Skip to main content
main-content

01.08.2011 | Research | Ausgabe 4/2011 Open Access

Critical Care 4/2011

Electrical impedance tomography measured at two thoracic levels can visualize the ventilation distribution changes at the bedside during a decremental positive end-expiratory lung pressure trial

Zeitschrift:
Critical Care > Ausgabe 4/2011
Autoren:
Ido G Bikker, Carsten Preis, Mahamud Egal, Jan Bakker, Diederik Gommers
Wichtige Hinweise

Electronic supplementary material

The online version of this article (doi:10.​1186/​cc10354) contains supplementary material, which is available to authorized users.

Competing interests

The authors declare that they have no competing interests.

Authors' contributions

IB and CP carried out the data acquisition, data processing, data analysis and statistical analysis and participated in drafting the manuscript. ME participated in the data acquisition, data processing and statistical analysis. DG and JB participated in data acquisition and drafting the manuscript. All authors read and approved the final version of the manuscript.

Abstract

Introduction

Computed tomography of the lung has shown that ventilation shifts from dependent to nondependent lung regions. In this study, we investigated whether, at the bedside, electrical impedance tomography (EIT) at the cranial and caudal thoracic levels can be used to visualize changes in ventilation distribution during a decremental positive end-expiratory pressure (PEEP) trial and the relation of these changes to global compliance in mechanically ventilated patients.

Methods

Ventilation distribution was calculated on the basis of EIT results from 12 mechanically ventilated patients after cardiac surgery at a cardiothoracic ICU. Measurements were taken at four PEEP levels (15, 10, 5 and 0 cm H2O) at both the cranial and caudal lung levels, which were divided into four ventral-to-dorsal regions. Regional compliance was calculated using impedance and driving pressure data.

Results

We found that tidal impedance variation divided by tidal volume significantly decreased on caudal EIT slices, whereas this measurement increased on the cranial EIT slices. The dorsal-to-ventral impedance distribution, expressed according to the center of gravity index, decreased during the decremental PEEP trial at both EIT levels. Optimal regional compliance differed at different PEEP levels: 10 and 5 cm H2O at the cranial level and 15 and 10 cm H2O at the caudal level for the dependent and nondependent lung regions, respectively.

Conclusions

At the bedside, EIT measured at two thoracic levels showed different behavior between the caudal and cranial lung levels during a decremental PEEP trial. These results indicate that there is probably no single optimal PEEP level for all lung regions.
Zusatzmaterial
Literatur
Über diesen Artikel

Weitere Artikel der Ausgabe 4/2011

Critical Care 4/2011 Zur Ausgabe

Neu im Fachgebiet AINS

Mail Icon II Newsletter

Bestellen Sie unseren kostenlosen Newsletter Update AINS und bleiben Sie gut informiert – ganz bequem per eMail.

Bildnachweise