The hypothesis that EIT can be used to monitor CO and SV was confirmed, but further studies are required before this technique can be applied in clinical practice. HR was determined robustly and accurately. For SV monitoring, promising results were obtained in 80% of the experiments. However, unexpected scaling of the cardiac EIT signal causing inaccurate estimation of SV remains an issue. Before robust assessment of SV by EIT is suitable for clinical practice, the cause of and compensation for undesired scaling effects need to be investigated.

A novel non-invasive technique for monitoring fluid content in the human bladder is described. Specifically, a precommercial electric impedance tomograph (EIT) was applied to measure and visualize impedance changes in the lower torso due to changes in bladder volume. Preliminary measurements were conducted during routine urodynamic tests of nine male paraplegic patients, in whom a contrast agent was slowly infused into the bladder for diagnostic purposes. In some patients, a good correlation between bladder volume and EIT measurements was found, whereas in others the correlation was still good but inverted, presumably due to a poor electrode positioning. These preliminary results indicate that a sufficiently accurate finite element modeling of the impedance distribution in the abdomen, and proper electrode positioning aids, are important prerequisites to enable this technology to be used for routine measurement of bladder volume.

Background In acute respiratory failure elevated intraabdominal pressure aggravates lung collapse, tidal recruitment, and ventilation inhomogeneity. Low positive end-expiratory pressure (PEEP) may promote lung collapse and intrapulmonary shunting, whereas high PEEP may increase dead space by inspiratory overdistension. The authors hypothesized that an electrical impedance tomography–guided PEEP approach minimizing tidal recruitment improves regional ventilation and perfusion matching when compared to a table-based low PEEP/no recruitment and an oxygenation-guided high PEEP/full recruitment strategy in a hybrid model of lung injury and elevated intraabdominal pressure. Methods In 15 pigs with oleic acid–induced lung injury intraabdominal pressure was increased by intraabdominal saline infusion. PEEP was set in randomized order: (1) guided by a PEEP/inspired oxygen fraction table, without recruitment maneuver; (2) minimizing tidal recruitment guided by electrical impedance tomography after a recruitment maneuver; and (3) maximizing oxygenation after a recruitment maneuver. Single photon emission computed tomography was used to analyze regional ventilation, perfusion, and aeration. Primary outcome measures were differences in PEEP levels and regional ventilation/perfusion matching. Results Resulting PEEP levels were different (mean ± SD) with (1) table PEEP: 11 ± 3 cm H2O; (2) minimal tidal recruitment PEEP: 22 ± 3 cm H2O; and (3) maximal oxygenation PEEP: 25 ± 4 cm H2O; P < 0.001. Table PEEP without recruitment maneuver caused highest lung collapse (28 ± 11% vs. 5 ± 5% vs. 4 ± 4%; P < 0.001), shunt perfusion (3.2 ± 0.8 l/min vs. 1.0 ± 0.8 l/min vs. 0.7 ± 0.6 l/min; P < 0.001) and dead space ventilation (2.9 ± 1.0 l/min vs. 1.5 ± 0.7 l/min vs. 1.7 ± 0.8 l/min; P < 0.001). Although resulting in different PEEP levels, minimal tidal recruitment and maximal oxygenation PEEP, both following a recruitment maneuver, had similar effects on regional ventilation/perfusion matching. Conclusions When compared to table PEEP without a recruitment maneuver, both minimal tidal recruitment PEEP and maximal oxygenation PEEP following a recruitment maneuver decreased shunting and dead space ventilation, and the effects of minimal tidal recruitment PEEP and maximal oxygenation PEEP were comparable. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Electrical impedance tomography (EIT) is a radiation-free technique generating cross-sectional images of the lung. EIT visualizes global and regional ventilation by illustrating the distribution of electrical bioimpedance. With an electrode belt around the patient's thorax, rotating injection-couples of a harmless alternating current allow voltage measurement of the remaining electrodes. This enables the reconstruction of a tomogram with highly dynamic changes within ventilation. We report on a female six-year-old patient with cystic fibrosis and complete destruction of the upper and middle lobe of the right lung. Lobectomy, a rare therapeutic option in patients with cystic fibrosis that needs to be considered in cases of severe localized destruction, was performed. We show a pre- and postoperative documentation of static (radiology) and dynamic investigation tools (spirometry) in correlation with EIT as a new non-invasive and radiation-free diagnostic tool for this patient group.