[Measuring bronchial obstruction in intensive care].

The nature and degree of bronchial obstruction is not easy to assess in the intensive care unit. The classic airway resistance measurement technique cannot be performed without heavy equipment and the patient's cooperation. On the basis of the forced oscillations technique, measurement of acoustical respiratory impedance is an extension, in a higher frequency range, of earlier dynamic compliance measurements, which are known to be sensitive to peripheral airway obstruction but unsuitable for critically ill patients. The main advantage of respiratory impedance measurement is simplicity, since the patient simply breathes freely for a minute in the apparatus. This method contributes an effective means of quantifying evolution and treatment during an asthmatic attack. It can also be used to monitor left heart failure.