Electric impedance tomography to monitor body positioning and chest physiotherapy in mechanically ventilated pediatric intensive care unit patients

To evaluate whether electrical impedance tomography (EIT), a non-invasive, bedside, radiation-free imaging tool that allows real-time ventilation monitoring, may help evaluate if children under mechanical ventilation exhibit a gravity-dependent ventilation phenomenon and positively respond to chest physiotherapy. Prospective observational study conducted from January 1st, 2023, to April 30th, 2024, in a 24-bed Pediatric Intensive Care Unit at a quaternary center. Children eligible were patients between one week and six years old who required mechanical ventilation for at least 24 h. One-hour episodes, involving postural changes or chest physiotherapy, were recorded and evaluated through the primary study outcome obtained by EIT, Delta Z, which surrogates mechanical ventilation tidal volume. The study included 25 patients and recorded 94 episodes. 69% of the patients were male. The median age and weight were 20 weeks and 5.5 kg. Acute bronchiolitis was the most common diagnosis upon admission (64%). 80% of the patients required invasive MV. 58% of the events involved PC, and 42% CPT. EIT showed an absence of a consistent gravity-dependent ventilation phenomenon, with high variability between patients. EIT-monitored CPT achieved a median 4% increase of Delta Z (p = 0.018). Children under mechanical ventilation may not follow a gravity-dependent ventilation phenomenon. EIT may provide a more precision-based approach to the delivery of effective CPT in pediatric patients.