scandinavica.

[38]  P. Neumann,et al.  Extravascular lung water and intrathoracic blood volume: double versus single indicator dilution technique , 1999, Intensive Care Medicine.

[39]  Inéz Frerichs,et al.  Assessment of respiratory system compliance with electrical impedance tomography using a positive end-expiratory pressure wave maneuver during pressure support ventilation: a pilot clinical study , 2014, Critical Care.

[40]  M. Sagy,et al.  A comparison among animal models of acute lung injury. , 1998, Critical care medicine.

[41]  T. Evans,et al.  Epidemiology of acute lung injury , 2005, Current opinion in critical care.

[42]  B. Brown,et al.  Applied potential tomography. , 1989, Journal of the British Interplanetary Society.

[43]  A. Perel,et al.  Accuracy of transpulmonary thermodilution versus gravimetric measurement of extravascular lung water , 2004, Critical care medicine.

[44]  S. Söndergaard,et al.  Electrical impedence tomography and heterogeneity of pulmonary perfusion and ventilation in porcine acute lung injury , 2009, Acta anaesthesiologica Scandinavica.

[45]  S. Stevens,et al.  Radiation and chest CT scan examinations: what do we know? , 2012, Chest.

[46]  E. Sivak,et al.  Value of extravascular lung water measurement vs portable chest x‐ray in the management of pulmonary edema , 1983, Critical care medicine.

[47]  Ola Stenqvist,et al.  Electrical impedance tomography applied to assess matching of pulmonary ventilation and perfusion in a porcine experimental model , 2009, Critical care.