[Respiratory inductive plethysmography in the functional evaluation of patients undergoing coronary by-pass surgery]

The functional respiratory changes following coronary by-pass surgery were previously evaluated with the traditional spirometric method. Aim of this work is to introduce the respiratory inductive plethismography (RIP), a well known non-invasive technique, into the study of those volumetric and ventilatory modifications. Eight cardioischemic patients were selected: all but one were free from pulmonary disorders. The tidal volume, the respiratory rate, the minute ventilation, the vital capacity and the relation between the abdominal and the thoracic part of the ventilatory act, were measured in the pre-intervention session and in the 1st, 3rd and 7th day after the operation of coronary by-pass. In the same sessions, except the 1st day after surgery, the maximal respiratory pressures were evaluated with traditional manometers. The functional changes of the examined parameters, statistically studied with the variance analysis, closely resemble the spirometric modifications registered by other authors. Furthermore the relative contributions of the thoracic and abdominal compartments of the pulmonary ventilation were evaluated, thanks to the non-invasive plethysmographic method. Rip makes it possible to measure the ventilatory pattern and some pulmonary volumes in the very early phases after thoracic surgery, without any trouble for the patient and in a non-collaborative state of consciousness, too.