Authors: Aleš Rára, Karel Roubík, Tomáš Tyll


Rara, A., Roubik, K., Tyll, T. Effects of pleural effusion drainage in the mechanically ventilated patient as monitored by electrical impedance tomography and end-expiratory lung volume: A pilot study. Journal of Critical Care, 59, October 2020, pp. 76-80.

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Purpose: In patients with pleural effusion (PLE) monitored by Electrical Impedance Tomography (EIT) an increase in end-expiratory lung impedance (EELI) is observed following evacuation of the PLE. We aimed at differentiating the effect of fluid removal from lung reaeration and describe the change in ventilation distribution.
Materials and methods: Mechanically ventilated patients were monitored by EIT during PLE evacuation. End-expiratory lung volume (EELV) was measured concurrently. We included a calibration maneuver consisting of an increase in positive end-expiratory pressure (PEEP) by 5 cm H2O. The ratio ΔEELI/ΔEELV was used to compare changes of EELI and EELV in response to the calibration maneuver and PLE evacuation. At the same time we assessed distribution of ventilation using changes in tidal variation.
Results: PLE removal resulted in a 6–fold greater increase in ΔEELI/ΔEELV when compared to the calibration maneuver (r = 0.84, p < .05). We observed a relative increase in ventilation in the area of the effusion (mean 7.1%, p < .006) and an overall shift of ventilation to the dorsal fraction of the lungs (mean 8%, p < .0002).
Conclusions: The increase in EELI in the EIT image after PLE removal was primarily due to the removal of the conductive effusion fluid.


[1]         G. Miserocchi, “Physiology and pathophysiology of pleural fluid turnover,” (in eng), Eur Respir J, vol. 10, no. 1, pp. 219-25, Jan 1997.

[2]         A. P. Walden, C. S. Garrard, and J. Salmon, “Sustained effects of thoracocentesis on oxygenation in mechanically ventilated patients,” (in eng), Respirology, vol. 15, no. 6, pp. 986-92, Aug 2010, doi: 10.1111/j.1440-1843.2010.01810.x.

[3]         E. C. Goligher, J. A. Leis, R. A. Fowler, R. Pinto, N. K. Adhikari, and N. D. Ferguson, “Utility and safety of draining pleural effusions in mechanically ventilated patients: a systematic review and meta-analysis,” (in eng), Crit Care, vol. 15, no. 1, p. R46, 2011, doi: 10.1186/cc10009.

[4]         K. Razazi et al., “Pleural effusion during weaning from mechanical ventilation: a prospective observational multicenter study,” (in eng), Ann Intensive Care, vol. 8, no. 1, p. 103, Nov 2018, doi: 10.1186/s13613-018-0446-y.

[5]         M. Balik et al., “Ultrasound estimation of volume of pleural fluid in mechanically ventilated patients,” (in eng), Intensive Care Med, vol. 32, no. 2, pp. 318-21, Feb 2006, doi: 10.1007/s00134-005-0024-2.

[6]         A. P. Walden, Q. C. Jones, R. Matsa, and M. P. Wise, “Pleural effusions on the intensive care unit; hidden morbidity with therapeutic potential,” (in eng), Respirology, vol. 18, no. 2, pp. 246-54, Feb 2013, doi: 10.1111/j.1440-1843.2012.02279.x.

[7]         E. L. V. Costa, R. G. Lima, and M. B. P. Amato, “Electrical impedance tomography,” Current Opinion In Critical Care, vol. 15, no. 1, pp. 18-24, 2009.

[8]         S. Leonhardt and B. Lachmann, “Electrical impedance tomography: the holy grail of ventilation and perfusion monitoring?,” (in eng), Intensive Care Med, vol. 38, no. 12, pp. 1917-29, Dec 2012, doi: 10.1007/s00134-012-2684-z.

[9]         J. Kobylianskii, A. Murray, D. Brace, E. Goligher, and E. Fan, “Electrical impedance tomography in adult patients undergoing mechanical ventilation: A systematic review,” (in eng), J Crit Care, vol. 35, pp. 33-50, 10 2016, doi: 10.1016/j.jcrc.2016.04.028.

[10]       I. Frerichs et al., “Chest electrical impedance tomography examination, data analysis, terminology, clinical use and recommendations: consensus statement of the TRanslational EIT developmeNt stuDy group,” (in eng), Thorax, vol. 72, no. 1, pp. 83-93, 01 2017, doi: 10.1136/thoraxjnl-2016-208357.

[11]       J. C. Denniston and L. E. Baker, “Measurement of pleural effusion by electrical impedance,” (in eng), J Appl Physiol, vol. 38, no. 5, pp. 851-7, May 1975.

[12]       J. R. Petersen, B. V. Jensen, H. Drabaek, K. Viskum, and J. Mehlsen, “Electrical impedance measured changes in thoracic fluid content during thoracentesis,” Clinical Physiology (Oxford, England), vol. 14, no. 4, pp. 459-466, 1994.

[13]       M. Arad, S. Zlochiver, T. Davidson, Y. Shoenfeld, A. Adunsky, and S. Abboud, “The detection of pleural effusion using a parametric EIT technique,” (in eng), Physiol Meas, vol. 30, no. 4, pp. 421-8, Apr 2009, doi: 10.1088/0967-3334/30/4/006.

[14]       J. H. Campbell, N. D. Harris, F. Zhang, B. H. Brown, and A. H. Morice, “Clinical applications of electrical impedance tomography in the monitoring of changes in intrathoracic fluid volumes,” (in eng), Physiol Meas, vol. 15 Suppl 2a, pp. A217-22, May 1994, doi: 10.1088/0967-3334/15/2a/027.

[15]       T. Becher, M. Bußmeyer, I. Lautenschläger, D. Schädler, N. Weiler, and I. Frerichs, “Characteristic pattern of pleural effusion in electrical impedance tomography images of critically ill patients,” (in eng), Br J Anaesth, vol. 120, no. 6, pp. 1219-1228, Jun 2018, doi: 10.1016/j.bja.2018.02.030.

[16]       S. H. Alves, M. B. Amato, R. M. Terra, F. S. Vargas, and P. Caruso, “Lung reaeration and reventilation after aspiration of pleural effusions. A study using electrical impedance tomography,” (in eng), Ann Am Thorac Soc, vol. 11, no. 2, pp. 186-91, Feb 2014, doi: 10.1513/AnnalsATS.201306-142OC.

[17]       J. Hinz et al., “End-expiratory lung impedance change enables bedside monitoring of end-expiratory lung volume change,” (in eng), Intensive Care Med, vol. 29, no. 1, pp. 37-43, Jan 2003, doi: 10.1007/s00134-002-1555-4.

[18]       C. Grivans, S. Lundin, O. Stenqvist, and S. Lindgren, “Positive end-expiratory pressure-induced changes in end-expiratory lung volume measured by spirometry and electric impedance tomography,” (in eng), Acta Anaesthesiol Scand, vol. 55, no. 9, pp. 1068-77, Oct 2011, doi: 10.1111/j.1399-6576.2011.02511.x.

[19]       K. Roubik, V. Sobota, and M. Laviola, “Selection of the Baseline Frame for Evaluation of Electrical Impedance Tomography of the Lungs,” presented at the 2015 Second International Conference on Mathematics and Computers in Sciences and in Industry (MCSI), Sliema, 2015.

[20]       K. Razazi et al., “Effects of pleural effusion drainage on oxygenation, respiratory mechanics, and hemodynamics in mechanically ventilated patients,” (in eng), Ann Am Thorac Soc, vol. 11, no. 7, pp. 1018-24, Sep 2014, doi: 10.1513/AnnalsATS.201404-152OC.

[21]       D. G. Markhorst, A. B. Groeneveld, R. M. Heethaar, E. Zonneveld, and H. R. Van Genderingen, “Assessing effects of PEEP and global expiratory lung volume on regional electrical impedance tomography,” (in eng), J Med Eng Technol, vol. 33, no. 4, pp. 281-7, 2009, doi: 10.1080/03091900802451240.

[22]       I. G. Bikker, S. Leonhardt, J. Bakker, and D. Gommers, “Lung volume calculated from electrical impedance tomography in ICU patients at different PEEP levels,” (in eng), Intensive Care Med, vol. 35, no. 8, pp. 1362-7, Aug 2009, doi: 10.1007/s00134-009-1512-6.

[23]       V. Sobota, M. Müller, and K. Roubík, “Intravenous administration of normal saline may be misinterpreted as a change of end-expiratory lung volume when using electrical impedance tomography,” Scientific Reports, vol. 9, no. 1, p. 5775, 2019/04/08 2019, doi: 10.1038/s41598-019-42241-7.

[24]       V. Sobota and K. Roubik, “Center of Ventilation—Methods of Calculation Using Electrical Impedance Tomography and the Influence of Image Segmentation,” 2016, pp. 1258-1263.

[25]       E. T. H. Fysh et al., “Clinically Significant Pleural Effusion in Intensive Care: A Prospective Multicenter Cohort Study,” (in eng), Crit Care Explor, vol. 2, no. 1, p. e0070, Jan 2020, doi: 10.1097/CCE.0000000000000070.

[26]       L. Vetrugno et al., “Utility of pleural effusion drainage in the ICU: An updated systematic review and META-analysis,” (in eng), J Crit Care, vol. 52, pp. 22-32, Aug 2019, doi: 10.1016/j.jcrc.2019.03.007.

[27]       Electrical impedance tomography:   The realization of regional lung monitoring., Dräger Medical GmbH EIT Booklet, Germany, 2011.

[28]       K. Buzkova, M. Muller, A. Rara, K. Roubik, and T. Tyll, “Ultrasound detection of diaphragm position in the region for lung monitoring by electrical impedance tomography during laparoscopy,” (in eng), Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub, vol. 162, no. 1, pp. 43-46, Mar 2018, doi: 10.5507/bp.2018.005.