[Peculiarities of respiration mechanics in spontaneously breathing newborn infants. 1. Principles of the measurement technics].

Disturbances of breathing mechanics may involve disturbances of ventilation as one cause of hypoxaemia. The qualitative and quantitative analysis of breathing mechanics has several diagnostical and therapeutical advantages, but their application in newborns, under conditions of spontaneous ventilation, is rendered more difficult by the missing co-operation of the newborns and by the missing of suitable measurement devices for a bedside measurement. The determination of parameters of breathing mechanics is based on the measurement of breathing flow rate (V), tidal volume (VT) and esophageal pressure (Pe). Bodyplethysmographs, face masks and nasal prongs can be used for the measurement of V and VT, however, face masks have the most methodological and technical advantages for the bedside application, moreover, they guarantee a very low injury of newborns. Until now the fluid-filled open catheter is used most frequently for the measurement of esophageal pressure, however, it will be replaced in future by the microtip pressure transducer (Tip-catheter), which offers fundamental advantages. In addition to these technical problems the complete clinical application of breathing mechanical investigations is rendered more difficult, because the standardization of the investigative conditions, the parameters and the proposals on evaluation techniques are absent until now.