[Comparative study of pre and post-operative dynamic respiratory indices in subjects undergoing total laryngectomy]

A spirometric measurement was carried out on patients with cancer of the laryn before and after surgery for total laryngectomy at the Istituto Policattedra of the University of Parma ENT Clinic. Postoperative spirometry was performed by means of a Vitalograph apparatus with the mouthpiece positioned right over the tracheal opening. The parameters considered were the dynamic respiratory indices (CV/MEVS - MEVS/CV). Forty patients was mostly based on the fact that, prior to laringectomy, all of them had been subjected to a spirometric measurement for aneasthesiologic purposes. According to the results obtained, the patients can be divided into three groups. The first group consists of 10 subjects in whom no improvement was observed in their MEVS value, which in some instances had actually worsened. The second group is composed of 20 patients in whom the spirometric values remained more or less steady. The third group comprises 20 patients who showed a marked improvement of their respiratory indices. In some of the latter patients the values obtained were even better than those in the normal range. However, the overall average results are not statistically significant, except for an average 9% improvement of MEVS due, as expected, to a reduction of the dead space following total laryngectomy and a corresponding, though very slight, 4% improvement of the Tiffenau ratio.