BACKGROUND: Electrical impedance tomography (EIT) is able to detect variations in regional lung electrical impedance associated with changes in both air and blood content and potentially capable of assessing regional ventilation-perfusion relationships. However, regional lung perfusion is difficult to determine because the impedance changes synchronous with the heart rate are of very small amplitude. OBJECTIVES: The aim of our study was to determine the redistribution of lung perfusion elicited by one-lung ventilation using EIT with a novel region-of-interest analysis. METHODS: Ten patients (65 +/- 9 years, mean age +/- SD) scheduled for elective chest surgery were studied after intubation with a double-lumen endotracheal tube during bilateral and unilateral ventilation of the right and left lungs. EIT data were acquired at a rate of 25 scans/s. Relative impedance changes synchronous with the heart rate were evaluated in the right and left lung regions. RESULTS: During bilateral ventilation, the mean right-to-left lung ratio of the sum of heart rate-related impedance changes was 1.12 +/- 0.20, but the ratio significantly changed (0.81 +/- 0.16 and 1.48 +/- 0.37) during unilateral left- and right-lung ventilation with reduced perfusion of the non-ventilated lung. Increased perfusion most likely occurred in the ventilated lung because the impedance values summed over both regions did not change (0.62 +/- 0.23 vs. 0.58 +/- 0.22) compared with bilateral ventilation. CONCLUSIONS: Our results indicate that redistribution of regional lung perfusion can be assessed by EIT during one-lung ventilation. The performance of EIT in detecting changes in lung perfusion in even smaller lung regions remains to be established. Copyright 2009 S. Karger AG, Basel.
BACKGROUND: Electrical impedance tomography (EIT) is able to detect variations in regional lung electrical impedance associated with changes in both air and blood content and potentially capable of assessing regional ventilation-perfusion relationships. However, regional lung perfusion is difficult to determine because the impedance changes synchronous with the heart rate are of very small amplitude. OBJECTIVES: The aim of our study was to determine the redistribution of lung perfusion elicited by one-lung ventilation using EIT with a novel region-of-interest analysis. METHODS: Ten patients (65 +/- 9 years, mean age +/- SD) scheduled for elective chest surgery were studied after intubation with a double-lumen endotracheal tube during bilateral and unilateral ventilation of the right and left lungs. EIT data were acquired at a rate of 25 scans/s. Relative impedance changes synchronous with the heart rate were evaluated in the right and left lung regions. RESULTS: During bilateral ventilation, the mean right-to-left lung ratio of the sum of heart rate-related impedance changes was 1.12 +/- 0.20, but the ratio significantly changed (0.81 +/- 0.16 and 1.48 +/- 0.37) during unilateral left- and right-lung ventilation with reduced perfusion of the non-ventilated lung. Increased perfusion most likely occurred in the ventilated lung because the impedance values summed over both regions did not change (0.62 +/- 0.23 vs. 0.58 +/- 0.22) compared with bilateral ventilation. CONCLUSIONS: Our results indicate that redistribution of regional lung perfusion can be assessed by EIT during one-lung ventilation. The performance of EIT in detecting changes in lung perfusion in even smaller lung regions remains to be established. Copyright 2009 S. Karger AG, Basel.
Authors: Peter A Muller; Jennifer L Mueller; Michelle Mellenthin; Rashmi Murthy; Michael Capps; Brandie D Wagner; Melody Alsaker; Robin Deterding; Scott D Sagel; Jordana Hoppe Journal: Physiol Meas Date: 2018-04-26 Impact factor: 2.833
Authors: Hazel R Carlisle; Ruth K Armstrong; Peter G Davis; Andreas Schibler; Inéz Frerichs; David G Tingay Journal: Intensive Care Med Date: 2010-09-21 Impact factor: 17.440
Authors: M G Crabb; J L Davidson; R Little; P Wright; A R Morgan; C A Miller; J H Naish; G J M Parker; R Kikinis; H McCann; W R B Lionheart Journal: Physiol Meas Date: 2014-04-08 Impact factor: 2.833
Authors: Caroline A Grant; Trang Pham; Judith Hough; Thomas Riedel; Christian Stocker; Andreas Schibler Journal: Crit Care Date: 2011-01-25 Impact factor: 9.097
Authors: Kimble R Dunster; Marlies Friese; John F Fraser; Gary J Cowin; Andreas Schibler Journal: Biomed Eng Online Date: 2012-09-04 Impact factor: 2.819