Background: Electrical impedance tomography (EIT) with indicator dilution may be clinically useful to measure relative lung perfusion, but there is limited information on the performance of this technique. Methods: Thirteen pigs (50e66 kg) were anaesthetised and mechanically ventilated. Sequential changes in ventilation were made: (i) right-lung ventilation with left-lung collapse, (ii) two-lung ventilation with optimised PEEP, (iii) two-lung ventilation with zero PEEP after saline lung lavage, (iv) two-lung ventilation with maximum PEEP (20/25 cm H 2 O to achieve peak airway pressure 45 cm H 2 O), and (v) two-lung ventilation under unilateral pulmonary artery occlusion. Relative lung perfusion was assessed with EIT and central venous injection of saline 3%, 5%, and 10% (10 ml) during breath holds. Relative perfusion was determined by positron emission tomography (PET) using 68 Gallium-labelled microspheres. EIT and PET were compared in eight regions of equal ventro-dorsal height (right, left, ventral, mid-ventral, mid-dorsal, and dorsal), and directional changes in regional perfusion were determined. Results: Differences between methods were relatively small (95% of values differed by less than 8.7%, 8.9%, and 9.5% for saline 10%, 5%, and 3%, respectively). Compared with PET, EIT underestimated relative perfusion in dependent, and overestimated it in non-dependent, regions. EIT and PET detected the same direction of change in relative lung perfusion in 68.9e95.9% of measurements. Conclusions: The agreement between EIT and PET for measuring and tracking changes of relative lung perfusion was satisfactory for clinical purposes. Indicator-based EIT may prove useful for measuring pulmonary perfusion at bedside.

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SUMMARYA new ventilation nomogram is presented intended for use in the newborn and infants of 3 kg to 20 kg. The nomogram is similar in construction to that previously presented for adults for use with the Engstrom respirator, but has other correction factors which are explained here. The nomogram is primarily intended to be used as a guide during anaesthesia and postoperative controlled ventilation. The comparatively rapid changes in the metabolism of small children make the suggested ventilatory volumes more susceptible to deviations from the actual demand for alveolar ventilation. Under such circumstances it is advisable to control the procedure with blood‐gas analysis.ZUSAMMENFASSUNGEs wird ein neues Ventilations‐Nomogramm vorgestellt, das zur Ver‐wendung bei Neugeborenen und Kleinkindern mit einem Gewicht von 3 bis 20 kg gedacht ist. Die Konstruktion des Nomogramms ist ähnlich des schon früher für Erwachsene zur Anwendung mit dem Engström‐Respirator eingeführten, enthält jedoch andere Korrektionsfaktoren, wie hier im Einzelnen angeführt wird. Das Nomogramm ist vor allem als Richtschnur während der Narkose und der postoperativen Beatmung gedacht. Die verhältnismässig raschen metabolischen Veränderungen bei kleinen Kindern führen dazu, dass die vorgeschlagenen Beatmungsvolumina leichter vom tatsächlichen alveolaren Ventilationsbedarf abweichen. Unter diesen Umständen empfiehlt es sich die Beatmung mittels Blutgas‐Analysen zu kontrollieren

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