[Study of the microviscosity of phospholopids in tracheal aspirates by fluorescence polarization. Its application to neonatal respiratory distress].

Microviscosity values obtained by fluorescence polarization in tracheal aspirates from 138 newborns are presented in this paper. Sixteen newborns intubated of other medical or chirurgical reasons than pulmonary affections were the control group. In the same period 122 newborns with respiratory distress were under investigation, the microviscosity values (in poises) in the control group were always less than 3 poises. This value is currently the higher found for phospholipids contained in bronchoalveolar lavages from normal adults. In the pathological group of neonates, the microviscosity values are always very high. When a favorable evolution was recorded (n = 80) the microviscosity values (pi) were less than 3.4 poises at the extubation time. In the unfavorable evolution group (n = 42) the values were always greater than 5 poises. The results the limits and validity of the method are discussed. The method appears simple and sensitive and is proposed as a tool to evaluate the functional proportion of the lung surfactant phospholipids.