Impedance tomography as a new monitoring technique.
OBJECTIVE
Electrical impedance tomography (EIT) noninvasively creates images of the local ventilation and arguably lung perfusion distribution at bedside. Methodological and clinical aspects of EIT when used as a monitoring tool in the intensive care unit are reviewed and discussed.


RESULTS
Whereas former investigations addressed the issue of validating EIT to measure regional ventilation, current studies focus on clinical applications such as detection of pneumothorax. Furthermore, EIT has been used to quantify lung collapse and tidal recruitment in order to titrate positive end-expiratory pressure. Indicator-free EIT measurements might be sufficient for the continuous measurement of cardiac stroke volume, but assessment of regional lung perfusion presumably requires the use of a contrast agent such as hypertonic saline.


CONCLUSIONS
Growing evidence suggests that EIT may play an important role in individually optimizing ventilator settings in critically ill patients.
Muders
Thomas
T
Department of Anesthesiology and Intensive Care Medicine, University of Bonn, Germany. t.muders@uni-bonn.de <t.muders@uni-bonn.de>
Luepschen
Henning
H
Putensen
Christian
C
D017097:Electric Impedance; D006801:Humans; D008171:Lung Diseases / Q000175:diagnosis / Q000503:physiopathology; D012123:Pulmonary Ventilation / Q000502:physiology*; D015656:Respiratory Mechanics / Q000502:physiology; D013318:Stroke Volume; D014054:Tomography / Q000379:methods*