[Evaluation of hearing by studying acoustic distortion products in noise-induced hearing loss]. / Prévision de l'audition par les produits de distorsions chez les sourds par le bruit.

In this work, the Authors want to verify the possibility of an objective method of cochlear function evaluation in subjects affected by chronic acoustic trauma, through the study of the acoustic distortion products. Undertaking 46 subjects, the researchers have demonstrated a direct correlation between the tonal acoustic threshold and that of the distortion products. This method was able to show the useful indications of an objective evaluation of acoustic capacity in non collaborating subject. Because of the large variability of intensity of the distortion products and their absence when the acoustic threshold is more than 50-60 dB HL, they by themselves, don't permit exact evaluation of the tonal threshold for a given frequency.

Diagnosing nasal hyperreactivity with positional rhinomanometry.

Positional rhinomanometry is a physiologic method for estimating nasal resistance, which is variable, difficult to predict, and linked to vasomotor activity of the functional system culminating in the turbinate valves. Thirty subjects suffering from allergic rhinitis, 25 patients affected by aspecific rhinitis, and 40 healthy controls underwent positional rhinomanometry. Test positions included the seated (baseline), supine, and recumbent (homolateral and contralateral to the nasal fossa under examination). In patients with perennial allergic rhinitis and in those with aspecific rhinitis, positional rhinomanometry elicited two pathologic responses: either an average percentage rise of more than 80% in nasal resistance in the supine and homolateral and contralateral recumbent positions compared with basal values, or a paradoxical fall in the supine and homolateral recumbent positions.

Laryngeal microsurgery under general anesthesia using small-bore endotracheal tubes: blood gas analysis.

This study reports variations observed under general anesthesia through small-bore endotracheal tubes in PO2, PCO2, HCO3, percentage saturation of O2, and pH levels in 39 patients who underwent laryngeal microsurgery lasting from 10 to 100 minutes. The tendency to an increase in PCO2 levels reached statistical significance only at the 100th minute but did not constitute a risk for patients as values remained within the limits of "permitted hypercapnia." PO2, percentage saturation of oxygen, and HCO3 levels did not vary significantly. pH values tended to fall (respiratory acidosis) in correlation to the increase in PCO2. Small-bore endotracheal tubes can safely be used for laryngeal microsurgery when operating times are not longer than 100 minutes.

[Positional rhinomanometry in hypertrophic vasomotor chronic rhinitis: considerations before and after functional surgery of turbinates]. / La rinomanometria posizionale nella rinite cronica ipertrofico-vasomotoria: osservazioni prima e dopo chirurgia funzionale dei turbinati.

The Authors report their experience regarding Positional Active Rhinomanometry performed before and after surgery in hypertrophic-vasomotor chronic rhinitis. Twenty-five patients suffering of hypertrophy of the turbinates and/or nasal vasomotor disorders were examined pre-operatively and 3, 6 and 12 months after inferior submucosal turbinoplasty. Tests were performed in the seated, supina, homolateral and contralateral positions with regard to the fossa in question. Values were compared with those of forty normal subjects. Pre-operative examinations showed a large number of paradoxical responses and very high increase in nasal resistance. Postoperative values were quite similar to those of normal subjects, a demonstration of the efficacy of surgical treatment of turbinates hyper-reactivity.

[Positional rhinomanometry in specific nasal hyperreactivity]. / La rinomanometria posizionale nella iperreattività nasale specifica.

Following up the results obtained in a previous work testing Positional Rhinomanometry in normal subjects, the authors performed this test in subjects affected with specific nasal hyperreactivity. The aim was to offer an objective evaluation of decubitus-caused variations in air flow resistance through the nasal cavities. Thirty subjects suffering from allergic rhinitis (18 from seasonal and 12 perennial allergic rhinitis) underwent Anterior Active Rhinomanometry during the intercritical period of the disease. Tests were performed in the seated, supine positions homolateral and contralateral to the fossa in question. The positional tests show a marked difference between normality and specific hyperreactivity as a consequence of paradoxical responses. Moreover it can indicate the greater increase in nasal resistance, expression of a clear disreactivity of the cavernous tissue stimulated by variations in posture and found mostly in the perennial allergic rhinitis subjects.

[Postural rhinomanometry in normal subjects]. / Rinomanometria posizionale nel soggetto normale.

Measurement of decubitus-caused variations in air flow resistance through the nasal cavities indicates the vascular reactivity of turbinate cavernous tissue and makes it possible to evaluate the variable component in nasal resistance; a component usually suppressed by previous pharmacological vasoconstriction. The aim of the present work has been to indicate normative values regarding variations in nasal resistance in different types of decubitus. The latter will be referenced for future studies regarding nasal vasomotor pathologies (specific or aspecific hyperreactivity). Eighty nasal cavities from normal subjects were examined by means of Anterior Active Rhinomanometry in the following positions: seated, supine, homolateral and contralateral to the fossa in question. As absolute values are highly variable even in normal subjects, the resistance variations in decubitus were expressed in percentage of basal value (seated position). In every decubitus there is an average increase in resistance due to the increased venous pressure in the cephalic area although the greatest statistical significance and lowest scattering of values is found in the supine position with 20 degrees head-trunk angle. Mean values and standard deviations are given and will be referenced for further studies on rhinopathology.

Auditory brainstem responses in noise-induced permanent hearing loss.

Fifty-four patients (108 ears) with presumed noise-induced hearing loss, were subjected to tonal and speech audiometry, impedance tests and measurements of auditory brainstem responses (ABR), in order to check for possible retrocochlear involvement. ABR data indicated that latency values of waves I, III and V, as well as III-I, V-III and V-I intervals fell within the normal range in all cases (M +/- 2 SD), even for fast repetition rates (51 stim/s). Poor waveform resolution of early components, particularly of wave I, was found in 12 ears (11.1%) and a total absence of evoked potentials not always related to the hearing loss, occurred in 5 ears (4.6%).