Electrical impedance tomography to determine optimal positive end-expiratory pressure in severe chronic obstructive pulmonary disease

Dynamic hyperinflation (DH) is a consequence of severe airflow obstruction in patients with asthma and chronic obstructive pulmonary disease (COPD). Incorrect setting of positive end-expiratory pressure (PEEP) can lead either to unopposed intrinsic PEEP (iPEEP) (when set too low) or to an increase in lung volume if PEEP is set above iPEEP. DH and iPEEP can lead to haemodynamic compromise [1], increased work of breathing and asynchrony [2]. PEEP setting is challenging because iPEEP is clinically difficult to quantify. Electrical impedance tomography (EIT) provides information on the temporal and spatial heterogeneity of ventilation [3]. EIT may prove useful in optimizing PEEP to overcome gas trapping and DH [4]. We present a method in which the use of EIT allowed selection of PEEP to provide the least DH and inhomogeneity of lung mechanics.