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Biomedical subjects

B Magnuson

Publications and source records attributed to B Magnuson.

25 records · Page 2Linked to original sources
PubMed1981

The atelectatic ear.

Direct measurements of middle ear pressure were performed in 14 children with recurrent middle ear effusion and deep retraction of the tympanic membrane. In 12 of the 22 ears studied, measurements showed that a high negative pressure in the middle ear space had been induced by sniffing. Results suggest that a combination of closing failure of the Eustachian tube and sniffing is the cause of effusion and progressive retraction of the tympanic membrane in these patients. It is further suggested that cholesteatoma, which was present in three of the patients, was also a result of sniff-induced negative pressure in the middle ear space.

Adolescent↗
PubMed1981

On the origin of the high negative pressure in the middle ear space.

It has generally been assumed that a high negative pressure in the middle ear space results from obstruction of the eustachian tube and the subsequent gas resorption through the middle ear mucosa. There is clinical evidence that quite a different mechanism is operating. The present experimental study verifies, with direct pressure recordings in cases of the retraction type of cholesteatoma and related conditions, that a high negative pressure can be generated by an active evacuation of air through the eustachian tube. The high negative pressure induced may explain the development of tympanic membrane retraction and pocketing, and the subsequent development of cholesteatoma.

Adult↗
PubMed1981

Tubal opening and closing ability in unilateral middle ear disease.

Eustachian tube function tests were performed simultaneously in both ears of 29 patients with strictly unilateral middle ear disease. In 15 of the patients eustachian tube closing failure was evidenced by sniff-induced negative pressure in one or both middle ears. The results of the pressure equalization test showed that there was no conclusive difference between the abilities of healthy and diseased ears to equalize pressure. The forced opening test indicated that the diseased ears had less resistant tubes, but there was a wide overlap of results. Since no distinct difference was seen, the clinical value of tubal function tests used presently seems to be severely restricted.

Adolescent↗
PubMed1981

Tympanoplasty and recurrent disease: sniff-induced high negative pressure in the middle ear space.

Eustachian tube function was studied in 18 patients who had developed recurrent middle ear disease after middle ear surgery on one ear. The types of recurrent disease included recurrent retraction of the tympanic membrane, recurrent cholesteatoma, columella penetration, postoperative perforation, and infection. Pressures in both of the middle ears, as well as in the nasopharynx, were recorded simultaneously. The ears of patients in this study were found to be able to equalize pressure as well as did normal ears examined previously. However, in 12 of the 18 ears that had been operated on, failure of eustachian tube closing with sniff-induced negative pressure in the middle ear was found. Additionally, in three patients, a similar condition was present in the contralateral ear. It is concluded that postoperative complications of the types described may be correlated with tubal closing failure and sniff-induced high negative pressure in the middle ear space.

Adolescent↗
PubMedDate not supplied

Eustachian tube pathophysiology.

Studies of eustachian tube physiology have mainly focused on the ability of the tube to open. For this reason, impaired opening ability has been regarded as the basis of eustachian tube malfunction. Characteristic patterns have been found in pressure measurements in patients with chronic middle ear disease. Simultaneous measurements of nasopharyngeal and middle ear pressures in patients with atelectatic tympanic membranes and retraction cholesteatoma have shown that high negative intratympanic pressure is generated by the voluntary act of sniffing. Eustachian tube malfunction in these patients is thus characterized by failure of the tube to close.

Cholesteatoma↗
PubMedDate not supplied

Human middle ear gas composition studied by mass spectrometry.

The purpose of this study was to develop a procedure for mass spectrometric measurement fitted to analyse the human middle ear gas composition, and to determine the partial pressures of the middle ear gases in adults with healthy ears. To avoid the risks of admixture of the gas sample with atmospheric air we used "on-line" sampling from the middle ear to the analysing equipment, and a new protective technique at the site of puncture. The inlet system was modified to achieve sufficiently low gas consumption. The system had excellent linearity, and model experiments showed that the described procedure gives a very high accuracy. Measurements of the gas composition in the middle ear in 10 adult subjects with healthy ears gave the following values: pO2 = 612.38 +/- 3.97 mmHg, pO2 = 40.85 +/- 3.68 mmHg, pAr = 7.09 +/- 0.08 mmHg and pCO = 52.69 +/- 5.54 mmHg.

Adult↗