Ann Oto Rhinol Laryn
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Ann Oto Rhinol Laryn · Dec 1997
Utility of helical computed tomography in the study of arytenoid dislocation and arytenoid subluxation.
Conventional computed tomography (CT) has been considered a mainstay in the evaluation of the larynx. A major difficulty with utilizing this modality, especially in the study of the arytenoid, is the time necessary to perform a thin-slice examination through a structure that has a propensity to move with respiration and swallowing. ⋯ A comprehensive radiographic examination illustrating the cricoarytenoid relationship in all of the subjects was completed in less than 20 seconds by using axial reconstructions in 2-mm-thick slices at 1-mm intervals, with subsequently derived sagittal and coronal reconstructions. Helical CT may be a useful adjunct in the diagnosis of arytenoid subluxation or dislocation.
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Ann Oto Rhinol Laryn · Jul 1997
Comparative StudyEpiglottic position after cricothyroidotomy: a comparison with tracheotomy.
Dysphagia is a known problem in patients with tracheotomy, but its association with cricothyroidotomy is not well studied. The purpose of this study was to evaluate dysphagia in patients with cricothyroidotomy and to determine if there is a reliable indicator of swallowing dysfunction in these patients. A review of charts for patients with modified barium swallow studies conducted at the New York University Medical Center Swallowing Disorders Center yielded three groups of patients: patients with cricothyroidotomy, patients with tracheotomy, and normal patients. ⋯ One mechanism of swallowing dysfunction is impaired posterior displacement of the epiglottis over the glottic aperture. This impaired epiglottic motion appears to be related to restricted laryngeal elevation secondary to tethering of the larynx anteriorly at the site of the cricothyroidotomy. Additionally, we noted a decrease in the opening of the upper esophageal sphincter.
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The middle ear (ME) steady state gas composition resembles that of mixed venous blood. We changed arterial and venous blood gases by artificially ventilating anesthetized guinea pigs and measured simultaneous ME gas changes during spontaneous breathing, hyperventilation, and hypoventilation. During hyperventilation, PaCO2 and PvCO2 (a = arterial, v = venous) decreased from 46.0 and 53.0 mm Hg to 17.9 and 37.5 mm Hg, respectively, while PaO2 and PvO2 (85.6 and 38.2 mm Hg) did not change. ⋯ The ME PCO2 increased simultaneously to 88.8 mm Hg and the ME PO2 decreased to 25.4 mm Hg. The ME PO2 decrease during hyperventilation may be explained by a 33% decrease in ME mucosa perfusion, calculated from the ME ventilation-perfusion ratio. This study shows that ME gas composition follows fluctuations of blood gas levels and thus may affect total ME pressure.
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Ann Oto Rhinol Laryn · Mar 1997
Role of ultrasound in the assessment of vocal cord function in infants and children.
The determination of the cause of stridor in the infant and child is an important directive for the otolaryngologist. The limitations of current clinical diagnostic techniques have provided the impetus for pursuing newer, more practical techniques to diagnose vocal cord paralysis in children. The purpose of this paper is to describe a new technique to image the larynx and determine its role in discerning vocal cord paralysis in children. ⋯ This investigation should not be interpreted as an endorsement for laryngeal ultrasound as a replacement for endoscopy in children. This work does indicate, however, that ultrasound is a technique that can accurately address the special issue of vocal cord mobility in infants and children. At present, this is the primary use for laryngeal ultrasound, although with additional investigation and sophistication it is likely that ultrasound of the larynx may become useful for other purposes.