Assessing effects of PEEP and global expiratory lung volume on regional electrical impedance tomography.

Objective: This study was performed to assess the value of electrical impedance tomography (EIT) as an indicator of tidal (V(T)) and end expiratory lung volume (EELV).

Methods: EIT measurements were performed in seven healthy piglets during constant tidal volume ventilation at incremental and decremental positive end-expiratory pressure (PEEP) levels. Tidal impedance changes were calibrated to volume using V(T) calculated from flow at the airway opening.

Regional lung volume changes in children with acute respiratory distress syndrome during a derecruitment maneuver.

Objective: Regional differences in lung volume have been described in adults with acute respiratory distress syndrome, but it remains unclear to what extent they occur in children. To quantify regional alveolar collapse that occurred during mechanical ventilation during a standardized suctioning maneuver, we evaluated regional and global relative impedance changes (relative DeltaZ) in children with acute respiratory distress syndrome using electrical impedance tomography.

Design: Prospective observational trial.

Lung volume recruitment after surfactant administration modifies spatial distribution of ventilation.

Rationale: Although surfactant replacement therapy is an established treatment in infant respiratory distress syndrome, the optimum strategy for ventilatory management before, during, and after surfactant instillation remains to be elucidated.

Objectives: To determine the effects of surfactant and lung volume recruitment on the distribution of regional lung ventilation.

Methods: Acute lung injury was induced in 16 newborn piglets by endotracheal lavage.

Respiratory inductive plethysmography accuracy at varying PEEP levels and degrees of acute lung injury.

Background And Objective: This study was performed to assess the accuracy of respiratory inductive plethysmographic (RIP) estimated lung volume changes at varying positive end-expiratory pressures (PEEP) during different degrees of acute respiratory failure.

Methods: Measurements of inspiratory tidal volume were validated in eight piglets during constant volume ventilation at incremental and decremental PEEP levels and with increasing severity of pulmonary injury. RIP accuracy was assessed with calibration from the healthy state, from the disease state as the measurement error was assessed, and at various PEEP levels.

Comparison of different methods to define regions of interest for evaluation of regional lung ventilation by EIT.

The measurement of regional lung ventilation by electrical impedance tomography (EIT) has been evaluated in many experimental studies. However, EIT is not routinely used in a clinical setting, which is attributable to the fact that a convenient concept for how to quantify the EIT data is missing. The definition of region of interest (ROI) is an essential point in the data analysis.